Suppression of active Arthus reaction by colchicine.

An effect of colchicine on the active Arthus reaction in rabbits was investigated in vivo with simultaneous evaluation of in vitro chemotactic activity of polymorphonuclear leukocytes. Arthus reactions were induced by intracutaneous injection of ovalbumin into rabbits preimmunized with ovalbumin. Colchicine, 1 mg/kg or 2 mg/kg, injected intraperitoneally one hour prior to the induction of the Arthus reaction, suppressed erythema and induration at 12 h, when histology showed decreased numbers of C3, suggestive of the presence of immune complexes, persisted to 24 h. In vitro chemotaxis of polymorphonuclear leukocytes using Boyden chamber techniques revealed suppression of the activity in the colchicine-treated animals at 6 and 12 h. These findings suggest that colchicine inhibits vascular injury by interfering with directional chemotaxis of polymorphonuclear leukocytes to the lesional sites.