535

ANTIBODIES TO DNA IN PATIENTS WITH RHEUMATOID ARTHRITIS AND JUVENILE RHEUMATOID ARTHRITIS CAROLYN BELL, NORMAN TALAL, and PETER H. SCHUR Antibodies to double-stranded DNA (DSDNA) were found in 18 patients with RA, in 5 patients with JRA, and in 5 patients with undiagnosed connective tissue disease. Five patients had clinical features consistent with both RA and SLE, 11 with only RA, and 5 with only JRA. Based on these observations, the presence of serum anti-DSDNA antibodies should not be used as a sole criterion in the diagnosis of SLE. Antibodies to double-stranded DNA (DSDNA) have been found in high titers in patients with systemic lupus erythematosus (SLE). T h e presence of

From the Department of Medicine, Harvard Medical School, Robert B. Brigham Hospital, Boston, Massachusetts, and the Section of Clinical Immunology and Arthritis, Veterans Administration Hospital and Department of Medicine, University of California, San Francisco, California. Supported by USPHS grants AM 11414, AM 05577, AM 12051, AM 5076, and AM 16140, and Research Support from the Veterans Administration. Carolyn Bell, M.D.: Research Fellow in Medicine, Harvard Medical School at the Robert B. Brigham Hospital, Boston, Massachusetts: Norman Talal, M.D.: Chief, Clinical Immunology and Arthritis Section, Veterans Administration Hospital, and Professor of Medicine, University of California, San Francisco, California; Peter H. Schur, M.D.: Associate Professor of Medicine, Harvard Medical School, and Physician, Robert B. Brigham Hospital, Boston, Massachusetts. Address reprint requests to Dr. Peter H. Schur, Robert B. Brigham Hospital, 125 Parker Hill Avenue, Boston, Massachusetts 02120. Submitted for publication October 15, 1974; accepted March 28, 1975. Arthritis and Rheumatism, Vol. 18, No. 6 (November-December 1975)

these antibodies is highly suggestive of SLE (1,2). As more sensitive tests have been developed, anti-DSDNA antibodies have been found occasionally i n patients with diseases other than SLE (3-8). Such antibodies have recently been observed in patients with rheumatoid arthritis (RA) and juvenile rheumatoid arthritis (JRA) (9). This paper describes a group of patients with RA, JRA, or connective tissue disease of unknown type who were found to have anti-DSDNA antibodies. Based on these observations it appears that the presence of anti-DSDNA antibodies cannot be used as a sole criterion for the diagnosis of SLE.

MATERIALS AND METHODS Chart Review Patients seen a t the Robert Breck Brigham Hospital whose sera were found to contain antibodies to DSDNA a n d whose clinical diagnosis was not systemic lupus erythematosus were included i n this study. T h e charts of these patients were then reviewed for those criteria recommended by the American Rheumatism Association for the diagnosis of RA, JRA, a n d SLE (10-12).

Immunoassays Antibodies to double-stranded DNA (DSDNA), single-stranded DNA (ssDNA), nucleoprotein (NP), and calf thymus nucleoprotein (CTN) were detected i n heatinactivated serum by the counterimmunoelectrophoresis technique previously described (9). Antibodies to DSDNA were quantitated using a cellulose ester filter radioimmunoassay (13). Antinuclear antibodies (ANA) were detected

BELL E T AL

536

Table 1. A R A Criteria for Rheumatoid Arthritis in Patients with Anti-DSDNA Antibodies Groups I ARA Criteria for RA

Sum of 4Groups

Morning stiffness Pain on motion of at least one joint Swelling of at least one joint Swelling of another joint Symmetrical swelling Subcutaneous nodules Rheumatoid factor test Poor mucin clot Synovial histology Rheumatoid nodule histology X-ray findings Number of positive ARA criteria for RA

22/24* 28/28 26/27 25/28 23/28 11/24 16/27 415 314 212 21/24 6

I1

I11

IV

SLE

RA

JRA

1Dx

515

4/5

213 515 314 315 1/5 013 0/5

o/o

11/11 13/13 13/13 12/13 13/13 7/13 11/13 212 2/2

111 414 7 (5-9)t

12/13 7 (6-9)

R A and

5/5

515 515 515 214 415 011

o/o

515

515 515 415 2/4 1/4

2/2 112 111 515 7 (5-10)

010 010 010

012 2 (2-4)

*Number positive per number examined. tRange.

by immunofluorescence using cryostat sections of snapfrozen mouse liver (14). Serial dilutions of sera were made whenever a positive reaction was detected in sera diluted 1 : l O . Polynucleotides were diluted i n 0.01 hi phosphatebuffered saline, p H 7.2 (PBS), and their concentrations were estimated by measuring optical density a t 260 p. Polynucleotides were aliquoted a t concentrations of 0.1 to I mg/ml and stored a t 4°C or -20°C. Nucleoprotein (NP) (Worthington Labs, Freehold, New Jersey) was dissolved i n PBS and usually sonicated. Deoxyribonucleic acid (calf thymus DNA) (Worthington Labs) was dissolved in PBS. Single-stranded DNA was prepared from DNA by heatdenaturation a t 100°C for 15 minutes, followed by immersion in a n ice bath. CTN was prepared from calf thymus nuclei as described by T a n and Kunkel (15). Serum complement levels were performed as previously described

('6).

RESULTS I n a 12-month period 7794 sera were examined for antinuclear antibodies by immunofluorescence. Of 277 sera from patients with SLE 42y0 were found to have precipitins to DSDNA, 56% to ssDNA, 23y0 to CTN, and 35y0 to NP. Of 448 sera from patients with RA 9% were found to have precipitins to DSDNA. Of 162 sera from patients with JRA 4% were found to have precipitins to DSDNA. I n all, there were 35 sera that had precipitins to DSDNA from 28 patients without evident clinical SLE. These patients were selected for further review based on the availability of their medical records, the adequacy of information in these medical records regarding diagnostic criteria for both RA and SLE, and the availability of more sera for further analysis.

T h e 28 patients in this study had an average of 6 ARA criteria for the diagnosis of RA and an average of only 2.5 criteria for SLE. T h e patients could be divided into four groups based on the number of criteria each had for RA and SLE: Group I, 5 patients who had 5 or more criteria for RA and 4 or more for SLE; Group 11, 13 patients who had 5 or more criteria for RA and less than 4 criteria for SLE; Group 111, 5 patients with JRA; and Group IV, 5 patients who had less than 5 criteria for RA and less than 4 criteria for SLE. Five patients were believed to have both classic RA and SLE (Group I) because they had an average of 7 criteria for RA and 6 criteria for SLE. All of these patients had morning stiffness, inflammation of many (including symmetrical) joints, and x-ray findings of demineralization, cartilage narrowing, erosions, and subluxations (Table 1). Two of the patients had subcutaneous nodules and 4 had a positive latex fixation test for rheumatoid factor. These patients also had a number of clinical features consistent with SLE (Table 2) such as skin lesions, hematologic abnormalities, and renal disease with proteinuria and cellular casts. Three patients had LE cells and all had high titers of ANA. Four patients had precipitins to ssDNA and one each to C T N and NP. T h e mean complement level was 150 CH,, U/ml with a range of 127 to 201 U/ml. T h e mean binding level for DNA was 81 cpm with a range of 15 to 201 cpm. Thirteen patients (Group 11) had features consistent with definite or classic RA (Table 1). All of the patients had morning stiffness and symmetrical inflam-

557

DNA ANTIBODIES I N RA AND JRA

Table 2. A R A Criteria for SLE in Patients with Anti-DSDNA Antibodies Groups

Criteria for SLE Butterfly rash Discoid lupus Raynaud's phenomenon AloDecia Photosensitivity Oral or nasopharyngeal ulceration Arthritis without deformity LE cells Chronic false-positive STS Profuse proteinuria Cellular casts Pleuritis or pericarditis Psychosis and/or convulsions Hemolytic anemia or leukopenia or thrombocytopenia ANA titer (mean) Precipitins to: DSDNA ssDNA CTN NP Binding to DNA (mean) Complement (CH,) levels (mean) Number of positive criteria for SLE (mean) ~

Sum of 4 Groups

I RA and SLE

I1

111

IV

RA

JRA

? Dx

2/22* 2/22 1/21 4/21 1/22 2/23 4/28 7ji9 0122 4/27 4/26 6/23 1/19

215 215 114 214 114 015 215 sj4 015 415 415 115 015

0/10 0/10 0111 1/10 0111 1/10 O/ 13 118 0111 O/ 13 o/ 12 2/ 10 1/10

014 oj4 0/3 113

013

014 115 215 015 015 015 214 o/ 1

013 013 014 014 114 115 112 011 014 014 114 013

11128 1/ 320

315 111280 (1:80-1:2560)f

118 11640 (1:4&1:2560)

215 11320 (1:8O-1: 1280)

015 1/80 (1:20-1: 160)

28/28 17/28 9/28 13/28 71 184 2.5

515 415 115 115 81 (15-201) 150 (127-178) 6 (5-7)

13/13

515 115 215 115 63 (27-130) 213 (185-232) 3 (1-4)

515 415 215 315 95 (18-193) 179 (141-266) l(1-3)

7/13 4/13 8/13 63 (8-188) 189 (131-268) 2 (1-3)

013

~~

*Number positive per number tested. tlange.

mation of multiple joints. Most patients had a positive latex fixation test for rheumatoid factors and xray findings of demineralization, cartilage narrowing, erosions, and subluxations. Many patients had palpable subcutaneous nodules of the elbows. Only a few of these patients had any features consistent with SLE; none had renal disease (Table 2). All of the patients had antinuclear antibodies, many in high titers. Many had antibodies to ssDNA, CTN, and/or N P in addition to antibodies to DNA. T h e mean CH,, level was 189 U/ml. T h e mean binding level for DNA was 63 cpm with a range of 8 to 188 cpm. JRA was diagnosed in 5 patients (Group 111) based on clinical features of polyarthritis, pericarditis, tenosynovitis, but primarily on an age of onset that was 14 years or less. I n addition 1 patient had features of spondylitis and 1 had features of Sjogren's syndrome. Furthermore these 5 patients had clinical symptoms and signs (Table 1) consistent with a diagnosis of definite or classic RA. Four had morning stiffness and all had inflammation of many (including symmetrical) joints. Two had subcutaneous nodules but only 1 had a positive latex fixation test. All had

x-ray findings of either demineralization, cartilage narrowing, subluxation, and/or erosions. These patients had few features consistent with SLE: 1 had alopecia, 2 had pleurisy, 2 had leukopenia, and 2 had LE cells. I n addition to anti-DNA antibodies, 1 patient had antibodies to ssDNA, 2 to CTN, and 1 to NP. T h e mean CH,, level was 213 U/ml. T h e mean binding level for DNA was 63 cpm with a range of 27 to 130 cpm. T h e fourth group of 5 patients (Group IV) was thought to have either possible SLE, RA, or connective tissue disease of unknown type. This group had a n average of only 2 criteria for RA (Table 1)primarily pain and swelling of a few joints. None had a positive latex fixation test, and x-rays, when taken, were negative. T h e patients had few features consistent with SLE: 1 patient had pleurisy and 1 had oral ulcers (Table 2). One patient had LE cells. ANA were present but not strikingly elevated. Many patients in this group had antibodies to ssDNA, CTN, and NP as well as to DNA. T h e mean binding level for DNA was 95 cpm, with a range of 18 to 193 cpm. T h e mean CH,, level was 179 U/ml.

BELL E T AL

538

DISCUSSION The data presented here suggest that antibodies to DSDNA can occur in patients who do not appear to have SLE but who have other related diseases. In the present study precipitins to DSDNA were found in 9% of sera from patients with RA, 47; of sera from patients with JRA, and 42y0 of sera from patients with SLE. Specificity of the reaction and demonstration that these precipitins represented antibodies were shown as follows: a) When sera that precipitated with DSDNA were absorbed with DSDNA, they no longer precipitated with DSDNA (9). b) T h e preparations of DSDNA did not appear to contain any (detectable) ssDNA as assessed by CIEP employing a rabbit antiserum to ssDNA that can detect as little as 0.03 Pg/ml of ssDNA. c) Digestion of DSDNA with desoxyribonuclease eliminated the reaction between sera antl DSDNA, whereas trypsin had no such effect. d) When CIEP plates were extensively washed with PBS and then stained with fluorescein-tagged antigamma globulin, the precipitin lines fluoresced (9). Antibodies to DSDNA are considered highly diagnostic for SLE and are found in the sera of most patients with SLE (17). These observations utilized several techniques, including double diffusion in agar (16), complement fixation (16), immunofluorescence (14), and hemagglutination (3). However, in utilizing these techniques, anti-DNA antibodies were also noted sporadically in patients with RA and related diseases (3-8). With the introduction of the more sensitive radioimmunoassays for DSDNA, a higher incidence of anti-DSDNA antibodies was noted in SLE patients (18,19). Furthermore these methods demonstrated that normal sera could bind a small amount of DSDNA. Hasselbacher and Leroy have observed that this binding by normal sera of DSDNA represents a true antigen-antibody reaction (20). T h e difference in antibodies to DSDNA between normals and patients with SLE therefore appears to be quantitative (20). O n the basis of the present study in which anti-DSDNA antibodies were found in 9% of RA patients and o n the observations of Johnson et al (21), who found antiDSDNA antibodies i n 16% of RA patients, it would seem that patients with RA have levels of antiDSDNA antibodies somewhere between those found in normals and those in patients with SLE. Thus the presence of anti-DSDNA antibodies cannot be used as an absolute criteria for the diagnosis of SLE. Rather it would appear that these antibodies are found in normal individuals, but increased levels

are found in patients with connective tissue disorders. T h e stiniiilus for this production is not known; however, in evaluating patients who may manifest one or more of the ARA criteria for SLE, the presence of anti-DSDNA antibodies should arouse strong suspicion of t h a t diagnosis. Baum and Ziff observed that patients with SLE had decreased levels of natural antibodies against E colt‘ antl Shigella and that SLE patients had significantly lower IgM antibody levels after active immunization with Brucella antigen than did normal people (22). I n contrast, Lee et a1 found no difference in humoral response to active immunization with Salmonella flagellin in patients with SLE antl RA and patients treated with azatliioprine as compared to normal matched controls (23). Bandilla also showed that patients with RA have a deficient IgM response to active immunization with keyhole limpet hemocyanin (24). Only after intense stimulation could adequate levels of IgM antibodies be achieved (24). However, patients with SLE develop high titers of IgG isohemagglutin antibody titers in response to injections with incompatible blood group antigens (25). Patients with SLE also have high titers of antiviral antibodies. Patients with RA and JRA have higher titers of IgG and IgM antibodies to IgG than do normal individuals or patients with osteoarthritis (26,27). These studies suggest that patients with SLE as well as with RA and JRA are capable of maintaining an enhanced antibody response to certain antigens. SLE and RA may well represent two groups of syndromes or diseases at different ends of a spectrum of related connective tissue disease. Because neither disease represents a well-defined homogeneous entity, and because both are characterized by somewhat similar clinical and immunologic features, it is not too surprising occasionally to see patients who manifest overlapping features said to be characteristic of one or the other. Which features can be said to be characteristic of SLE or RA? Are these two diseases? Do these diseases represent a broad spectrum, or are there occasionally patients who have both diseases, assuming that RA and SLE are separate entities? Of the 11 ARA criteria for RA (10) most are seen only in patients with RA; however “rheumatoid factors” and “x-ray findings” consistent with RA are occasionally seen in patients with SLE (28). A number of the 14 proposed ARA criteria for SLE have also been observed i n patients with RA. Raynaud’s phenomenon has been noted in 10% of patients with RA

539

DNA ANTIBODIES IN RA AND JRA

(29), and LE cells have been reported in from 0.6% to 24y0 of patients with RA (30,31). Glomerulonephritis is a common but not universal complication of SLE. Patients with RA rarely develop glomerulonephritis. Pollack et a1 noted lesions in renal biopsies consistent with lupus nephritis in 2 of 41 patients with supposed RA. Subsequent analysis of the clinical and laboratory data of these patients caused their physicians to change the diagnosis from RA to SLE. When autopsies were performed, however, Pollack found “rheumatoid” glomerulitis characterized by mild endothelial hyperplasia without significant epithelial cell changes and without exudative features in 6 of 16 patients with RA (32). Berman and Dubois noted renal lesions on biopsy consistent with early lupus nephropathy in 5 of 6 RA patients who did not appear clinically to have SLE but had positive LE preps (33). T h e authors therefore concluded that these patients probably had early SLE. Goldfine et al were unable to find any evidence of functional renal disease in 85 RA patients with positive LE preps (30). One must conclude that glomerulonephritis exists very rarely, if at all, in patients with RA. If a patient with RA has glomerulonephritis, the clinical and laboratory data should be reviewed carefully for the presence of another disease, eg SLE (alone or coexisting). Pulmonary complications develop frequently in patients with SLE or RA. T h e most common type of pulmonary involvement in patients with RA is pleurisy, usually without detectable pleural effusion; it has been noted i n 21y0 of patients with RA (34). Pleurisy occurs in 45y0 of patients with SLE; however pleural fibrosis has been noted in 83% of patients with SLE (35). Popper et a1 (36) found diffusion and radiologic abnormalities consistent with interstitial fibrosis in 10 of 30 F U patients, whereas none of 30 osteoarthritis patients was found to have this abnormality. I n contrast, Walker and Wright (37) noted x-ray changes of mottling and reticulation in only Zyo of 516 patients with RA. Eisenberg et al (38) estimated that only 3% of SLE patients have interstitial fibrosis. Acute pulmonary vasculitis has been observed in 19% of patients with SLE (35) but has been said to be. rare in patients with RA (34). T h e incidence of myocarditis or pericarditis in patients with SLE or RA is similar, 45Y0 and 30y0, respectively, when examined at autopsy (39,40). However clinical myocarditis in patients with RA is rare, but is found in 8% of patients with SLE (34,40). Pericarditis is found in 27% of patients with SLE and

29y0 of patients with RA (34,40). Therefore there appear to be few cardiopulmonary abnormalities that facilitate differentiation of patients with RA from those with SLE. Fries and Siegal (41) have also critically assessed the usefulness of the preliminary criteria for the classification of SLE. They found an individual ARA criterion in only 42y0 of patients diagnosed as having SLE. Furthermore they found that as many as 10% of patients with RA and 16% of patients with scleroderma could be diagnosed as having SLE by these ARA criteria. They felt that this lack of sensitivity diminished the effectiveness of the criteria. These studies point to the urgent need for more stringent criteria for RA, JRA, and SLE as well as for more specific serologic techniques to facilitate their diagnosis.

ACKNOWLEDGMENTS The authors wish to acknowledge the fine technical assistance of Ms. Lynda Wolfson and Ms. Diane DeAngelis.

REFERENCES 1. Ginsberg B, Keiser H: A millipore filter assay for anti-

2.

3.

4.

5.

6.

7.

8.

9.

body to native-DNA in sera of patients with SLE. Arthritis Rheum 16: 199-207, 1973 Lucian0 L, Rothfield NF: Patterns of nuclear fluorescence and DNA binding activity. Ann Rheum Dis 32: 337-342, 1973 Koffler D, Carr RI, Agnello V, et al: Antibodies to polynucleotides: distribution in human serums. Science 166:1648-1649, 1969 Sturgill BC, Carpenter RR, Strauss AJL, et al: Antibodies in systemic lupus erythematosus and myasthenia gravis which react with thermally denatured. DNAcoated bentonite. Proc SOCExp Biol 115:246-251, 1964 Bickel YB, Barnett EV, Pearson CM: Immunofluorescent patterns and specificity of human antinuclear antibodies. Clin Exp Immunol 3:641-656, 1968 Franco AE, Schur PH: Hypocomplementemia in rheumatoid arthritis. Arthritis Rheum 14:281-238, 1971 Robitaille P, T a n EM: Relationship between deoxyribonucleoprotein and deoxyribonucleic acid antibodies in systemic lupus erythematosus. J Clin Invest 523316323, 1973 Tan EM: An immunologic precipitin system between soluble nudeoprotein and serum antibody in systemic lupus erythematosus. J Clin Invest 46:735-745, 1968 Schur PH, DeAngelis D, Jackson JM: Immunological detection of nucleic acids and antibodies to nucleic acids and nuclear antigens by counterimmunoelectrophoresis. Clin Exp Immunol 17:209-218, 1974

540

10. Ropes M, Bennett GM, Cobb S: Revision of diagnostic criteria for rheumatoid arthritis. Arthritis Rheum 2: 16-20, 1959 11. Brewer EJ, Bass JC, Cassidy JT, et al: Criteria for the classification of juvenile rheumatoid arthritis. Bull Rheum Dis 23:712, 1972-1973 12. Cohen AS, Reynolds WE, Franklin EC, et al: Preliminary criteria for the classification of systemic lupus erythematosus. Bull Rheum Dis 21 :643-648, 1971 13. Attias MR, Sylvester RA, Tala1 N: Filter radioimmunoassay for antibodies to reovirus RNA in systemic lupus erythematosus. Arthritis Rheum 16:719-725, 1973 14. Gonzalez EN, Rothfield N: Immunoglobulin class and pattern of nuclear fluorescence in systemic lupus erythematosus. N Engl J Med 274: 1333-1338, 1966 15. T a n EM, Kunkel HG: Characteristics of a soluble nuclear antigen precipitating with sera of patients with systemic lupus erythematosus. J Immunol 96:464-471, 1966 16. Schur PH, Sandson J: Immunological factors and clinical activity in lupus erythematosus. N Engl J Med 278: 533-538, 1968 17. Levine L, Stollar BD: Nucleic acid immune systems. Prog Allergy 12:161-191, 1968 18. Wold RT, Young FE, T a n EM: Deoxyribonucleic acid antibody: a method to detect its primary interaction with deoxyribonucleic acid. Science 161:806-807, 1968 19. Pincus P, Schur PH, Rose JA, et al: Measurement of serum DNA-binding activity in systemic lupus erythematosus. N Engl J Med 281:701-707, 1969 20. Hasselbacher P,Leroy EL: Serum DNA-binding activity i n healthy subjects and in rheumatic disease. Arthritis Rheum 17:63-71, 1974 21. Johnson GD, Edmonds JP, Holborow EJ: Precipitating antibody to DNA detected by two-stage electroimmunodiffusion. Lancet 2:883-885, 1973 22. Baum J, Ziff M: Decreased 19s antibody response to bacterial antigens in SLE. J Clin Invest 48:758-767, 1969 23. Lee AKY, Mackay IR, Rowley MJ, et al: Measurement of antibody-producing capacity to Flagellin in man. Clin Exp Immunol 9:507-518, 1971 24. Bandilla KK, Pitts NC, McDuffie FC: IgM deficiency in immune response of patients with RA. Arthritis Rheum 13:214-221, 1970 25. Zingale SB, Sanchez Avalos JC, Andrado JA, et al: Appearance of anticoagulant factors and certain “autoimmune” antibodies following antigenic stimulation

BELL E T AL

with blood group substances in patients with SLE. Arthritis Kheum 6:581-598, 1963 26. Bianco NE, Panush RS, Stillman JS, et al: Immunologic studies of juvenile rheumatoid arthritis. Arthritis Rheum 14:685-696, 1971 27. Panush RS, Bianco NE, Schur PH: Serum and synovial fluid IgG, IgA and IgM anti-gamma globulins in rheumatoid arthritis. Arthritis Rheum 14:737-747, 1971 28. Kantor GL, Bickel YB, Barnett EV: Coexistence of systemic lupus erythematosus and rheumatoid arthritis. Report of a case and review of the literature with clinical, pathologic and serologic observations. Am J Med 47:433444, 1969 29. Short CL, Bauer W, Reynolds WE: Rheumatoid Arthritis. Cambridge, Harvard University Press, 1957 30. Goldfine LJ, Stevens MB, Masi AT, et al: Clinical significance of the LE cell phenomenon in rheumatoid arthritis. Ann Rheum Dis 24:153-160, 1965 31. Sigler JW, Monto RW, Ensign DC, et al: T h e incidence of the LE cell phenomenon in patients with RA (a 2 year study). Arthritis Rheum 1:115-121, 1958 32. Pollack VE, Pironi CI, Steck IE, et al: T h e kidney in rheumatoid arthritis studies by renal biopsy. Arthritis Rheum 5: 1-8, 1962 33. Berman LB, Dubois EL: Renal biopsy in rheumatoid arthritis with LE cells. Arthritis Rheum 5:283-284, 1962 34. Pearson CM: Rheumatoid arthritis and systemic manifestations. Ann Intern Med 65:llOl-1130, 1966 35. Gross M, Easterly JR, Earle R H : Pulmonary alterations in SLE. Am Rev Resp Dis 105:572-577, 1972 36. Popper MS, Bogdonoff ML, Hughes RL: Interstitial rheumatoid lung disease. Chest 62: 243-248, 1972 37. Walker WC, Wright V: Pulmonary lesions and rheumatoid arthritis. Medicine 47:501-529, 1968 38. Eisenberg H, Dubois EL, Sherwin RP, et al: Diffuse interstitial disease in SLE. Ann Intern Med 79:37-45, 1973 39. Lebowitz WB: T h e heart in rheumatoid arthritis (rheumatoid disease). A clinical and pathologic study of 62 cases. Ann Intern Med 55:102-123, 1963 40. Dubois EL: Lupus Erythematosus. Second edition. Los Angeles, University of South California Press, 1974, p p 268-270 41. Fries JF, Siege1 RC: Testing the preliminary criteria for classification of SLE. Ann Rheum Dis 32:171-177, 1973