Disturbance of the Epstein-Barr virus-host balance in rheumatoid arthritis patients: a quantitative study.

Rheumatoid arthritis (RA), seronegative spondyloarthropathy (SA) and osteoarthritis (OA) patients receiving no steroid or disease-modifying therapy have been monitored, along with healthy controls, for their prevailing level of Epstein-Barr virus (EBV) infection using four independent indices of the EBV-host balance, levels of virus shedding in throat washings as measured by a cord-blood transformation assay of improved sensitivity, frequency of virus-infected B cells in the circulating blood as measured by the rate of 'spontaneous' transformation in limiting dilution cultures, antibody titres to viral antigens, and virus-specific cytotoxic T cell responsiveness as measured in the in vitro regression assay. All four parameters indicated significant disturbance of the virus-host balance accompanying RA, the range of values exhibited by RA patients as a group in each case extending beyond the normal control range in the direction of more active infection. However, observations with SA and OA patients suggested that such a disturbance may not be RA-specific.