Increase in OKM1+ granular lymphocytes in patients with rheumatoid arthritis.

Patients with very active rheumatoid arthritis that was being treated only with nonsteroidal antiinflammatory drugs had increased numbers of peripheral blood OKM1+ lymphocytes. In 3 patients, 90 degrees light scatter analysis revealed a double lymphocyte peak. When sorted, the high scatter peak contained a large percentage of granular lymphocytes. Patients with mild-to-moderately active rheumatoid arthritis had normal levels of OKM1+ lymphocytes, but when the drugs were discontinued, the activity of the disease and the numbers of OKM1+ cells increased. Administration of piroxicam was associated with clinical improvement and a decrease in levels of OKM1+ cells. OKM1+ granular lymphocytes are increased in some rheumatoid arthritis patients, and their numbers may correlate with clinical disease activity and/or therapy.