A study of the role of parvovirus B19 in rheumatoid arthritis

Serum and synovial tissue from 26 patients with rheumatoid arthritis (RA) (according to the diagnostic criteria of the American Rheumatism Association) and 26 patients with osteoarthritis (OA) were examined. Among the RA group, the female to male ratio was 4.2:1, and the age range was 44-82 yr with a mean of 64.0 yr; joints from which synovium was sampled were hip (n = 12), knee (n = 9), ankle (n = 3) and shoulder (n = 2). The duration of rheumatoid disease ranged from 6 to 24 yr with a mean of 13.9 yr. Among the OA group, the female to male ratio was 2.25:1, and the age range was 51-88 yr with a mean of 68.2 yr; joints from which synovium was sampled were hip (n = 18) and knee (n = 8). Twenty-one patients from the RA group and 20 patients from the OA group had evidence of previous parvovirus B19 infection (serum anti-B19 IgG), and all patients from both groups were serum anti-B19 IgM negative. Synovial sections from all 52 patients were stained with mouse monoclonal antibodies, 3H8 (to B19 capsid proteins) and alpha-P (to blood group P antigen). All tissue sections examined were found to be negative for both B19 capsid proteins and blood group P antigen. Using a nested polymerase chain reaction (PCR) assay, all patients were negative for serum B19 DNA. However, B19 DNA was demonstrated in the synovium of 10 of 26 RA patients and 9 of 26 OA patients; uncorrected chi 2 value = 0.08; degrees of freedom = 1; P = 0.77. All 19 patients testing positive for synovial B19 DNA had evidence of prior exposure to B19 infection (serum anti-B19 IgG). In conclusion, although there is published evidence of chronic rheumatoid-like arthropathy following acute parvovirus B19 infection, our findings do not support the involvement of B19 in the aetiopathogenesis of RA.