Biliary phosphatidylcholine and lysophosphatidylcholine profiles in sclerosing cholangitis

AIM:To analyze phospholipid profiles in intrahepatic bile from patients with primary sclerosing cholangitis(PSC)and secondary sclerosing cholangitis(SSC).METHODS:Intrahepatic bile specimens collected via endoscopic retrograde cholangiography from 41 patients were analyzed.Fourteen of these patients were diagnosed with PSC,10 with SSC,11 with choledocholithiasis or no identifiable biliary disease,and 6 with cholangiocellular carcinoma(CCC).Bile acid,cholesterol,protein,and bilirubin contents as well as pancreas lipase activity in bile were determined by biochemical methods.Phosphatidylcholine(PC)and lysophosphatidylcholine(LPC)species were quantified using nanoelectrospray ionization tandem mass spectrometry.RESULTS:Bile from all the examined patient groups showed a remarkably similar PC and LPC species composition,with only minor statistical differences.Total biliary PC concentrations were highest in controls(8030±1843 mol/L)and lowest in patients with CCC(1969±981 mol/L)(P=0.005,controls vs SSC and CCC,respectively,P<0.05).LPC contents in bile were overall low(4.2%±1.8%).Biliary LPC/PC ratios and ratios of biliary PC to bilirubin,PC to cholesterol,PC to protein,and PC to bile acids showed no intergroup differences.CONCLUSION:PC and LPC profiles being similar in patients with or without sclerosing cholangitis,these phospholipids are likely not of major pathogenetic importance in this disease group.