Treatment with high-dose (400 mg/kg/day) intravenous immunoglobulin (IVIg) shows benefit in many autoimmune diseases but is very expensive. Low-dose IVIg has also been shown to be effective in inhibiting adjuvant arthritis in the rat. This pilot, randomized, double-blind, placebo-controlled trial was conducted to assess the use of low-dose IVIg in patients with treatment-refractory rheumatoid arthritis (RA).
Twenty patients with active RA were recruited. Ten patients received IVIg and 10 received albumin. Study subjects were given 6 courses of either IVIg (5 mg/kg) or albumin (5 mg/kg), once every 3 weeks. Baseline medications were continued and not changed throughout the study.
There were no complications. Five patients dropped out before the 18-week followup visit. No significant differences between treatment groups were noted during the 18-week trial in terms of global activity indices (patient or physician assessment), joint swelling, joint pain or tenderness, erythrocyte sedimentation rate, C-reactive protein level, or rheumatoid factor. The protocol was terminated prematurely because of reported contamination of IVIg by hepatitis C virus. None of the patients showed evidence of hepatitis C infection by serologic analysis or by polymerase chain reaction.
Low-dose IVIg, as administered in this trial, does not show a therapeutic effect in patients with refractory RA.