T cell cytotoxicity to Epstein-Barr virus infected B cells: comparison of patients with rheumatoid arthritis and their HLA identical siblings.

Specific T cell cytotoxicity to Epstein-Barr virus (EBV) infected B cells is reported to be abnormal in rheumatoid arthritis (RA). The regression phenomenon was used to determine whether the immunoregulatory defect in RA is restricted to T cells, B cells, or HLA type. Peripheral blood T and B cells from patients with RA and their HLA identical healthy siblings were mixed in varying ratios with and without EBV, and thymidine incorporation was measured on days 7, 14, and 21. The results suggest that the T cell abnormality is related to disease activity and that an inherent defect exists in the rheumatoid B cell which is independent of disease activity.