EFFECT OF SULFASALAZINE ON B-CELL HYPERACTIVITY IN PATIENTS WITH RHEUMATOID-ARTHRITIS

Objective. We investigated the in vitro immunomodulatory effects of sulfasalazine on B cells in rheumatoid arthritis (RA). Methods. Reversed hemolitic plaque assay and H-3-thymidine incorporation were measured. Results. B cells from patients with RA showed hyperactivity to stimulation by Staphylococcus aureus Cowan I. Sulfasalazine significantly inhibited this B cell hyperactivity in a dose dependent manner. The kinetic study and a decrease in H-3-thymidine incorporation on Day 3 indicate that sulfasalazine inhibited the early phase (0-48 h) of B cell proliferation in these patients. Sulfapyridine also inhibited B cell hyperactivity in these patients, but 5-aminosalicylic acid and N-acetylsulfapyridin had no significant effect. Conclusion. Sulfasalazine exhibited a direct immunosuppressive effect on B cell hyperactivity in patients with RA, which may be responsible for its therapeutic effectiveness in this disorder.