Long-term effect of nonsteroidal anti-inflammatory drugs on the production of cytokines and other inflammatory mediators by blood cells of patients with osteoarthritis.

Most of the previous studies dealing with the effect of nonsteroidal anti-inflammatory drugs (NSAIDs) on the synthesis of inflammatory mediators involved in joint damage have been done in cells cultured in vitro or in blood cells from patients treated for short periods of time. In this work we have evaluated the long-term effect of aceclofenac, a new NSAID, and diclofenac on the production of a series of inflammatory mediators by blood cells from 30 patients with severe knee osteoarthritis. Both aceclofenac and diclofenac significantly inhibited prostaglandin E2 (PGE2) synthesis by blood mononuclear and polymorphonuclear cells after 180 days of treatment. However, no clear effect was noted on leukotriene B4 (LTB4) and platelet activating factor (PAF) production. The generation of O-2 by polymorphonuclear cells, stimulated with FMLP, was decreased after 15 days of treatment with both drugs, but reached normal values after 180 days. Interleukin-1 beta (IL-1 beta) production decreased significantly at 180 days with both drugs in the group of high producer patients. In a few (n = 3) patients with high basal mononuclear cell tumor necrosis factor alpha (TNF alpha) production, this also decreased on treatment for 180 days with the NSAIDs. In the remaining low TNF alpha-producing patients, TNF alpha production tended to increase. Interleukin-6 (IL-6) synthesis was not affected by aceclofenac while it was diminished by diclofenac. The decrease in IL-6 in all treated patients was significantly correlated with a worsening of the clinical condition. On the whole, these data could afford a pathogenetic basis for the long-term employment of these drugs in patients with inflammatory conditions.