SERUM BILE-ACIDS AND URSODEOXYCHOLIC ACID TREATMENT IN CYSTIC FIBROSIS-RELATED LIVER-DISEASE

Increased circulating levels of hepatotoxic bile acids may contribute to the cholestasis characteristic of cystic fibrosis-related liver dis ease. The aims of this study were to compare serum bile acid profiles in patients with cystic fibrosis with and without liver disease, and t o evaluate the effect of treatment with ursodeoxycholic acid, a non-he patotoxic bile acid, on liver biochemistry and serum bile acids in pat ients with cystic fibrosis-related liver disease. Fasting and postpran dial serum bile acid levels were analysed in 15 patients (nine males; median age 18 years) with cystic fibrosis-related liver disease and co mpared with serum bile acid levels in 18 cystic fibrosis patients (12 males; median age 22 years) without liver disease and 10 control subje cts. Fasting and postprandial serum levels of primary and secondary se rum bile acids were analysed using high-performance liquid chromatogra phy. Liver biochemistry and serum bile acids were measured in six cyst ic fibrosis patients with liver disease before and 6 months after trea tment with ursodeoxycholic acid 20 mg/kg/day and compared with six con trol patients with cystic fibrosis-related liver disease. Total fastin g and postprandial serum bile acid levels were significantly (P<0.01) elevated in patients with liver disease compared to those without live r disease and controls. The fasting glycine conjugates of cholic acid, chenodeoxycholic acid and deoxycholic acid, and the fasting and postp randial taurine conjugates of cholic acid and chenodeoxycholic acid we re significantly (P<0.05) elevated in liver disease patients compared to patients without liver disease and controls. After 6 months' treatm ent with ursodeoxycholic acid, although the serum was significantly sa turated with ursodeoxycholic acid and significant improvements in live r biochemistry were observed in the treatment group, there was no sign ificant reduction in the levels of individual serum bile acids. Althou gh circulating levels of potentially hepatotoxic serum bile acids are elevated in patients with cystic fibrosis-related liver disease, impro vements in liver biochemistry associated with ursodeoxycholic acid tre atment cannot be attributed solely to alterations in levels of endogen ous bile acids.