Steffi Lopens, Germany
Medipan GmbH Research and DevelopmentPresenter of 1 Presentation
GLYCOPROTEIN 2 (GP2) IS PRESENT IN BILE AND MIGHT PLAY A ROLE IN THE PATHOGENESIS OF LITHOGENIC CONDITIONS
Abstract
Background and Aims
Glycoprotein 2 (GP2) IgA has been linked with severity and carcinogenesis in primary sclerosis cholangitis (PSC). The presence of GP2 being a specific marker for mature microfold cells with immunomodulating features has not yet been demonstrated in the biliary tract. Given the putative pathophysiological role of autoimmunity to GP2 in chronic cholestatic conditions, we investigated if GP2 is expressed in the biliary tract and affects bile lithogenicity.
Methods
GP2 was analyzed in serum from healthy individuals and bile samples acquired during living liver donation surgery (N = 10) as well as endoscopic retrograde cholangiopancreatography (ERCP) for recurrent gallstones (N = 12). GP2 was also investigated in gallstones from six patients undergoing cholecystectomy. GP2 concentrations in bile and gallstone extracts were determined employing ELISA and immunoblot. Immunofluorescence was used to confirm the presence of GP2 in stone cryosections.
Results
GP2 was detected in all bile samples from both healthy individuals and patients undergoing ERCP. GP2 concentrations in bile in each group were significantly (P < 0.05) higher than in serum from healthy individuals. Comparison of biliary GP2 showed that its levels in patients undergoing repetitive ERCP were significantly (P < 0.05) higher as compared to liver donors. Analysis of gallbladder stone extracts demonstrated GP2 presence using ELISA and immunoblot, which was confirmed by immunofluorescence.
Conclusions
We demonstrated that GP2 is present in bile and gallstones. Biliary GP2 levels are increased in gallstone disease. The role of GP2 in benign and precancerous hepatobiliary disorders warrants further investigation.