RESUMEN
OBJECTIVE: To determine the prevalence and clinical significance of human parvovirus B19 (B19) infection in patients with rheumatoid arthritis (RA). METHODS: One hundred patients with RA and 94 apparently healthy blood donor controls were enrolled for study. Plasma samples of patients and controls were examined for the presence of anti-B19-specific antibodies by ELISA. B19 DNA was detected in plasma and peripheral blood leukocyte (PBL) samples of all patients and controls as well as in synovial fluid cells of 38 RA patients by nested polymerase chain reaction. Disease activity and clinical manifestations were determined in RA patients with and without markers of B19 infection. RESULTS: IgM anti-B19-specific antibodies were detected in 24.0% of RA patients; B19 DNA was found in plasma and/or PBL, synovial fluid cells in 34.0% (34 patients); in 14.0% of the cases (14 patients) both markers were found. In blood donor controls, anti-B19 IgM antibodies were observed in 16.0% (15 donors) and B19 DNA in 6.4% (6 donors); all donors with detectable B19 genomic DNA were IgM-positive. The disease activity in patients with and without B19 infection was similar, while the frequency of clinical complications was significantly higher in the patients with anti-B19 IgM antibodies. Moreover, liver failure and sicca syndrome were observed in the viremic patients only. CONCLUSION: Our study confirms observations regarding a high prevalence of B19 DNA in patients with RA, and a possible role of this viral infection in the pathogenesis of RA.