Impaired killer cell generation in the autologous mixed leukocyte reaction by rheumatoid arthritis lymphocytes.

Natural killer-like cells are generated along with interleukin-2 (IL-2) in the autologous mixed leukocyte reaction (AMLR). Patients with active rheumatoid arthritis (RA), but not those whose disease is in remission, are poor producers of AMLR killer cells. This defect cannot be explained by age, medications, or serum factors. The impaired generation of natural killer-like cells was not influenced by gamma-interferon but could be partially restored by addition of indomethacin to the AMLR culture, or by culturing RA T cells with exogenous IL-2. However, the response of RA T cells to IL-2 was significantly less than that of controls. These results suggest that the defect in the generation of AMLR killer cells in patients with active RA may be due in part to defective production of IL-2 and a lesser sensitivity of RA T cells to IL-2.