In vitro correction of a deficiency of Con A-induced suppressor cell function in primary biliary cirrhosis by a pharmacological concentration of colchicine

Patients with primary biliary cirrhosis (PBC) have been previously reported to have immunoregulatory abnormalities. We tested the effect of in vitro colchicine on PBC patients' suppressor cell function in order to determine whether colchicine can correct their suppressor cell deficiency. PBC patients' mononuclear cells were cultured for 44 h with concanavalin A (Con A) as well as with or without colchicine at a pharmacological concentration (10^-8 M) or at a suprapharmacological concentration (10^-5M) and then tested for their ability to suppress proliferation of phytohaemagglutinin stimulated healthy volunteers' mononuclear cells. Eleven PBC patients had significantly (P < 0.001) decreased suppressor cell function (12 ± 15%, mean ± s.d.) as compared to 37 healthy volunteers (43 ± 12%). The suprapharmacological concentration of colchicine did not significantly affect the PBC patients' suppressor cell function (16 ± 15%). In contrast, in the nine PBC patients tested with the pharmacological concentration of colchicine, their suppressor cell function was increased to 40 ± 20% which was significantly different than without colchicine (P < 0.01) or with the suprapharmacological concentration of colchicine (P = 0.02) but not significantly different than healthy volunteers. Thus, in vitro colchicine at a pharmacological concentration corrects PBC patients' deficiency of Con A-induced suppressor cell function raising the possibility that oral colchicine might be clinically useful as an immunomodulating drug in PBC.