Clinical and immunogenetic characterization of Mexican patients with 'rhupus'

The coexistence of systemic lupus erythematosus and rheumatoid arthritis (rhupus), is a rare clinical condition. To date, 50 cases of rhupus have been described worldwide; however, the lack of clinical criteria for this rheumatic condition has created confusion in the characterization of this disorder. Nevertheless, in this paper we describe a comprehensive clinical and serological characterization of a cohort of 22 Mexican patients with rhupus, supported by generic HLA-DR phenotyping. We found that rhupus patients have a special clinical behavior. In this setting, the signs and symptoms of rheumatoid arthritis prevail, little organic damage associated with systemic lupus erythematosus (SLE) exists and none of the cases present thrombosis or morbidity during pregnancy in spite of presenting a high frequency of anticardiolipin antibodies. We also found an increased frequency of HLA-DR1 and HLA-DR2 alleles compared to healthy ethnically matched controls, systemic lupus erythematosus and rheumatoid arthritis patients.     

Measurement of anticardiolipin antibodies and its significance in systemic lupus erythematosus

A method for detection of anticardiolipin (ACL) antibodies with enzyme-linked immunosorbent assay was developed. Microtitre plates were coated with cardiolipin at a concentration of 20 micrograms/ml by evaporation under 4 degree centigrade overnight. Non-specific binding of diluted sera was eliminated by blocking of plates with 10% fetal calf serum in phosphate buffered saline (FCS/PBS) for 2 hours at room temperature. Sera (50 microliters/well) at a dilution of 1:100 were incubated for 2 hours at room temperature. Horseradish peroxidase conjugated rabbit anti-human IgG, IgM, IgA at a dilution of 1:2000, 1:1000, 1:500 respectively was added to the wells, and incubated for one and half hours at room temperature. The results were read at 490nm after incubation with substrates at 37 degree centigrade. 85 patients with systemic lupus erythematosus (SLE), 45 with rheumatoid arthritis (RA), 25 with progressive systemic scleroderma (PSS), and 18 primary Sjogren's syndrome were tested. The frequency of ACL antibody in SLE (48%) was much higher than that in RA (11%), PSS (12), SS (5.5). Three isotypes of ACL (IgG, IgM, IgA) were detected in the study with predominance of IgG isotype. ACL antibody was significantly associated with thrombosis, cutaneous vasculopathy, thrombocytopenia, and spontaneous abortion in patients with SLE. Strong relationship between ACL antibody and lupus anticoagulant was found. There was no correlation between ACL and anti-DNA antibodies, nor was ACL and VDRL test. The level of ACL antibody could be reduced by use of corticosteroids.     

Antiphospholipid antibodies in the connective tissue diseases: their relation to the antiphospholipid syndrome and forme fruste disease

Anticardiolipin antibodies (aCL) were measured in the sera of patients with different connective tissue diseases and spondyloarthropathies. Elevated antibody binding was found in systemic lupus erythematosus (SLE), rheumatoid arthritis, scleroderma, primary sicca syndrome, dermatopolymyositis and psoriatic arthritis but not in ankylosing spondylitis. The 15 highest binding SLE patients included 10 with Raynaud's phenomenon, 5 with livedo reticularis, 7 with vasculitis, 3 with major thrombotic episodes and 3 with spontaneous abortions. aCL were also measured in patients with these clinical features in isolation. Seven of 18 patients with multiple thromboses and 3/22 with multiple spontaneous abortions had raised aCL binding. Normal or near normal levels were found in patients with idiopathic thrombocytopenia, livedo reticularis, a single cerebral thrombosis and uncomplicated myocardial infarction.     

IgM anti-dsDNA antibodies in systemic lupus erythematosus: negative association with nephritis

Antibodies against dsDNA of the IgM class were measured in sera of 352 patients with systemic lupus erythematosus, 81 blood donors and 189 patients with rheumatoid arthritis using a new ELISA based on human recombinant dsDNA as antigen. IgM anti-dsDNA antibodies were found in 52.3% of the sera from patients with systemic lupus erythematosus, but in none of the sera from 81 normal controls and 189 patients with rheumatoid arthritis. The association of these autoantibodies with 31 clinical and 37 laboratory parameters was calculated. There was a highly significant negative correlation between IgM anti-dsDNA antibodies and nephritis as well as all the laboratory parameters indicating renal disease (elevated serum creatinine concentration, proteinuria, erythrocyte casts in the urine). IgM anti-dsDNA antibodies indicate protection of lupus patients against the development of lupus nephritis. Further experiments will show whether application of IgM anti-dsDNA antibodies is effective in treating lupus nephritis. Received: 10 August 1998 / Accepted: 11 September 1998     

Antibodies to and elevations of beta 2 microglobulin in the serum of ankylosing spondylitis patients

Antibodies to beta 2 microglobulin are found in systemic lupus erythematosus patients and are important in the lymphocytotoxic reactions of sera from such patients. In this study, beta 2 microglobulin antibodies were measured with the use of an enzyme-linked immunosorbent assay with purified beta 2 microglobulin antigen and peroxidase-labeled anti-human IgG or IgM. IgG antibodies to beta 2 microglobulin were found in 68% of 22 patients with ankylosing spondylitis. This incidence was higher than the 5% in 80 controls (P less than 0.01) and similar to the 71% incidence found in 35 patients with systemic lupus erythematosus. Eleven (27%) of 41 patients with rheumatoid arthritis had elevated levels of antibodies to beta 2 microglobulin (P less than 0.01). The mean antibody levels expressed in enzyme units were 0.125 for patients with ankylosing spondylitis, 0.157 for those with systemic lupus erythematosus, 0.101 for those with rheumatoid arthritis, and 0.067 for controls. IgM anti-beta 2 microglobulin was not significantly different from controls. A competitive binding assay with enzyme-labeled beta 2 microglobulin was used to determine serum beta 2 microglobulin. These values were also found to be elevated in 48% of patients in all 3 disease categories (P less than 0.01). Beta 2 microglobulin antibodies and serum beta 2 microglobulin did not correlate with each other, renal diseases or antinuclear antibodies in patients with systemic lupus erythematosus, with rheumatoid factor or severity of articular disease in patients with rheumatoid arthritis, or with peripheral arthritis or iritis in those with ankylosing spondylitis. Although antibodies to beta 2 microglobulin might reflect a general disturbance of immune regulation in patients with systemic lupus erythematosus, their presence in those with ankylosing spondylitis, a disease closely associated with a specific HLA allotype and not usually associated with formation of autoantibody, suggests that they might play a role in the pathogenesis of the latter disease.     

Reassessing the status of antiphospholipid syndrome in systemic lupus erythematosus.

The antiphospholipid syndrome was initially described in 1986. To reassess the validity of antiphospholipid antibodies in systemic lupus erythematosus (SLE), 95 patients with SLE were studied. Their antiphospholipid antibody profile was analysed and correlated with clinical findings such as thrombosis, abortions, or thrombocytopenia. A low prevalence of these antibodies was found (13 patients; 14%) with a high specificity for thrombosis (92%) and abortions (92%). The importance of anticardiolipin antibodies as a risk factor for thrombosis or abortions, or both, in patients with SLE is reaffirmed by this work.     

Skin basement membrane immunofluorescence in rheumatoid arthritis

Thirty-nine patients with rheumatoid arthritis were studied for the presence of skin basement membrane immunofluorescence. Punch biopsies from normal sun-exposed skin of the forearm were negative for basement membrane immunofluorescence in all cases, except one which was read as questionable. No correlation with serum antinuclear antibody or lupus erythematosus cells was observed. Skin immunofluorescence studies are helpful in differential diagnosis when patients with a clinical picture of rheumatoid arthritis present with serum antinuclear antibodies and lupus erythematosus cells. Positive basement membrane immunofluorescence is strong evidence of systemic lupus erythematosus.     

Skin basement membrane immunofluorescence in rheumatoid arthritis: lack of diagnostic correlation.

Thirty-nine patients with rheumatoid arthritis were studied for the presence of skin basement membrane immunofluorescence. Punch biopsies from normal sun-exposed skin of the forearm were negative for basement membrane immunofluorescence in all cases, except one which was read as questionable. No correlation with serum antinuclear antibody or lupus erythematosus cells was observed. Skin immunofluorescence studies are helpful in differential diagnosis when patients with a clinical picture of rheumatoid arthritis present with serum antinuclear antibodies and lupus erythematosus cells. Positive basement membrane immunofluorescence is strong evidence of systemic lupus erythematosus.     

Anti-citrullinated peptide antibodies in lupus patients with or without deforming arthropathy

The objective was to study the association of antibodies against cyclic citrullinated peptides (anti-CCP) in patients with lupus articular damage. We studied 34 systemic lupus erythematosus patients (30 women) with (n = 14) or without (n = 20) deforming arthropathy. Anti-DNA and arthritis were mandatory inclusion criteria for both groups. As controls, 34 patients with rheumatoid arthritis and nine patients with rheumatoid arthritis and systemic lupus erythematosus (rhupus) were included. Anti-CCP and rheumatoid factor were determined by ELISA and nephelometry respectively. All patients had recent x-ray films of the hands that were evaluated according to Sharp's method. Systemic lupus erythematosus patients had a mean 6.50 +/- 0.86 (SD, range 5-8) American College of Rheumatology (ACR) criteria, rheumatoid arthritis patients met 5.38 +/- 0.60 (range 4-6) ACR criteria for rheumatoid arthritis and rhupus patients had 5.78 +/- 0.44 (range 5-6) criteria for rheumatoid arthritis and 5.11 +/- 0.78 (range 4-6) for systemic lupus erythematosus. Systemic lupus erythematosus patients, with or without deforming arthropathy, had normal serum anti-CCP concentrations. In contrast, rheumatoid arthritis and rhupus patients had 30- and 23-fold higher than normal amounts of anti-CCP (p < 0.001, both comparisons). Rheumatoid arthritis (97%) and rhupus (100%) patients were more frequently positive for anti-CCP than SLE patients with (7%) or without (5%) deforming arthropathy (p < 0.001, both comparisons). Patients with lupus deforming arthropathy were more frequently positive for rheumatoid factor (65%) than patients with non-deforming arthritis (15%) (p = 0.005). Patients with lupus deforming arthropathy had similar frequency of erosions and mean Sharp's score than rhupus patients. Anti-CCP antibodies do not associate with lupus arthropathy, whether deforming, non-deforming or erosive.     

Immunoglobulin deposits in the dermo-epidermal junction zone in patients with systemic lupus erythematosus. Rheumatoid arthritis and temporal arteritis compared by serological testing including alpha2-macroglobulin.

In biopsies from normal-looking skin, immune complexes in the dermo-epidermal junction zone were found by a direct immunofluorescence technique in 14 of 17 patients with systemic lupus erythematosus, in 6 of 12 patients with rheumatoid arthritis, but in none of 10 patients with temporal arteritis and 25 normal controls. Blood samples were obtained simultaneously from all patients and high titres of IgG organ-nonspecific antinuclear factors with complement-fixing properties were found to be closely related to systemic lupus erythematosus. IgG granulocyte-specific antinuclear factors were related with rheumatoid arthritis, while high concentrations of plasma fibrinogen were characteristic of temporal arteritis. No significant increases or differences in blood values of alpha2-macroglobulin were found between the groups and no correlation was found with deposits in the skin.     

Antiphospholipid antibodies in mixed connective tissue disease

Summary We studied the prevalence and clinical significance of antiphospholipid antibodies (ab) in 28 patients affected with well-defined mixed connective tissue disease (MCTD). Forty-two patients affected with systemic lupus erythematosus (SLE) and 60 healthy subjects were also evaluated, as controls. In MCTD the prevalence of anticardiolipin (aCL) ab was: IgG high level 17.8% (p<0.01 versus healthy controls), IgG low level 7.1% and IgM high level 7.1%. No patients had low level of aCL IgM, lupus anticoagulant or false positive VDRL. The aCL profile was similar to that found in SLE patients, but in SLE all prevalences were higher than in MCTD. Furthermore, in MCTD patients the aCL ab were correlated with thrombocytopenia but not with recurrent thrombosis and/or abortions.     

The binding of antihistone antibodies to Crithidia luciliae kinetoplasts is growth cycle-dependent

The Crithidia luciliae immunofluorescence (CLIF) assay is widely used to test for native DNA (nDNA) antibodies in the diagnosis and management of systemic lupus erythematosus. However, sera from patients with drug-induced lupus erythematosus or rheumatoid arthritis, which should not contain nDNA antibodies, occasionally react with the CL kinetoplast. We examined 36 sera from patients with systemic lupus erythematosus, rheumatoid arthritis, Sj?gren's syndrome, and drug-induced lupus erythematosus, who had positive CLIF tests. All 36 sera were also antinuclear antibody-positive with homogeneous and/or peripheral staining patterns on mouse kidney substrates. After hydrochloric acid extraction of the CL smears to remove histone and other nuclear protein antigens, 14 of the 36 sera no longer produced a positive result on the CLIF test. Ten of these 14 sera again gave a positive CLIF result after the hydrochloric acid-extracted Crithidia substrate had been reconstituted with purified histone. These studies demonstrated that kinetoplast binding was due to antihistone antibodies in at least 10 of 36 initially CLIF-positive sera. Antihistone antibodies were then purified with a histone-affinity column, and these purified antibodies were reactive with CL kinetoplasts. Thus, the CLIF test is not specific for nDNA antibodies. Additional studies using CL from different days of culture indicated that histone antigen expression in the CL kinetoplast was a function of the life cycle of this organism and is most readily detected 2 days after initiation of culture.     

Nailfold capillary microscopy in connective tissue disease: a quantitative morphological analysis.

Photomicrographs were taken of front line nailfold capillary loops in 18 healthy women (controls) and 42 women with established connective tissue disease (14 rheumatoid arthritis, 19 systemic lupus erythematosus, nine scleroderma). Measurements were made of apex width, maximum limb and loop widths, capillary length, interpeak distance, and frequency per linear millimetre. A numerical index for assessing capillary dilatation was derived, based on the mean of the apex plus maximum limb widths. Results show considerable overlap in subject means. Statistical analysis showed no difference between rheumatoid arthritis and control groups. Patients with systemic lupus erythematosus had slightly larger loops at a lower frequency (not statistically significant); three patients with an abnormal capillary index also had high titres of ribonucleoprotein antibody. Six scleroderma patients had abnormal indices, two of whom had high titre ribonucleoprotein antibody. No relation between capillary morphology and clinical features was found.     

Antiphosphatidylethanolamine antibody as the sole antiphospholipid antibody in systemic lupus erythematosus with thrombosis.

A previously healthy 34-year-old woman, was diagnosed as having systemic lupus erythematosus (SLE), with membranous glomerulopathy which improved rapidly. Neither lupus anticoagulant nor anticardiolipin antibodies were detected in her plasma. After three months of total remission, she developed a severe pulmonary thromboembolism for which no specific biological cause was found. Her plasma was analysed for different antiphospholipid antibodies: lupus anticoagulant and anticardiolipin antibodies were again negative. Using an ELISA prepared with either five different anionic phospholipids or zwitterionic phosphatidylethanolamine, solely an anti-phosphatidylethanolamine IgG was discovered in her plasma. In lupus patients, the presence of antiphospholipid antibodies is now well recognized as a high risk factor for repeated thrombosis and/or recurrent abortions. This case suggests that the presence of antiphosphatidylethanolamine antibody should be investigated in cases of unexplained thrombosis in SLE, where the usual clinical and biological investigations have failed to shed light.     

Connective tissue diseases in the hospital outpatient service in Lomé (Togo)

PURPOSE: There have been few studies of connective tissue diseases in Africa. METHODS: A retrospective study was conducted in order to describe the various connective tissue diseases and their semiological profile in patients attending the dermatology and rheumatology units at Lomé hospital. RESULTS: Clinical examinations showed that eighty-four (0.2%) out of the 34,169 patients were suffering from connective tissue diseases. Diseases that were encountered were the following: scleroderma (18 cases), systemic lupus erythematosus (four cases), discoid lupus erythematosus (15 cases), rheumatoid arthritis (29 cases), polymyositis and dermatomyositis (16 cases), juvenile rheumatoid arthritis (one case), giant cell arteritis (one case). Raynaud's syndrome was present in six out of the 18 patients suffering from scleroderma. Nephrotic syndrome was observed in a patient suffering from systemic lupus erythematosus. A septicemia caused this patient's death. Two patients suffering from polymyositis had cancer. No etiology was found in the 14 other patients. Hip involvement was present in two patients suffering from rheumatoid arthritis. Patients with rheumatoid arthritis had no systemic involvement (nodulitis, vasculitis). CONCLUSION: Our results are in agreement with those of previous studies on connective tissue diseases in Africa. However, further studies are required to better understand the epidemiological and semiological profiles of connective tissue diseases in Africa.     

Demonstration of increased influenza-A-antibody levels in the serum of patients with chronic polyarthritis

Patients with rheumatoid arthritis show increased levels of anti-influenza-A antibodies in their sera compared to healthy controls and patients with other inflammatory rheumatic diseases (systemic lupus erythematosus, ankylosing spondylitis and psoriatic arthritis). These antibody levels are dependent on the activity of rheumatoid arthritis.     

Determination of autoantibodies to annexin XI in systemic autoimmune diseases

Annexin XI, a calcyclin-associated protein, has been shown to be identical to a 56,000 Da antigen recognized by antibodies found in sera from patients suffering from systemic autoimmune diseases. In this work hexahistidine-tagged recombinant annexin XI (His6- rAnn XI) was used as antigen in ELISA experiments for determination of autoantibodies to annexin XI in sera of patients with systemic rheumatic autoimmune diseases. Immunoblotting with HeLa cell extract and with His6-rAnn XI as antigen was used for confirmation of positive ELISA results. We found eleven anti-annexin XI positive sera (3.9%) out of 282 sera from patients with systemic rheumatic diseases. The highest number of annexin XI positive sera were found in primary antiphospholipid syndrome (3/17), and in subacute lupus erythematosus (1/6), while lower frequencies of positive sera were found in patients with systemic sclerosis (5/137), rheumatoid arthritis (1/21), and systemic lupus erythematosus (1/58). Sera from healthy donors and patients with chronic infections were negative, except for one Salmonella typhimurium antibody positive serum. Autoantibodies to annexin XI were found to relate to thrombosis, but not to other clinical or laboratory features. A relation between antibodies to annexins and thrombosis has so far only been known for annexin V.     

Antibodies to Sm and RNP. Prognosticators of disease involvement

The charts of 150 consecutive patients found to have antibodies to Sm, ribonucleoprotein (RNP), or both were examined to determine these antibodies' possible associations with certain clinical conditions as well as their diagnostic specificities. Patients with anti-Sm were more likely to have renal disease and antibodies to double-stranded DNA, single-stranded DNA, and nuclear protein than were patients with anti-RNP. No clinical associations were found for anti-RNP. Although most of the patients with antibodies to Sm, RNP, or both had systemic lupus erythematosus, some had other diagnoses, including cutaneous lupus, drug-induced lupus, rheumatoid arthritis, juvenile arthritis, mixed connective tissue disease, Raynaud's disease, progressive systemic sclerosis, miscellaneous rheumatic and nonrheumatic diseases, and undifferentiated connective tissue disease syndromes. These findings suggest that these antibodies may be associated with some diseases, but are not disease-specific.     

Antibodies to protein P in systemic lupus erythematosus.

A synthetic peptide was used to develop an enzyme linked immunosorbent assay (ELISA) to detect antibodies to the ribosomal proteins P0, P1, and P2. Significantly increased levels of IgG antibodies to protein P were found in 16% (18/116) of patients with systemic lupus erythematosus but slightly increased levels were detected in 2% (2/98) of patients with rheumatoid arthritis and one normal control subject. No association was observed between the presence of IgG antibodies to protein P and either lupus psychosis or depression. Sequential studies in individual patients failed to show an association between antibody levels and the development of psychosis.     

Serotonin content of platelets in inflammatory rheumatic diseases

Significantly decreased platelet serotonin contents were measured in rheumatoid arthritis, systemic lupus erythematosus (SLE), progressive systemic sclerosis, and mixed connective tissue disease. An inverse relationship between platelet serotonin levels and clinical disease activity was observed in both rheumatoid arthritis and systemic lupus erythematosus. SLE patients with multiple organ involvement showed the lowest platelet serotonin values. No correlation was observed between platelet serotonin contents and nonsteroidal antiinflammatory drug treatment, presence of circulating platelet reactive IgG, or the amount of circulating immune complexes. The results are interpreted as indicating platelet release occurring in vivo during inflammatory episodes of the rheumatic disorders investigated.