Biliary bile acids in primary biliary cirrhosis: Effect of ursodeoxycholicacid

Bile acid composition in fasting duodenal bile was assessed at entry and at 2 years in patients with primary biliary cirrhosis (PBC) enrolled in a ran domized, double-blind, placebo-controlled trial of ursodeoxycholic acid (UD CA) (10-12 mg/kg/d) taken as a single bedtime dose. Specimens were analyzed by a high-pressure liquid chromatography method that had been validated ag ainst gas chromatography. Percent composition in bile (mean rt SD) for 98 p atients at entry for cholic (CA), chenodeoxycholic (CDCA), deoxycholic (DCA ), lithocholic (LCA), and ursodeoxycholic (UDCA) acids, respectively, were 57.4 +/- 18.6, 31.5 +/- 15.5, 8.0 +/- 9.3, 0.3 +/- 1.0, and 0.6 +/- 0.9. Va lues for CA were increased, whereas those for CDCA, DCA, LCA, and UDCA were decreased when compared with values in normal persons. Bile acid compositi on of the major bile acids did not change after 2 years on placebo medicati on. By contrast, in patients receiving UDCA for 2 years, bile became enrich ed with UDCA on average to 40.1%, and significant decreases were noted for CA (to 32.2%) and CDCA (to 19.5%). No change in percent composition was obs erved for DCA and LCA. Percent composition at entry and changes in composit ion after 2 years on UDCA were similar in patients with varying severity of PBC. In patients whose bile was not enriched in UDCA (entry and placebo-tr eated specimens), CA, CDCA, DCA, and the small amount of UDCA found in some of these specimens were conjugated to a greater extent with glycine (52%-6 4%) than with taurine (36%-48%). Treatment with UDCA caused the proportion of all endogenous bile acids conjugated with glycine to increase to 69% to 78%, while the proportion conjugated with taurine (22%-31%) fell (P < .05). Administered UDCA was also conjugated predominantly with glycine (87%).