C/in. exp. Immunol. (1979) 37, 58-67.
Immunochemical characteristics of antibodies to DNA in patients with active systemic lupus erythematosus S. P. BALLOU & I. KUSHNER Department of Medicine, Case Western Reserve University at Cleveland Metropolitan General Hospital, Cleveland, Ohio 44109, USA
(Accepted for publication 13 November 1978)
SUMMARY
To investigate the suggestion that qualitative immunochemical characteristics of antibodies to DNA (anti-DNA) may be of importance in the pathogenesis of nephritis in systemic lupus erythematosus (SLE), we used the Crithidia luciliae (CL) immunofluorescence test to determine the titre, immunoglobulin (Ig) class and complement-fixing activity of anti-DNA in thirty-five patients with active SLE. Eighteen of these patients had active lupus nephritis (Group I) and the remaining seventeen had no clinical evidence of renal involvement (Group II). Anti-DNA was detected in twenty-eight patients, and was present more frequently and in higher titre (P< 0.01) in Group I than in Group II. Anti-DNA of all three Ig classes studied (IgG, IgM and IgA) was present in twenty-three out of twenty-eight cases. The ratio of IgG to IgM anti-DNA did not differ in the two groups of patients. Complement-fixing antibodies were detected in thirteen patients in Group I and five patients in Group II. The titre of complement-fixing activity was strongly correlated with titre of anti-DNA. DNA-binding capacity was also determined in these patients by a millipore filter (MF) assay. A highly significant correlation between DNA binding by MF and CL was found in Group I patients, while no correlation was found in Group II patients. These findings suggest that (1) anti-DNA with specificity for determinants found in CL, presumably native DNA, are more highly correlated with the presence of active renal lupus than are antibodies directed toward other DNA determinants, and (2) the major characteristic of antiDNA found to be associated with nephritis was quantity of antibody. Most patients had antiDNA of all Ig classes regardless of the presence of renal disease. Complement-fixing activity of anti-DNA could not be related to the occurrence of renal disease independently of anti-DNA titre. INTRODUCTION Antibodies to DNA (anti-DNA) are a characteristic and virtually specific finding in patients with active systemic lupus erythematosus (SLE). Although most strongly associated with active lupus nephritis, anti-DNA may be found in many patients with active lupus who have no clinical evidence of renal disease (Casals, Friou & Myers, 1964; Schur & Sandson, 1968). It has therefore been suggested that quantitative or qualitative differences in the immunochemical characteristics of such antibodies may effect their potential to precipitate or to reflect active renal disease in patients with SLE (Gershwin & Steinberg, 1974; Tron & Bach, 1977). Many studies have noted a relation between the quantity of anti-DNA and the occurrence of nephritis (Casals et al., 1964; Pincus, Schur & Rose, 1969). The role of the qualitative characteristics of such Correspondence: Dr S.P. Ballou, Cleveland Metropolitan General Hospital, 3395 Scranton Road, Cleveland, Ohio 44109, USA.
0099-9104/79/0070-0058502.00 (0 1979 Blackwell Scientific Publications 58
Immunochemical characteristics of anti-DNA in SLE
59
antibodies has been harder to ascertain (Soothill & Steward, 1971; Johnson, Edwards & Holborow, 1973; Tojo & Friou, 1968). Most investigators have felt that the specificity of such antibodies for the native configuration of DNA is of primary importance (Koffler et al., 1969). However, the inability of most recently employed DNA binding methods to detect only this limited population within the spectrum of DNA antibodies (Samaha & Irwin, 1975; Davis et al., 1978a) has precluded definitive evaluation of this hypothesis. Other qualitative immunochemical characteristics of anti-DNA- such as precipitating capacity, avidity, immunoglobulin class, and complement-fixing activity-may also be of importance in relation to lupus nephritis (Tron & Bach, 1977; Barnett, 1977), but methodological limitations have permitted only a limited assessment of these characteristics. A recently introduced immunofluorescence test for the detection of anti-DNA affords the opportunity to investigate some of these questions. This method employs the kinetoplast of the haemoflagellate Crithidia luciliae (CL), as substrate, and permits the detection of antibodies directed largely against native DNA (Aarden, deGroot & Feltkamp, 1975). In addition, this technique permits the characterization of the immunoglobulin class and complement-fixing ability of anti-DNA. In order to investigate these immunochemical characteristics of anti-DNA, we employed the CL method to study sera from thirty-five patients with active SLE, with and without clinical renal disease. Results were compared with those obtained by a commonly used millipore filter (MF) method (Ginsberg & Keiser, 1973). We considered four questions. (1) Are antibodies directed primarily against native DNA determinants more closely associated with active nephritis than are antibodies with a more heterogeneous spectrum of reactivity? (2) Is active renal disease related to amount of anti-DNA? (3) Does the immunoglobulin class of anti-DNA bear an important relationship to the presence of active nephritis? (4) Is the complement-fixing capacity of anti-DNA related to the development of nephritis?
MATERIALS AND METHODS Patients. Serum specimens from thirty-five patients with active SLE were studied. All patients fulfilled the preliminary ARA criteria for SLE (Cohen et al., 1971); thirty-one were untreated at the time of study. Three of the remaining four patients had been treated with 20-60 mg of prednisone daily for 1-4 weeks; prior treatment could not be ascertained in the fourth patient. Activity of lupus was felt to exist if at least two of the following manifestations were present: (1) active synovitis, (2) active serositis, (3) active central nervous system involvement, (4) thrombocytopenia (platelet count < 100,000/mm3), (5) diffuse skin involvement, (6) unexplained fever (temperature > 38&50C) and (7) constitutional symptoms including weight loss, anaemia, myalgias and arthralgias; without evidence ofother disease which could be held responsible for these symptoms. Patients were felt to have active lupus nephritis if there was presence of either (a) active urine sediment, (b) recent onset of proteinuria (> 500 mg/24 hr), or (c) an increase of serum creatinine concentration of > 0 3 mg/dl. The patients were divided into two groups: Group I: eighteen patients who met the above criteria for active lupus nephritis. In thirteen of these patients nephritis was confirmed by biopsy: six with focal proliferative, four with diffuse proliferative, and three with membranous glomerulonephritis. Group 2: seventeen patients who met the criteria for active SLE but showed no clinical evidence of nephritis. The complement component C3 (tested by radial immunodiffusion) was normal in twelve of these patients. One patient, with normal C3 at time of study, developed diffuse proliferative glomerulonephritis 1 yr later. Two patients were lost to follow-up after study; none of the other fourteen patients subsequently showed clinical evidence of nephritis over a mean follow-up period of 3j yr (range 1-12 yr). Immunofluorescence method. Anti-DNA (CL) was determined using a standard indirect immunofluorescence technique as described previously (Crowe & Kushner, 1977). A fluorescein-labelled polyspecific antiserum directed against human IgG, IgM and IgA (Behring Diagnostics, Somerville, New Jersey) was used for screening, and serum specimens were considered positive for anti-DNA if kinetoplast fluorescence was observed at a minimum serum dilution of 1: 10. Immunoglobulin (Ig) class of anti-DNA (CL) was determined employing fluorescein-labelled monospecific antisera directed against human IgG, IgM or IgA (Behring). The immunological specificity of these antisera was tested by prior absorption with purified immunoglobulins IgG and IgM obtained by separation of a mixed cryoglobulin on a Sephadex G-200 column. Four representative sera (CS, SB, ASO, HD), which demonstrated positive staining with all three antisera, were studied; two were from patients with renal disease and two from patients without renal disease. Immunofluorescent staining with anti-IgG was abolished by absorption with purified IgG but not IgM, while the opposite results were found when anti-IgM was used. Absorption with these two purified immunoglobulins did not effect staining with anti-IgA in three instances; IgM absorption abolished staining by one serum from a patient without renal disease (ASO). Detection ofcomplement-fixing activity. The complement-fixing (CF) activity of anti-DNA (CL) was determined by a modification of the triple sandwich technique employed by Parker & Turner (1976). Following the application of pre-heated (56°C for 30 min) patient's serum to slides, fresh frozen (- 70°C) normal human serum was applied, followed by fluorescein-
S. P. Ballou
60
& I.
Kushner
labelled antisera directed against either C3 (Behring) or C4 (Kallestad Laboratories, Minneapolis, Minnesota). Serum specimens were initially tested undiluted for CF activity; if positive, serial titres were done. When attempts were made to test for Clq binding using a similar method with fluorescein-labelled anti-Clq (Behring), kinetoplast fluorescence was observed in all specimens, presumably as a result of the known ability of Clq to bind to DNA (Agnello et al., 1969). DNA binding technique. DNA binding capacity was also determined using a modification of the MF technique of Ginsberg & Keiser (1973). As antigen we employed calf thymus DNA (Sigma Chemical Co., St. Louis, Missouri) which was labelled with 125I and passed through an 0-45 i type HA millipore filter (Millipore Corporation, Bedford, Massachusetts) prior to testing. Binding in excess of 50 pg DNA/ml is regarded as abnormal in this laboratory. Statistical methods. Statistical comparisons of data were carried out using the following tests where appropriate: Student's t-test, Mann-Whitney U test, Fischer exact test and correlation coefficient by linear regression.
RESULTS The serological and clinical data concerning the eighteen patients with active lupus renal disease shown in Table 1 and of the seventeen with active lupus without renal disease in Table 2.
are
Comparison ofanti-DNA (CL) with D.NA-binding capacity by MF In preliminary studies (Ballou & Kushner, 1979), anti-DNA (CL) testing in thirty-five patients revealed that seventeen out of eighteen (94%) of patients in Group I had significantly elevated levels, compared with eleven out of seventeen (64% ) patients in Group II (Fig. 1). This difference is statistically significant (P 0 036). The titres of anti-DNA (CL) in patients in Group I (median 1:160) were significantly higher than those in Group II (median 1:20) (P< 0 01). =
TABLE 1. Anti-DNA in eighteen patients with active lupus nephritis
Ig class of antiDNA
Patient
Anti-DNA (MF)*
Anti-DNA (CL)t
IgG IgM
IgA
CF activity of anti-DNA
Anti-C3 Anti-C4
J.S. C.S.
54 41-6
1280 1280
1280 1280 640 80
640 320
160 320
160 80
I.S. J.Mi.
n.d. 33-3 28-6
1280 640 640
320 1280 160
160 640 640
80 640 320
80 80
80 40 10
340 26 5 36-4 38 5 27-6 18-7 4-6 21-2 18-8 11-7 4-5
320 320 320 320 160 160 80 40 40 20 20 10
320 640 160 160 160 40 80 80 80 20 Neg.
320 320 80 80 160 20 40 80 40 1 80
80 160 80 40 80 40 20 20 10 1 20
Neg.
n.d.
A.E.
Neg.
Criteria for nephritis
Bx-diffuse proliferative GN Proteinuria (875 mg/24 hr); tcreatinine (2-1 mg/dl) Bx-diffuse proliferative GN Bx-focal proliferative GN Proteinuria (830 mg); active urine sediment
J.Mo. J.B. S.S. T.T. S.B. J.H. W.A. D.M. H.S. C.Ls. L.M. C.B. M.W.
0-2 0-7
* ,ug DNA bound/ml. t Reciprocal titre.
Neg. Neg. n.d.
80 320 40 4 80 1-5 Neg. 1-5 1-5 2
Neg.
Neg. Neg.
n.d.
n.d.
Bx-focal proliferative GN Active urine sediment Bx-focal proliferative GN Active urine sediment Bx-diffuse proliferative GN Neg. Bx-diffuse proliferative GN 10 Bx-focal proliferative GN 10 Bx-focal proliferative GN 1 Bx-membranous GN Neg. Bx-membranous GN 1 Bx-focal proliferative Neg. Proteinuria (9 6 g/24 hr) n.d. Bx-membranous GN 20 160 40 10 40
MF = millipore filter method for detection of anti-DNA; CL = Crithidia luciliae method for detection of anti-DNA; Ig = immunoglobulin; CF = complement-fixing; Neg. = negative; n.d. = not determined; Bx = biopsy; GN = glomerulonephritis.
Immunochemical characteristics of anti-DNA in SLE
61
TABLE 2. Anti-DNA in seventeen patients with active lupus without nephritis
CF activity of anti-DNA
Ig class of antiDNA
Patient A.St. A.So. M.S. L.T. C.La. K.H. L.A. T.G. L.Y. H.D. H.H. J.W. D.F. Y.D. E.H. C.R. G.J.
Anti-DNA (MF)*
Anti-DNA (CL)t
12-7 20.0 17-1 26 4 17-0 26-0
160 160 160 80 80 80 40 40 20 20 10 1 Neg. Neg. Neg.
22-2
33-4 25 3 38-5 22-9 29-1 2-3 1.9 2-1 0-8 07
Neg. Neg.
IgG IgM
IgA
80 80 80 20 80 160 80 80 10 Neg. 40 20 40 20 20 10 10 Neg. 20 20 10 10 n.d. n.d. n.d. n.d. n.d. n.d. n.d. n.d. n.d. n.d. n.d. n.d.
40 20 80 40 Neg. 20 40 10 1 10 10 n.d. n.d. n.d. n.d. n.d. n.d.
Manifestations of activity
Anti-C3 Anti-C4 2 20 Neg. 2 Neg. 40 10 Neg. Neg. Neg. Neg. n.d. n.d. n.d. n.d. n.d. n.d.
1 20 Neg. 10 Neg. 20 10 10 Neg. Neg. Neg. n.d. n.d. n.d. n.d. n.d. n.d.
Arthritis; thrombocytopenia; rash Pleuritis; fever; dementia Arthritis; pleuritis; vasculitic ulcer Arthritis; pleuritis; Arthritis; pleuritis; psychosis Rash; myositis Arthritis; anaemia Arthritis; constitutional symptoms Arthritis; fever; myositis Pleuritis; fever; carditis Arthritis; fever Arthritis; fever; pleuritis Arthritis; thrombocytopenia Arthritis; fever; pericarditis Arthritis; fever Fever; thrombocytopenia; psychosis Arthritis; fever; pleuritis; hemiparesis
* ,pg DNA bound/ml. t Reciprocal titre. MF = Millipore filter method for detection of anti-DNA; CL = Crithidia luciliae method for detection of anti-DNA; Ig = immunoglobulin; CF = complement-fixing; Neg. = negative; n.d. = not determined.
1280H
640h-
00
320k l
160k 8l1
o
8:1
Number of patients
Median titre of anti-DNA (CL) detected by polyspecific antisera
23 1 3
1:160 1:20 1:20
1
1:10
*0
41 _
o _0
21
3_.
m
gm A
211--
O
4
C)
Immunochemical characteristics of antibodies to DNA in patients with active systemic lupus erythematosus S. P. BALLOU & I. KUSHNER Department of Medicine, Case Western Reserve University at Cleveland Metropolitan General Hospital, Cleveland, Ohio 44109, USA
(Accepted for publication 13 November 1978)
SUMMARY
To investigate the suggestion that qualitative immunochemical characteristics of antibodies to DNA (anti-DNA) may be of importance in the pathogenesis of nephritis in systemic lupus erythematosus (SLE), we used the Crithidia luciliae (CL) immunofluorescence test to determine the titre, immunoglobulin (Ig) class and complement-fixing activity of anti-DNA in thirty-five patients with active SLE. Eighteen of these patients had active lupus nephritis (Group I) and the remaining seventeen had no clinical evidence of renal involvement (Group II). Anti-DNA was detected in twenty-eight patients, and was present more frequently and in higher titre (P< 0.01) in Group I than in Group II. Anti-DNA of all three Ig classes studied (IgG, IgM and IgA) was present in twenty-three out of twenty-eight cases. The ratio of IgG to IgM anti-DNA did not differ in the two groups of patients. Complement-fixing antibodies were detected in thirteen patients in Group I and five patients in Group II. The titre of complement-fixing activity was strongly correlated with titre of anti-DNA. DNA-binding capacity was also determined in these patients by a millipore filter (MF) assay. A highly significant correlation between DNA binding by MF and CL was found in Group I patients, while no correlation was found in Group II patients. These findings suggest that (1) anti-DNA with specificity for determinants found in CL, presumably native DNA, are more highly correlated with the presence of active renal lupus than are antibodies directed toward other DNA determinants, and (2) the major characteristic of antiDNA found to be associated with nephritis was quantity of antibody. Most patients had antiDNA of all Ig classes regardless of the presence of renal disease. Complement-fixing activity of anti-DNA could not be related to the occurrence of renal disease independently of anti-DNA titre. INTRODUCTION Antibodies to DNA (anti-DNA) are a characteristic and virtually specific finding in patients with active systemic lupus erythematosus (SLE). Although most strongly associated with active lupus nephritis, anti-DNA may be found in many patients with active lupus who have no clinical evidence of renal disease (Casals, Friou & Myers, 1964; Schur & Sandson, 1968). It has therefore been suggested that quantitative or qualitative differences in the immunochemical characteristics of such antibodies may effect their potential to precipitate or to reflect active renal disease in patients with SLE (Gershwin & Steinberg, 1974; Tron & Bach, 1977). Many studies have noted a relation between the quantity of anti-DNA and the occurrence of nephritis (Casals et al., 1964; Pincus, Schur & Rose, 1969). The role of the qualitative characteristics of such Correspondence: Dr S.P. Ballou, Cleveland Metropolitan General Hospital, 3395 Scranton Road, Cleveland, Ohio 44109, USA.
0099-9104/79/0070-0058502.00 (0 1979 Blackwell Scientific Publications 58
Immunochemical characteristics of anti-DNA in SLE
59
antibodies has been harder to ascertain (Soothill & Steward, 1971; Johnson, Edwards & Holborow, 1973; Tojo & Friou, 1968). Most investigators have felt that the specificity of such antibodies for the native configuration of DNA is of primary importance (Koffler et al., 1969). However, the inability of most recently employed DNA binding methods to detect only this limited population within the spectrum of DNA antibodies (Samaha & Irwin, 1975; Davis et al., 1978a) has precluded definitive evaluation of this hypothesis. Other qualitative immunochemical characteristics of anti-DNA- such as precipitating capacity, avidity, immunoglobulin class, and complement-fixing activity-may also be of importance in relation to lupus nephritis (Tron & Bach, 1977; Barnett, 1977), but methodological limitations have permitted only a limited assessment of these characteristics. A recently introduced immunofluorescence test for the detection of anti-DNA affords the opportunity to investigate some of these questions. This method employs the kinetoplast of the haemoflagellate Crithidia luciliae (CL), as substrate, and permits the detection of antibodies directed largely against native DNA (Aarden, deGroot & Feltkamp, 1975). In addition, this technique permits the characterization of the immunoglobulin class and complement-fixing ability of anti-DNA. In order to investigate these immunochemical characteristics of anti-DNA, we employed the CL method to study sera from thirty-five patients with active SLE, with and without clinical renal disease. Results were compared with those obtained by a commonly used millipore filter (MF) method (Ginsberg & Keiser, 1973). We considered four questions. (1) Are antibodies directed primarily against native DNA determinants more closely associated with active nephritis than are antibodies with a more heterogeneous spectrum of reactivity? (2) Is active renal disease related to amount of anti-DNA? (3) Does the immunoglobulin class of anti-DNA bear an important relationship to the presence of active nephritis? (4) Is the complement-fixing capacity of anti-DNA related to the development of nephritis?
MATERIALS AND METHODS Patients. Serum specimens from thirty-five patients with active SLE were studied. All patients fulfilled the preliminary ARA criteria for SLE (Cohen et al., 1971); thirty-one were untreated at the time of study. Three of the remaining four patients had been treated with 20-60 mg of prednisone daily for 1-4 weeks; prior treatment could not be ascertained in the fourth patient. Activity of lupus was felt to exist if at least two of the following manifestations were present: (1) active synovitis, (2) active serositis, (3) active central nervous system involvement, (4) thrombocytopenia (platelet count < 100,000/mm3), (5) diffuse skin involvement, (6) unexplained fever (temperature > 38&50C) and (7) constitutional symptoms including weight loss, anaemia, myalgias and arthralgias; without evidence ofother disease which could be held responsible for these symptoms. Patients were felt to have active lupus nephritis if there was presence of either (a) active urine sediment, (b) recent onset of proteinuria (> 500 mg/24 hr), or (c) an increase of serum creatinine concentration of > 0 3 mg/dl. The patients were divided into two groups: Group I: eighteen patients who met the above criteria for active lupus nephritis. In thirteen of these patients nephritis was confirmed by biopsy: six with focal proliferative, four with diffuse proliferative, and three with membranous glomerulonephritis. Group 2: seventeen patients who met the criteria for active SLE but showed no clinical evidence of nephritis. The complement component C3 (tested by radial immunodiffusion) was normal in twelve of these patients. One patient, with normal C3 at time of study, developed diffuse proliferative glomerulonephritis 1 yr later. Two patients were lost to follow-up after study; none of the other fourteen patients subsequently showed clinical evidence of nephritis over a mean follow-up period of 3j yr (range 1-12 yr). Immunofluorescence method. Anti-DNA (CL) was determined using a standard indirect immunofluorescence technique as described previously (Crowe & Kushner, 1977). A fluorescein-labelled polyspecific antiserum directed against human IgG, IgM and IgA (Behring Diagnostics, Somerville, New Jersey) was used for screening, and serum specimens were considered positive for anti-DNA if kinetoplast fluorescence was observed at a minimum serum dilution of 1: 10. Immunoglobulin (Ig) class of anti-DNA (CL) was determined employing fluorescein-labelled monospecific antisera directed against human IgG, IgM or IgA (Behring). The immunological specificity of these antisera was tested by prior absorption with purified immunoglobulins IgG and IgM obtained by separation of a mixed cryoglobulin on a Sephadex G-200 column. Four representative sera (CS, SB, ASO, HD), which demonstrated positive staining with all three antisera, were studied; two were from patients with renal disease and two from patients without renal disease. Immunofluorescent staining with anti-IgG was abolished by absorption with purified IgG but not IgM, while the opposite results were found when anti-IgM was used. Absorption with these two purified immunoglobulins did not effect staining with anti-IgA in three instances; IgM absorption abolished staining by one serum from a patient without renal disease (ASO). Detection ofcomplement-fixing activity. The complement-fixing (CF) activity of anti-DNA (CL) was determined by a modification of the triple sandwich technique employed by Parker & Turner (1976). Following the application of pre-heated (56°C for 30 min) patient's serum to slides, fresh frozen (- 70°C) normal human serum was applied, followed by fluorescein-
S. P. Ballou
60
& I.
Kushner
labelled antisera directed against either C3 (Behring) or C4 (Kallestad Laboratories, Minneapolis, Minnesota). Serum specimens were initially tested undiluted for CF activity; if positive, serial titres were done. When attempts were made to test for Clq binding using a similar method with fluorescein-labelled anti-Clq (Behring), kinetoplast fluorescence was observed in all specimens, presumably as a result of the known ability of Clq to bind to DNA (Agnello et al., 1969). DNA binding technique. DNA binding capacity was also determined using a modification of the MF technique of Ginsberg & Keiser (1973). As antigen we employed calf thymus DNA (Sigma Chemical Co., St. Louis, Missouri) which was labelled with 125I and passed through an 0-45 i type HA millipore filter (Millipore Corporation, Bedford, Massachusetts) prior to testing. Binding in excess of 50 pg DNA/ml is regarded as abnormal in this laboratory. Statistical methods. Statistical comparisons of data were carried out using the following tests where appropriate: Student's t-test, Mann-Whitney U test, Fischer exact test and correlation coefficient by linear regression.
RESULTS The serological and clinical data concerning the eighteen patients with active lupus renal disease shown in Table 1 and of the seventeen with active lupus without renal disease in Table 2.
are
Comparison ofanti-DNA (CL) with D.NA-binding capacity by MF In preliminary studies (Ballou & Kushner, 1979), anti-DNA (CL) testing in thirty-five patients revealed that seventeen out of eighteen (94%) of patients in Group I had significantly elevated levels, compared with eleven out of seventeen (64% ) patients in Group II (Fig. 1). This difference is statistically significant (P 0 036). The titres of anti-DNA (CL) in patients in Group I (median 1:160) were significantly higher than those in Group II (median 1:20) (P< 0 01). =
TABLE 1. Anti-DNA in eighteen patients with active lupus nephritis
Ig class of antiDNA
Patient
Anti-DNA (MF)*
Anti-DNA (CL)t
IgG IgM
IgA
CF activity of anti-DNA
Anti-C3 Anti-C4
J.S. C.S.
54 41-6
1280 1280
1280 1280 640 80
640 320
160 320
160 80
I.S. J.Mi.
n.d. 33-3 28-6
1280 640 640
320 1280 160
160 640 640
80 640 320
80 80
80 40 10
340 26 5 36-4 38 5 27-6 18-7 4-6 21-2 18-8 11-7 4-5
320 320 320 320 160 160 80 40 40 20 20 10
320 640 160 160 160 40 80 80 80 20 Neg.
320 320 80 80 160 20 40 80 40 1 80
80 160 80 40 80 40 20 20 10 1 20
Neg.
n.d.
A.E.
Neg.
Criteria for nephritis
Bx-diffuse proliferative GN Proteinuria (875 mg/24 hr); tcreatinine (2-1 mg/dl) Bx-diffuse proliferative GN Bx-focal proliferative GN Proteinuria (830 mg); active urine sediment
J.Mo. J.B. S.S. T.T. S.B. J.H. W.A. D.M. H.S. C.Ls. L.M. C.B. M.W.
0-2 0-7
* ,ug DNA bound/ml. t Reciprocal titre.
Neg. Neg. n.d.
80 320 40 4 80 1-5 Neg. 1-5 1-5 2
Neg.
Neg. Neg.
n.d.
n.d.
Bx-focal proliferative GN Active urine sediment Bx-focal proliferative GN Active urine sediment Bx-diffuse proliferative GN Neg. Bx-diffuse proliferative GN 10 Bx-focal proliferative GN 10 Bx-focal proliferative GN 1 Bx-membranous GN Neg. Bx-membranous GN 1 Bx-focal proliferative Neg. Proteinuria (9 6 g/24 hr) n.d. Bx-membranous GN 20 160 40 10 40
MF = millipore filter method for detection of anti-DNA; CL = Crithidia luciliae method for detection of anti-DNA; Ig = immunoglobulin; CF = complement-fixing; Neg. = negative; n.d. = not determined; Bx = biopsy; GN = glomerulonephritis.
Immunochemical characteristics of anti-DNA in SLE
61
TABLE 2. Anti-DNA in seventeen patients with active lupus without nephritis
CF activity of anti-DNA
Ig class of antiDNA
Patient A.St. A.So. M.S. L.T. C.La. K.H. L.A. T.G. L.Y. H.D. H.H. J.W. D.F. Y.D. E.H. C.R. G.J.
Anti-DNA (MF)*
Anti-DNA (CL)t
12-7 20.0 17-1 26 4 17-0 26-0
160 160 160 80 80 80 40 40 20 20 10 1 Neg. Neg. Neg.
22-2
33-4 25 3 38-5 22-9 29-1 2-3 1.9 2-1 0-8 07
Neg. Neg.
IgG IgM
IgA
80 80 80 20 80 160 80 80 10 Neg. 40 20 40 20 20 10 10 Neg. 20 20 10 10 n.d. n.d. n.d. n.d. n.d. n.d. n.d. n.d. n.d. n.d. n.d. n.d.
40 20 80 40 Neg. 20 40 10 1 10 10 n.d. n.d. n.d. n.d. n.d. n.d.
Manifestations of activity
Anti-C3 Anti-C4 2 20 Neg. 2 Neg. 40 10 Neg. Neg. Neg. Neg. n.d. n.d. n.d. n.d. n.d. n.d.
1 20 Neg. 10 Neg. 20 10 10 Neg. Neg. Neg. n.d. n.d. n.d. n.d. n.d. n.d.
Arthritis; thrombocytopenia; rash Pleuritis; fever; dementia Arthritis; pleuritis; vasculitic ulcer Arthritis; pleuritis; Arthritis; pleuritis; psychosis Rash; myositis Arthritis; anaemia Arthritis; constitutional symptoms Arthritis; fever; myositis Pleuritis; fever; carditis Arthritis; fever Arthritis; fever; pleuritis Arthritis; thrombocytopenia Arthritis; fever; pericarditis Arthritis; fever Fever; thrombocytopenia; psychosis Arthritis; fever; pleuritis; hemiparesis
* ,pg DNA bound/ml. t Reciprocal titre. MF = Millipore filter method for detection of anti-DNA; CL = Crithidia luciliae method for detection of anti-DNA; Ig = immunoglobulin; CF = complement-fixing; Neg. = negative; n.d. = not determined.
1280H
640h-
00
320k l
160k 8l1
o
8:1
Number of patients
Median titre of anti-DNA (CL) detected by polyspecific antisera
23 1 3
1:160 1:20 1:20
1
1:10
*0
41 _
o _0
21
3_.
m
gm A
211--
O
4
C)
