Multiple abnormalities in immunoregulatory function of synovial compartment T cells in patients with rheumatoid arthritis. Recognition of a helper augmentation effect.

Analyses of the synovial tissue and fluid T lymphocytes obtained from patients with rheumatoid arthritis revealed multiple functional defects in the regulation of autologous blood B cell differentiation into cells secreting immunoglobulin. These abnormalities were not found in peripheral blood T lymphocytes from the same patients. Although the patients selected showed elevated levels of T cells expressing the T8 differentiation antigen as well as Ia antigens there was little demonstrable suppression of the blood B cell differentiation. Furthermore, the synovial T cells exhibited only minimal helper or inducer activity when tested in the same system. In contrast, patient's blood T lymphocytes gave levels of help and suppression that were not distinguishable from that of normal individuals. Co-culture experiments of blood and synovial T lymphocytes did not reveal any evidence for enhanced suppression; indeed, in most patients these co-cultures resulted in marked augmentation of helper function, a phenomenon designated "helper augmentation". These data provide evidence that rheumatoid synovial lymphocytes are characterized by marked abnormalities in immunoregulatory T cell function, including divergence of cellular activity from the immune function predicted by surface phenotype and a capacity for "helper augmentation", a novel T cell function in man.