To study the role of cytomegalovirus (CMV) in the etiology of rheumatoid arthritis (RA).
Polymerase chain reaction (PCR), immunoperoxidase staining for CMV specific antigens, virus isolation and antibody assays were applied to study samples from patients with RA of less than one year's duration.
By PCR, CMV DNA was detected in granulocytes from 3 of 24 synovial fluid (SF) samples and in 10 of 43 peripheral blood samples of patients with RA. These figures are not significantly different from those observed for the control groups (reactive arthritis, other arthropathies, healthy individuals). By immunoperoxidase staining, no evidence for the CMV antigens was observed in the SF cells. All the virus isolations were negative, and the level of CMV specific circulating antibodies in RA was not different from that in the other groups.
In spite of the negative results, the potential role of CMV in the etiology of RA cannot be totally excluded on the basis of these results; the mutual contribution of the triggering agent and the host response in genetically susceptible individuals is discussed.