Objectives To objectively assess the efficacy and tolerability of anti-IFN-g in treating patients with active RA.

Methods Thirty patients with active RA were randomly assigned to receive intramuscularly injections of anti-IFN-g, antibodies to tumour necrosis factor a (anti-TNF) or placebo for 5 consecutive days (10 patients on each treatment regimen). The patients were clinically assessed daily for 7 days, then weekly up to the 28-th day. Clinical, laboratory and ultrasound indices were used for the evaluation of the treatment efficacy.

Results Both anti-cytokines were equally effective and significantly superior to placebo. Twelve patients stopped treatment due to the lack of efficacy: 1 on anti-TNF, 2 on anti-IFN-g and 9 on placebo. According to the physician?s assessment improvement was achieved by the 7-th day on anti-TNF in 9 patients, on anti-IFN-g in 7, and on placebo in 2. At the 28-th day the corresponding figures were 8, 8, and 0, respectively. By the 28-th day each of the anti-cytokine groups showed significant improvement in 5 clinical measures including numbers of swollen and painful joints, pain and fatigue. The single patient in the placebo group who completed the trial had no positive changes in the disease activity. The thickness of the inflamed synovial membrane assessed by the ultrasound method decreased significantly only on anti-IFN-g (both by the 7-th and by the 28-th days).

Conclusion The results obtained suggest that IFN-g plays an important role in the pathogenesis of RA. The use of antibodies to this cytokine can be considered as a promising approach to the therapy of RA, especially its treatment-resistant forms.