Influence of HLA-DR alleles on rheumatoid arthritis: susceptibility and severity in Argentine patients.

OBJECTIVE: To determine the frequency of shared epitopes in our population of patients with rheumatoid arthritis (RA) and to investigate whether the presence of these alleles is associated with a more aggressive form of disease. METHODS: Demographic and clinical data were obtained from 140 patients with RA, 123 female, mean age 49.9+/-11.7 years and mean disease duration 9.4+/-6.3 years. Radiographs of both hands were taken and scored by Larsen's method. HLA-DR alleles were determined by PCR-SSP. The control group comprised 202 healthy ethnic-matched subjects. RESULTS: DR4 was significantly more frequent in patients with RA than controls, and was observed in 70/140 patients (50%) versus 47/202 controls (23.27%) (odds ratio 3.25, CI 1.99-5.35, Pcorr 5 x 10(-5)). Within DR4 subtypes *0404 and *0401 were the most commonly found (37.7 and 29%, respectively). DR3 and DR11 exerted a protective effect with significantly higher frequency in controls than in patients with RA. When patients were divided into 2 groups according to disease severity (radiographic score) the frequency of alleles with QKRAA and QRRAA sequences was similar in both groups. Although with lower frequency, subtype *1001 alone was significantly more frequent in the severe-condition group [7 (13.5%) vs 3 (3.4%), p = 0.03]. CONCLUSION: These results are in accordance with findings observed in Caucasians and differ from other Latin American populations. However shared epitope alleles failed to correlate with more severe disease with the exception of subtype *1001 which, although infrequent, was significantly more frequent in patients with relevant radiological damage.

Human immunodeficiency virus infection search for musculoskeletal manifestations and mimicking of rheumatologic disorders.

This study involved 50 human immunodeficiency virus (HIV)-positive patients in various stages of the disease to identify signs and symptoms suggestive of rheumatologic disorders and to determine how frequently such findings mimic rheumatologic pictures. Control subjects were 25 ambulatory HIV-negative patients with similar risk factors, mostly drug abuse. Although arthralgias and myalgias were reported in both groups, arthritis was only detected in the HIV-positive group. Twenty-four HIV cases presented two or more signs or symptoms suggestive of rheumatic disorders versus only six non-HIV cases (p < 0.04). Some features were suggestive of systemic lupus erythematosus, vasculitis-panarteritis nodosa, Sjögren's syndrome, Behcet's syndrome and rheumatoid arthritis, although no patients met criteria for these diseases. Reiter's syndrome was diagnosed in two (4%) HIV-positive patients. On correlating CD4 lymphocyte levels and rheumatic symptomatology, the more severely immunocompromised cases were found to present musculoskeletal manifestations with greater frequency. Potential HIV infection should be considered in differential diagnosis of questionable cases of rheumatic disease to avoid both misdiagnosis and the institution of therapies liable to worsen the immunodeficiency syndrome.