Abnormal biliary lipid composition in cystic fibrosis. Effect of pancreatic enzymes.

Because of the increased incidence of gallstones in cystic fibrosis we compared 
biliary lipid composition in 26 patients with cystic fibrosis, seven children 
with cholelithiasis but no cystic-fibrosis and 13 controls. Eighteen of the 
cystic fibrosis group had cholecystograms, and only one had gallstones. In 
14 patients with cystic fibrosis who had stopped taking pancreatic enzymes 
for one week molar percentage of lipid composition accounted for by 
cholesterol (mean +/- S.E., 16.3 +/- 2.9) and saturation index (2.0 
+/- 0.3) were comparable to values of the cholelithiasis group and 
higher (P less than 0.01) than those of controls. In 12 
patients with cystic fibrosis taking pancreatic enzymes, molar percentage of cholesterol 
(8.6 +/- 1.7) and saturation index (1.0 +/- 0.1) did not 
differ from those of controls; in cystic fibrosis there was a 
preponderance of cholic over chenodeoxycholic acid both off (1.7 +/- 0.2) 
and on (1.9 +/- 0.3) therapy as compared to the cholelithiasis 
(0.7 +/- 0.1) and control (0.8 +/- 0.0) groups. The glycine/taurine 
ratio of conjugated bile acids were lower in enzyme-treated patients with 
cystic fibrosis (3.7 +/- 0.6) than in patients off treatment (6.4 
+/- 1.0), but was higher (P less than 0.01) than in 
controls (1.8 +/- 0.2). Bile is lithogenic in untreated cystic fibrosis 
and responds to pancreatic enzymes. 