THU0108 Antibodies to parvovirus b19 in rheumatoid arthritis and osteoarthritis

Background Parvovirus B19 may cause an acute or chronic polyarthropathy, which in many cases fulfils the criteria of the American College of Rheumatology for the diagnosis of rheumatoid arthritis (RA). Additionally, parvovirus B19 has been implicated in the pathogenesis of RA. Objectives The aim was to investigate the presence of antibodies to parvovirus B19 in patients with RA and osteoarthritis (OA). Methods In the study were included 50 patients with RA, 24 patients with OA and 26 healthy controls. In all patients IgG and IgM antibodies to parvovirus B19 were measured by indirect immunofluorescence. In patients found to be positive for IgM antibodies to parvovirus B19 results were further confirmed by Western blot. Results In 28 of 50 patients with RA (56%) and in 7/26 of the controls (26.9%) IgG antibodies to parvovirus B19 were detected (x2, p 0.05). In 11 of 50 patients with RA (22%) IgM antibodies to parvovirus B19 were detected and the results were further confirmed by Western blot, while in none of the patients with OA and in none of the controls were IgM antibodies observed (x2, p 0.05, respectively). Conclusion The prevalence of antibodies to parvovirus B19 was found to be increased in patients with RA as compared to controls. In patients with OA the prevalence of antibodies to parvovirus B19 was found to be comparable to that in controls. These results indicate either that infection with parvovirus B19 may be implicated in the pathogenesis of RA, as previously discussed in the literature, or that some cases of chronic polyarthropathy due to parvovirus B19 may have been misdiagnosed as rheumatoid arthritis.