Effects of piroxicam and D-penicillamine on T lymphocyte subpopulations, natural killer cells and rheumatoid factor production in rheumatoid arthritis.

The effects of piroxicam and D-penicillamine on T lymphocytes, NK cell activity and rheumatoid factor production as well as clinical parameters were studied in patients with rheumatoid arthritis. The level of total rheumatoid factor fell during treatment with D-penicillamine (p less than 0.02) and there was a positive correlation (K greater than 0.50, p less than 0.05) between this fall in rheumatoid factor and the improvement of several clinical activity parameters. No significant change was observed in the level of rheumatoid factor during treatment with piroxicam. Natural killer cell activity decreased from 21.1 +/- 2.5 to 15.8 +/- 1.9 after treatment with piroxicam for 3 weeks (p less than 0.05) as compared with changes in the controls. No change in natural killer cell activity was seen after treatment with D-penicillamine. Moreover, no significant changes in the numbers of T4+ and T8+ lymphocytes nor in the numbers of HLA-DR positive T cells were seen in the two treatment groups. Both laboratory and clinical activity parameters improved during the treatment with D-penicillamine, while only subjective parameters improved during treatment with piroxicam.