Evaluation of Infants and Childron with RocurrontInfoction ARTHUR J. AMMANN DIANE W. WARA

FROM THE MOMENT an infant leaves the sterile atmosphere of the uterus he is constantly assaulted by foreign antigens in the form of microbial agents (bacteria, viruses, fungi and protozoa) and inert agents inhaled from the atmosphere or ingested during feeding. The function of the immune system is to prevent or retard the local establishment, systemic access or widespread dissemination of these agents. It is now apparent that the immune system is a highly sophisticated array of individual components functioning together to prevent infection, autoimmune disease and malignancy (Fig. 1). Detailed reviews of recent advances in immunology are availableA, z The first component of the immune system, antibody-mediated immunity, is mediated by the immunoglobulins in the secretions, interstitial spaces and plasma. The second system consists of cell-mediated immunity: its functions are carried out by small lymphocytes in the blood and peripheral lymphoid tissue. The phagocytic system consists of various phagocytic cells in the blood and tissue, which are engaged primarily in the killing of microorganisms. Finally, complement components act synergistically with the other systems of immunity to enhance the containment of microbial infection. Inheritance plays an important role in many aberrations of the immune system. Therefore, the majority of patients are infants and children with an increased susceptibility to multiple infections early in life. This monograph is arranged to provide an over-all discussion of the immune system, signs and symptoms of immunodeficiency and clinical and laboratory evaluation and treatment. The tables are designed to clarify the evaluation and treatment of infants and children with recurrent infection.

PHYSIOLOGY OF IMMUNITY

(~)

~

Protecti on viral

thymus

fungal (~) I

/

Q

~1 ~. LT. MAF') "~

~ ' ~

lyml~ocyte

~

comp~*~llent

complement

[U cell J~llr'~l')--->lmmunogtobulins-~" bacteria viral reinfection \ j' ~ (~) kjG tda,smacell IgM parasites

t/

a4-.%~176 ~, bone ooo~o.~o~_~_.o

I~ IgD IgE

al~rsens

phagocytosl$ malignancy

Fig. 1.--Physiology of immunity. Schematic representation of development of immune system. The numbers refer to known defects in the development of immunity: (1) severe combined immunodeficiency, (2) Di George syndrome, (3)thymic hypoplasla with abnormal immunoglobulin synthesis, (4) chronic mucocutaneous candidiasis, (5) Wiskott-Aldrich syndrome, (6) congenital hypogammaglobulinemia, (7) acquired hypogammaglobulinemia, (8) selective IgA deficiency, (9) chronic g ranulomatous disease, (10) malignancy.

ANTIBODY-MEDIATED IMMUNITY The development of the immune system is schematically represented in Figure 1. The development of competent humeral and cellular immunity probably follows the division of a population of stem cells into two cell lines. One line travels to the bursa cquiv.alent to become "B lymphocytes," destined to produce immunoglobulins.3 The second cell line, influenced by the thymus gland, becomes "T lymphocytes," competent in cellular immune function. Experimental evidence indicates that in the avian species the organ responsible for controlling the differentiation of immunoglobulin-producing cells is the bursa of Fabricius. In man, there is no direct evidence that an equivalent organ exists; however, several investigators consider that the tonsils, adenoids, Peyer's patches and appendix collectively form the bursa equivalent. 4 Other investigators feel that this function now resides in the bone marrow of man. ~ Regardless of the location of the bursa equivalent, it is agreed that cells that leave the equivalent of this organ are programmed to function as bone marrow or bursa-derived "B cells." B ceils reside in tissue but also circulate in the peripheral blood where they comprise approximately 20-30% of the total blood lymphocytes

and appear under ordinary light microscopy as lymphocytes of medium to large size. 6 On a peripheral blood smear, B lymphocytes cannot be distinguished from T lymphocytes. However, immunoglobulinlike receptors are prcsent on the surface membranes of B lymphocytes. Thus, these cells can be identified specifically by immunofluorescent technics. In the tissue, B cells can be identified as plasma cells under light microscopy5 Studies have shown that B lymphocytes may transform into plasma cells capable of synthesizing and secreting specific antibody. It is probable that the peripheral blood B cells serve to recognize foreign antigen, while the tissue B cells serve to synthesize specific antibody, which is subsequently distributed systemically? The function of B ceUs is the production of specific antibody. Collectively, all of the antibody molecules are called immunoglobufins. Although antibody specificity is diverse, collections of antibody molecules can be divided into classes and subclasses according to molecular structure. Each antibody molecule is composed of two heavy chains and two light chains linked together by disulfide bonds) A portion of the amino acid sequence of both the heavy and light chains is variable and a portion is constant. The ability to identify the immunoglobulin class in which an antibody belongs resides in the Fc portion of the heavy chain of the molecule. This fragment of the molecule is distinct chemically for each of the five separate immunoglobulin classes. The Fc fragment of the molecule also determines the specific functions of the immunoglobulin classes, such as complement fixation and placental passage. The fragment of the molecule composed both of heavy and light chains is the antibody-combining portion (Fab), which is highly variable in amino acid sequence and permits the diversification necessary for combination with the multiplicity of antigens that an individual encounters. Each immunoglobulin class has unique characteristics and specific functions (Table 1).l~ Immunoglobulin G (IgG), a low molecular weight immunoglobulin of approximately 150,000, is the most abundant, comprising 70-80% of the total immunoglobulins. It is distributed intravascularly and throughout the interstitial spaces. The mean adult concentration is 1,200 mg/dl (see Table 2 for normal immunoglobulin values at various ages). IgG has the longest half-life of the immunoglobulins: 25-27 days. The majority of IgG antibodies

T A B L E 1.--PROPERTIES OF IMlqUNOGLOBULINS IGG

IGM

Molecular weight 150,000 900,000 Mean adult concen- 1,200 150 tration, mg/dl Binds complement -}-tPlacental transfer + 0 Half-life (days) 25 5

IcA

IcD

IcE

170,000-370,000 180,000 200,000 300 3 0.03 0 0 7

0 0 3

0 0 3

T A B L E 2 . - - L E V E L S OF I M M U N E GLOBULINS IN SERUM OF NORMAL SUBJECTS AT DIFFERENT AGES*

AGE

Newborn l-3mo 4-6 mo 7-12 mo 13-24 mo 25-36 mo 3-5yr 6-8yr 9-11 yr 12-16 yr Adults

LEVELOF " / G ]~IG/DL (RANGE)

1,031 -4- 200 (645-1,244) 430 + 119 (272-762) 427 • 186 (206-1,125) 661 -+-219 (279-1,533) 762 -----209 (258-1,393) 892• 183 (419-1,274) 929 ~228 (569-1,597) 923• (559-1,492) 1,124-+-235 (779-1,456) 946"+'124 (726-1,085) 1,158• (569-1,919)

LE~,qELOF ~/ i~I },IO/DL (RANGE)

ll • 5 (5-30) 3 0 • 11 (16-67) 43 ~ 17 (10-83) 54 -+-23 (22-147) 58 • 23 (14-114) 61 "+"19 (28-113) 56"+-18 (22-100) 65• (27-118) 79• (35-132) 59-----20 (35-72) 99• (47-147)

LEVELOF ^/ A ~IG/DL (RANGE)

LEVELOF TOTAL ~'-G LOBULIN I~,IG/DL (RANGE)

2+ 3 (0-11 ) 21 • 13 (6-56) 28 4- 18 (8-93) 37 "~ 18 (16-98) 50 -----24 (19-119) 71 -----37 (19-235) 93~27 (55-152) 124~45 (54-221) 131 - 4 - 6 0 (12-208) 148~63 (70-229) 200~61 (61-330)

1,044 -4- 201 (660-1,439) 481 • 127 (324-699) 498 -+-204 (228-1,232) 752 "+"242 (327-1,687) 870 "+ 258 (398-1,586) 1,024-4-205 (499-1,418) 1,078-----245 (730-1,771) 1,112"4"293 (640-1,725) 1,334-----254 (966--1,639) 1,153"+169 (833-1,284) 1,457-+'353 (730-2,365)

*From Stiehm, E. R., and Fudenberg, tt. tf.: Serum levels of immune globulins in health and disease: A survey, Pediatrics 37:715, 1966.

bind complement, and are both actively and passively transferred across the placenta from the maternal circulation. IgG may be con-, sidered the memory antibody as it is this antibody class that persists for long time periods following antigenic stimulation. The majority of antibodies against viruses, bacteria and fungi are in the IgG class. Blocking antibodies, which occur following allergy desensitization and in malignancies, are primarily of the IgG class. IgG is the primary immunoglobulin class contained in commercial g a m m a globulin. The effectiveness of g a m m a globulin injections is determined b); passive protection and the long half-life of IgG. Immunoglobulin M ( I g M ) is a high molecular weight immunoglobulin of approximately 900,000, comprising 5 - 1 0 % of the total immunoglobulins. The mean adult concentration is 150 mg/dl. IgM is contained primarily in tile intravascular space and is fbrmed most rapidly following primary immunization. The half-life of,IgM is short: 3 - 5 days. Newborn babies do not normally have IgM preseht in their cord blood as it usually does not cross the placenta and is not synthesized in utero. The major antibodies to polysaccharide-containing organisms and gram-negative bacteria are in the IgM class. Isohemagglutinins and anti-Rh antibodies, rheumatoid factor and heterophil 6

antibodies are usually included in this class. There is evidence that the spleen plays an important role in IgM 15roduction. 11 Immunoglobulin A (IgA) is contained both in the secretions and in the serum. TM In the serum, IgA comprises 10-15% of the total immunoglobulins, is contained primarily in the intravascular space and consists of a low molecular weight molecule of approximately 170,000. The mean adult serum concentration is 300 mg/dl. In the secretion lgA is linked to a 30,000 molecular weight "piece" called secretory piece or transport piece. Two molecules of IgA joined with secretory piece constitute secretory IgA. Secretory IgA retains antibody activity following digestion by pepsin and acid and may thus remain active in the intestinal tract under conditions that might destroy other antibody molecules. IgA is effective in local immunity. It has been well documented that local infection can be prevented by secretory IgA and that response to local immunization (such as by oral poliomyelitis virus) is dependent on secretory IgA. Secretory IgA is found in colostrum and breast milk in concentrations 10-100 times that of serum. 13 IgA does not cross the placenta and does not bind complement. Its half-life is approximately 7 days. Immunoglobulin D (IgD) is present in the serum in low amounts, comprising Iess than 1% of the total immunoglobulins. The mean adult serum concentration is 3 mg/dl. Little is known concerning the specific function of this immunoglobulin class. Antibody activity against a variety of microbial agents has been demonstrated, but there is no convincing evidence that IgD has a unique function. The molecular weight is approximately 180,000. Immunoglobulin E (IgE) is one of the more unique and "potent" immunoglobulin classes but is present in the serum in the lowest concentration, comprising less than 0.01% of the total immunoglobulins. TM The mean adult concentration is 0.03 mg/dl. IgE is present in the plasma in an unattached form and can be quantitated only by radioimmunoassay. Serum IgE is also bound to basophils and, in tissue, to mast cells and basophils. A variety of pharmacologic agents are released when specific antigen combines with IgE antibody attached to mast cells or basophils. The pharmacologic agents then result in allergic reactions. These agents have been identified as histamine, SRS-A (slow-reacting substance of anaphylaxis) and eosinophilic chemotactic factor. IgE does not cross the placenta. The serum half-life is approximately 7 days, but the half-life of IGE bound to cells may be much longer. The molecular weight is approximately 200,000. Competent antibody-mediated immunity can be characterized by the presence of normal circulating amounts of immunoglobulin, normal secretory immunoglobulin and a functional antibody response following antigenic challenge. The spectrum of antibody deficiency syndromes can vary from a complete absence of all immunoglobulins to absence of a single class of immunoglobulin or any combination of deficiencies involving the five immunoglobulin classes. 7

Rarely, an individual may have normal levels of all immunoglobufins but may not be able to respond with an increase in functional antibody following exposure to antigen. 15 The development of specific antibody cannot always be viewed as resulting in immediate or longrange benefit to the individual. Although the development of IgE antibodies may prevent specific local damage caused by foreign antigens to the lung and intestinal tract, it may induce severe asthma as well. Antibodies may also develop against the "wrong" antigens: those previously rccognized as self. Chronic production of antibody in inappropriate amounts can result in the deposition of antibody and antigen as a complex in tissue, with secondary disease such as the nephritis of systemic'lupus erythematosus. Malignant proliferation of a clone of antibody-producing cells, termed myeloma, can occur following the uncontrolled production of antibody. Although such malignancies are rare in children, the presence of chronic intrauterine infection such as syphilis or toxoplasmosis may result in the production of myelomalike antibody production. 16 Antibody may also "block" beneficial effects such as the cellular destruction of malignant cells. 17

CELl-MEDIATED IMMUNITY Differentiation of stem cells into a population of competent mediators of cellular immunity occurs in the thymus. Cells that have come under thymic influence are termed T cells. It has been demonstrated that stem cells migrate to the thymus and from there are distributed throughout the lymphoreticular system. The epithelial portion of the thymus is necessary for normal T cell function. The maturation of stem cells into mature T cells may occur as a result of direct contact with the epithelial portion of the thymus or by means of a hormonal mechanism. Several thymic hormones have been studied, including thymosin, thymic humoral factor and thymin. Each of these has the capability of replacing some of the functions of the thymus. Maturation of thymic cells proceeds through several steps, as studied in animal models. Three subpopulations of T ceils have been described. To cells are immature cells that proceed to T1 cells. They are spleenseeking and have large amounts of surface theta antigen and a short half-life. T_o cells are long-lived, lymph-node-seeking cells with little surface theta antigen. The necessity of the thymus for the maintenance of normal immune function was first clearly demonstratcd by thymectomy performed in animals, which resulted in a wasting syndrome. Less profound effects were achieved if thymectomy was delayed until adult life. In man, thymectomy in the newborn period (as in cardiac surgery or radiation) does not result in a wasting syndrome or immediate immunodeficiency, probably because the thymectomy is incomplete. In addition, it appears that cellular immune function is well established in the human fetus and that distribution of T ceils throughout the reticuloendothelial system occurs early. Thus, at birth cell-mediated immunity

is carried out by a well-established population of mature long-lived lymphocytes capable of responding by repeated division. Currently there is no specific way in which individual T ceils can be identified in human tissue. Experience with immunodeficiency disorders, however, suggests that collections of T cells occur in specific locations such as the periarteriolar area of the spleen and in so-called T-cell-dependent areas of the lymph node. These are located in the paracortical and perifollicular regions of the lymph nodes. In the peripheral blood of man, 65-75% of the circulating lymphocytes are T cells. They can be identified by their ability to form "rosettes" with shecp red blood cells. This appears to be characteristic of T cells of virtually all animal species. On scanning electron microscopy T cells have surfaces with fewer and blunter villi than B cells. In the mouse a specific surface marker for T cells has been identified and termed thcta antigen. This has allowed a more precise determination of the location and function of T cells. A grc.at deal of evidence has accumulated to indicate that T-B interaction is required for normal antibody production. This interaction may result from direct cell contact or the elaboration of T cell products. T cells ha~,e the property of reacting to specific antigens. In general, they have carrier specificity, while B cells are hapten-specific. As T ceils lack immunoglobulin rcceptors on their surface, the means by which they recognize specific antigens and subsequently react with B cells to produce antibody is not clear. Some investigators feel that T ceils have IgM-like receptors, while others have theorized that T cells have the function of concentrating antigen. Transfer factor may also be a T cell product, which, in contrast to some of the nonspecific effects of lymphokines, may serve to regulate the cellular immune response to specific antigens. Transfer factor is a low molecular weight (2,000-3,000) substance obtained from normal lymphocytes. It has the capability of transferring the specific cellmediated immunity of a donor to a normal recipient, as evidenced by delayed hypersensitivity skin tests. There is some recent evidence that transfer factor may contain R N A components. Once a lymphocyte has become sensitized to a specific antigen, it will react to that antigen again on second exposure either by going into blast transformation and/or by releasing a variety of the substances termed lymphokines. Some lymphokines, such as the migration inhibition factor (MIF), have been identified specifically. MIF is released from lymphocytes following exposure to antigen. In vitro MIF prevents the migration of macrophages out of a capillary test tube. In vivo it may prevent macrophages from leaving areas of infection. Lymphocytes also release interferon as well as cytotoxie substances following stimulation by a variety of agents. These lymphokines serve to amplify the function of T cells. Lymphocytes may have a direct cytotoxic effect on other cells and thus act to control the replication and dissemination of foreign cells such as foreign lymphocytes and malignant cells. The T cell is responsible for the rejection of foreign

grafts such as skin or kidney grafts. Cell-mediated immunity is important primarily in protection against viral, fungal and protozoal infections as well as against malignancy and graft-versus-host reaction. As in antibody-mediated immunity, not all cell-mediated immune reactions may be beneficial. Excessive sensitization and subsequent release of lymphokines may result in severe local and systemic reactions, e.g., poison oak dermatitis and "farmer's lung." In other instances individuals may develop sensitization to common environmental agents such as Aspergillus, which may result in chronic lung disease.

PHAGOCYI"OSIS Phagocytosis is the process of cells ingesting replicating and nonreplicating agents encountered in the environment in order to contain or destroy them. TM Various types of phagocytic cells are known to exist. Neutrophils, which are the primary circulating phagocyte, are produced in the bone marrow at an extremely rapid rate. The normal individual produces .an estimated 120 billion neutrophils each day. Neutrophil survival in the circulation is short, with a half-life of 6--7 hours. Macrophages are phagocytic cells that reside in the tissue, especially the spleen, lymph nodes, bone marrow and pulmonary alveolar system. The liver sinusoids contain a type of macrophage termed a Kupffer cell. Monocytes are derived from the bone marrow and then may differentiate into tissue macrophages. A characteristic feature of neutrophils and tissue macrophages is the high intracellular content of granules, which contain hydrolytic enzymes associated with lysosomes. In order for phagocytes to perform their protective role they must be produced in adequate numbers and mobilized at the appropriate time. Prior to phagocytosis foreign agents such as bacteria must interact with serum proteins. The preparation of bacteria for phagocytosis is termed opsonization. Most bacteria require interaction with specific antibodies and complement. After opsonization the bacteria-antibodycomplement unit adhercs to the phagocyte and is phagocytosed by pinocytosis. Phagocytic intracellular metabolic activity is then stimulated; H.~O., is produced that interacts with halides and lysosomal enzymes such as myeloperoxidase to kill bacteria. Chemotaxis is the movement of a phagocytic cell toward an area of inflammation. The phagocytic cell must have the ability to respond by mobilization toward specific chemotactic factors derived from certain bacteria. Chemotactic factors are released from bacteria following activation of the complement system. Antibody reacts with antigen on the surface of the microbial agent, and the antigen-antibody complex activates complement components sequentially. C1, C4 and C2 form a complex that activates C3 and C5, yielding chemotactie fragments C3a and C5a. The alternate complement pathway can be activated directly by microorganisms, or proteases released from bacteria can 10

also generate C3a and C5a. Other factors known to have chemotactic activity include the trimolecular complex of C5, C6 and C7, kallikrein, plasminogen activator and lymphokines. Phagocytes possess a selective ability to recognize foreign agents. The mechanism for this form of recognition is not completely known but involves both humoral and phagocytic activity. The humoral aspect of recognition is due to the presence of opsonins, which are composed primarily of immunoglobulins of the IgG class. The interaction between a foreign particle and specific antibody is termed opsonization. Normal opsonic activity will not occur without both the Fab and the Fc portions of the immunoglobulin molecule. The Fab portion adheres spccifically to bacteria, while the Fc portion attaches to receptors on phagocytic cells. Bacteria may also activate the alternate complement pathway to enhance the deposition of fragments of C3. C3 then attaches to complement receptors on phagocytic cells. 19 The phagocytic cell recognition of an opsonized particle as foreign depends on the presence of receptor molecules on the surface of the phagocytic ceils. Phagocytic cells are known to have receptors both for complement components and for the Fc portion of immunoglobulin molecules. The ectoplasm of the phagocytic cells forms pseudopodia in a spreading action that is similar to the movement of phagocytic cells on smooth surfaces. The pseudopodia surround the particle and fuse on the distal side, thus encasing the particle in a phagocytic vacuole or phagosome. Ingestion is an active process requiring ATP, glycolysis, glycogenolysis and Qxidative phosphorylation. Agents that increase intracellular levels of cyclic AMP or inhibit glycolysis decrease the rate of ingestion; steroids in high doses decrease the rate of phagocytosis. Following the ingestion of opsonized foreign particles, cytoplasmic organelles fuse with the membrane of the phagosome and then disappear from the cytoplasm by a mechanism termed degranulation. The granules contain enzymes that act with other cell metabolites to destroy the foreign particle. Compounds that increase cyclic AMP levels impair the process of degranulation, while compounds that increase cyclic G M P levels enhance degranulation. Steroids and antimalarial drugs may impede degranulation because of their ability to prevent the disruption of granule membranes. Following the ingestion of microbial agents or particles by phagocytic cells there is a rapid increase in oxygen consumption and hydrogen peroxide production and a tenfold increase in the oxidation of glucose through the hexose monophosphate shunt, z0 Considerable controversy surrounds the enzymatic basis of this oxidative burst. Two oxidases specifically involved in the oxidative burst have been identified in human neutrophils: NADPH oxidase and NADH oxidase. The oxidase enzymes reduce oxygen to a superoxide anion. The superoxide anion may then spontaneously or enzymatically be reduced to 11

hydrogen peroxide, or it may react with already formed hydrogen peroxide to yield extremely reactive hydroxyl radicals. The production of hydrogen peroxide and hydroxyl radicals occurs within the phagosomes. The phagosome membranes are permeable by hydrogen peroxide, which then can easily enter the cytoplasm of the cells. Two systems are present within neutrophils to detoxify the hydrogen peroxide: coupled enzymatic reactions involving reduced glutathione and catalases. Reduced glutathione is then regenerated through the hexose monophosphate shunt. Catalases that may break down hydrogen peroxide are present within the cytoplasm of the cell. A variety of nonspecific microbicidal systems are known to exist in neutrophils. Certain bacteria, such as pneumococci, may be killed by changes in the pH within the phagocytic vacuoles. Several cationic proteins that have selective bactericidal activity against certain gramnegative and gram-positive organisms are present. Lactoferrin has bacteriostatic properties and lysozomes are capable of hydrolyzing the mucopolysaccharides of bacterial cell walls. The hydrogen-peroxide-myeloperoxidase-halide system is probably the most important of the bactericidal systems in the neutrophil. Iodide is the most potent of the halides. Iodination of bacterial cell walls occurs when iodide is employed in a cell-free system with myeloperoxidase and a hydrogen peroxide generating system. Iodination has been demonstrated within the neutrophil following particle ingestion; iodination rates correlate with bacterial killing rates. Iodination and superoxide generation may be important for optimal bactericidal activity within the phagocyte. COMPLEMENT Complement consists of a series of nine serum factors that act sequentially to amplify the effect of antibody-mediated immunity, cellmediated immunity and phagocytosis. The molecular weight of these substances varies from 79,000 to 400,000. z~ The first component of complement (C1) can be divided into three subcomponents consisting of Clq, C l r and Cls. C l q is capable of binding to the Fc portion of immunoglobulin molecules, primarily IgG. When C l q is activated by antigen, it in turn activates Clr, which is followed by activation of Cls. Cls binds to C4, and an additional enzymatic site is uncovered on C1 that affects the cleavage of C2. One of the fragments (C2a) combines with a fragment of C4 (C4b) to form C3 convertase. C3 is present in the serum in highest concentrations (approximately 150 mg/dl). If C3 is available, it is split by the C3 convertase into two fragments (C3a and C3b). C3b acquires proteolytic enzymatic activity that is responsible for the cleavage of C5. When C5 combines with C6 and C7, an active complex is formed that is capable of interacting with C8 and C9, carrying out the final steps of the complement sequence. 19

An alternate pathway to the activation of complement components exists. Two factors have been identified, properdin and factor B (GBG), that can bypass the initial three components of complement (C1, C4 and C2) and activate C3 directly. The entire pathway can also be activated by nonimmunologic mechanisms. Trypsin, lysosomal enzymes and bacterial proteases can activate the complement system directly. Plasmin, an active protein in the clotting mechanism, is capable of activating C1. Complement has several biologic effects. The binding of complement to IgG and IgM involves the complement system in the antibodymediated immune mechanism. Complement facilitates opsonization and immune adherence to phagocytes by foreign particles. In addition, phagocytic cells have specific binding sites for C3 that may further serve to bind antigen-antibody complexes. There is rccent evidence that fixation of C5 may be necessary for the phagocytosis of certain organisms. Two complement-associated factors (C3a and C5a), which affect smooth muscle contraction, are termed anaphylatoxins. Additionally, both C3a and C5a have chemotactic activity. GENERAL CLINICAL PRESENTATION OF IMMUNODEFICIENCY DISORDERS In the absence of a set of specific clinical symptoms or signs suggesting immunodeficiency, such as in chronic mucocutaneous candidiasis or ataxia-telangiectasia, it may be difficult to determine when an immunologic evaluation should begin and which studies should be performed. However, there are many suggestive signs and symptoms that may help the clinician (Table 3). The age of onset of symptoms is directly related to the severity of the deficiency. Infants with congenital hypogammaglobulinemia may remain asymptomatic until passively transferred maternal IgG is no longer present (5-6 months of age). At this time they may experience recurrent otitis media and pneumonia. Infants with severe combined immunodeficiency disease (deficient antibody- and cell-mediated immunity) do not have sufficient protection from maternal antibody alone and usually are severely ill by 3 months of age. Acquired immunodeficiency may occur at any age, and the fact that a child or adult has not had a history of repeated or severe infections does not rule out immunodeficiency of recent onset. Secondary immunodeficiency may be associated with a variety of diseases, such as protein-losing enteropathy, malignancy and severe viral illness, or with immunosuppressive therapy. The number of infections that a "normal" infant or child may experience before the physician begins an immunologic investigation is difficult to ascertain, but certain factors should be considered. The following conditions should be viewed with suspicion: (1) repeated respiratory infections in an infant under 3 months of age; (2) repeated 13

T A B L E 3 . - - C L I N I C A L FEATURES ASSOCIA'IED ~.VITII II'.II'.IUNODEFICIENCY

A. Features frequently present and highly suspicious: I. Chronic infection. 2. Recurrent infection (greater than expected). 3. Unusual infecting agents. 4. Incomplete clearing between episodes of infection or incomplete response to treatment. B. Features frequently present and moderately suspicious: I. Skin rash (eczema, monilia, etc.). 2. Diarrhea (chronic or prolonged). 3. Growth failure. 4. Hepatosplenomegaly. 5. Recurrent abscesses. 6. Recurrent osteom2~elitis. C. Features associated with specific immunodeficiency disorders: !. Alaxia. 2. Telangiectasia. 3. Short-limbed dwarfism. 4. Cartilage-hair hypoplasia. 5. Idiopathic endocrinopathy. 6. Partial alblnlsm. 7. Thrombocytopenia. 8. Eczema. 9. Tetany.

infcctions in an infant under 9 months of age who has virtually no exposure to infcctious agcuts, e.g., an only child, little contact with other children; (3) rcpeatcd infections that rcsult in complications, e.g., chronically draining cars, bronchiectasis, chronic or intermittent diarrhea, sccondary infcction such as candidiasis. On tile other hand, an evaluation might be delayed if repeated rcspiratory infcctions are associated with a strong family history of allergy, if the child is one of many siblings or if he is attcnding nurscry school for the first time. The interval between infections is an important factor for the physician to consider when evaluating the possible presence of intmunodeficicncy. Most normal infants and childrcn, in spite of cxpcriencing repeated infections, have periods of wcll-bcing between infcctions. In contrast, immunodeficient infants and children frequently are continuously a n d / o r chronically ill. This usually results in failure to thrive, with growth retardation. An important clue to the presence of immunodcficiency is the prcsencc of unusual or opportunistic organisms. The diagnosis of Ptlettmocystis carinii, Aspergillus or Serratia marcescens infections should suggest to the clinician that an intmediarc immunologic evaluation be obtained. The diagnosis of an infcction that occurs rcpeatcdly with common microbial agents should also point him toward an immunologic evaluation. Recurrent infection with Pneumococcus and Hemophil,s hz[l, enzae is found in patients with the Wiskott-Aldrich syndrome. Chronic Candida iufcction, cspccially when resistant to therapy, may indicate the prcscnce of cellular 1.4

immunodeficiency. Infection with microbial agents of normally low pathogenicity, e.g., Staphylococcus albus or Serratia marcescens, suggests that a phagocytic defect may be p~:esent. Patients with immunodeficiency disorders may develop infections in unusual locations. Chronic nail or mouth infections with Candida, liver abscess or osteomyelit!s without an appropriate antecedent cause may be the initial manifestation of immunodeficiency. The infant who develops severe candidiasis involving the mucous membranes, which is resistant to therapy and without appropriate inducing events (breast feeding, broad spectrum antibiotics), should receive an evaluation of cellular immunity. Unusual complications of routine events may be the initial presentation of immunodeficiency. Many of these follow routine immunization. In the past any infant with severe cellular immunodeficiency who received a smallpox immunization developed progressive vaccinia. Although this is rarely observed any more, paralytic poliomyelitis and progressive encephalitis have recently been reported in immunodeficient patients who had received attenuatcd live virus immunization.22, 23 Certain physical findings may be associated with immunodeficiency disorders. These cover virtually every organ system and will be mentioned only briefly, with details discussed under specific disorders. Many immunodeficiency disorders have associated hematologic abnormalities. Thrombocytopenia in a male infant suggests a diagnosis of the Wiskott-Aldrich syndrome. Neutropenia has been described in a number of immunodeficicncy diseases but is not specific. Lymphopenia is common in cellular immunodeficiency disorders. Neurologic manifestations may result from meningitis or encephalitis. Ataxia may be the initial manifestation of the ataxia-telangiectasia syndrome. Endocrinologic manifestations of immunodeficiency disease may relate to congenital malformations involving the 3d and 4th branchial arches or to autoimmune disease. In the Di George syndrome both the thymus and parathyroids fail to develop. Neonatal hypocalcemic tetany is frequently the first abnormality noted by ihe clinician. An autoimmune phenomenon associated with idiopathic hypoparathyroidism, Addison's disease or pernicious anemia may prccede other manifestations of chronic mucocutaneous candidiasis. Dermatologic manifestations are a frequent finding in immunodeficiency diseases. Chronic eczema, classically present in the WiskottAldrich syndrome, may also be observed in other immunodeficiency disorders. Vitiligo may be associated with both autoimmune disease and immunodeficiency. Recurrent skin abscesses are found primarily in disorders of phagocytosis. The skin is almost always involved in the graft-versus-host reaction, a complication of severe cellular immunodeficicncy in which viable cells (such as from a blood transfusion) are not rejected by the patient. In the acute form the rash can appear as a maculopapular lesion and may be confused with a viral syndrome. 15

Chronically, the rash appears as a desquamating lesion confused with Letterer-Siwe disease, or acrodermatitis enteropathica. Gastrointestinal involvement is frequent in immunodeficiency, with diarrhea as the primary symptom. Diarrhea may be found in immunodeficiency disease with either antibody, cellular or phagocytic defects. A high incidence of celiac disease is found in patients with selective IgA deficiency. S~vere diarrhea is also seen in graft-versus-host disease. Sinopulmonary infection is an early symptom of immunodeficiency. Radiologic changes are not specific, however, and similar x-ray findings occur with chronic asthma or cystic fibrosis. The reticuloendothelial and lymphatic systems are frequently abnormal in patients with immunodeficiency. Severe hepatosplenomegaly is found in patients with the Chediak-Higashi syndrome and the graftversus-host reaction, with more moderate enlargement in patients with chronic granulomatous disease. Lymphoid tissue is classically absent in patients with congenital sex-linked hypogammaglobulinemia and severe combined immunodeficiency disease; patients with other immunodeficiency disorders may have normal or hypertrophied lymph nodes. This is particularly true in thymic hypoplasia syndromes and chronic granulomatous disease. Metabolic abnormalities are extremely rare in immunodeficiency disorders. Thus far, only two have been described, one in the enzymatic pathways involved in phagocytosis (chronic granulomatous disease) and the other a deficiency of the enzyme adenosine deaminase, z4 found in a number of patients with combined immunodeficiency. Genitourinary involvement in immunodeficiency disease is rare. It is surprising that recurrent urinary tract infections do not occur more frequently in this patient population. Joint and bone involvement have been described in a variety of diseases. An arthritis, similar to that seen in patients with rheumatoid arthritis, has been described in patients with hypogammaglobulinemia. The arthritis responds promptly to gamma globulin therapy. Shortlimbed dwarfism, metaphyseal dysostosis and other bony abnormalities have been described in antibody and cellular immunodeficiency. Osteomyelitis, usually with low grade pathogens, is found frequently in patients with chronic granulomatous disease. The type of infection may suggest which function of the immune system might be deficient. Abnormalities of cellular immunity are associated with susceptibility to viral, fungal and protozoal infections and with an increased incidence of malignancy and autoimmune disease. Defective antibody immunity is associated with recurrent bacterial infection. Recurrent viral infection may also occur but is usually not overwhelming. Defective phagocytosis is usually associated with recurrent bacterial infection resulting in chronic abscess formation. Complement deficiencies are associated with recurrent bacterial infection and autoimmune disorders. 16

LABORATORY STUDIES The following laboratory studies are organized into two groups of tests: screening tests and tests capable of establishing a definitive diagnosis. The screening tests will detect more severe and general disorders of immune function, while the definitive tests detect more restricted abnormalities. Scrccning studics are readily available and can be performed in the physician's office or obtained through routine laboratory tests. Complex studies are generally available at most major medical centers. ANTIBODY-MEDIATED IMMUNITY (TABLE 4 )

Protein electrophoresis.Iprotein electrophoresis should not be used as a screening test as it is capable of detecting only severe hypogammoglobulinemia and not selective immunoglobulin deficiencies. The procedure is of benefit in detecting " M " proteins, which are a result of myelomas; however, they are extremely rare in children. lmmunoelectrophoresis.--Immunoelcctrophoresis is a rapid method that provides a semiquantitative estimation of immunoglobulins, certain complement components and other serum proteins. The method can detect specifically IgG, IgM and IgA. Normal to elevated values can be observed with this test, but it is not sufficiently sensitive to detect low values, nor can it detect IgD and IgE in normal serum. In the hands of an experienced individual this method provides a good semiquantitative method at relatively reduced expense. Specific immunoglobtdhl qttantitation.--Quantitation of immunoglobulins is currently the most popular method of obtaining specific TABLE 4.--EVALUATIONOF ANTIBODY-~|EDIATEDIMMUNITY COMMENT

TEST

I. Protein electrophoresis 2. Immunoelectrophoresis 3. Immunoglobulin quantitation 4. Radioimmunoassay 5. Schick test

6. Isohemagglutinins

7. Specific antibody response 8. B cells 9. X-ray of nasopharynx

Use only to diagnose hypogammaglobuline-

mia. Not sensitive below 30 mg/dl. Best procedure for IgG, IgM, IgA and IgD quantitation. IgE quantitation. Not generally available. DPT immunization must be complete. Subject to error under 6 months of age and I month after gamma globulin therapy. Titer ~>1:4 after i year of age. Tetanus, diphtheria, mumps, polio, etc. Do not immunize with live agent if immunedeficiency is suspected. Measurement of the number of circulating B cells. Normal 25-30%. Useful in hypogammaglobulinemia. May be normal in some immunodeficiency disorders. 17

values of serum IgG, IgM and IgA. The study is performed by radial diffusion in agar with appropriate standards, and results are expressed as immunoglobulin levels in/ng/dl or mg/ml. The method cannot be used to detect IgE. Normal values of spccific immunoglobulins are available; all values obtained in an individual must be compared with age (see Table 1). This is particularly important in younger infants and children whose immune system is developing and who normally have increasing quantities of immunoglobulin as they become older. The accuracy of this method is 10-15%. Values must therefore be at least 2 standard deviations from the mean before they can be considered abnormal. Immunoglobulin G deficiency should be considered only if values are below 250 mg/dl. Deficiency of IgM and IgA cannot be considered significant unless values are below 10 mg/dl. Measurement of IgM in cord blood or in newborn infants may be useful in the detection of intrauterine infection. While normal IgM values do not preclude this diagnosis, values greater than 20 mg/dl in the cord blood and greater than 30 mg/dl in the serum after 2 days of life are consistent with a diagnosis o[ intrauterine infection. This represents premature stimulation of the immune system by a chronic infectious agent in utero. Diffuse elevations of immunoglobulins may be seen at any age as a result of chronic infection and/or inflammation. Infants and children with cystic fibrosis, osteomyclitis and systemic lupus erythcmatosus may all have increased immunoglobutins. Depressed immunoglobulins may be seen as a result of congenital absence, as in hypogammaglobulinemia or selective IgA deficiency. Depressed values have also been observed in the nephrotic syndrome, in protein-losing enteropathy and secondary to malignancy. Secretory IgA is the major immunoglobulin in the secretions. IgA is absent in the secretions of 98% of individuals with selective IgA deficiency. It is sufficient to screen those who are suspected of having a defect in the IgA system simply by measuring serum IgA. No cases of absent secretory IgA and normal serum IgA have been described. The value of measuring IgD is undetermined as the significance of antibodies in the IgD class has not been established. IgE can be quantitated only by a radioimmunoassay technic that is not generally available. Elevated levels have been found in allergy, parasite infections, eczema and certain immunodeficiency disorders associated with depressed cellular immunity. The use of IgE quantitation as an aid to a specific diagnosis is generally not helpful because of the wide variation in values. Decreased values have been described in hypogammaglobulinemia, in ataxiatelangiectasia, as an isolated deficiency in normal subjects and in two patients with recurrent infection.25 Specific antibody prodttction.--In rare instances patients may have normal quantitative immunoglobulins that do not function. In order to demonstrate intact antibody-mediated immunity in a patient, the clinician must demonstrate both normal quantitative immunoglobulins 18

and the ability of the patient to mount a specific antibody response. Normal infants and children who have completed the entire course o[ diphtheria-pertussis-tetanus (DPT) immunization have adequate levels of antibody against diphtheria toxin. The antibody will neutralize diphtheria toxin, and no reaction will be observed following skin testing with Schick reagent. The test is of use as a screening procedure. However, individuals who have not been completely immunized may have a nonreactive Schick test. Those who have received gamma globulin recently (within 30 days) or infants who still have maternal antibody (up to 6 months of age) may have nonreactive Schick tests that falsely indicate the presence of actively synthesized antibody. The presence of isohemagglutinins may be used to indicate antibody formation. Isohemagglutinins normally develop as a result of the crossreaction between the polysaccharides of Escherichia coli that colonize the gut and red blood group antigens A and B. As gut colonization continues with age, in individuals of the appropriate blood group type, specific cross-reacting antibody increases. A child aged 1 year or older should have a titer of more than 1:4 of anti-A and/or anti-B. The study is not valid in individuals who have recently received gamma globulin, in infants who still have the presence of maternal antibody or in those aged less than 1 year who have not had sufficient time to develop isohemagglutinins. The production of other specific antibodies can be measured if appropriate exposure has been documented. The clinician may measure antibody to typhoid, Pneumococcus, measlcs, rubella, polio, tetanus, etc. The availability of these antibody measurements largely reflects services provided by local laboratories as well as public health services. It is important to emphasize that no patient suspected of having an immunodeficiency disorder should receive live or attenuated virus immunization in an attempt to document specific antibody production. Cases of paralytic poliomyelitis have been described in immunodeficient infants who had received attenuated polio vaccine. Other less purified vaccines such as typhoid should also be used with caution as these result in severe Schwartzman-like reactions in immunodeficient patients. Only highly purified nonreplicating immunizing agents should be used for testing of immunodeficient individuals. )(-ray o[ adenoids.--This procedure has been recommended in the past to aid'in the diagnosis of hypogammaglobulinemia. It is of value primarily in children over 2 years of age suspected of having congenital hypogammaglobulinemia. Children with acquired hypogammaglobulinemia and other immunodeficiency syndromes may actually have lymph node hypertrophy. Quantitation of B cells.--Lymphocytes in the peripheral blood may be identified specifically as B cells by the presence of immunoglobulin receptors on their surface. This test is usually performed by immunofluorescence and is available only in specialized laboratories. The study may be helpful in differentiating congenital from acquired hypogammaglobulinemia. In the latter instance there are normal numbers 19

of peripheral blood lymphocytes that stain for immunoglobulin; in congcnital hypogammaglobulincmia there are no cells that stain for immunoglobulin. CELL-MEDIATED IMMUNITY (TABLE 5 )

Total lymphocyte cotmt.--The total lymphocyte count is obtained by multiplying the total white blood cell count by the percentage of lymphocytcs. In a normal individual at any age this value should be greater than 1,200/mm'~. The patient with a total lymphocyte count of less than 1,200/mm 3 should be suspected of having a defect in cellmediated immunity. Lymphopenia may also be secondary to immunosuppressive agents, viral infection, malignancy or autoimmune discase. Regardless of the cause of lymphopcnia, total lymphocyte counts of less than 800/mm ~ arc frccluently associatcd with infections by opportunistic organisms. Patients who have acute illnesses associated with lymphopenia should have their white blood cell count rcpeated 2 - 3 weeks after recovery from the illness as the lymphocyte count will usually return to normal aftcr this interval. Ahhough a depressed lymphocyte count is useful for the screening of primary and secondary immunodcficiency, the total lymphocyte count may on occasion be normal or even clcvatcd in severe immunodcficiency. In this instance, while lymphocytes are normal in number, they are not ncccssarily functioning cells. Skhl tests [or delayed hypersensitivity.--The application of specific antigens by intradermal injection may result in the exprcssion of competent cell-mediated immunity, as evidenccd by erythema and induraTABLE 5.--EvALUA'tION OF CELL-MEDiATEDIMMUNITY TEST

COMMENT

1. Total lymphocyte count 2. Delayed hypersensitivity skin tests

Normal at any age ~, 1,200/mm3 Use Candida, mumps, PPD (purified prorein derivative) and SKSD (streptokinasestreptodornase 4/~/0.I ml) Test T cclls for response to mitogcn, antigens and foreign cclls. Expressed as

3. Lymphocyte response to mitogens (PHA), antigens and allogeneie cells (mixed lymphocyte culture, MLC) 4. T cell rosettes 5. Migration inhibition factor (MIF) 6. X-ray of thymus 7. Chemical sensitization (dinitrochlorobenzcne) 8. Skin graft

stimulated counts divided by resting counts equals stimulation index. Measures the number of eirculaling T ceils. Normal >65%. Lymphokine released from sensitized T cells causing inhibition of macrophage migration. Useful only in newborn period in absence of stress. Not recommended. Difficult to perform and may be hazardous. Not recommended. Sensitization to histocompatibility antigens may occur. 20

tion. Several requirements must be fulfilled in order for these tests to be valid. The examiner must be certain of the activity of the antigen. It is advisable to test the antigens in normal individuals known to have a history of the specific disease. The delayed hypersensitivity skin test should be read at 24- and 48-hour intervals. On occasion, individuals who have large amounts of circulating antibody will develop an Arthus-like reaction 6-8 hours following injection of antigen. This may be confused with a delayed hypersensitivity reaction. Skin tests are of value only when a documented history of previous exposure to the antigen has occurred. A negative skin test may mean lack of appropriate exposure rather than lack of normal immunity. Approximately 85% of the adult population will be positive to one or more delayed hypersensitivity skin tests. In the pediatric population this percentage is much lower because of lack of appropriate exposure. If a child has had adequate immunization to mumps, this skin test is of value. Mild Candida diaper dermatitis that is easily controlled with medication will usually not result in a positive skin test to Candida antigen. However, the child who is over 1 year of age and has severe Candida dermatitis and thrush resistant to therapy should have a positive skin test. The usual battery of skin tests used in the pediatric population consists of Candida (obtained from Hollister Stier as Dermatophytin O), PPD, streptokinase-streptodornase (obtained from Lederle as Varidase and diluted to 40 units/ml of streptokinase and 1 unit/ml of streptodornase), mumps antigen and, in selected areas, either coccidioidomycosis or histoplasmosis. All antigens are injected intradermally in a volume of 0.1 ml. Other methods of testing delayed hypersensitivity are available. In the past dinitrochlorobenzene (DNCB) or dinitroflu6rbenzene (DNFB) have been used, but their use is not recommended as the initial sensitization may result in a permanent scar in infants and children who prove to have normal cellular immunity. In addition, it is frequently difficult to be certain of subsequent test dose concentrations, as both DNCB and DNFB are in acetone solutions and are relatively unstable. Skin grafting is also not a recommended procedure as the skin graft may sensitize the recipient to foreign histocompatible antigens. X-ray oI thymus.~The presence of a thymie shadow on the chest x-ray of a newborn makes the diagnosis of defective cellular immunity highly unlikely. The procedure in older children is less useful as the thymus is difficult to visualize beyond 1 year of age. If there is a history of severe stress, the thymus may become significantly small and may not be visualized on either anteroposterior or lateral views of the chest even during the newborn period. In the past a pneumomediastinum was performed to outline the thymus gland; however, this procedure may be dangerous and is no longer recommended. Lymphocyte sthmdation by mitogens,zG Peripheral blood lympho21

cytes can be obtained from the patient and separated from other blood components. These isolated lymphocytes are placed in culture and stimulated with a variety of mitogens. Numerous animal and human studies indicate that phytohemagglutinin (PHA) is a specific mitogen for thymic-derived lymphocytes, testing the affcctor function of lymphocytes by measuring their ability to transform into blast cells. Defective lymphocyte transformation is usually seen in severe forms of cellular immunodeficiency disease. Chronic or debilitating disease may result in depressed lymphocyte transformation, but absent transformation is usually seen only in congenital cellular immunodeficiency. Severe depression of lymphocyte transformation has been seen in congenital viral infections such as the rubella syndrome. Increased lymphocyte transformation has been observed in patients who have received multiple blood transfusions, in some normal newborns and in allergic individuals. Their cells may be "turned on" by foreign antigen stimulation in vivo. Results of lymphocyte stimulation by mitogen are usually expressed as resting counts followed by stimulated counts. The resting count indicates the amount of radioactive material that is taken up by dividing cells in culture without a specific stimulant. This is expressed as the number of radioactive counts per minute (cpm). Stimulated counts are the result of cell division following stimulation by a mitogen in culture. If the stimulated counts are divided by the resting counts, a stimulation index (SI) is obtained. The example below illustrates a normal resting and stimulated lymphocyte response to PHA, a depressed response and an absent response. The latter is seen most frequently in severe cellular immunodeficiency disease. Some investigators express results as the percentage of a normal control. RESTING C O U N T S

Normal Depressed Absent

330 285 186

STIMULATED

40,125 4,720 294

SI

% NORMAL

122.0 17.0 1.6

100.0 14.0 1.3

Sthmdation o[ lymphocytes by specific antigen.27----Isolated peripheral blood lymphocytes can be stimulated by specific antigen. This study appears to be more sensitive than delayed hypersensitivity skin tests in determining previous exposure and normal reactivity to an antigen. Thus, a person who is suspected of having cellular immunity to a particular antigen but has a negative delayed hypersensitivity skin test to that antigen may demonstrate transformation of lymphocytes when they are exposed to antigen. The study is performed by the culture of Iymphocytes in the presence of antigen. A radioactive label is placed in the culture and the amount of uptake measured in a manner similar to PHA stimulation of lymphocytes. Resting counts, stimulated counts and a stimulation index are obtained. As the number of cells "turned on" by a specific antigen are fewer than those turned on by a general mitogen (PHA), the stimulated counts are much lower than 22

that following mitogen stimulation. The stimulation index will be comparably lower. An example is provided below. ANTIGEN

RESTING

STIMULATED

INDEX

PPD Candida

550 550

6,160 660

11.2 1.2

It can be seen from the above illustration that the individual's lymphocytes respond to stimulation with purified protein derivative (PPD), indicating prior exposure and current recognition of this antigen. The patient's lymphocytes did not respond to Candida antigen, indicating either a specific defect in the ability to recognize Candida antigen or lack of previous exposure. Had the lymphocytes been obtained from an individual with chronic mucocutaneous candidiasis, a specific defect could have been defined. Lymphocyte sthnulation by [oreign cells (mixed lymphocyte ctdture).ZS--The ability of lymphocytes to recognize foreign cells can be tested in lymphocyte culture by mixing the patient's lymphocytes with foreign donor lymphocytes. Isolated peripheral blood lymphocytes are obtained from both the patient and a histoincompatible donor. The histoincompatible ceils provide a stimulus that causes normal thymicderived lymphocytes to divide. This division can be measured by the uptake of radioactive materials, such as in mitogen, or antigen stimulation of lymphocytes. As both patient and donor cells are mixed together in the same test tube, a method has been devised to block the response of one of the groups of cells. Thus, the patient's ability to recognize foreign lymphocytes can be measured by placing either foreign mitomycin-C-treated lymphocytes or irradiated lymphocytes in with the patient's cells. The mitomycin or irradiated ceils cannot divide but provide the necessary antigenic stimulus. The uptake of radioactive labeled material is therefore a measurement of the activity of the patient's cells. T cell rosettes. 29 Thymic-derived lymphocytes have the peculiar property of permitting the binding of sheep red blood cells to their surface membranes and are then termed T cell rosettes. The percentage of T cells binding sheep red blood cells in the peripheral blood can be quantitated specifically. Normal individuals have a mixture of T and B cells in the peripheral blood. The approximate mean percentage of T cells is 65 - 5%. T cell rosettes do not measure a particular function of thymic-derived cells but merely indicate their quantitative presence. Severely depressed T cell rosettes ( < 2 0 % ) are seen in cellular immunodefieiency disorders. Depression of T cell rosettes has also been observed in acute and chronic viral infections, malignancy and immunosuppressive therapy. Elevated T cell rosettes have been described in infectious mononucleosis. Lymphokh~es.3O---T cells, following exposure to specific antigen or mitogens, have the capability of releasing lymphokines that may act in a specific manner or may recruit other mediators of the immune sys23

tern. Migration inhibitory factor ( M I F ) has been partially characterized and is released in vitro following exposure of sensitized lymphocytes to antigens3 ~ This lymphokine prevents the migration of macrophages from an area surrounding lymphocytes in the presence of antigen. M I F is felt to correlate well with delayed hypersensitivity and lymphocyte stimulation by antigen. Interferon is also released from lymphocytes and functions in the control of viral infection3 z Cytotoxins can be released from lymphocytcs into areas of inflammation following specific activation of lymphocytes by antigen. Cell-mediated lymphocytotoxicityYmThe ability of isolated lymphocytes to destroy foreign target cells has been termed cell-mediated lymphocytotoxicity. This function involves two phases: first, the recognition of cells as foreign, and second, the destruction of the foreign cells. This test has not been evaluated completely in all primary and secondary immunodeficiency disorders. SUMMARY.--The various functions of cell-mediated immunity may be viewed in a similar manner to the various functions of immunoglobulins. Certain studies of cell-mediated immune function detect major abnormalities. As studies become more refined, selective deficiencies in T cell immunity are uncovered. This parallels the findings in antibody-mediated immunity, in which total immunoglobulin deficiency was first discovered, followed by selective deficiencies in immunoglobulin production.

PHAGOCYTOSIS (TABLE 6) Peripheral white blood cell count and differentiah----Neutropenia is significant when the neutrophil count (percentage of neutrophils • total white blood cell count) is less than 1,200 mm 3. Occasionally the total neutrophil count may be suppressed as a result of severe infection such as staphylococcal septicemia. Neutropenia occasionally is

T A B L E 6.--EVALUATION OF PHAGOCYTOSIS TEST

COMMENT

1. Total neutrophil count 2. Routine staining of peripheral blood smear 3. Nitroblne tetrazolium test (NBT) 4. Bacterial killing curve

Normal > 1,200/mm 3. Abnormal granules seen in Chediak-Higashi syndrome. Qualitatively and quantitatively abnormal in chronic granulomatous disease. Ahnormal in chronic granulomatous disease and certain specific phagocytic disorders. Abnormal in certain disorders associated with recurrent bacterial infections. Decreased in certain disorders associated with recurrent bacterial infection. Abnormal in C5 dysfunction (Leiner's syndrome). Abnormal in lazy leukocyte syndrome.

5. Chemotaxis, glass wool adherence, etc. 6. C3 CHr,0 (hemolytic complement) 7. C5 functional assay 8. Random migration

24

seen following viral infection but is more frequently a result of drug reactions or the use of immunosupp.ressivc agents. In the neonatal period neutropenia may be the result of auto- or isoantibody that has been transferred placentally from the maternal circulation; in this case the antibody is formed hgainst the infant's white blood cells. The rare Chediak-Higashi syndrome can be diagnosed when giant granules are observed in the cytoplasm of peripheral blood leukocytes seen on routine Wright stain smears. Hyposplenism is suggested by the finding of Howell-Jolly bodies in peripheral red blood cells. Sickle cell preparation (or eqtdvalenO.--Children with sickle cell anemia have an increased incidence of recurrent or severe infections caused by Pneumococcus, Salmonella or other organisms. Nitrobhte tetrazolium dye test.34--Nitroblue tetrazolium (NBT) is normally a colorless compound that is reduced by metabolically activated neutrophils to a dark blue insoluble substance. Neutrophils containing reduced NBT (blue compound) are termed NBT-positive cells. Normally, greater than 6% of neutrophils arc spontaneously NBT-positive. A much higher percentage of neutrophils are NBTpositive when they are obtained from patients with active bacterial infections. Neutrophils from children with chronic granulomatous disease (CGD) give a negative NBT test even in the presence of severe bacterial infection. In addition, if CGD is suspected, a "stimulated" NBT test should be performed by exposing the leukocytes of the patient to solid particles or endotoxin along with the dye in vitro. Normally, greater than 60% of neutrophils respond to these stimuli by becoming NBT-positive, whereas in CGD the neutrophils remain NBT-negative. The qualitative NBT test described above can be used as a screening study and is becoming more widely available, whereas a quantitative NBT test is performed only in more specialized laboratories. The quantitative NBT test can be used to diagnose the carrier state of CGD as well as the disease itself. Bacterial and fungal killhlg curves.--These studies are performed in specialized laboratories when the patient is suspected of having either CGD or a killing defect for a particular organism. The test is performed by incubating the patient's peripheral leukocytes with a predetermined number of organisms; optimally the patient's cells are incubated with an organism with which he has been infected previously. The intracellular killing of these organisms by the patient's cells is compared to the killing by cells obtained from a normal control. Patients with CGD may fail to kill the ingested organism or may kill it more slowly than normal. Peroxidase stab1. This study can be performed simply on an unfixed blood smear in any hematology laboratory. Normal neutrophils contain peroxidase. Complete deficiencies and mosaic deficiencies have been observed in some patients with overwhelming bacterial and fungal infections,z5 Chemotaxis.--Chemotaxis is the specific migration of phagocytic 25

cells toward an agent. Specific migration can be measured in several different manners. The skin window technic (Rebuck) is a simple procedure that measures leukocyte mobility and provides qualitative information.~6 The skin is usually abraded and a glass cover slip placed over the skin for varying periods of time. The number and types of cells that migrate into the area and adhere to the glass cover slip are then determined. Recently, the Boyden chamber has been used in measurements of cellular chemotaxis; phagocytic ceils are placed on one side of a millipore filter and a chemotactic source on the other. The number of cells that migrate through the millipore filter toward the chemotactie source is then determined. Modifications of this technic employ radio-labeled cells and permit a larger number of studies to be performed. 37 Other studies of phagocytic cells.--Random migration of cells can be determined by placing the buffy coat of the peripheral blood in an upright capillary tube and measuring the distance of random migration over a specific time period, zs The ability of peripheral leukocytes to adhere to cotton wool or glass wool columns has also been used to detect defects in phagocytosis.39 The disorders detected by these means appear to be rare, and their clinical usefulness as a screening procedure has not yet been fully determined. Complement assays.--Several defects in phagocytosis are associated with complete complement deficiencies. One of these disorders can be detected easily by measuring the third component of complement.4~ C3 can be quantitated in most hospital laboratories in a manner similar to that used for the quantitation of immunoglobulins. Normal C3 values are usually greater than 100 mg/dl. The hemolytic complement assay is a general screening procedure for measuring tzomplement components; hemolytic complement may be depressed in any of the individual complement deficiencies. Normal values vary with individual laboratories but are usually reportcd as greater than 25 units/ml. Use of hemolytic complement assay as a screening procedure has resulted in detection of Clq, C l r and Cls deficiencies associated with recurrent infections and autoimmune disease. 41-4~ C5 dysfunction, which is a disorder associated with recurrent infections, resembles Leiner's disease. Patients with this disorder have normal levels of C5, but the C5 functions abnormally.4~ The latter assay is performed only in specialized laboratories.

ANTIBODY DEFICIENCY SYNDROMES CONGENITAL SEX-LINKED HYPOGAMMAGLOBULINEMIA.--DefinilioIL

--This is a sex-linked recessive disorder associated with total immunoglobulins of less than 250 mg/dl. Cellular immunity is intact in affected patients. Major clinical/eatures.---~e onset of symptoms usually does not occur until after the loss of maternal immunoglobulin at approximately 5 months of age. Lymphoid tissue is absent. Recurrent infec26

tions in the form of otitis media, meningitis and pneumonia are often caused by Pneumococcus or Hemophilus influenzae. Diarrhea and malabsorption may be present in older patients. Chronic lung disease may develop if treatment has been delayed or inadequate. Diagnosis.---Hypogammaglobulinemia may be detected on immunoglobulin electrophoresis and with specific quantitation. All five classes of immunoglobulin are usually deficient. Total immunoglobulins are less than 250 mg/dl, and IgG is less than 200 mg/dl. No antibody response is observed following immunization. B cells are usually absent in the peripheral blood. 6 Studies of cellular immunity are normal. Treatment.--Gamma globulin, frozen plasma and antibiotics are used (see section on reconstitution below). ACQUIRED VARIABLE-ONSET HYPOGAMMAOLOBULINEMIA.--Defillition.--An acquired disorder that may occur at any age, this is associated with hypogammaglobulinemia. Both sexes are affected. Major clhffcal [eatures.--Signs and symptoms are similar to those found in sex-linked hypogammaglobulinemia, but presentation as chronic malabsorption is more frequent. Diagnosis.--Abnormal studies are identical to those found in sexlinked hypogammaglobulinemia except that normal numbers of B cells are usually found in the peripheral blood. 6 In addition, this disorder may be associated with a thymoma, which makes routine chest x-rays mandatory. Treatment.---The treatment is the same as for congenital hypogammaglobulinemia. SELECTIVE IcA OEFXCIENCY.---Definition.--Patients with selective IgA deficiency have less than 5 mg/dl of serum IgA and normal to increased levels of other immunoglobulins. Major clhlical [eatures.---There is an increased incidence of allergy, sinopulmonary infection, gastrointestinal tract disease and autoimmune disease. 45 The age of onset of symptoms may vary considerably and may be related to compensatory mechanisms and/or environmental factors. Diagnosis.--A diagnosis is established when less than 5 mg/dl of serum IgA is found. Ninety-eight percent of the patients also have absent salivary IgA. IgG and IgM may be elevated. The entity is frequently associated with other abnormalities such as the presence of low molecular weight IgM. Autoantibody and antibody to milk are found with increased frequency. As the patients lack IgA, they are capable of making antibodies against it. Some of the patients who have these antibodies have experienced anaphylactic reactions following the infusion of blood products containing IgA. Treatment.--Gamma globulin should not be given as such patients are capable of making normal antibodies in the other immunoglobulin classes. Patients with recurrent sinopulmonary infection appear to have a decreased number of severe secondary infections when treated with broad spectrum antibiotics at the onset of a respiratory illness 27

(even if it is suspected to be viral). The patients should be followed closely for the development of autoimmune disease. The treatment of associated diseases such as celiac disease or asthma is the same as in individuals with normal IgA. If patients require blood, only packed washed red blood cells should be used. Some blood banks have IgAdeficient donors available who can be used to cross-match with IgAdeficient recipients. TRANSIENT IIYPOGAMMAGLOBULINEMIA OF

INFANCY.-----Defillilioll.

---Hypogammaglobulinemia occurs between 5 and 18 months of age and becomes normal spontaneously.4G Major clhdcal /eatures.--Early symptoms are recurrent bacterial infections that may be severe enough to result in sepsis or meningitis. Diagnosis.--Immunoglobulins drop below "physiologic" levels some time after 5 months of age, with IgG less than 250 mg/dl; IgM and IgA may be normal or depresscd. Cell-mediated immunity is intact. Treatment.---Patients may require gamma globulin injections for 3-6 months until they begin to produce their own antibodies. Immunoglobulins should be checked once each month prior to a gamma globulin injection. Gamma globulin should be discontinued when evidence of active antibody formation is found. SELECTIVE IGM DEFlCmNCV.--Definition.wThis rare disorder is associated with absent (less than 5 mg/dl) IgM and normal cellmediated immunity. Major clinical [eatures.--There is a marked susceptibility to infection with rapidly multiplying polysaccharide-containing organisms such as Pneumococcus and Hemophilus il,fluenzae. 47 Sudden death has occurred. Treatment.--There are insufficient numbers of patients to draw definite conclusions. It would appear, however, that continuous prophylactic treatment with ampicillin is warranted.

CELLULAR IMMUNODEFICIENCY SYNDROMES TtIYMIC HYPOPLASIA WITtl ttYPOPARATItYROIDISM (DI GEORGE

SYNDROME).---Definition.---The complete syndrome consists of thymic hypoplasia, hypoparathyroidism, congenital heart disease and abnormal facies.48 Both males and females are affected. Major clinical [eatures.--Newborn infants may present with hypocalcemia resistant to treatment and/or congenital heart disease. The face may be characteristic, with an antimongoloid slant of the eyes, hypertelorism and a "carp"-shaped mouth. Recurrent infection and chronic candidiasis occur early in infancy. Diagnosis.--Hypocalcemia and hyperphosphatemia are persistent. Immunoglobulins are usually normal but antibody response following antigen challenge is either diminished or absent. Cellular immune function evaluated during the neonatal period may be absent or rela98

tively normal; the percentage of circulating thymic-derived lymphocytes is usually depressed. Cellular immune function becomes abnormal during infancy. Variants of the Di George syndrome have been described with mild immunologic defects or with spontaneous return of cell-mediated immunity. Treatment.--Fetal thymus transplant, vitamin D and/or parathormone arc used. CHRONIC MIdCOCUTANEOUS CANDIDIASIS.--Definition.~This c o n dition is associated with chronic Candida infection of the skin, mucous membranes and nails. Some patients may have an associated idiopathic endocrinopathy.49 Major clhffcal [eamres.--Candida may appear at any age and may be extensive, covering skin and mucous membranes, or it may affect just the nails. A granulomatous variety exists with large "heaped-up" Candida lesions on the skin and nails. Idiopathic cndocrinopathy may prcccde or follow the chronic Candida infection. Hypoparathyroidism and Addison's disease are the most comnlon associated endocrinopathies. Diagnosis.--Absencc of a positive delaycd hypersensitivity reaction to Candida in the presence of chronic Candida is characteristic of the disorder. Peripheral blood lymphocytes may fail to respond to Candida or may not produce migration inhibition factor (MIF) in vitro. Other studies of cellular immunity are normal. Studies of antibodymediated immunity including antibodies to Candida arc normal. Autoantibody directed against endocrine organs is present frequently and may precede the development of an idiopathic cndocrinopathy. Treatment.---The cndocrinopathy is treated in a standard manner. In over 50% of the patients the chronic Candida clears when treated with transfer factor and intravenous amphotericin B. ~0 Other patients are resistant to all forms of treatment. Topical antifungal therapy is uniformly unsuccessful. One patient has been successfully treated with a thymus transplant.

COMBINED (ANTIBODY AND CELLULAR) IMMUNODEFICIENCY SEVERE COMBINED IMMUNODEFICIENCY DISEASE (SCID).--Definition.--This disorder is characterized by the complete absence of both

cellular and antibody-mediated immunity.,~1 Inheritance may be either sex-linkcd or autosomal recessive. Major clhlical features.--Severe and chronic infection occurs in infancy. Otitis media, pneumonia, diarrhea and chronic Candida are common, as is Pneumocystis carinii. Sonic newborns may have a maternal-fetal graft-versus-host reaction with skin rash, diarrhea and hepatosplenomegaly, while others acquire a graft=versus-host reaction following unirradiated blood transfusions. Without treatment few infants survive beyond l year of age. 29

Diagnosis.---All studies of antibody-mediated and cell-mediated immunity are abnormal. Occasionally some infants have evidence of IgM production. Treatment.---The preferred treatment is a bone marrow transplantation from a histocompatible donor. In all instances this must be a mixed lymphocyte culture identical sibling donor. ~2 A more distant relative has been used on rare occasions when mixed lymphocyte culture identity is found. 5z In the absence of an appropriate bone marrow donor, gamma globulin should be given. Recently fetal thymus transplantation has successfully rcconstituted cellular immunity~a (see details of treatment under reconstitution section below). If an infant with SCID presents with pulmonary infiltrate, a lung biopsy (open lung biopsy preferred) should be performed to establish an etiology. If Pnettmocystis carinii is present, the patient should be treated with pentamidine or pyrimethamine-sulfa. TIIYMIC ttYPOPLASIA W1Ttl ABNORMAL IMMUNOGLOBULIN SYNTttESIS (NEZELOF SYNDROMZ).--Definition.----There may be varied de-

grees of cellular and antibody deficiency.~z The disorder affects both males and females and has a variable onset. Progression is usually related to the severity of the underlying immunodeficiency. Major clhdcal/eatttres.---Depending on the severity of the defect, symptoms may begin in infancy or after several years of life. Recurrent pneumonia, sepsis and frequent otitis mcdia are usual findings. Patients may have diminished or increased lymphoid tissue. Diagnosis.---Studies of antibody-mediated immunity are usually abnormal. Patients may have a deficiency or elevation of one or more immunoglobulins. The antibody response to antigens is either poor or absent. Some patients may have a nonreactive Schick test following DPT immunization, or isohemagglutinins may be present, suggesting that at one time they were able to make specific antibody. Variable deficiencies of cell-mediated immunity are also found. Delayed hypersensitivity skin tests are usually absent. Lymphopenia, lymphocyte response to mitogens, antigens and allogeneic cells, and T cell rosettes may all be abnormal, or only a single test may be abnormal. Treatment.--Experience with histocompatible bone marrow transplantation in such patients is limited. Recently, transfer factor has been given with some successP 6 Other patients have been reconstituted sucessfully with fetal thymus transplants. If the patient is unable to make antibody, gamma globulin and fresh frozen plasma infusions should be given. Intermittent or continuous prophylactic broad spectrum antibiotics may be useful. IMMUNODEFICIENCY WITH

ATAXIA-TELANGIECTASIA.---DefiIlilion.~

Ataxia-telangiectasia is associated with recurrent sinopulmonary infection. Variable degrees of antibody and cellular immunodeficiency are present. 57 The disorder is inherited as an autosomal recessive trait. Major clhdcal/eatttres.--Onset of the disorder may be in early infancy and it may present as recurrent sinopulmonary infection, or ataxia may occur as the patient first begins to sit or walk. Telangiecta30

sia may occur first during infancy or as late as 8 years of age. Any of the major symptoms may precede the others. As the disease progresses, physical disability becomes more severe with increasing ataxia, dysconjugate gaze and mental retardation. Chronic pulmonary disease usually occurs. There is an increased incidence of malignancy, primarily lymphosarcoma, in older patients. All signs and symptoms have variable courses, and two patients have survived beyond 40 years of age. Diagnosis.---Antibody deficiency is variable. Approximately 40% of the patients have IgA deficiency, while others may have normal immunoglobulins or varying combinations of depressed values. Specific antibody production may be normal early in the disease or severely impaired. Varying degrees of cellular immunodeficiency are also found. As a patient becomes older, progressive deterioration of cellular immune function usually occurs. Treatment.--Gamma globulin and/or frozen plasma should be given to patients unable to make antibody. The use of continuous or intermittent antibiotics may be helpful in controlling sinopulmonary infection. Transfer factor has been tried with limited success. Fetal thymus transplantation has been reported to provide reconstitution of cellular immune function. Experience with histocompatible bone marrow transplantation is limited. IMMUNODEFICIENCY WITtl ECZEMA AND TItROMBOCYTOPENIA (WIS-

KOTT-ALDRICII SYNDROME).--Definition.---The complete syndrome consists of eczema and thrombocytopenia associated with recurrent infectionPs Inheritance is in a sex-linked recessive manner. Major clhffcaI [eatttres.----The earliest manifestations, which usually occur during the newborn period, are petechiae and bleeding secondary to thrombocytopenia. Bleeding may also occur following a circumcision. Subsequently, bleeding from the gastrointestinal tract following a viral illness is frequent. Severe and recurrent infection with polysaccharide-containing organisms usually occurs after 5 months of age. As the patients become older, bleeding becomes less problematical, and eczema and recurrent infection become more severe. An increased incidence of lymphoreticular malignancy is found in older patients with this disease. Diagnosis.--A diagnosis can usually be made early since thrombocytopenia is present at birth. Patients are unable to make antibody following immunization with polysaccharide antigen. Characteristically, isohemagglutinins are absent and the serum lgM is low, with an elevated IgA. As the patients become older, they fail to respond to other antigcns and begin to demonstrate defects in cell-mediated immunity. Treatment.--Since patients may die suddenly from overwhclming infection, aggressive and early antibiotic treatment is needed and should be directed primarily toward Pncumococcus, Meningococcus and Hemophilns hlflttenzae. Gamma globulin and frozen plasma have often been used. ~9 Transfer factor has been beneficial in some pa31

tients,6~ and a successful bone marrow transplant has been reported. Gt IMMUNODEFICIENCY WITtl SllORT-LIMBED

DWARFISM.---Definition.

--Short-limbed dwarfism is associated with varying degrees of antibody and/or cellular immunodeficiency.G2 Patients with cellular immunodeficiency may also have cartilage-hair hypoplasia. Both sexes are affected. Major clinical leatm'es.--This form of dwarfism may be distinguished from achondroplasia clinically; the extremities are symmetrically shortened and the head size is normal. At birth and during infancy redundant skin folds are prominent in the neck, axillae and inguinal areas. Additional symptoms relate to the associated immunodeficiency. Those with combined immunodeficiency usually have infection early in infancy and rarely survive beyond 1 year of age. Only two patients have been described with short-limbed dwarfism and isolated antibody-mediated immunodeficiency.63 Their course seems to be similar to that of patients with congenital hypogammaglobulinemia. Patients with short-limbed dwarfism and cellular immunodeficicncy are extremely susceptible to varicella and progressive vaccinia, although they appear to tolerate other viral infections without adverse complications.6~ Many have cartilage-hair hypoplasia; the hair is abnormally thin and light in color. Diagnosis.----Short-limbed dwarfism is associated with x-ray findings of metaphyseal dysplasia. Cartilage-hair hypoplasia is diagnosed by the presence of light-colored, fine, sparse hair with a reduced diameter. Immunologic abnormalities are characteristic of the type of associated defect, e.g., antibody deficiency, cellular deficiency or combined immunodeficiency. Treatment.---Treatment is that of the associated immunodeficiency disease. COMBINED IMMUNODEFICIENCY WITII ADENOSINE DEA/~,IINASE DE-

FICXENCY.---Definition.~This is a variable'disease distinguishable by the absence of the enzyme adenosine deaminase in erythrocytes, leukocytes and tissue. G~,GGBoth males and females are affected. The disease may be diagnosed in utero following amniocentesis and enzyme assay of cultured fibroblasts. Major clbzical ]eatttres.--Onset of symptoms is variable and related to the degree of immunodcficiency. Susceptibility to a wide variety of microbial infections has been reported. Pneumonia, recurrent otitis media, sepsis and meningitis are frequent. Diagnosis.--Combined immunodeficiency is usually found, with variable degrees of cellular and antibody immunodeficiency present. Adenosine deaminase, as measured in erythrocytes, leukocytes, tissue and plasma, is absent. X-rays show a 50% incidence of abnormalities of the pelvis, spine and rib cage. Treatment.---Treatment is that of the associated immunodeficiency. Bone marrow transplantation from histocompatible donors has been successful in severely deficient patients. 67 Gamma globulin and antibiotics are useful when antibody deficiency is present. 32

GRAFT-VERSUS-IIOST REACTION (GVHR).--Definition.--GVHR is not a primary immunodeficiency disease. It occurs in patients with cellular immunodeficiency who are incapable of rejecting foreign ceils and who receive immunocompetent ceils that are histoincompatible with their own. In this situation cell chimerism occurs, andboth patient and donor lymphocytes continue to circulate in the patient's peripheral blood. In addition, the donor cells attack the patient's tissues (i.e., skin, gastrointestinal tract, lung, kidney and central nervous system), resulting in clinical disease. The source of immunocompetent donor cells may be blood transfusions, fresh plasma, maternal cells or attempts at immunotherapy, e.g., bone marrow, thymus transplantation. Major clhffcal [eatures.---There are two major forms of GVHR: acute and chronic. The acute form, which occurs 7-30 days following an infusion of immunocompetent cells, is associated with a maculopapular rash, hepatosplenomegaly, diarrhea and taehypnea.6s A fulminant acute form presents as toxic epidermal necrolysis. 69 The chronic form, which is associated with a hyperkeratotic scaling skin rash, hepatosplenomegaly, hair loss, chronic diarrhea and wasting, may be confused with histiocytosis-X,q0 Diagnosis.--The presence of characteristic physical findings in an immunodeficient patient strongly suggests the diagnosis of GVHR. A skin biopsy may be diagnostic in the chronic form of the disease. The diagnosis is confirmed when sex chromosome or HL-A chimerism is demonstrated in the peripheral blood of the patient. Unfortunately, only 50% of patients with strongly suspected GVHR have documented cell chimerism. Treatment.--Many treatments have been attempted but none are effective in an established GVHR. Rarely, a patient who receives a successful bone marrow transplant may have amelioration of the GVHR as reconstitution of the patient's cellular immune system is achieved.71

COMPLEMENT ABNORMALITIES C1Q, C1R AND Cls DEFICIENCIES.--Definition.--Clq, C l r and Cls deficiencies are usually inherited defects of individual complement components affecting both males and females.4H3 Major clhffcal [eatures.--Each deficiency may be associated with a systemic lupus-like syndrome and an increased susceptibility to bacterial infection. Diagnosis.--The defect can be detected by determination of individual complement components, which are usually performed only in specialized laboratories. Total hemolytic complement determination may be used as a screening procedure and is usually low. Treatment.---Treatment of the systemic lupus-like syndrome is identical to that of the disease when it is not associated with a complement deficiency. Congenital deficiency of complement components 33

should be differentiated from low complement secondary to immunecomplex deposition in patients with systemic lupus erythematosus; treatment of the lupus-like syndrome with prednisone and/or immunosuppressants will not alter complement values if a complement deficiency is associated. In these patients parameters other than complement should be used to adjust therapy. There is no treatment for the complement abnormalities in inherited C1 q, CI r and C ls deficiency. C3 DEFICmNCY.----Definition.---This is a rare deficiency of the third component of complement secondary to hypercatabolism of C3. 4~ Major clinical [eatttres.---Recurrent bacterial infection including pneumonia, otitis and sinusitis occurs. Diagnosis.--Decreased levels of C3 are diagnostic of this deficiency. Treatment.--Acute infection is treated with antibiotics. C5 OYSFUNCTION.--Definition.----Afamilial dysfunction of the fifth component of complement results in severe seborrheic dermatitis, diarrhea and sepsis." Both males and females are affected. Major clinical [eatures.--Infants with this disorder resemble those with Leiner's disease. They have severe seborrhea, recurrent sepsis and chronic diarrhea. Diagnosis.--Total hemolytic complement and specific C5 quantitation may be normal. A defect in phagoeytosis of yeast particles, which is corrected when C5 is added, has been demonstrated. Treatment.--Fresh plasma infusions have been recommended. However, patients with C5 dysfunction have clinical symptomatology in common with patients who have deficient cell-mediated immunity. Normal cellular immunity should be demonstrated in these patients before fresh plasma is used as therapy since the potential of inducing a graft-versus-host reaction with infusions of fresh blood products exists if deficient cellular immunity is present in the patient. PHAGOCYTIC ABNORMALITIES LAZY LEUKOCYTE SYNDROME.---Definilion.--A defective phagocytic response to chemotactic stimuli is associated with severe recurrent infection and neutropenia. TM Both males and females are affected. Major clhlical [eatures.---The syndrome is characterized from infancy by recurrent stomatitis, otitis, gingivitis and low grade fevers. Diagnosis.---Severe peripheral neutropenia exists in spite of a normal bone marrow examination. Isolated neutrophils have abnormal chemotaxis and impaired random migration. Rebuck window response by the patient is abnormal. Phagocytosis is present, and cellular and antibody-mediated immunity is intact. Treaonent.--Infections are treated with antibiotics. NEUTROPENiA.---Definition.---Neutropenia exists when the circulating level of neutrophils is below 1,200/mm 3. Most causes of neutropenia are unknown. In some instances it may be due to an isoimmune phenomenon as a result of placental passage of antibodies directed against the neutrophils. 34

Major clhdcal ]eatures.--In general, patients with uncomplicated neutropenia have a good prognosis, perhaps because they are able to mobilize monocytes in a compensatory manner. Infections, if they occur, may be frequent but are generally not severe. Some patients with neutropenia have recurrent aphthous ulcers. Disorders that are associated with neutropenia as well as depresscd numbers of mononuclear cells are usually also associated with severe infections. The pancytopenias of bone marrow failure and drug-induced agranulocytosis are invariably fatal because of infection with bacteria and opportunistic organisms. Diagnosis.---Peripheral blood count with a total granulocyte count of less than 1,200/mm 3 establishes the diagnosis. Treatment.--Antibiotics are given for severe infection. Leukocyte infusions are used cautiously. TUFTSIN DEFIClEr~CY.--Definition.--This is a familial deficiency of tuftsin, a phagocytosis-stimulating tetrapeptide 73 that is cleaved off a parent immunoglobulin molecule in the spleen. It has been described i n two families. Tuftsin appears to be absent in splenectomized patients. Major clhffcal [eatures.--The disorder is associated with both local and systemic severe bacterial infections. Diagnosis.--Determination of tuftsin levcls in specialized laboratories determines the diagnosis. Treatment.--Gamma globulin is administered routinely, and acute bacterial infections are treated with appropriate antibiotics. CItRONIC GRANULOMATOUSOlSEASE.--Definition.--Chronic granulomatous disease (CGD) is an inherited defect of leukocyte bactericidal function. Ingestion of microbial agents is normal, but killing of certain microbial agents is abnormal. TM The intracellular metabolism of leukocytes and monocytes is abnormal; because of an enzyme deficiency (NADP oxidase or NADPH oxidase) free hydrogen radicals are not produced, oxygen is not consumed, hydrogen peroxide is not formed and bacterial wall destruction does not occur. Major clhdcal [eatures.--CGD is inherited primarily as a sex-linked recessive trait. Recently an autosomal recessive form of the disease was described. Children with this disorder present primarily with lymphadenopathy, hepatosplenomegaly, pneumonia and chronic draining lymph nodes. 75 The onset of symptoms usually occurs by 2 years of age. Other presenting symptoms may be osteomyelitis, persistent diarrhea, perianal abscess and ulcerative stomatitis. An important clue to the diagnosis of this disorder is the presence of an infection associated with unusual bacterial agents. The isolation of Staphylococcus aureus or Staphylococcus epidermidis, Serratia marcescens, Candida or Aspergillus from an osteomyelitis or pulmonary infection should alert the physician to the possibility of CGD. Diagnosis.--All studies of antibody- and cell-mediated immunity are normal. The diagnosis may be established by performing a bacterial killing curve with the patient's cells and an organism isolated 35

from an infection in the patient; if CGD is present, the patient's cells will not kill the bacteria at a normal rate. A good screening procedure for diagnosis is the quantitative nitroblue tetrazolium dye test; if a patient has CGD, his cells will not reduce the dye from white to blue. In many laboratories oxygen consumption and bacterial iodination procedures are used as additional diagnostic studies. Phagocytic cells from the mothers of affected males with CGD display intermediate defects in bacterial killing and quantitative nitroblue tetrazolium dye reduction. These studies are useful for detecting the carrier state in female adult relatives as well as fcmale siblings of the patient. Treatment.---Treatment of this disorder has not been entirely successful although earlier diagnosis has resulted in a considerable improvement in prognosis. Currently, patients with this disorder are known to survive into teen-age years and beyond. Therapy with continuous antibiotics has been attempted, primarily with sulfisoxazole (Gantrisin). More recently rifampicin has been used in the treatment of a single patient with CGD5 6 The basis for the use of antibiotics has been the in vitro demonstration of improved killing of microorganisms. There are insufficient clinical studies to determine if this mode of therapy will result in increased in vivo killing and improved patient prognosis. An experimental approach to therapy has been granulocyte infusions77 during an acute infection. However, because of the difficulty of obtaining large numbers of granulocytes, their short half-life and the relative expense of this procedure, insufficient experience is available as yet to document specific benefit. The single most important point in management of such patients is the prompt diagnosis of the microbial agent responsible for infection. Most of the bacterial agents to which these patients are susceptible respond to antibiotics. Aspergillus is the most difficult organism to treat and in most instances must be treated with intravenous amphotericin B. MYELOPEROXIDASEDEFICI~NCV.--Definition.----Deficient myeloperoxidase is demonstrated in peripheral blood leukocytes. Several patients with complete myeloperoxidase deficiency have been described. 7s Major clhlical [eatures.~These patients are susceptible to Candida and staphylococcal infections. Diagnosis.--Patient's cells are unable to kill Candida and Staphylococcus in vitro. There is absence of peroxidase demonstrated in staining of the peripheral blood smear. Treatment. There is no specific treatment for this disorder. Infection is treated with appropriate antibiotics. GLUCOSE-6-PItOSPHATE DEI1YDROGENASEDEFICIENCY.mDefinilioII. --Both males and females have been described with a syndrome of complete absence of leukocyte glucose-6-phosphate dehydrogenase activity.79 Major clinical Jeatttres.---Patients may have a clinical presentation similar to that seen in males with chronic granulomatous disease (CGD). 79 One patient was also described who had absence of the 36

enzyme in red blood cells and presented with chronic nonspherocytic hemolytic anemia. Diagnosis.Iphagocytosis of microbial agents is normal, but killing is abnormal, similar to the defect found in CGD. Treatment. Treatment is similar to that of CGD as such patients are susceptible to virtually the identical organisms. CIIEDIAr:-HIGAStll SYNOROME.--Defitlition.-----The Chediak-Higashi syndrome is an autosomal recessive disorder associated with severe bacterial infections, partial oculocutaneous albinism and giant cytoplasmic granules in many ceils including peripheral blood leukocytes. Major clhlical ]eatures.--Recurrent bacterial infections, partial albinism, hepatosplenomcgaly and central nervous system abnormalities are consistent findings, s~ There is a high incidence of lymphoreticular malignancy. Diagnosis.--The characteristic inclusions can be observed under ordinary light microscopy of a peripheral blood smear. Defects in neutrophil chemotaxis as well as intracellular killing of organisms have been described in this disorder. 8~ In contrast to patients with chronic granulomatous disease there is abnormal killing of streptococci and pneumococci as well as staphylococci and Serratia marcescens. Killing of these organisms is not absent but is delayed in time. Treatment.---Specific organisms are treated with antibiotics. JOB'S sYNoROME.--Definition.--Job's syndrome was originally described as a disorder affecting fair-skinned red-headed females with a history of recurrent "cold" staphylococcal abscesses of the skin and lymph nodes3 z Major clh~ical [eatures.--Recurrent cold abscesses with occasional systemic involvement are present. Diagnosis.~The exact defcct in this disorder has not been described. It is difficult at present to make an exact diagnosis in all patients evaluated. Treatment.--Appropriate antibiotics are given for infections. SPLENIC DEFICIENCY DlSORDERS.--Definitiott.-----There is increased susceptibility to infection with polysaccharide-containing organisms in patients with splencctomy. Major clhtical [eatures.~Increased susceptibility to polysaccharidecontaining organisms may occur following splenectomy at any age; however, the most important prognostic factors appear to be the age of the patient at the time of splenectomy, the presence of an adequate number of opsonins in the form of antibody (specifically IgM) and no additional disorder compromising immune function. It has been shown that the young animal is dependent on the spleen for the containment of rapidly multiplying organisms; pneumococci, Hemophihts hlfluenzae and meningococci fall into this category. In man, in the absence of adequate levels of antibody, the spleen assumes primary importance in the prevention of overwhelming infection from these organisms. Increased amounts of specific IgM antibody form against 37

these organisms as an infant is exposed with increasing age. The specific IgM antibody provides a second barrier against rapid multiplication of organisms. The susceptibility of older individuals with splenectomy to overwhelming infection requires an additional immunologic defect. Thus, patients with sickle cell disease who have defects in complement in addition to autosplenectomy have an increased susceptibility to infection at any age. s3 Patients who have had splenectomy for staging of Hodgkin's disease may be unable to form antibody or have defective cell-mediated immunity in addition to the splenectomy, s4 Treatment.----The treatment of patients who have had splenectomy is not uniformly agreed on. However, infants who have had splenectomy probably should receive prophylactic antibiotics until approximately 3 years of age, when the susceptibility to infection decreases significantly. The antibiotics that are suggested may vary, but ampicillin appears to be the best choice. In the future many patients will probably receive immunization with purified polysaccharide vaccines, which are currently being tested but are not available for general u s e . 85

SPECIFIC RECONSTITUTION OF CELLULAR OR ANTIBODY DEFICIENCY (TABLES 7, 8 AND 9)

Gamma globtdhl.--Gamma globulin is the primary means of replacing antibody passively. Commercially prepared g a m m a globulin consists primarily of IgG with only trace amounts of IgA and IgM present. The initial dose is approximately 0.2 m l / k g given as one intramuscular injection. The amount of g a m m a globulin administered should be governed by two factors: the dose necessary to control infections and the amount that can be tolerated by the patient. Initially, a single monthly injection is usually adequate and will result in prevention of pneumonia, meningitis and recurrent otitis media. If infections are not controlled, a gradual increase by 1-2 m l / m o n t h can be T A B L E 7.--IMMUNOTttERAPY FOR ANTIBODY DEFICIENCY DISORDERS TREATMENT

COMMENT

1. Gamma globulin

Contains primarily IgG. Starting dose 0.2 ml/kg given i.m. once each month. Increase total dose until symptoms are controlled. Total dose may be divided into once every 2 weeks or once each week if once a month is too painful. 1-14 years, I unit i.v. each month. ~>14 years, 1-2 units. Can be substituted for i.m. gamma globulin or added to gamma globulin if adequate control has not been achieved. Various regimens may be useful if gamma globulin and i.v. plasma do not control symptoms. Continuous or intermittent broad spectrum therapy may be useful. (Use caution in selecting patients.)

2. Frozen plasma

3. Antibiotics

38

T A B L E 8.--IMMuNOTI1ERAPY FOR CELLULAR DEFICIENCY DISORDERS TREATMENT

COMN|ENT

l. Bone marrow transplant

Curative in cellular immunodeficiency disorders when a histocompatible donor is available (usually a sibling). Experimentally available. Has been used with some success in specific cellular immunodeficiency disorders such as chronic mucocutaneous candidiasis and Wiskott-Aldrich syndrome. Experimentally available. Curative in Di George syndrome. Other thymic hypoplasia patients may also respond. Experimentally available. May partially correct cellular immunity in deficient patients. Experimental only. Experience is very limited.

-2. Transfer factor

3. Fetal thymus transplant 4. Thymosin 5. Antiviral agents, interferon, etc. 6. Lymphocyte infusions

Unmatched lymphocyte infusions are not recommended as risk of graft-versus-host reaction is great.

added until a m a x i m u m tolerated dose has been reached. If additional g a m m a globulin is necessary, the total dose m a y then be divided into two equal injections given at the same time. F u r t h e r increases should be accomplished by dividing the dose into an equivalent a m o u n t given biweekly. Weekly injections of g a m m a globulin are preferred by m a n y older patients. If severe pain results from g a m m a globulin injections, a local anesthetic can be mixed with the agent at the time of injection. Anaphylactic-like reactions to g a m m a globulin have been described but are not true allergic reactions. T h e y are primarily due to aggregate formation and can be avoided by removing aggregates with ultracentrifugation. 86 Fresh frozen plasma.--If satisfactory control of infection is not achieved with biweekly injection of g a m m a globulin in m a x i m u m amounts, fresh frozen plasma m a y be used in addition for passive replacement of antibody. One unit of frozen plasma m a y be given

T A B L E 9.----IMMUNOTIIERAPY FOR PttAGOCYTIC DISORDERS TREATMENT

COMMENT

1. Granulocyte infusions

Cells usually obtained by leukophoresis or cell separators. Normals or chronic myelocytic leukemics used. Cells have very short half-lives. Sensitization to histocompatibility antigens is high. Beneficial effect not clearly established. Capable of replacing missing or nonfunctioning complement components such as C3 and C5. Some evidence that continuous sulfisoxazole or rifampicin may prevent infection in chronic granulomatous disease. Experience is limited.

2. Fresh or frozen plasma 3. Antibiotics

39

between ages 11/~ and 14 years. A maximum of 2 units may be administered thereafter. The frozen plasma is administered once a month, alternating at 2-week inter~'als with gamma globulin injections. Although frozen plasma contains larger amounts of IgM and IgA than does gamma globulin, the short half-life of IgA and IgM does not significantly alter the serum levels of these two immunoglobulins. Nevertheless, some benefit in addition to that obtained from gamma globulin injections may be achieved by fresh frozen plasma infusions on a temporary basis. The danger of transmitting hepatitis through the use of fresh frozen plasma can be reduced by screening all donors for hepatitis-associated antigen. In addition to passive antibody replacement, fresh frozen plasma may be used to treat patients with certain isolated complement deficiencies by replacing the complement component. Transfer ]actor.--Transfer factor, which is a low molecular weight substance obtained from the lymphocytes of normal individuals, has the capability of imparting the delayed hypersensitivity reactions of the donor to the recipient, s7 Considerable controversy surrounds the effectiveness of transfer factor in complete correction of cell-mediated immunity; it has been documented to be of some benefit to patients with certain cellular immunodeficiency syndromesP 6, 6o Most patients with cellular immunodeficiency should receive the benefit of a trial of transfer factor since its side-effects are minimal. Transfer factor is administered intramuscularly, and a beneficial effect may be seen in a period of days to weeks following administration. It is usually selected on the basis of the known sensitivity of the donor. A patient with chronic Candida infection and cellular immunodeficiency would be treated with the transfer factor from a donor who had documented Candida infection and a positive delayed hypersensitivity skin test to Candida. Use of transfer factor has been most successful in patients with chronic mucocutaneous candidiasis. 49 The most prolonged remissions in this disease follow the combined use of transfer factor and amphotericin B. There is no evidence of reconstitution of antibody-mediated immunity by transfer factor and it therefore should not be expected to benefit patients with isolated antibody deficiency syndromes, s6 Bone marrow transplantation.--Transplantation of histocompatible bone marrow into a patient with antibody and cellular immunodeficiency may result in a permanent cure. The major obstacle to bone marrow transplantation is the requirement of a histocompatible bone marrow donor. The greatest likelihood of an identical match is among the patient's siblings. The parents of the patient with immunodeficieney are by definition histoincompatible because each one has one allele that is incompatible with their child. On a statistical basis, one in four siblings would be expected to be an identical match. The mixed lymphocyte culture (MLC) test is the best procedure for determining whether a match exists. A bone marrow transplant is possible if, when donor cells are mixed with rccipient (patient) cells in vitro, no reac40

tion occurs. Evidence of an in vitro reaction between the donor and recipient cell populations indicates that a severe graft-versus-host reaction will follow the transplant. T h e H L - A and MLC locus may, rarely, be inherited separately. Under these circumstances a close relative (other than the parents) may be HL-A nonidentical but MLC identical. A successful bone marrow transplant has been performed with such a combinationP3 Fetal thymtts transplantation.---The first successful use of a fetal thymus transplant was in a patient with thymic hypoplasia and hypoparathyroidism (Di George syndrome). 48 Reconstitution of cellular immunity was relatively rapid, complete and permanent. Recently, fetal thymus transplantation has been used to reconstitute patients completely or partially with a variety of cellular immunodeficiency diseases. ~4 In some instances reconstitution has been only temporary, whereas in others it has been permanent, lasting as long as 3 years. The danger of a graft-versus-host reaction appears to be minimal when fetal thymus transplantation is used in patients with thymic hypoplasia and abnormal immunoglobulin synthesis. A mild graftversus-host reaction may be observed following fetal thymus transplantation in patients with severe combined immunodeficiency disease. Transplantation of a thymus of less than 14 weeks' gestational age appears to minimize the possibility of a severe graft-versus-host reaction. Fetal liver transplantation.---Numerous fetal liver transplantations have been attempted, most resulting in a severe graft-versus-host reaction. If a very immature fetal liver is used, the graft-versus-host reaction appears to be less severe. However, no known survivors of this procedure currently exist and it is therefore difficult to evaluate the benefit of the procedure in the absence of additional cases. Thymoshz therapy.----A thymic humoral factor, thymosin, has recently been isolated from bovine thymus. In a small number of patients with thymic hypoplasia and immunoglobulin synthesis, partial reconstitution of cellular immunity and clinical improvement have followed a series of daily subcutaneous thymosin injections. This has been maintained by weekly injections of the hormone. 8s Lymphocyte hzfusions.--Lymphocyte infusions have been used occasionally in patients with cellular immunodeficiency disease. This is a dangerous procedure as most lymphocytes cannot be matched for histocompatibility. The foreign lymphocytes have the potential of inducing a fatal graft-versus-host reaction in the recipient. Gramdocyte hzfusions.mGranulocyte infusions from unmatched donors have been used in a number of disorders associated with severe leukopenia. Since it is difficult to obtain adequate numbers of cells, those obtained by plasmapheresis or leukapheresis of patients with chronic myelocytic leukemia have been used. The cells are usually radiated with 1,500 R, which does not interfere with phagocytic function but does interfere with lymphocyte replication; thus, the possibility of a severe graft-versus-host reaction is diminished by radiation. 41

Only a few studies exist that demonstrate the benefit of repeated infusions of white blood cells. These suggest that closely related individuals should be used to obtain optimal effects. CHRONIC CARE OF THE PATXENT.---Antibiotic therapy.--Antibiotics are useful adjuncts in the treatment of antibody and cellular immunodeficiency syndromes. Some patients require antibiotic treatment only during documented infections. Others, particularly those with pulmonary disease, may have prolonged periods of illness following viral infections. Illness may be secondary to superimposed bacterial infection in spite of the absence of documented evidence of secondary infection following appropriate evaluation. Some patients may show clinical improvement following broad spectrum antibiotic treatment. In addition, a group of patients with antibody deficiency syndromes appears to benefit from "prophylactic" therapy. The reported dangers of prophylactic antibiotic treatment have not been a significant problem in children with primary immunodeficiency disease. However, the physician should remain alert to infection by opportunistic organisms by obtaining cultures at regular intervals. Ampieillin, 250 mg twice a day, has frequently been effective in infants and children. Kefiin has also been effective for prophylactic therapy. Gantrisin and ampicillin have been used prophylactically in patients with chronic granulomatous disease. Recently, rifampicin has been reported to be of benefit. Aggressive diagnostic measures are the key to appropriate antibiotic treatment and can be life-saving during suspected infection. A child with documented chronic granulomatous disease who presents with a pulmonary infiltrate may have Aspergillus, staphylococcal or Serratia marcescens infection. It is imperative that a specific diagnosis be made because appropriate antibiotic therapy for these organisms may be toxic. Lung biopsies (preferably open biopsy) are invaluable in this regard. Since immunodeficient patients are susceptible to opportunistic organisms, one must be certain that more than one organism is not responsible for clinical manifestations. Multiple infections with a variety of organisms have been described; they include Candida and Pneumocystis carinii or Candida and toxoplasmosis. Aspergillus infection can be treated successfully with amphotericin B given intravenously. Pneumocystis carhffi infection can be treated with pentamidine or pyrimethamine-sulfa. Pulmonary care.--In spite of optimal replacement therapy for the underlying primary immunodeficiency disease and long-term treatment with antibiotics many patients develop chronic pulmonary disease. In a child older than 5 years deterioration of pulmonary function indicates the necessity of specific pulmonary function tests to be performed every 6 months. Younger children are not able to cooperate sufficiently for testing. Any child with an underlying immunodeficiency disease who experiences recurrent pneumonia, persistent pulmonary infiltrates on chest x-ray or deterioration of pulmonary function tests 42

should receive routine pulmonary physical therapy with percussion and drainage. Depending on the severity of pulmonary disease, a child may require percussion and drainage only during an acute pneumonia, or he may require routine therapy several times a day. Pulmonary physical therapy can be taught to family members and can be accomplished easily at home. Chronic otitis m e d i a . - - A s with pulmonary care, in spite of optimal therapy, younger children often develop chronic otitis media and seeondary hearing loss. The placement of polyethylene tubes and adenoidectomy when excessive lymphoid tissue is present, along with appropriate antibiotics and decongestant therapy, appear to control otitis media in children with underlying immunodeficiency disease. In addition, as the incidence of otitis media decreases in these children, the incidence of pneumonia also appears to diminish. Use o[ blood prodttcts.-----Any whole blood product infused into a child with documented cellular immunodeficiency should be radiated with 3,000 R. Because of differences at the histocompatibility locus between the blood donor and the patient, unless lymphocytes contained in blood products are killed, fatal graft-versus-host reactions may occur. The most accessible way to eliminate viable lymphocyte populations in whole blood products is by radiation. Patients with selective IgA deficiency may develop antibodies to IgA if IgA-containing products are received. Normal donor blood and gamma globulin, because each contains IgA, are most likely to induce antibody production in such patients. If anti-IgA antibodies develop in significant titers, subsequent exposure to IgA (such as by a second blood transfusion) may result in an anaphylactie reaction. Thus, patients with selective IgA deficiency should never receive gamma globulin; if a blood transfusion is necessary, ideally blood should be obtained from an IgA-deficient donor. However, this is often impossible, and the use of washed packed red cells instead of whole blood minimizes patient exposure to lgA.

ACKNOWLEDGMENT The authors wish to express their gratitude to Ms. Ellen Hoffman for her editorial and administrative assistance in preparing this manuscript. REFERENCES 1. Stiehm,E. R., and Fulginiti,V. A. (eds.) : Immunologic Disorders in Infants and Children (Philadelphia: W. B. Saunders Co., 1973). 2. Amos, B. (ed.): Progress in hnmunology (New York: Academic Press, 1971). 3. Lawton, A. R., and Cooper, M. D.: Development of Immunity. Phylogeny and Ontogeny,in Stiehm, E. R., and Fulginiti, V. A. (eds.): lmmmzo/ogic Disorders in h,fants and Children (Philadelphia: W. B. SaundersCo., 1973), pp. 28-41. 4. Cooper, M. D., Gabrielsen, A. E., and Good, R. A.: Role of the thymus and 43

5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19.

20. 21. 22. 23. 24. 25.

other central lymphoid tissues in immunological disease, Annu. Rev. Med. 18:113, 1967. Claman, H. N., Chaperon, E. A., and Triplett, R. F.: Thymus-marrow cell combinations--synergismin antibody production, Proc. Soc. Exp. Biol. Med. 122:1167, 1966. Stiehm, E. R.: Immunoglobulins and Antibodies, in Stiehm, E. R., and Fulginiti, V. A. (eds.) : Immunologic Disorders in Infants attd ChiMren (Philadelphia: W. B. Saunders Co., 1973), pp. 42-66. Askonas, B. A., and Williamson, A. R.: Biosynthesis of immunoglobulinson polyribosomes and assembly of the IgG molecule, Proc. R. Soc. Lond. (Biol.) 166:232, 1966. Marchalonis, J. I.: Lymphocyte receptors for antigen, J. Med. (Basel) 5: 329, 1974. Tomasi, T. B., Jr.: Human gamma globulin, Blood 25:382, 1965. Roitt, I.: Essential Immunology (2d ed.; Oxford: Blackwell Scientific Publications, 1971). Ellis, E. F., and Smith, R. T.: The role of the spleen in immunity, with special reference to the post-splenectomy problem in infants, Pediatrics 37: I I I, 1966. Tomasi, T. B.: Studies on the Immunoglobulin A Proteins of Serum and Nonvascular Fluids, Doctoral thesis, Rockefeller University, New York, 1965. Ammann, A. J., and Stiehm, E. R.: Immune globulin levels in colostrum and breast milk, and serum from formula and breast fed newborns, Proc. Soc. Exp. Biol. Med. 122:1098, 1966. Berg, T., and Johansson, S. G. O.: Immunoglobulin levels during childhood with special regard to lgE, Acta Paediatr. Scan& 58:513, 1969. Blecher, T. E., Soothill, J. F., Voyce, M. A., and Walkers, W. H. C.: Antibody deficiency syndrome: A case with normal immunoglobulin levels, Clin. Exp. Immunol. 3:47, 1968. Weinberg, A. G., McCracken, G. H., LoSpalluto, J., and Luby, I. P.: Monoclonal macroglobulinemia and cytomegalic inclusion disease, Pediatrics 51: 518, 1973. Hellstrom, K. E., and Hellstrom, I.: Immunologic defenses against cancer, Hosp. Pract. Jan., 45, 1970. Davis, A. T., and Quie, P. G.: Phagocytes and Phagocytosis, in Stiehm, E. R., and Fulginiti, V. A. (eds.): lmmttnologic Disorders hi In]ants and Children (Philadelphia: W. B. Saunders Co., 1973), pp. 85-98. Huber, H., Policy, M. J., Linskott, W. D., Fudenberg, II. H., and MtillerEberhard, H. J.: Human monocytes: Distinct receptor sites for the third component of complement and for immunoglobulin G, Science 162:1281, 1968. Sbarra, A. J., and Karnovsky, M. L.: The biochemical basis of phagocytosis. I. Metabolic changes during ingestion of particles by polymorphonuclear leukocytes, J. Biol. Chem. 234:1335, 1959. Colten, H. R., and Rosen, F. S.: The Serum Complement System, in Stiehm, E. R., and Fulginiti, V. A. (eds.): Immunologic Disorders hz In/ants and Children (Philadelphia: W. B. Saunders Co., 1973), pp. 99-106. Chang, T. W., Weinstein, L., and MacMahon, H. E.: Paralytic poliomyelitis in a child with hypogammaglobulinemia: Probable implication of type 1 vaccine strain, Pediatrics 37:630, 1966. MacCallum, F. O.: The role of humoral antibodies in protection against and recovery from bacterial and virus infections in hypogammaglobulinemia, Med. Res. Counc. Spec. Rep. Ser. (Lond.) 310: 72, 197 I. Giblett, E. R., Anderson, J. E., Cohen, F., Pollara, B., and Meuwissen, H. J.: Adenosine-deaminase deficiency in two patients with severely impaired cellular immunity, Lancet 2:1067, 1972. Ammann, A. J., Cain, W. A., lshizaka, K., Hong, R., and Good, R. A.: 4,4

26. 27. 28. 29. 30. 31.

32. 33. 34. 35. 36. 37. 38. 39. 40. 41. 42. 43. 44. 45. 46. 47.

ImmunoglobulinE deficiency in ataxia-telangiectasia, N. Engl. J. Med. 281: 469, 1969. Craddock, C. G., Longmire, R., and McMillan, R.: Lymphocytes and the immune response. Part II, N. Engl. J. Med. 285:378, 1971. Leguit, P., Meinesz, A., Huismans, L., and Eijsvoogel, V. P.: The use of an antigen cocktail in the lymphocyte transformation test, Clin. Exp. Immunol. 14:149, 1973. Bach, F. H.: Transplantation: Pairing of donor and recipient, Science 168: 1170, 1970. Fleisher, T. A., Luckasen, J. R., Sabad, A., Gehrtz, R. C., and Kersey, J. H.: T and B lymphocyte subpopulations in children, Pediatrics 55:162, 1975. Pick, E., and Turk, J. L.: The biological activities of soluble lymphocyte products, Clin. Exp. Immunol. 10: I, 1972. Rocklin, R. E., Rosen, F. S., and David, J. R.: In vitro lymphocyte response of patients with immunologic deficiency diseases. Correlation of production of macrophage inhibitory factor with delayed hypersensitivity, N. Engl. J. Med. 282:1340, 1970. Epstein, L. B., and Cline, M. J.: Chronic lymphocytic leukaemia. Studies on mitogen-stimulated lymphocyte interferon as a new technique for assessing T lymphocyte effector function, Clin. Exp. lmmunol. 16:553, 1974. Holm, G., Stejskal, V., and Perlmann, P.: Cytotoxic effects of activated lymphocytes and their supernatants, Clin. Exp. lmmunol. 14:169, 1973. Park, B. H., Fikrig, S. M., and Smithwick, E. M.: Infection and nitroblue tetrazolium reduction by neutrophils: A diagnostic aid, Lancet 2:532, 1968. Lehrer, R. I., Hanifin, J., and Cline, M. J.: Defective bactericidal activity in myeloperoxidase-deficient human neutrophils, Nature (Lond.) 223:78, 1969. Bullock, J. D., Robertson, A. F., Bodenbender, M. T., Kontras, S. B., and Miller, C. E.: Inflammatory response in the neonate re-examined, Pediatrics 44:58, 1969. Gallin, J. I., Clark, R. A., and Kimball, H. R.: Granulocyte chemotaxis: An improved in vitro assay enploying 51CR-labeled granulocytes, J. Immunol. 110:233, 1973. Miller, M. E., Oski, F. A., and Harris, M. B.: Lazy leukocyte syndrome, Lancet 1:665, 1971. Baehner, R. L.: Disorders of leukocytes leading to recurrent infection, Pediatr. Clin. North Am. 19:935, 1972. Alper, C. A., Colten, H. R., Rosen, F. S., Rabson, A. R., Macnab, G. M., and Gear, J. S. S: Homozygous deficiency of C3 in a patient with repeated infections, Lancet 2:1179, 1972. Wara, D. W., Reiter, E. O., Doyle, N. E., Gewurz, H., and Ammann, A. J.: Persistent Clq deficiency in a patient with a systemic lupus erythematosuslike syndrome, J. Pediatr. (in press). Day, N. K., Geiger, S. R., de Bracco, F,I., F,ioncada, B., Windhorst, D., and Good, R. A.: C l r deficiency: An inborn error associated with cutaneous and renal disease, J. Clin. Invest. 51 : 1102, 1972. de Bracco, M. M. E., Windhorst, D., Stroud, R. M., and Moncada, B.: The autosomal recessive mode of inheritance of C l r deficiency in a large Puerto Rican family, Clin. Exp. lmmunol. 16:183, 1974. Miller, M. E., and Nilsson, U. R.: A familial deficiency of the phagocytosisenhancing activity of serum related to a dysfunction of the fifth component of complement (C5), N. Engl. J. Med. 282:354, 1970. Ammann, A. J., and Hong, R.: Selective lgA Deficiency, in Stiehm, E. R., and Fulginiti, V. A. (eds.) : lmmulzologic Disorders hi In/ants and Childrel, (Philadelphia: W. B. Saunders Co., 1973), pp. 199-214. Rosen, F. S., and Janeway, C. A.: The gamma globulins. IlL The antibody deficiency syndromes, N. Engl. J. Med. 275:709, 1966. Hobbs, J. R., Milner, R. D. G., and Watt, P. J.: Gamma-M deficiency predisposing to meningococcal septicemia, Br. Med. J. 4:583, 1967. 45

48. Di George, A. M.: Congenital Absence of the Thymus and Its Immunologic Consequences: Concurrence with Congenital Hypoparathyroidism, in Bergsma, D., and Good, R. A. (eds.) : Immltnologic Deficiency Diseases in Man (Birth Defects Original Article Series, Vol. 4, No. I) (Baltimore: Williams & Wilkins Co., 1968). 49. Kirkpatrick, C. H., Rich, R. R., and Bennett, J. E.: Chronic mucocutaneous candidiasis: Model building in cellular immunity, Ann. Intern. Meal. 74:955, 1971. 50. Schulkind, M. L., Adler, W. H., Altemeier, W. A., and Ayoub, E. M.: Transfer factor in the treatment of a case of chronic mucocutaneous candidiasis, Cell. Immunol. 3:606, 1972. 51. Hitzig, W. H.: Congenital Thymic and Lymphocytic Deficiency Disorders, in Stiehm, E. R., and Fulginiti, V. A. (eds.): lmnumologic Disorders in ln[ants and Children (Philadelphia: W. B. Saunders Co., 1973), pp. 215-235. 52. Buckley, R. H.: Transplantation, in Stiehm, E. R., and Fulginiti, V. A. (eds.) : Immunologic Disorders hz In[ants and Children (Philadelphia: W. B. Saunders Co., 1973), pp. 591-623. 53. Dupont, B., Andersen, V., Sonderstrup Hansen, G., and Svejgaard, A.: Abnormal mixed lymphocyte reactions in the family of a patient with severe combined immunodeficiency,Transplantation 14:557, 1972. 54. Ammann, A. J., Wara, D. W., Salmon, S., and Perkins, H.: Thymus transplantation. Permanent reconstitution of cellular immunity in a patient with sex-linked combined immunodeficiency, N. Engl. J. Med. 289:5, 1973. 55. Lawlor, G. J., Jr., Ammann, A. J., Wright, W. C., Jr., La Franchi, S. H., Bilstrom, D., and Stiehm, E. R: The syndrome of cellular immunodeficiency with immunoglobulins,J. Pediatr. 84:183, 1974. 56. Ammann, A. J., Wara, D., and Salmon, S.: Transfer factor: Therapy in patients with deficient cell mediated immunity and deficient antibody mediated immunity, Cell. Immunol. 12:94, 1974. 57. Peterson, R. D. A., Cooper, M. D., and Good, R. A.: Lymphoid tissue abnormalities associated with ataxia-telangiectasia, Am. J. Med. 41:342, 1966. 58. Cooper, M. D., Chase, H. P., Lowman, J. T., Krivit, W., and Good, R. A.: Wiskott-Aldrich syndrome: Immunologic deficiency disease involving the afferent limb of immunity, Am. J. Med. 44:499, 1968. 59. Stiehm, E. R., Vaerman, J. P., and Fudenberg, H. H.: Plasma infusions in immunologic deficiency states. Metabolic and therapeutic studies, Blood 28:918, 1966. 60. Levin, A. S., Spitler, L. E., Stites, D. P., and Fudenberg, H. H.: WiskottAldrich syndrome, a genetically determined cellular immunologic deficiency: Clinical and laboratory responses to therapy with transfer factor, Proc. Natl. Acad. Sci. U.S.A. 67:821, 1970. 61. Bach, F. H., Albertini, R. J., Anderson, J. L., Joo, P., and Bortin, M. M.: Bone marrow transplantation in a patient with Wiskott-AIdrich syndrome, Lancet 2:1364, 1968. 62. McKusick, V. A., Elderidge, E., Hosteler, J. A., Ruangwit, U., and Egeland, J. A.: Dwarfism in the Amish. II. Cartilage-hair hypoplasia, Bull. Johns Hopkins Hosp. 116:285, 1964. 63. Ammann, A. J., Sutliff, W., and Millinchick, E.: Antibody mediated immunodeficiency in short-limbed dwarfism, J. Pediatr. 84:200, 1974. 64. Lux, S. E., Johnston, R. B., August, C. S., Say, B., Penchaszadeh, V. B., Rosen, F. S., and McKusick, V. A.: Chronic neutropenia and abnormal cellular immunity in cartilage-hair hypoplasia, N. Engl. J. Med. 282:234, 1970. 65. Meuwissen, H. J., Pollara, B., and Pickering, R. J.: Combined immunodefieiency disease associated with adenosine deaminase deficiency, J. Pcdiatr. 86:169, 1975. 66. Dissing, J., and Knudsen, B.: Adenosine deaminase deficiency and combined immunodeficiencysyndrome, Lancet 2:1316, 1972. 67. Parkman, R., Gelfand, E. W., Rosen, F. S., Sanderson, A., and Hirschhorn, 46

68. 69. 70. 71. 72. 73. 74. 75. 76. 77. 78. 79.

80. 81. 82. 83. 84. 85. 86. 87. 88.

R.: Severe combined immunodeficiencyand adenosine deaminase deficiency, N. Engl. J. Med. 292:714, 1975. Hathaway, W. E., Brangle, R. W., Nelson, T. L., and Roeckel, I. E.: Aplastic anemia and alymphocytosis in an infant with hypogammaglobulinemia" Graft versus host reaction? J. Pediatr. 68:713, 1966. Ammann, A. J., Tooley, W. H., and I-long, R.: Toxic epidermal necrolysis, Lancet 2:484, 1972. Cederbaum, S. D., Niwayama, G., Stiehm, E. R., Neerhout, R. C., Ammann, A. J., and Berman, W., Jr.: Combined immunodeficiency manifested by the Letterer-Siwe syndrome, Lancet 1:958, 1972. Ammann, A. J., Meuwissen, H. J., Good, R. A., and Hong, R.: Successful bone marrow transplantation in a patient with humoral and cellular immunity deficiency, Clin. Exp. Immunol. 7:343, 1970. Miller, M. E., Oski, F. A., and Harris, M. B.: Lazy leukocyte syndrome, Lancet 1:665, 1971. Constantopoulos, A., and Najjar, V. A.: Tuftsin deficiency syndrome, Acta Paediatr. Scand. 62:645, 1973. Holmes, B., Quie, P. G., Windhorst, D. B., and Good, R. A.: Fatal granulomatous disease of childhood. An inborn abnormality of phagocytic function, Lancet 1:1225, 1966. Johnston, R. B., Jr., and McMurray, J. S.: Chronic familial granulomatosis: Report of five cases and a review of the literature, Am. J. Dis. Child. 114: 370, 1967. Ezer, G., and Soothill, J. F.: Intracellular bactericidal effects of rifampicin in both normal and chronic grannlomatous disease polymorphs, Arch. Dis. Child. 49:463, 1974. Raubitschek, A. A., Levin, A. S., Stites, D. P., Shaw, E. B., and Fudenberg, H. H.: Normal granulocyte infusion therapy for aspergillosis in chronic granulomatous disease, Pediatrics 51:230, 1973. Lehrer, R. I.: Measurement of candidacidal activity of specific leukocyte types in mixed cell populations. II. Normal and chronic granulomatous disease eosinophils, Infect. lmmun. 3:800, 1971. Cooper, M. R., De Chatelet, L. R., La Via, M. F., McCall, C. E., Spurr, C. L., and Baehner, R. L.: Complete deficiency of leukocyte glucose-6-phosphate dehydrogenase with defective bactericidal activity, J. Clin. Invest. 51: 769, 1972. Blume, R. S., Bennett, J. ~I., Yankee, R. A., and Wolf, S. M.: Defective granulocyte regulation in the Chediak-Higashi syndrome, N. Engl. J. Med. 279:1009, 1968. Clark, R. A., and Kimball, H. R.: Defective granulocyte chemotaxis in the Chediak-Higashi syndrome, J. Clin. Invest. 50:2645, 1971. Davis, S. D., Schaller, J., and Wedgwood, R. J.: Job's syndrome. Recurrent "cold" staphylococcal abscesses, Lancet I : 1013, 1966. Winklestein, J. A., and Drachman, R. H.: Deficiency of pneumococcal serum opsonizing activity in sickle-cell disease, N. Engl. J. Med. 279:459, 1968. Ravry, M., Maldonado, N., Velez-Garcia, E., Montalvo, J., and Santiago, P. J.: Serious infection after splenectomy for the staging of Hodgkin's disease, Ann. Intern. Med. 77:11, 1972. Ammann, A. J.: Severe sepsis in patients splenectomized for blood dyscrasia, J.A.M.A. 227:214, 1974. Ellis, E. F., and Henney, C. S.: Adverse reactions following administration of human gamma globulin, J. Allergy Clin. Immunol. 43:45, 1969. Fudenberg, H. H., Levin, A. S., Spitler, L. E., Wybran, J., and Byers, V.: The therapeutic uses of transfer factor, Hosp. Pract. 95:104, 1974. Wara, D. W., Goldstein, A. L., Doyle, N. E., and Ammann, A. J.." Thymosin activity in patients with cellular immunodeficiency,N. Engl. J. Med. 292:70, 1975. 47