Demonstration of anti-rubella antibody-secreting cells in rheumatoid arthritis patients

In the present study we describe a plaque-forming cell assay using erythrocytes coated with viral antigen, which detected anti-viral antibody-secreting cells against various viral antigens. These anti-viral antibody-secreting cell were studied in normal individuals with known viral infections and in rheumatoid arthritis patients. Rubella anti-viral antibody-secreting cells were present after induction in the peripheral blood of eight out of ten patients. No plaques were seen before induction. Synovial tissue of seven patients out of ten showed rubella-antigen-specific plaques before induction. In all three patients tested, the numbers of plaques increased after induction. The peripheral blood of only one patient showed plaque-forming cells against mumps virus and cytomegalovirus (CMV) antigen. No other patients showed any plaque against CMV, respiratory syncytial virus, mumps virus, measles virus, adenovirus, and varicella zoster virus antigens. The method appears to be promising in studying viral antibody-secreting cells in human immunopathology.