Alteration of Bile Acid Transporter Expression in Patients with Early Cholestasis Following Living Donor Liver Transplantation

Background : Intrahepatic cholestasis can occur early after living donor liver transplantation (LDLT). We investigated the changes in the expressions of the bile acid transporters and the liver histology in the patients who suffered with early cholestasis (EC) following LDLT. Methods : The histological differences between 15 graft livers with EC after LDLT and 5 graft livers with biliary stricture following LDLT were evaluated. The hepatic mRNA levels of the bile canaliculi transporters (BSEP, MRP2, MRP3, MDR1, MDR3, NTCP) in 40 (20 graft livers, 20 matched donor livers) liver biopsy tissues were analyzed by performing real-time reverse-transcription polymerase chain reaction (RT-PCR). Results : Microscopic examination revealed hepatocellular and/or bile canalicular cholestasis around acinar zone 3 in the livers of the patients with EC. In the livers with biliary stricture, the cholestasis was dominantly observed in the hepatocytic cytoplasm and in the bile ductules around the portal area rather than around acinar zone 3. The BSEP and MRP2 mRNA levels in the EC livers were significantly reduced by 44% and 23%, respectively (p=0.000), compared to the matched donor livers. The levels of MDR3 and NTCP mRNA in the EC livers increased by 738% (p=0.000) and 281% (p<0.01), respectively. The change of the expressions of the bile acid transporters in the patients with biliary stricture was less significant than that in the EC group. Conclusions : These results suggest that the altered expressions of the bile acid transporters may play a role in the pathogenesis of EC following LDLT.