INHIBITION OF INTERLEUKIN-8 SYNTHESIS BY INTRAARTICULAR METHOTREXATE THERAPY IN PATIENTS WITH RHEUMATOID-ARTHRITIS

5 Patients with definite RA and knee effusions under constant doses of DMARD therapy were treated with up to 6 intraarticular injections of 10 mg methotrexate (MTX) every 3 to 7 days. A matched randomized contr ol group who received a single i.a. injection of 40 mg triamcinolone h exacetonide (TC) was monitored according to the same protocol. The int raarticular granulocyte counts and IL-8 levels decreased in all MTX tr eated patients on day 10-13 and stayed low in those patients who could be re-evaluated after 13 weeks. Compared to the IL-8 levels, the othe r tested cytokine levels showed only minor changes on day 10-13. There was no need for re-injection in the TC group during the 13 week study phase. We conclude that intraarticular MTX therapy results in a stron g decrease of SF-granulocyte counts. This effect may be due to the imp airment of IL-8 mediated chemotaxis by decreased IL-8 synthesis in syn ovial fluid mononuclear cells. Clinically, repeated intraarticular MTX therapy results in a worse 13 week outcome than i.a. steroid treatmen t measured in an intention-to-treat analysis.