Immunologic evaluation of rheumatoid arthritis and therapy with levamisole.

The haemolytic complement activity and the complement components C3, C4 and C1q were significantly increased in the sera of 43 patients with classic or definite rheumatoid arthritis. The increased complement activity was fairly well correlated with an increased sedimentation rate, increased IgG levels and rheumatoid factor positivity. The E-rosette formation of T-lymphocytes measured in 16 rheumatoid arthritis patients was significantly depressed. These 16 patients were treated with levamisole 50 mg t.i.d. Four patients discontinued treatment because of side-effects. The remaining 12 patients were re-examined clinically and immunologically after a mean treatment period of 3.9 (range : 2.5-8) months. A significant reduction in haemolytic complement activity, C3, IgG and sedimentation rate and a significant increase in E-rosette forming cells were observed, and these were accompanied by a significant clinical improvement. These findings are discussed in view of the new concept that the basic defect in rheumatoid arthritis could be a disturbance of the interaction of T-and B-cells and faulty suppressor T-cells. According to this hypothesis, levamisole restores cell-mediated immune reactivity, thereby affecting the natural course of rheumatoid arthritis.