Antibiotics as disease modifiers in arthritis.

The tetracyclines, especially minocycline, are supposed to have antiarthritic properties. Their efficacy has been tested in open clinical studies on RA patients. Recently a double-blind placebo-controlled trial was performed which revealed the antirheumatic properties of minocycline. The mode of action of the tetracyclines in arthritis is unknown, but could be linked to the immunosuppressive activity seen in vitro. The antiproliferative effect of minocycline in cloned synovial T-cells is demonstrated; moreover IFN-gamma production in cloned synovial T-cells is inhibited by minocycline.