OBJECTIVE Based on the immunosuppressive effects of blood transfusions in organ transplantation, we determined the effect of a blood transfusion on disease activity of rheumatoid arthritis (RA). METHOD In this double-blind pilot study, 40 patients with active RA were randomly assigned to receive a HLA-DRB1-matched blood transfusion (n = 30) or placebo (n = 10). Disease activity was scored according
to the American College of Rheumatology response criteria during 6 months of follow-up. RESULTS After 1 month and 6 months, respectively, 6 and 16% of patients fulfilled the response criteria in the blood transfusion group compared to none and 30%, respectively, in the placebo group. Following correction for the increase in haemoglobin levels, a majority of the response parameters in the blood transfusion group showed significant improvement compared to the placebo group. CONCLUSION A DRB1-matched blood transfusion shows improvement of symptoms in several RA patients. Additional studies are required to identify blood transfusion regimens that enhance the potential for therapeutic responses.