Correlative studies of rheumatoid factors and anti-viral antibodies in patients with rheumatoid arthritis.

An analysis of the relationship between the immune response to ubiquitous herpes family viruses, namely Epstein-Barr virus (EBV), cytomegalovirus (CMV), and varicella-zoster virus (VZV) and the presence of rheumatoid factors (RF), which are autoantibodies characteristic of patients with rheumatoid arthritis (RA), was conducted. Antibody profiles (RF, anti-viral antibodies) were monitored in the serum of the RA patients, and in normal individuals. No patient was found to have circulating RF in the absence of anti-viral antibodies. When the patients and normal controls were subdivided according to the presence of serum RF, it was found that when RF were present, the frequency of anti-CMV antibodies, but not anti-EBV or anti-VZV antibodies, was significantly higher (P = 0.02) when compared with RF-negative individuals. The titres of anti-CMV but not anti-VZV antibodies were found to increase in the RA patients with disease duration. To see if these viruses could stimulate RF production in vitro, peripheral blood mononuclear cells (PBMC) isolated from the patients and normal controls were stimulated with viral antigens. PBMC from normal controls, but not from RA patients, appeared to be responsive to viral antigen stimulation and produced RF. These data suggest that the immune response to CMV, to a greater extent than to EBV or VZV, correlates with the presence of RF.