RESUMEN
The aetiology of rheumatoid arthritis [RA] is largely unknown, however, a viral infective theory is becoming popular as a possible underlying cause. In the present study sera from twenty five patients with RA, eight osteoarthritis and sixteen health control subjects were examined for the presence of anti-rubella, anti-Epstein-Barr [EB] and antibodies to hepatitis B core [anti HBc] using haemagglutination-inhibition, direct haemagglutination and enzyme- linked immunosorbent assay [ELISA] respectively. Also, the level of circulating immune complex [CIC] was measured by the polyethylene glycol precipitation method. The aim of the present study is to assess the relationship between some antiviral antibodies and the clinical types and activity states of the rheumatoid disease. The data showed that anti-rubella antibodies were significantly higher in RA patients than control group, the higher the titre the more active is RA as evidenced from the positive correlation with the erythrocyte sedimentation rate [ESR]. No such findings were observed with neither ED or anti HBc antibodies. Interestingly, all seronegative patients were also negative for anti HBc antigen as well. The level of CIC was higher in RA patients than in control group with a positive significant correlation with the rheumatoid factor level. Anti-rubella antibodies seem to play a pathogenetic role in RA. The exact nature of which needs to be elucidated