Apolipoprotein E Polymorphism and Cholesterol in Stones and Bile of Patients with Cholelithiasis

Park, Ju Sang; Seo, Dong Wan; Yoo, Kyo Sang; Park, Kwang Min; Lee, Young Joo; Chun, Sa Il; Min, Won Ki; Lee, Sung Koo; Kim, Myung Hwan; Lee, Sung Gyu; Min, Young Il

Abstract

BACKGROUND/AIMS
Apolipoprotein E4 (apo E4) has been reported to be a risk factor for cholesterol gallstone formation. As a cause of cholesterol gallstone formation, increased hepatic uptake of cholesterol absorbed from intestine and enhanced biliary cholesterol secretion in patients carrying apo E4 genotype have been suggested, but there is little direct evidence supporting cholesterol supersaturation in the bile. Furthermore, it is unclear whether apo E polymorphism is associated with intrahepatic duct (IHD) stone formation. We performed this study to elucidate the relationship between apo E genotypes and the cholesterol content of bile and stones in patients with gallbladder (GB) stones or IHD stones. METHODS:Fourty-seven patients with GB stones and 43 patients with IHD stones were enrolled in this study. Apo E genotype, bile composition and stone composition were analyzed. RESULTS: Apo E genotypes and cholesterol content of stones were not significantly different between the patients with GB stone and the patients with IHD stone. The bile composition and cholesterol content of gallstone in the patients showed no significant difference according to apo E genotypes.
CONCLUSIONS
Apo E4 genotype is not associated with an enhanced biliary cholesterol secretion and high cholesterol content in GB or IHD stones.