Serum interleukin-2 and tumor necrosis factor-alpha in primary biliary cirrhosis: decrease by colchicine and relationship to HLA-DR4.

Colchicine improves liver function tests and survival in primary biliary cirrhosis (PBC); however, its mechanism of action in PBC is unknown. Because elevated interleukin-2 (IL-2) and tumor necrosis factor-alpha (TNF) have been found in various inflammatory diseases, we measured serum levels of IL-2 and TNF in 28 PBC patients before and during treatment with either colchicine or placebo. Compared with normal controls, untreated PBC patients had increased serum IL-2 (39 +/- 13 U/ml vs. 0.8 +/- 0.5) and TNF (549 +/- 162 pg/ml vs. nondetectable). During colchicine treatment, both IL-2 and TNF levels decreased significantly (57 +/- 24 to 40 +/- 22, p less than 0.04; 586 +/- 295 to 445 +/- 295, p less than 0.02). No significant changes in IL-2 or TNF levels occurred in the placebo-treated patients. DR4-positive patients had elevated levels of IL-2 at entry, compared with DR4-negative patients (67 +/- 26 vs. 14 +/- 5, p less than 0.04). The effect of colchicine in PBC may be due, in part, to modulation of IL-2 and TNF levels. Alternatively, the changes in IL-2 and TNF may simply reflect the overall improvement in biochemical tests of liver function related to colchicine therapy. DR4 appears to relate to serum levels of these cytokines in PBC and, possibly, also to the response to colchicine.