UVEITIS ASSOCIATED WITH SARCOIDOSIS AND ANGIOTENSIN CONVERTING ENZYME* BY Robert N. Weinreb, MD (BY INVITATION) AND
SamuelJ. Kimura, MD INTRODUCTION
THE DIAGNOSIS OF SARCOID uvEms
IS SUGGESTED BY THE SIMULTANEOUS PRES-
ence of granulomatous uveitis and systemic sarcoidosis. Patients with granulomatous uveitis may, however, present without the typical cinicoradiographic findings of sarcoidosis or histologic evidence of noncaseating granulomas. Since there are no pathognomonic ophthalmologic findings of sarcoidosis, a biochemical marker for sarcoidosis would be a useful diagnostic adjuvant in these cases. Elevations of serum angiotensin converting enzyme (ACE) have been associated with active sarcoidosis. 1.2 Although not specific for this disease, ACE may represent a sensitive biochemical marker for it when corroborating signs are present, In this investigation, the ACE activity of patients with granulomatous uveitis in the presence and absence of systemic sarcoidosis was evaluated. MATERIALS AND METHODS SUBJECTS
Patients were divided into three groups as follows: Group I (Systemic Sarcoidosis): 20 patients with systemic sarcoidosis as determined by clinicoradiographic findings and a positive biopsy. All of them had ophthalmic manifestations of sarcoidosis and ten had uveitis. Group II (Granulomatous Uveitis): 27 patients with granulomatous uveitis (according to the criteria of Woods3) and no evidence of systemic *From the Clinical Research Center for Eye Disease of the Department of Ophthalmology and the Francis I. Proctor Foundation for Research in Ophthalmology, University of California School of Medicine, San Francisco, California. Supported in part by a Sammy Davis Jr Award from Fight for Sight, Inc, NYC to Dr Weinreb. TR. AM. OPHTH. Soc. vol. LXXVII, 1979
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sarcoidosis. Those patients with granulomatous uveitis in whom a uveitis syndrome was identified were excluded from this group and placed in Group III. Complete blood counts, luetic serology, and serum calcium were within normal limits in all cases. Chest roentgenograms were either normal or showed non-specific changes which were not typical of sarcoidosis. Non-reactive purified protein derivative (PPD) and positive cutaneous delayed hypersensitivity were present in all but three cases. Two of these three cases were not tested with universal skin antigens, however. Group III (other Uveitis Syndromes): 17 patients with other uveitis syndromes, both granulomatous and nongranulomatous (four patients with toxoplasmosis; three with chronic cyclitis; two with Behcet's disease, ankylosing spondylitis, tuberculosis; and one with Fuchs' heterochromic cyclitis, acute multifocal placoid pigment epitheliopathy, histoplasmosis, birdshot choroidopathy). Patients with uveitis that did not fit into wellrecognized syndromes were excluded from this group. All patients were examined by the authors during 1978-79 at the following locations: the Eye Clinic of the University of California, San Francisco; San Francisco General Hospital; and the Uveitis Survey Clinic of the Francis I Proctor Foundation at the University of California, San Francisco. Patients were seen in the Uveitis Survey Clinic only by referral. Controls consisted of sera from 72 normal subjects obtained from BioScience Laboratories, Van Nuys, California. These were not age or sex matched to any of the other groups. ACE ASSAY
After informed consent was obtained, peripheral venous blood was drawn and allowed to clot for approximately one hour at room temperature. The serum was removed and stored at -20°C. ACE was assayed by Bio-Science Laboratories, Van Nuys, California using the method of Lieberman.4 The serum sample was incubated with hippuryl-histidyl-leucine; the hippuric acid liberated by the action of ACE on the substrate was extracted and quantitated spectrophotometrically. The mean serum ACE level in 72 normal subjects was 22 + 6.3 (SD) nmollml/min. Three of the 72 normal subjects (4.2%) had ACE activity exceeding two standard deviations above the mean. This is consistent with other studies.5 RESULTS
Three groups of patients were tested for serum angiotensin converting enzyme (ACE) in this study.
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TABLE I: CLINICAL DATA RACE
SEX
GROUPS*
NO.
AGE**
MALE
FEMALE WHITE
BLACK
31 35 37 Control subjects 72 13 37 6 14 5 Systemic sarcoid 20 Granulomatous 17 33 6 21 8 uveitis 27 Other uveitis syndromes 17 46 7 10 10 6 *Group I (Systemic Sarcoid); Group II (Granulomatous Uveitis); Group Syndromes). **Median age for group in years. tNumber of patients using either topical or systemic corticosteroids at determination.
OTHER STEROIDSt
2
7
2
10
1
2
III (other Uveitis the time of ACE
Clinical data for all subjects are summarized in Table I. The women outnumbered the men in all groups. Whereas, in Groups I (Systemic Sarcoidosis) and II (Granulomatous Uveitis), the majority of the patients were black (65% and 68% respectively), in Group III (other Uveitis Syndromes) they were in a clear minority (35%). The median age was lowest (33) and the number of patients who were using either topical or systemic corticosteroids at the time of ACE determination was highest (37%) in Group II. Only a small number of patients in Group III were using corticosteroids (12%) while slightly greater than one-third were using them in Group I (35%). ACE activity for all groups and control subjects is depicted schematically in Fig 1. Since corticosteroid administration may lower ACE activity in certain individuals,6 each group has been divided into two subgroups. The "steroid" subgroup consists of those subjects who were using either topical or systemic corticosteroids at the time of ACE determination; subjects in TABLE II: MEAN ACE ACTIVITY IN UVEITIS SARCOIDOSIS, AND CONTROLS MEAN ± SE*
(P VALUE)f
Groups Control subjects Systemic sarcoid
No steroid
Steroid**
22.0 ± 0.7 57.9 7.4 (P < 0.001) 41.5 + 4.4 (P < 0.001) 23.4 ± 2.1 (P > 0.2)
40.3 + 5.1 (P < 0.02) 35.6 ± 4.8 (P < 0.05) 27.0 ± 2.0 (P > 0.5)
Granulomatous uveitis Other uveitis syndromes *nmolmin/ml **Patients using topical or systemic corticosteroids at the time of ACE determination. fTwo-tailed P value compared with controls, using the two-independent sample t-test with separate vanance estimates.
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Angiotensin and Sarcoid 120
* Normal Values oExceeding 2 S.D. above Control Mean
0
10 E
-5
80
-0 0
00
E
0
0
60
0
-0
0
8
w
8
0
uJ
40
a
w
(I)
0
0
0 ---
-
--
---------
Q-
-
-
-
-
-
-
0f
-70
2
0NoSteroid Steroid No Steroid Steroid No Steroid Steroid CONTROL SUBJECTS
SYSTEMIC SARCOIDOSIS FIGURE
GRANULOMATOUS UVEITIS
OTHER UVEITIS SYNDROMES
1
ACE activity in uveitis, sarcoidosis, and controls. Normal values are those within two standard deviations (2 SD) of control mean. ACE activity above broken line exceeds control mean by 2 SD. Group I (Systemic Sarcoid); Group II (Granulomatous Uveitis); Group III (other Uveitis
Syndromes).
the "no steroid" subgroup were not using corticosteroids at that time. ACE activity for both the control subjects and Group III was almost always within two standard deviations of the mean. In contrast, ACE values for many ofthe patients in Groups I and II exceeded the mean by two standard deviations or more. This was particularly noticeable for the patients who were not using corticosteroids (Table II). Figure 2 shows the similar number of patients with elevated ACE activity in Groups I and II, as well as the paucity of elevated ACE values in the control subjects and Group III. Mean ACE activity for all groups and control subjects is summarized in Table II. Compared to controls, mean ACE activity in Groups I and II was significantly elevated. In contrast, mean ACE activity for Group III was not significantly different when
compared with controls.
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ELEVATED ACE ACTIVITY IN UVEITIS, SARCOIDOSIS & CONTROLS lot * NO STERIOD = >
10/3
0
STEROID
60 40
20 3/72 0
1
CONTROL SUBJECTS
1/15
i
~~~~~~~~~0/2
SYSTEMIC SARCOIDOSIS
GRANULOMATUS OTHER JVEITIS UVEITIS
SYNDROMES
FIGURE 2
Elevated ACE activity in uveitis, sarcoidosis, and controls. Fractions represent ACE values for each group exceeding two standard deviations above the control mean. Group I (Systemic Sarcoid); Group II (Granulomatous Uveitis); Group III (other Uveitis Syndromes). DISCUSSION
The current study focused on the question of whether patients with granulomatous uveitis, who lacked clinicoradiographic and histologic evidence of sarcoidosis, had elevated serum ACE activity. To do this, ACE activity in three groups of patients was measured. The first group (Group I) consisted of patients with systemic sarcoidosis and its associated ophthalmic manifestations. Patients with granulomatous uveitis and undetectable systemic sarcoidosis comprised the second group (Group II). The final group (Group III) was made up of those patients who had well-defined uveitis syndromes, both granulomatous and nongranulomatous. A highly significant elevation of mean ACE activity in Group II compared with controls was found. Mean ACE activity was also elevated in Group I, as would be expected since the association ofelevated ACE values with active sarcoidosis is well-described.1 2 In contrast, no significant statistical difference was found for Group III. Furthermore, the number of patients with ACE values exceeding two standard deviations above the control mean was similarly increased for Groups I and II when compared
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with Group III and controls. These data clearly indicate that ACE activity was increased in some patients with granulomatous uveitis and no other evidence of sarcoidosis. Since corticosteroids tend to diminish ACE activity in patients with sarcoidosis,6 the effect of corticosteroids on ACE activity was also studied. Seven patients in Group I were using systemic corticosteroids (two, in combination with topical corticosteroids) for various durations at the time of ACE determination. These patients had significantly lower mean ACE activity than those in the "no steroid" subgroup, thereby confirming other studies. In Group II, ten patients were using topical corticosteroids (one, in combination with systemic corticosteroid) for various durations at the time of ACE determination. In this group, too, mean ACE activity of "steroid" patients was lower than the "no steroid" subgroup. For both Groups I and II, the percentage of patients with elevated ACE activity was lower in the "steroid" subgroup. Hence, it appears that the elevated ACE activity of Group II patients may be suppressed by even the topical administration of corticosteroids. In Group III, there were only two patients using corticosteroids and a valid comparison to the "no steroid" subgroup could not be made. Although it is not absolutely specific, in the absence of supporting clinical or histologic evidence, serum ACE appears to be of value as a biochemical marker for sarcoidosis . The number of false positives is low; in this study it was 4.2% for healthy controls and 5.9% for other uveitis syndrome patients, which is similar to that found by others.5 Also, increased ACE activity has been reported to occur only in leprosy,7 Gaucher's disease,8 and primary biiary cirrhosis9 in addition to sarcoidosis. The ophthalmologic pattern associated with these entities is easily distinguished from that found in sarcoidosis. A mild chronic iritis occurs in about one fifth of patients with leprosy.10 However, the presence of iris pearls (lepromas) and iris atrophy as well as the association with other ocular and systemic findings is readily, but rarely, recognized. Gaucher's disease and primary biliary cirrhosis have not been associated with granulomatous uveitis and are also uncommon. Therefore, the simultaneous presence of granulomatous uveitis that does not fit into a well-recognized syndrome and increased serum ACE activity is highly suggestive that the uveitis is associated with sarcoidosis (sarcoid uveitis). The source of the increased serum ACE activity in these patients has not been identified. If systemic disease is indeed absent, then perhaps sarcoid granulomas in the eye are producing enough ACE to result in elevated serum levels. Since serum ACE levels probably reflect the total body mass of granulomas,3 it is more reasonable that clinically quiescent sarcoidosis is
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Weinreb et al present, which cannot be detected by current diagnostic means. Gallium scans may be useful in differentiating these two alternatives, since they can show uptake in certain small units of intensely involved tissues such as lacrimal glands and maybe even the globe. It has been reported that elevated serum lysozyme levels might be useful in diagnosing sarcoidosis,11 especially for patients with a clinical picture of sarcoid uveitis. 12 Serum lysozyme is elevated in a large number of conditions, however, and therefore is ofless value in diagnosis and management. At least one fifth ofpatients with sarcoidosis develop symptoms related to the eye or its adnexa as the first manifestations of their disease."4 Our results indicate that ocular involvement in sarcoidosis may be more common than generally recognized; furthermore, it may be diagnosed in the absence of otherwise undetectable systemic disease. Since early recognition and treatment of ocular sarcoid may prevent visual loss, ACE may also be a useful ancillary diagnostic test when confronted by patients with iris nodules, acute iritis, conjunctival lesions, band keratopathy, chorioretinitis, periphlebitis, chorioretinal nodules, vitreous cells or hemorrhage, retinal or optic disc neovascularization, and lacrimal gland or optic nerve disease of unknown cause. Serum ACE provides an inexpensive, rapid, and reliable screening test for systemic sarcoidosis, especially in the presence of corroborative signs. Nevertheless, the definite diagnosis of sarcoidosis, either systemic or ocular, depends on histologic confirmation in the appropriate tissue. Since intraocular tissue is not easily obtainable, evaluation of serum ACE may prove to be a useful indicator of ocular sarcoid. SUMMARY
Sarcoid uveitis is usually a presumptive diagnosis based on the simultaneous presence of uveitis and clinicoradiographic or histologic findings of sarcoidosis. The elevation of serum ACE in some patients with granulomatous uveitis is strongly presumptive of sarcoid uveitis even in the absence of these findings. Serum ACE may prove to be a useful indicator of ocular sarcoid in the absence of otherwise undetectable systemic disease. REFERENCES
1. Lieberman J: A new confirmatory test for sarcoidosis. Serum angiotensin converting enzyme. Am Rev Respir Dis 109:743, 1974. 2. Silverstein E, Friedland J, Lyons H, et al: Serum angiotensin converting enzyme activity in sarcoidosis. Clin Res 23:352A, 1975.
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3. Woods AC: Endogenous Inflammation ofthe Uveal Tract. Baltimore, Williams & Wilkins Co, 1961, Chap 2. 4. Lieberman J: Elevation of serum angiotensin converting enzyme (ACE) level in sarcoidosis. Am J Med 59:365, 1975. 5. Silverstein, Friedland J, Kitt M, et al: Increased serum angiotensin converting enzyme activity in sarcoidosis. IsrJ Med Sci 13:995, 1977. 6. Silverstein E, Friedland J, Lyons H: Serum angiotensin converting enzyme in sarcoidosis: clinical significance. Isr J Med Sci 13:1001, 1977. 7. Lieberman J, Rea T: Serum angiotensin converting enzyme in leprosy and coccidiomycosis. Ann Intern Med 87:422, 1977. 8. Lieberman J, Beutler E: Elevation of serum angiotensin converting enzyme in Gaucher's disease. N Engl J Med 194:1442, 1976. 9. Studdy P, Bird R, James D, et al: Serum angiotensin converting enzyme (SACE) in sarcoidosis and other granulomatous disorders. Lancet 11:1331, 1978. 10. Shields J, Waring G, Monte L: Ocular findings in leprosy. AmJ Ophthalmol 77:880, 1974. 11. Pascual R, Gee B, Finch S: Serum lysozyme analysis in diagnosis and evaluation of sarcoidosis. N Engl J Med 289:1074, 1973. 12. Weinberg R, Tessler H: Serum lysozyme in sarcoid uveitis. Am J Ophthalmol 82:105, 1976. 13. Nosal A, Schleissner LX, Mishkin F, et al: Angiotensin converting enzyme and gallium scan in noninvasive evaluation of sarcoidosis. Ann Intern Med 90:328, 1979. 14. ObenaufC, Shaw H, Sydnor C, et al: Sarcoidosis and its ophthalmic manifestations. AmJ Ophthalmol 86:648, 1978.
DISCUSSION
DR IRVING H. LEOPOLD. Sarcoidosis is a generalized non-necrotizing granulomatous disease of unknown etiology characterized by depressed, cell mediated immunity, increased humoral immunoglobulin levels, granulomatous reaction to injected processed sarcoid tissue (Kveim-Siltzbach antigen) and apparent clinical manifestations, including uveitis, orbital masses, hyperealciuria and hyperprolactinemia. 1 In 1974,2 Lieberman noted raised concentrations of serum angiotensin converting enzyme (also called ACE) in 15 patients. This has been confirmed by other investigators such as Silverstein and his co-workers,3 and Fanberg and his co-workers.4 ACTION OF ENZYME
Serum angiotensin I converting enzyme is a metalloenzyme, a dipeptidyl carboxy peptidase, which catalyzes the conversion of decapeptide angiotension I to the pressor octapeptide angiotensin II and L-Histadyl-L-Leucine the terminal dipeptide. Serum angiotensin I converting enzyme also inactivates bradykinin. This serum angiotensin converting enzyme (ACE) is present in high concentrations in lung tissue and in the vascular bed of patients with sarcoidosis. It is found in high concentrations in non-necrotizing granulomatous lymph nodes of sarcoidosis patients. It is recognized that it is not a specific test for sarcoid but has value as an aid in diagnosis. Last year at this meeting in a discussion of a paper on orbital sarcoidosis by Nichols, Mishkin and Yanoff, Doctor Kimura raised the question of the potential value ofACE in confirming the diagnosis of sarcoidosis and this year Doctor Kimura
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and his co-workers have presented evidence that this test can be of value in sarcoid, which seems to be manifested primarily in the ocular structures. RELATED ENZYMES-MACROPHAGE ACTIVrTY
There appears to be a close correlation between serum lysozyme values and serum angiotensin converting enzymes. Silverstein and his co-workers found that lysozyme activity was also elevated in sarcoid lymph nodes.9 Serum angiotensin converting enzyme and serum lysozyme were significantly positively correlated in 16 sarcoidosis patients, suggesting a relationship between the two. The markedly elevated angiotensin converting enzyme in sarcoid granulomatous lymph nodes suggests the possibility of other biologically active and perhaps clinically significant molecules, eg, enzymes, may be elaborated in the granulomatous sarcoidosis. This may mean that serum ACE may be an indicator of high macrophage activity and the macrophages and epithelioid cells may be a souce of the ACE as well as other enzymes such as lysozyme. According to some investigators, a significant elevation of serum ACE occurs in approximately 60% ofactive sarcoidosis patients and tends to diminish with increasing duration of disease and in the majority of the patients who are on corticosteroid therapy.2.3'5,6 CORTICOSTEROID EFFECT
It is not yet clear whether there is any consistent corticosteroid effect on serum
ACE, for there are some patients on corticosteroid therapy for two to four years with elevated serum ACE values which in some instances are extremely high as reported by Fanberg.4 There is evidence in the literature that sarcoid granulomas may be actively synthesizing ACE and this results in the elevation of serum ACE levels. Apparently extensively fibrotic sarcoid lymph nodes have been analyzed and have shown normal or only slightly elevated ACE, suggesting that obliteration of granulomas in sarcoid lymph nodes diminishes their ACE content and that this obliteration may be related to the tendency to diminution of serum ACE with time. ACE was not elevated in tuberculous lymph nodes or in experimental granulomas, suggesting that elevation of ACE may have some specificity for the granulomas of sarcoidosis rather than being characteristic of all granulomas.79 NATURE OF ENZYME
It is not known whether the ACE found in sarcoid patients is the same as that found in other individuals. However, studies of ph activity, modulators, polycrylamidegel electrophoresis, and sephadex G-200 gel filtration have shown marked similarity of all the angiotensin converting enzymes. Perhaps the ACE of sarcoid is more heat labile than that found in normal lung or lymph node. It suggests a new possibility that an abnornal ACE may be present in sarcoidosis.
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CORRELATION WITH OTHER STUDIES
Studies by Stanislas-Leguern Marsax and Amoux demonstrated no statistical difference in serum ACE between groups of patients in radiological stages of mild to severe disease. Nor were the ACE values different in patients with disease durations of more than or less than two years. Neither the number of extra pulmonary organs involved nor immunoglobulin values nor ESR Kveim or Mantoux results had any relation to ACE levels. However, they did find that patients with granulomas on bronchial biopsy had higher ACE values than those without granulomas. They did bronchoalveolar lavage and found a much higher percentage of lymphocytes in the sarcoid patients than in controls. There was a significant correlation between the percentage of lymphocytes in the presence of bronchial granulomas in the bronchial biopsy specimen but there was no correlation between the percentage of alveolar lymphocytes and ACE activity. SITES OF SYNTHESIS OF ENZYME
Serum angiotensin is thought to be produced also by endothelial cells of blood vessels. SilversteinO has reported increased angiotensin converting values in lymph nodes and suggests that the sarcoid granulomas, particularly epithelioid cells, may be actively synthesizing ACE. It would be helpful to know the site of synthesis, storage, excretion of ACE and its relationship to the immunological disturbances. Does it suppress cell mediated immunity? ENZYME LEVELS IN OTHER DISEASES
Patients with various lung disorders include cystic fibrosis, emphysema, asthma, lung cancer, tuberculosis, and pulmonary fungal diseases were found to have reduced levels of serum ACE in comparison with healthy controls. The patients with active sarcoidosis had mean ACE levels of approximately twice that of the controls. By contrast, serum ACE was normal in sarcoidosis patients receiving therapeutic doses ofcorticosteroids or who had undergone spontaneous resolution of disease so that the elevated ACE levels appear to be associated with the active disease process and no.t to be a predisposing genetic factor. Other non-pulmonary granulomatous diseases including Hodgkin's, regional enteritis, ulcerative colitis, and cirrhosis of the liver were not associated with elevated serum ACE levels. It seems reasonable that a measurement of serum ACE may be useful as a test for confirming a diagnosis of active sarcoidosis. Dr Kimura and his co-workers have demonstrated that this may be a helpful diagnostic aid in sarcoidosis with predominating ocular manifestations. OTHER SUBSTANTIATING DIAGNOSTIC TESTS
Although the data is convincing, it possibly might be more conclusive if these patients also had confirmation provided by biopsy ofthe conjunctiva or the lacrimal
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gland or enlarged lymph node. A number of years ago working with Doctor Steven Rosenthal and Lewis Siltzbach at Mt. Sinai Hospital we were able to show that patients with ocular manifestations ofsarcoid often revealed positive lacrimal gland biopsies which permitted diagnosis of the disease much sooner than could be obtained by the Kveim-Siltzbach test and in whom roentgenograms and pulmonary changes were not yet significant, and in whom an enlarged lymph gland could not be obtained easily. OCULAR LEVEL OF ENZYME
It would also be helpful and informative to know the intraocular fluid levels of ACE in normal eyes as compared to those with varying activity of sarcoidosis and other forms of uveitis. Attempts to determine ifangiotensin I converting enzyme exists in normal aqueous humor of rabbits, dogs and monkeys by Ikemoto and Yamamoto were not successful. 13 Perhaps secondary aqueous humor will show the enzyme. It will be necessary to determine ifthis enzyme arises locally from macrophages, etc, or secondarily from the plasma. Tear analyses in our laboratories by Anderson and Richman have suggested the presence of measureable quantities of the ACE in normal eyes. One might wonder whether tear analyses might also be helpful in differentiating patients with sarcoid uveitis. INHIBrTOR OF ENZYME
It should be noted that there is an inhibitor of ACE.",2 A snake venom extract has been shown to inhibit ACE, in turn producing a drop in blood pressure in hypertensive patients, but this was orally inactive. Structural studies of the converting enzyme led to the synthesis of a similarly structured competitive inhibitor succinyl-L-Proline and successively more potent inhibitors which culminated in the synthesis of the orally potent captopril (Sq. 14.255 Squibb). One might wonder what such inhibition might do to sarcoid patients other than: decrease their angiotensin II by inhibition of converting enzyme; lead to accumulation of bradykinin by similar inhibition of Kininase II; inhibition of aldosterone secretion and sodium retention by a reduction of angiotensin III. SUMMARY
As in all fruitful research, many interesting questions are raised-Why, for example, do most active sarcoidosis victims not show hypertension? Is it because the degree of hypertension is related to the amount of substrate angiotensin I and not the amount of enzyme, or is there a natural increase of an inactivating enzyme ofthe increased ACE? Someone will no doubt determine the effect of captopril on the enzyme (ACE) levels in sarcoidosis. This is obviously a very stimulating presentation. REFERENCES 1. Turkington RW,
76:545, 1972.
Macindoe JH: Hyperprolactinemia in Sarcoidosis. Ann Intern Med
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2. Lieberman J: Elevation of Serum Angiotensin Converting Enzyme (ACE) Level in Sarcoidosis. AmJ Med 59:365, 1975. 3. Silverstein E, Friedland J, Lyons H, et al: Serum Angiotensin Converting Enzyme in Sarcoidosis. Klin Res 23:352, 1975. 4. Fanberg BL, Schoenberger MD, Bachus B, et al: Elevated Serum Angiotensin I Converting Enzyme in Sarcoidosis. Am Rev Respir Dis 114:525, 1976. 5. Silverstein E, Friedland J, Lyons H, et al: Markedly Elevated Angiotensin Converting Enzymes in Lymph Nodes Containing Non-Necrotizing Granulomas in Sarcoidosis. Proc Natl Acad Sci USA 73:2137, 1976. 6. Silverstein E, Friedland J, Lyons H, et al: Elevation of Angiotensin Converting Enzymes in Granulomatous Lymph Nodes and Serum in Sarcoidosis, Clinical and Possible Pathogenic Significance. Ann NY Acad Sci 278:498, 1976. 7. Osserman EF, Lawler OP: Serum and Urinary Lysozyme Muramidase (in Monocytic and Monomyelocytic Leukemia). J Exp Med 124:921, 1966. 8. Pascual RS, Gee JPL, Finch SC: Usefulness of Serum Lysozyme Measurement in Diagnosis and Evaluation of Sarcoidosis. N Engl J Med 289:1074, 1973. 9. Silverstein E, Friedland J, Ackerman T: Elevation of Granulomatous Lymph Node and Serum Lysozyme in Sarcoidosis and Correlation with Angiotensin Converting Enzyme. Am J Clin Pathol 68:219, 1977. 10. Gordon S, Todd J, Cohn ZA: In Vitro Synthesis and Secretion of Lysozyme by Mononuclear Phagocytes. J Exp Med 139:1228, 1974. 11. Brunner HR, et al: Oral Angiotensin Converting Enzyme Inhibitor in Long Term Treatment of Hypertensive Patients. Ann Intern Med 90:19, 1979. 12. Cushman DW, et al: Design of New Hypertensive Drugs: Potent and Specific Inhibitors of Angiotensin Converting Enzyme. Prog Cardiovasc Dis 21:176, 1978. 13. Ikemoto F, Yamamoto K: Renin-angiotensin System in the Aqueous Humor of Rabbits, Dogs and Monkeys. Exp Eye Res 27:723, 1978.
DR MORTON GOLDBERG. The angiotensin converting enzyme may well turn out to be a valuable diagnostic aid in assessing patients with signs of ocular sarcoid in the absence of signs of systemic sarcoid. I believe I interpreted the authors' data correctly when they showed that only 12 of 27 such patients had abnormally elevated values of ACE. But perhaps of even more diagnostic value is the serum lysozyme test. For example, Doctors Tessler and Weinberg of the Illinois Eye and Ear Infirmary showed in similar patients (that is, granulomatous uveitis suggesting ocular sarcoid in the absence of signs of systemic sarcoid) that 14 of 15 had an elevated serum lysozyme value. Until these data can be confirmed, perhaps the intelligent clinical course would be to obtain both enzyme tests and evaluate any such patients with both the ACE level and the serum lysozyme value. DR ANDREW P. FERRY. I should like to thank Doctors Weinreb and Kimura for calling to our attention the presence of altered levels of serum ACE in patients with sarcoidosis. Doctor Robert S. Weinberg, to whose work Doctor Goldberg alluded, is now with us in Richmond and has been studying serum lysozyme and serum ACE levels in patients with sarcoid uveitis. In 20 patients with sarcoid uveitis studied thus far, both serum lysozyme and ACE were elevated in 18. Ofthe two remaining patients, one had elevated serum lysozyme and the other had elevated serum ACE.
292 Weinreb et al Doctor Weinberg also has been studying tear enzymes in these patients. After having determined that ACE is present in tears, he found a remarkably high correlation between levels of ACE in the serum and in the tears of patients with sarcoid uveitis. In the normal population, tear lysozyme levels usually are very high, but this does not appear to be the case with tear ACE levels. It therefore seems that studying tear ACE levels in patients suspected of having sarcoid uveitis may provide a real payoff. DR STEVEN PODOS. There are other proteins associated with sarcoid which also can be studied by the people who are doing this, such as serum macrophage inhibiting factor and lysosyme. I believe that something nonspecific is responsible and further studies may clarify the situation.
DR SAIICHI MISHIMA. I would like to thank Doctor Weinreb for showing this very important test for the diagnosis of sarcoidosis. As I have shown in my slide on Behcet's disease, sarcoidosis is also a frequent disease entity in Japan and its diagnosis is a problem. The question we asked is with what degree of accuracy we can diagnose sarcoidosis from the ocular symptoms, inotherwords, whether we can give weight to certain ocular findings or combination of findings in the diagnosis. In this connection, we compiled 53 cases with so-called ocular sarcoidosis among which 33 cases were later diagnosed as having systemic sarcoidosis. No single ocular symptom could be highly correlated with the disease but a combination of bilateral disease and peripheral anterior synechia was found in 28 cases of sarcoidosis whereas in only 4 cases with this combination, the diagnosis could not be confirmed. The typical peripheral anterior synechia is shown here (slide). In conclusion, among symptoms of so-called ocular sarcoidosis, bilateral peripheral anterior synechiae are of significance for the diagnosis. DR ROBERT N. WEINREB. I would like to thank Doctor Leopold, Doctor Mishima, and the other distinguished members for their remarks. Doctor Leopold, we have detected small, but measureable ACE activity in aqueous samples obtained during cataract surgery in several non-sarcoid patients. We have also been fortunate to study a 35-year-old black woman with systemic sarcoid and granulomatous uveitis who underwent a peripheral iridectomy for secondary glaucoma. Serum ACE activity was elevated as was the ratio of (aqueous ACE activity)/(aqueous protein) compared with (serum ACE activity)/(serum protein). We have also examined a young white woman with granulomatous uveitis and undetectable systemic sarcoid whose ratio of (aqueous ACE activity)/(aqueous protein) was increased compared with (serum ACE activity)/(serum protein). These results may indicate that intraocular tissues or cells within them can synthesize or selectively concentrate ACE. To date, we have not investigated tear enzyme levels, but this could prove to be a useful screening test as Doctor Leopold has suggested. Doctor Goldberg and Doctor Ferry, elevations of serum lysozyme and serum ACE are closely associated in systemic sarcoid. Further, we have compared their
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activities in many cases of granulomatous uveitis with or without systemic sarcoid and have found them to be closely correlated. As Doctor Leopold mentioned in his discussion, we feel that serum lysozyme is too nonspecific a test; serum lysozyme activity is elevated in some entities that can be confused with ocular sarcoid. Doctor Podos, thank you for your comments. Perhaps, these may also prove to be chemical markers for ocular sarcoid. Doctor Mishima, we have not routinely gonioscoped patients with granulomatous uveitis looking for small "tented" peripheral anterior synechiae. You have suggested that these are frequently associated with ocular sarcoid, and it would be interesting to correlate their presence with ACE activity.
SamuelJ. Kimura, MD INTRODUCTION
THE DIAGNOSIS OF SARCOID uvEms
IS SUGGESTED BY THE SIMULTANEOUS PRES-
ence of granulomatous uveitis and systemic sarcoidosis. Patients with granulomatous uveitis may, however, present without the typical cinicoradiographic findings of sarcoidosis or histologic evidence of noncaseating granulomas. Since there are no pathognomonic ophthalmologic findings of sarcoidosis, a biochemical marker for sarcoidosis would be a useful diagnostic adjuvant in these cases. Elevations of serum angiotensin converting enzyme (ACE) have been associated with active sarcoidosis. 1.2 Although not specific for this disease, ACE may represent a sensitive biochemical marker for it when corroborating signs are present, In this investigation, the ACE activity of patients with granulomatous uveitis in the presence and absence of systemic sarcoidosis was evaluated. MATERIALS AND METHODS SUBJECTS
Patients were divided into three groups as follows: Group I (Systemic Sarcoidosis): 20 patients with systemic sarcoidosis as determined by clinicoradiographic findings and a positive biopsy. All of them had ophthalmic manifestations of sarcoidosis and ten had uveitis. Group II (Granulomatous Uveitis): 27 patients with granulomatous uveitis (according to the criteria of Woods3) and no evidence of systemic *From the Clinical Research Center for Eye Disease of the Department of Ophthalmology and the Francis I. Proctor Foundation for Research in Ophthalmology, University of California School of Medicine, San Francisco, California. Supported in part by a Sammy Davis Jr Award from Fight for Sight, Inc, NYC to Dr Weinreb. TR. AM. OPHTH. Soc. vol. LXXVII, 1979
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sarcoidosis. Those patients with granulomatous uveitis in whom a uveitis syndrome was identified were excluded from this group and placed in Group III. Complete blood counts, luetic serology, and serum calcium were within normal limits in all cases. Chest roentgenograms were either normal or showed non-specific changes which were not typical of sarcoidosis. Non-reactive purified protein derivative (PPD) and positive cutaneous delayed hypersensitivity were present in all but three cases. Two of these three cases were not tested with universal skin antigens, however. Group III (other Uveitis Syndromes): 17 patients with other uveitis syndromes, both granulomatous and nongranulomatous (four patients with toxoplasmosis; three with chronic cyclitis; two with Behcet's disease, ankylosing spondylitis, tuberculosis; and one with Fuchs' heterochromic cyclitis, acute multifocal placoid pigment epitheliopathy, histoplasmosis, birdshot choroidopathy). Patients with uveitis that did not fit into wellrecognized syndromes were excluded from this group. All patients were examined by the authors during 1978-79 at the following locations: the Eye Clinic of the University of California, San Francisco; San Francisco General Hospital; and the Uveitis Survey Clinic of the Francis I Proctor Foundation at the University of California, San Francisco. Patients were seen in the Uveitis Survey Clinic only by referral. Controls consisted of sera from 72 normal subjects obtained from BioScience Laboratories, Van Nuys, California. These were not age or sex matched to any of the other groups. ACE ASSAY
After informed consent was obtained, peripheral venous blood was drawn and allowed to clot for approximately one hour at room temperature. The serum was removed and stored at -20°C. ACE was assayed by Bio-Science Laboratories, Van Nuys, California using the method of Lieberman.4 The serum sample was incubated with hippuryl-histidyl-leucine; the hippuric acid liberated by the action of ACE on the substrate was extracted and quantitated spectrophotometrically. The mean serum ACE level in 72 normal subjects was 22 + 6.3 (SD) nmollml/min. Three of the 72 normal subjects (4.2%) had ACE activity exceeding two standard deviations above the mean. This is consistent with other studies.5 RESULTS
Three groups of patients were tested for serum angiotensin converting enzyme (ACE) in this study.
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TABLE I: CLINICAL DATA RACE
SEX
GROUPS*
NO.
AGE**
MALE
FEMALE WHITE
BLACK
31 35 37 Control subjects 72 13 37 6 14 5 Systemic sarcoid 20 Granulomatous 17 33 6 21 8 uveitis 27 Other uveitis syndromes 17 46 7 10 10 6 *Group I (Systemic Sarcoid); Group II (Granulomatous Uveitis); Group Syndromes). **Median age for group in years. tNumber of patients using either topical or systemic corticosteroids at determination.
OTHER STEROIDSt
2
7
2
10
1
2
III (other Uveitis the time of ACE
Clinical data for all subjects are summarized in Table I. The women outnumbered the men in all groups. Whereas, in Groups I (Systemic Sarcoidosis) and II (Granulomatous Uveitis), the majority of the patients were black (65% and 68% respectively), in Group III (other Uveitis Syndromes) they were in a clear minority (35%). The median age was lowest (33) and the number of patients who were using either topical or systemic corticosteroids at the time of ACE determination was highest (37%) in Group II. Only a small number of patients in Group III were using corticosteroids (12%) while slightly greater than one-third were using them in Group I (35%). ACE activity for all groups and control subjects is depicted schematically in Fig 1. Since corticosteroid administration may lower ACE activity in certain individuals,6 each group has been divided into two subgroups. The "steroid" subgroup consists of those subjects who were using either topical or systemic corticosteroids at the time of ACE determination; subjects in TABLE II: MEAN ACE ACTIVITY IN UVEITIS SARCOIDOSIS, AND CONTROLS MEAN ± SE*
(P VALUE)f
Groups Control subjects Systemic sarcoid
No steroid
Steroid**
22.0 ± 0.7 57.9 7.4 (P < 0.001) 41.5 + 4.4 (P < 0.001) 23.4 ± 2.1 (P > 0.2)
40.3 + 5.1 (P < 0.02) 35.6 ± 4.8 (P < 0.05) 27.0 ± 2.0 (P > 0.5)
Granulomatous uveitis Other uveitis syndromes *nmolmin/ml **Patients using topical or systemic corticosteroids at the time of ACE determination. fTwo-tailed P value compared with controls, using the two-independent sample t-test with separate vanance estimates.
283
Angiotensin and Sarcoid 120
* Normal Values oExceeding 2 S.D. above Control Mean
0
10 E
-5
80
-0 0
00
E
0
0
60
0
-0
0
8
w
8
0
uJ
40
a
w
(I)
0
0
0 ---
-
--
---------
Q-
-
-
-
-
-
-
0f
-70
2
0NoSteroid Steroid No Steroid Steroid No Steroid Steroid CONTROL SUBJECTS
SYSTEMIC SARCOIDOSIS FIGURE
GRANULOMATOUS UVEITIS
OTHER UVEITIS SYNDROMES
1
ACE activity in uveitis, sarcoidosis, and controls. Normal values are those within two standard deviations (2 SD) of control mean. ACE activity above broken line exceeds control mean by 2 SD. Group I (Systemic Sarcoid); Group II (Granulomatous Uveitis); Group III (other Uveitis
Syndromes).
the "no steroid" subgroup were not using corticosteroids at that time. ACE activity for both the control subjects and Group III was almost always within two standard deviations of the mean. In contrast, ACE values for many ofthe patients in Groups I and II exceeded the mean by two standard deviations or more. This was particularly noticeable for the patients who were not using corticosteroids (Table II). Figure 2 shows the similar number of patients with elevated ACE activity in Groups I and II, as well as the paucity of elevated ACE values in the control subjects and Group III. Mean ACE activity for all groups and control subjects is summarized in Table II. Compared to controls, mean ACE activity in Groups I and II was significantly elevated. In contrast, mean ACE activity for Group III was not significantly different when
compared with controls.
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ELEVATED ACE ACTIVITY IN UVEITIS, SARCOIDOSIS & CONTROLS lot * NO STERIOD = >
10/3
0
STEROID
60 40
20 3/72 0
1
CONTROL SUBJECTS
1/15
i
~~~~~~~~~0/2
SYSTEMIC SARCOIDOSIS
GRANULOMATUS OTHER JVEITIS UVEITIS
SYNDROMES
FIGURE 2
Elevated ACE activity in uveitis, sarcoidosis, and controls. Fractions represent ACE values for each group exceeding two standard deviations above the control mean. Group I (Systemic Sarcoid); Group II (Granulomatous Uveitis); Group III (other Uveitis Syndromes). DISCUSSION
The current study focused on the question of whether patients with granulomatous uveitis, who lacked clinicoradiographic and histologic evidence of sarcoidosis, had elevated serum ACE activity. To do this, ACE activity in three groups of patients was measured. The first group (Group I) consisted of patients with systemic sarcoidosis and its associated ophthalmic manifestations. Patients with granulomatous uveitis and undetectable systemic sarcoidosis comprised the second group (Group II). The final group (Group III) was made up of those patients who had well-defined uveitis syndromes, both granulomatous and nongranulomatous. A highly significant elevation of mean ACE activity in Group II compared with controls was found. Mean ACE activity was also elevated in Group I, as would be expected since the association ofelevated ACE values with active sarcoidosis is well-described.1 2 In contrast, no significant statistical difference was found for Group III. Furthermore, the number of patients with ACE values exceeding two standard deviations above the control mean was similarly increased for Groups I and II when compared
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with Group III and controls. These data clearly indicate that ACE activity was increased in some patients with granulomatous uveitis and no other evidence of sarcoidosis. Since corticosteroids tend to diminish ACE activity in patients with sarcoidosis,6 the effect of corticosteroids on ACE activity was also studied. Seven patients in Group I were using systemic corticosteroids (two, in combination with topical corticosteroids) for various durations at the time of ACE determination. These patients had significantly lower mean ACE activity than those in the "no steroid" subgroup, thereby confirming other studies. In Group II, ten patients were using topical corticosteroids (one, in combination with systemic corticosteroid) for various durations at the time of ACE determination. In this group, too, mean ACE activity of "steroid" patients was lower than the "no steroid" subgroup. For both Groups I and II, the percentage of patients with elevated ACE activity was lower in the "steroid" subgroup. Hence, it appears that the elevated ACE activity of Group II patients may be suppressed by even the topical administration of corticosteroids. In Group III, there were only two patients using corticosteroids and a valid comparison to the "no steroid" subgroup could not be made. Although it is not absolutely specific, in the absence of supporting clinical or histologic evidence, serum ACE appears to be of value as a biochemical marker for sarcoidosis . The number of false positives is low; in this study it was 4.2% for healthy controls and 5.9% for other uveitis syndrome patients, which is similar to that found by others.5 Also, increased ACE activity has been reported to occur only in leprosy,7 Gaucher's disease,8 and primary biiary cirrhosis9 in addition to sarcoidosis. The ophthalmologic pattern associated with these entities is easily distinguished from that found in sarcoidosis. A mild chronic iritis occurs in about one fifth of patients with leprosy.10 However, the presence of iris pearls (lepromas) and iris atrophy as well as the association with other ocular and systemic findings is readily, but rarely, recognized. Gaucher's disease and primary biliary cirrhosis have not been associated with granulomatous uveitis and are also uncommon. Therefore, the simultaneous presence of granulomatous uveitis that does not fit into a well-recognized syndrome and increased serum ACE activity is highly suggestive that the uveitis is associated with sarcoidosis (sarcoid uveitis). The source of the increased serum ACE activity in these patients has not been identified. If systemic disease is indeed absent, then perhaps sarcoid granulomas in the eye are producing enough ACE to result in elevated serum levels. Since serum ACE levels probably reflect the total body mass of granulomas,3 it is more reasonable that clinically quiescent sarcoidosis is
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Weinreb et al present, which cannot be detected by current diagnostic means. Gallium scans may be useful in differentiating these two alternatives, since they can show uptake in certain small units of intensely involved tissues such as lacrimal glands and maybe even the globe. It has been reported that elevated serum lysozyme levels might be useful in diagnosing sarcoidosis,11 especially for patients with a clinical picture of sarcoid uveitis. 12 Serum lysozyme is elevated in a large number of conditions, however, and therefore is ofless value in diagnosis and management. At least one fifth ofpatients with sarcoidosis develop symptoms related to the eye or its adnexa as the first manifestations of their disease."4 Our results indicate that ocular involvement in sarcoidosis may be more common than generally recognized; furthermore, it may be diagnosed in the absence of otherwise undetectable systemic disease. Since early recognition and treatment of ocular sarcoid may prevent visual loss, ACE may also be a useful ancillary diagnostic test when confronted by patients with iris nodules, acute iritis, conjunctival lesions, band keratopathy, chorioretinitis, periphlebitis, chorioretinal nodules, vitreous cells or hemorrhage, retinal or optic disc neovascularization, and lacrimal gland or optic nerve disease of unknown cause. Serum ACE provides an inexpensive, rapid, and reliable screening test for systemic sarcoidosis, especially in the presence of corroborative signs. Nevertheless, the definite diagnosis of sarcoidosis, either systemic or ocular, depends on histologic confirmation in the appropriate tissue. Since intraocular tissue is not easily obtainable, evaluation of serum ACE may prove to be a useful indicator of ocular sarcoid. SUMMARY
Sarcoid uveitis is usually a presumptive diagnosis based on the simultaneous presence of uveitis and clinicoradiographic or histologic findings of sarcoidosis. The elevation of serum ACE in some patients with granulomatous uveitis is strongly presumptive of sarcoid uveitis even in the absence of these findings. Serum ACE may prove to be a useful indicator of ocular sarcoid in the absence of otherwise undetectable systemic disease. REFERENCES
1. Lieberman J: A new confirmatory test for sarcoidosis. Serum angiotensin converting enzyme. Am Rev Respir Dis 109:743, 1974. 2. Silverstein E, Friedland J, Lyons H, et al: Serum angiotensin converting enzyme activity in sarcoidosis. Clin Res 23:352A, 1975.
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3. Woods AC: Endogenous Inflammation ofthe Uveal Tract. Baltimore, Williams & Wilkins Co, 1961, Chap 2. 4. Lieberman J: Elevation of serum angiotensin converting enzyme (ACE) level in sarcoidosis. Am J Med 59:365, 1975. 5. Silverstein, Friedland J, Kitt M, et al: Increased serum angiotensin converting enzyme activity in sarcoidosis. IsrJ Med Sci 13:995, 1977. 6. Silverstein E, Friedland J, Lyons H: Serum angiotensin converting enzyme in sarcoidosis: clinical significance. Isr J Med Sci 13:1001, 1977. 7. Lieberman J, Rea T: Serum angiotensin converting enzyme in leprosy and coccidiomycosis. Ann Intern Med 87:422, 1977. 8. Lieberman J, Beutler E: Elevation of serum angiotensin converting enzyme in Gaucher's disease. N Engl J Med 194:1442, 1976. 9. Studdy P, Bird R, James D, et al: Serum angiotensin converting enzyme (SACE) in sarcoidosis and other granulomatous disorders. Lancet 11:1331, 1978. 10. Shields J, Waring G, Monte L: Ocular findings in leprosy. AmJ Ophthalmol 77:880, 1974. 11. Pascual R, Gee B, Finch S: Serum lysozyme analysis in diagnosis and evaluation of sarcoidosis. N Engl J Med 289:1074, 1973. 12. Weinberg R, Tessler H: Serum lysozyme in sarcoid uveitis. Am J Ophthalmol 82:105, 1976. 13. Nosal A, Schleissner LX, Mishkin F, et al: Angiotensin converting enzyme and gallium scan in noninvasive evaluation of sarcoidosis. Ann Intern Med 90:328, 1979. 14. ObenaufC, Shaw H, Sydnor C, et al: Sarcoidosis and its ophthalmic manifestations. AmJ Ophthalmol 86:648, 1978.
DISCUSSION
DR IRVING H. LEOPOLD. Sarcoidosis is a generalized non-necrotizing granulomatous disease of unknown etiology characterized by depressed, cell mediated immunity, increased humoral immunoglobulin levels, granulomatous reaction to injected processed sarcoid tissue (Kveim-Siltzbach antigen) and apparent clinical manifestations, including uveitis, orbital masses, hyperealciuria and hyperprolactinemia. 1 In 1974,2 Lieberman noted raised concentrations of serum angiotensin converting enzyme (also called ACE) in 15 patients. This has been confirmed by other investigators such as Silverstein and his co-workers,3 and Fanberg and his co-workers.4 ACTION OF ENZYME
Serum angiotensin I converting enzyme is a metalloenzyme, a dipeptidyl carboxy peptidase, which catalyzes the conversion of decapeptide angiotension I to the pressor octapeptide angiotensin II and L-Histadyl-L-Leucine the terminal dipeptide. Serum angiotensin I converting enzyme also inactivates bradykinin. This serum angiotensin converting enzyme (ACE) is present in high concentrations in lung tissue and in the vascular bed of patients with sarcoidosis. It is found in high concentrations in non-necrotizing granulomatous lymph nodes of sarcoidosis patients. It is recognized that it is not a specific test for sarcoid but has value as an aid in diagnosis. Last year at this meeting in a discussion of a paper on orbital sarcoidosis by Nichols, Mishkin and Yanoff, Doctor Kimura raised the question of the potential value ofACE in confirming the diagnosis of sarcoidosis and this year Doctor Kimura
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and his co-workers have presented evidence that this test can be of value in sarcoid, which seems to be manifested primarily in the ocular structures. RELATED ENZYMES-MACROPHAGE ACTIVrTY
There appears to be a close correlation between serum lysozyme values and serum angiotensin converting enzymes. Silverstein and his co-workers found that lysozyme activity was also elevated in sarcoid lymph nodes.9 Serum angiotensin converting enzyme and serum lysozyme were significantly positively correlated in 16 sarcoidosis patients, suggesting a relationship between the two. The markedly elevated angiotensin converting enzyme in sarcoid granulomatous lymph nodes suggests the possibility of other biologically active and perhaps clinically significant molecules, eg, enzymes, may be elaborated in the granulomatous sarcoidosis. This may mean that serum ACE may be an indicator of high macrophage activity and the macrophages and epithelioid cells may be a souce of the ACE as well as other enzymes such as lysozyme. According to some investigators, a significant elevation of serum ACE occurs in approximately 60% ofactive sarcoidosis patients and tends to diminish with increasing duration of disease and in the majority of the patients who are on corticosteroid therapy.2.3'5,6 CORTICOSTEROID EFFECT
It is not yet clear whether there is any consistent corticosteroid effect on serum
ACE, for there are some patients on corticosteroid therapy for two to four years with elevated serum ACE values which in some instances are extremely high as reported by Fanberg.4 There is evidence in the literature that sarcoid granulomas may be actively synthesizing ACE and this results in the elevation of serum ACE levels. Apparently extensively fibrotic sarcoid lymph nodes have been analyzed and have shown normal or only slightly elevated ACE, suggesting that obliteration of granulomas in sarcoid lymph nodes diminishes their ACE content and that this obliteration may be related to the tendency to diminution of serum ACE with time. ACE was not elevated in tuberculous lymph nodes or in experimental granulomas, suggesting that elevation of ACE may have some specificity for the granulomas of sarcoidosis rather than being characteristic of all granulomas.79 NATURE OF ENZYME
It is not known whether the ACE found in sarcoid patients is the same as that found in other individuals. However, studies of ph activity, modulators, polycrylamidegel electrophoresis, and sephadex G-200 gel filtration have shown marked similarity of all the angiotensin converting enzymes. Perhaps the ACE of sarcoid is more heat labile than that found in normal lung or lymph node. It suggests a new possibility that an abnornal ACE may be present in sarcoidosis.
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CORRELATION WITH OTHER STUDIES
Studies by Stanislas-Leguern Marsax and Amoux demonstrated no statistical difference in serum ACE between groups of patients in radiological stages of mild to severe disease. Nor were the ACE values different in patients with disease durations of more than or less than two years. Neither the number of extra pulmonary organs involved nor immunoglobulin values nor ESR Kveim or Mantoux results had any relation to ACE levels. However, they did find that patients with granulomas on bronchial biopsy had higher ACE values than those without granulomas. They did bronchoalveolar lavage and found a much higher percentage of lymphocytes in the sarcoid patients than in controls. There was a significant correlation between the percentage of lymphocytes in the presence of bronchial granulomas in the bronchial biopsy specimen but there was no correlation between the percentage of alveolar lymphocytes and ACE activity. SITES OF SYNTHESIS OF ENZYME
Serum angiotensin is thought to be produced also by endothelial cells of blood vessels. SilversteinO has reported increased angiotensin converting values in lymph nodes and suggests that the sarcoid granulomas, particularly epithelioid cells, may be actively synthesizing ACE. It would be helpful to know the site of synthesis, storage, excretion of ACE and its relationship to the immunological disturbances. Does it suppress cell mediated immunity? ENZYME LEVELS IN OTHER DISEASES
Patients with various lung disorders include cystic fibrosis, emphysema, asthma, lung cancer, tuberculosis, and pulmonary fungal diseases were found to have reduced levels of serum ACE in comparison with healthy controls. The patients with active sarcoidosis had mean ACE levels of approximately twice that of the controls. By contrast, serum ACE was normal in sarcoidosis patients receiving therapeutic doses ofcorticosteroids or who had undergone spontaneous resolution of disease so that the elevated ACE levels appear to be associated with the active disease process and no.t to be a predisposing genetic factor. Other non-pulmonary granulomatous diseases including Hodgkin's, regional enteritis, ulcerative colitis, and cirrhosis of the liver were not associated with elevated serum ACE levels. It seems reasonable that a measurement of serum ACE may be useful as a test for confirming a diagnosis of active sarcoidosis. Dr Kimura and his co-workers have demonstrated that this may be a helpful diagnostic aid in sarcoidosis with predominating ocular manifestations. OTHER SUBSTANTIATING DIAGNOSTIC TESTS
Although the data is convincing, it possibly might be more conclusive if these patients also had confirmation provided by biopsy ofthe conjunctiva or the lacrimal
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gland or enlarged lymph node. A number of years ago working with Doctor Steven Rosenthal and Lewis Siltzbach at Mt. Sinai Hospital we were able to show that patients with ocular manifestations ofsarcoid often revealed positive lacrimal gland biopsies which permitted diagnosis of the disease much sooner than could be obtained by the Kveim-Siltzbach test and in whom roentgenograms and pulmonary changes were not yet significant, and in whom an enlarged lymph gland could not be obtained easily. OCULAR LEVEL OF ENZYME
It would also be helpful and informative to know the intraocular fluid levels of ACE in normal eyes as compared to those with varying activity of sarcoidosis and other forms of uveitis. Attempts to determine ifangiotensin I converting enzyme exists in normal aqueous humor of rabbits, dogs and monkeys by Ikemoto and Yamamoto were not successful. 13 Perhaps secondary aqueous humor will show the enzyme. It will be necessary to determine ifthis enzyme arises locally from macrophages, etc, or secondarily from the plasma. Tear analyses in our laboratories by Anderson and Richman have suggested the presence of measureable quantities of the ACE in normal eyes. One might wonder whether tear analyses might also be helpful in differentiating patients with sarcoid uveitis. INHIBrTOR OF ENZYME
It should be noted that there is an inhibitor of ACE.",2 A snake venom extract has been shown to inhibit ACE, in turn producing a drop in blood pressure in hypertensive patients, but this was orally inactive. Structural studies of the converting enzyme led to the synthesis of a similarly structured competitive inhibitor succinyl-L-Proline and successively more potent inhibitors which culminated in the synthesis of the orally potent captopril (Sq. 14.255 Squibb). One might wonder what such inhibition might do to sarcoid patients other than: decrease their angiotensin II by inhibition of converting enzyme; lead to accumulation of bradykinin by similar inhibition of Kininase II; inhibition of aldosterone secretion and sodium retention by a reduction of angiotensin III. SUMMARY
As in all fruitful research, many interesting questions are raised-Why, for example, do most active sarcoidosis victims not show hypertension? Is it because the degree of hypertension is related to the amount of substrate angiotensin I and not the amount of enzyme, or is there a natural increase of an inactivating enzyme ofthe increased ACE? Someone will no doubt determine the effect of captopril on the enzyme (ACE) levels in sarcoidosis. This is obviously a very stimulating presentation. REFERENCES 1. Turkington RW,
76:545, 1972.
Macindoe JH: Hyperprolactinemia in Sarcoidosis. Ann Intern Med
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2. Lieberman J: Elevation of Serum Angiotensin Converting Enzyme (ACE) Level in Sarcoidosis. AmJ Med 59:365, 1975. 3. Silverstein E, Friedland J, Lyons H, et al: Serum Angiotensin Converting Enzyme in Sarcoidosis. Klin Res 23:352, 1975. 4. Fanberg BL, Schoenberger MD, Bachus B, et al: Elevated Serum Angiotensin I Converting Enzyme in Sarcoidosis. Am Rev Respir Dis 114:525, 1976. 5. Silverstein E, Friedland J, Lyons H, et al: Markedly Elevated Angiotensin Converting Enzymes in Lymph Nodes Containing Non-Necrotizing Granulomas in Sarcoidosis. Proc Natl Acad Sci USA 73:2137, 1976. 6. Silverstein E, Friedland J, Lyons H, et al: Elevation of Angiotensin Converting Enzymes in Granulomatous Lymph Nodes and Serum in Sarcoidosis, Clinical and Possible Pathogenic Significance. Ann NY Acad Sci 278:498, 1976. 7. Osserman EF, Lawler OP: Serum and Urinary Lysozyme Muramidase (in Monocytic and Monomyelocytic Leukemia). J Exp Med 124:921, 1966. 8. Pascual RS, Gee JPL, Finch SC: Usefulness of Serum Lysozyme Measurement in Diagnosis and Evaluation of Sarcoidosis. N Engl J Med 289:1074, 1973. 9. Silverstein E, Friedland J, Ackerman T: Elevation of Granulomatous Lymph Node and Serum Lysozyme in Sarcoidosis and Correlation with Angiotensin Converting Enzyme. Am J Clin Pathol 68:219, 1977. 10. Gordon S, Todd J, Cohn ZA: In Vitro Synthesis and Secretion of Lysozyme by Mononuclear Phagocytes. J Exp Med 139:1228, 1974. 11. Brunner HR, et al: Oral Angiotensin Converting Enzyme Inhibitor in Long Term Treatment of Hypertensive Patients. Ann Intern Med 90:19, 1979. 12. Cushman DW, et al: Design of New Hypertensive Drugs: Potent and Specific Inhibitors of Angiotensin Converting Enzyme. Prog Cardiovasc Dis 21:176, 1978. 13. Ikemoto F, Yamamoto K: Renin-angiotensin System in the Aqueous Humor of Rabbits, Dogs and Monkeys. Exp Eye Res 27:723, 1978.
DR MORTON GOLDBERG. The angiotensin converting enzyme may well turn out to be a valuable diagnostic aid in assessing patients with signs of ocular sarcoid in the absence of signs of systemic sarcoid. I believe I interpreted the authors' data correctly when they showed that only 12 of 27 such patients had abnormally elevated values of ACE. But perhaps of even more diagnostic value is the serum lysozyme test. For example, Doctors Tessler and Weinberg of the Illinois Eye and Ear Infirmary showed in similar patients (that is, granulomatous uveitis suggesting ocular sarcoid in the absence of signs of systemic sarcoid) that 14 of 15 had an elevated serum lysozyme value. Until these data can be confirmed, perhaps the intelligent clinical course would be to obtain both enzyme tests and evaluate any such patients with both the ACE level and the serum lysozyme value. DR ANDREW P. FERRY. I should like to thank Doctors Weinreb and Kimura for calling to our attention the presence of altered levels of serum ACE in patients with sarcoidosis. Doctor Robert S. Weinberg, to whose work Doctor Goldberg alluded, is now with us in Richmond and has been studying serum lysozyme and serum ACE levels in patients with sarcoid uveitis. In 20 patients with sarcoid uveitis studied thus far, both serum lysozyme and ACE were elevated in 18. Ofthe two remaining patients, one had elevated serum lysozyme and the other had elevated serum ACE.
292 Weinreb et al Doctor Weinberg also has been studying tear enzymes in these patients. After having determined that ACE is present in tears, he found a remarkably high correlation between levels of ACE in the serum and in the tears of patients with sarcoid uveitis. In the normal population, tear lysozyme levels usually are very high, but this does not appear to be the case with tear ACE levels. It therefore seems that studying tear ACE levels in patients suspected of having sarcoid uveitis may provide a real payoff. DR STEVEN PODOS. There are other proteins associated with sarcoid which also can be studied by the people who are doing this, such as serum macrophage inhibiting factor and lysosyme. I believe that something nonspecific is responsible and further studies may clarify the situation.
DR SAIICHI MISHIMA. I would like to thank Doctor Weinreb for showing this very important test for the diagnosis of sarcoidosis. As I have shown in my slide on Behcet's disease, sarcoidosis is also a frequent disease entity in Japan and its diagnosis is a problem. The question we asked is with what degree of accuracy we can diagnose sarcoidosis from the ocular symptoms, inotherwords, whether we can give weight to certain ocular findings or combination of findings in the diagnosis. In this connection, we compiled 53 cases with so-called ocular sarcoidosis among which 33 cases were later diagnosed as having systemic sarcoidosis. No single ocular symptom could be highly correlated with the disease but a combination of bilateral disease and peripheral anterior synechia was found in 28 cases of sarcoidosis whereas in only 4 cases with this combination, the diagnosis could not be confirmed. The typical peripheral anterior synechia is shown here (slide). In conclusion, among symptoms of so-called ocular sarcoidosis, bilateral peripheral anterior synechiae are of significance for the diagnosis. DR ROBERT N. WEINREB. I would like to thank Doctor Leopold, Doctor Mishima, and the other distinguished members for their remarks. Doctor Leopold, we have detected small, but measureable ACE activity in aqueous samples obtained during cataract surgery in several non-sarcoid patients. We have also been fortunate to study a 35-year-old black woman with systemic sarcoid and granulomatous uveitis who underwent a peripheral iridectomy for secondary glaucoma. Serum ACE activity was elevated as was the ratio of (aqueous ACE activity)/(aqueous protein) compared with (serum ACE activity)/(serum protein). We have also examined a young white woman with granulomatous uveitis and undetectable systemic sarcoid whose ratio of (aqueous ACE activity)/(aqueous protein) was increased compared with (serum ACE activity)/(serum protein). These results may indicate that intraocular tissues or cells within them can synthesize or selectively concentrate ACE. To date, we have not investigated tear enzyme levels, but this could prove to be a useful screening test as Doctor Leopold has suggested. Doctor Goldberg and Doctor Ferry, elevations of serum lysozyme and serum ACE are closely associated in systemic sarcoid. Further, we have compared their
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activities in many cases of granulomatous uveitis with or without systemic sarcoid and have found them to be closely correlated. As Doctor Leopold mentioned in his discussion, we feel that serum lysozyme is too nonspecific a test; serum lysozyme activity is elevated in some entities that can be confused with ocular sarcoid. Doctor Podos, thank you for your comments. Perhaps, these may also prove to be chemical markers for ocular sarcoid. Doctor Mishima, we have not routinely gonioscoped patients with granulomatous uveitis looking for small "tented" peripheral anterior synechiae. You have suggested that these are frequently associated with ocular sarcoid, and it would be interesting to correlate their presence with ACE activity.
