Lymphocyte phenotype studies of rheumatoid arthritis patients treated with methotrexate.

Seventy nine patients with rheumatoid arthritis (RA) were monitored for 12 months. Forty eight individuals were treated weekly with a low dose of methotrexate (MTX), and 31 received nonsteroid antiinflammatory drugs (NSAID) only. The mean total dose of MTX was 413 mg with a range from 250 to 735 mg. The phenotype of lymphocytes was analyzed using double immunofluorescence and a panel of monoclonal antibodies. The clinical status of 33 MTX-treated patients improved, in 9 neither clinical nor laboratory improvement was noticed. Six patients were withdrawn from the study because of adverse reactions. We observed no changes in the percentage of CD3, CD4, CD8 and CD25 positive lymphocytes in both MTX and NSAID-treated groups. However, the percentage of CD19 positive cells significantly decreased during 12 month observation (15.1 +/- 6.5% v.s. 10.2 +/- 5.0, p < 0.01) in MTX-treated subjects. Moreover, this percentage increased (9.4 +/- 6.7% v.s. 17.1 +/- 1.1%, p < 0.01) in NSAID-treated patients.