Long term treatment of rheumatoid arthritis with high doses of intravenous immunoglobulins: effects on disease activity and serum cytokines.

OBJECTIVE--To evaluate the effects of long term treatment of rheumatoid arthritis (RA) with high doses of intravenous immunoglobulins (IVIg). METHODS--Ten patients with active RA and prior unsuccessful treatment with at least one slow acting antirheumatic drug were treated with 400 mg/kg of IVIg for the first three days and then once a month for 12 months. Clinical evaluation and laboratory analysis were performed every month. Serum levels of tumour necrosis factor alpha (TNF alpha), soluble interleukin-2 receptor (sIL-2R), IL-1 alpha, IL-1 beta, IL-6 and interferon gamma (IFN gamma) were measured at baseline and at three monthly intervals for 15 months. RESULTS--Although laboratory parameters were not influenced by the treatment, a late but significant clinical improvement was observed after six months. Serial measurement of cytokines revealed a rapid and persistent decrease in serum TNF alpha and a late and significant reduction in sIL-2R concentrations. CONCLUSION--This study suggests that IVIg can ameliorate the symptoms and improve the functional capability of RA patients. This effect is associated with a partial modulation of serum concentrations of inflammatory cytokines and, more interestingly, with a late decrease in sIL-2R which correlated with the late reduction in disease activity.