Decrease of the OKT8 positive T cell subset in polymyalgia rheumatica. Lack of correlation with disease activity.

Peripheral T cell populations were investigated in 35 patients suffering from polymyalgia rheumatica. The total number of T cells was low compared with those of a control group of similar age (P less than 10(-3). This decrease was demonstrated by using both classic E-rosette and monoclonal antibody techniques (OKT3, and OKT4 + OKT8) and was shown to be secondary to a selective T8 defect (P less than 10(-9). There was no correlation between the decrease in T8 (a cytotoxic suppressor T cell subset) and steroid therapy, disease activity, and temporal arteritis, nor between this decrease and the T gamma percentage and the presence of circulating immune complexes (CIC). The T gamma cell percentage was low in the patient group (P less than 10(-5) and correlated with the presence of detectable CIC (P less than 0.05). In contrast to the T8 and T gamma defects, concanavalin A-stimulated cells from 5 selected patients were found capable of suppressing in vitro anti-trinitrophenyl response. This suppression was found in both autologous and allogeneic experiments. From these data one can assume that an immune anomaly (T8 defect) could be the origin of CIC and the disease occurrence.