Nonsteroidal anti-inflammatory drugs and immunologic function. Overview of the European experience.

A large number of nonsteroidal anti-inflammatory drugs are available in Europe. There appears to be little difference in overall clinical effectiveness of these drugs, despite individual patient variation, suggesting a common mode of action. Occasionally, a nonsteroidal anti-inflammatory drug will show some evidence of a more impressive anti-rheumatic effect, perhaps related to a more prolonged or different mode of action. The evidence for an immunologic effect of nonsteroidal anti-inflammatory drugs is largely derived from in vitro studies. In patients with rheumatoid arthritis treated with piroxicam, there are no overall changes in lymphocyte numbers or T4/T8 ratios, but numbers of activated cells expressing la decrease and rheumatoid factor titers may also fall. It is suggested that this is not a direct immunosuppressive effect, but one that is related to local inhibition of polymorphonuclear leukocyte-derived free radical production within the joint, which may lower the antigenic load of IgG altered by free radicals, with subsequent diminished immune stimulation.