The possible impact of sortilin in reducing HBsAg expression in chronic hepatitis B.

Hepatitis B virus (HBV) infection is a major global health problem. Chronically infected people are at risk for progressive hepatic fibrosis and consequent cirrhosis. Hepatitis B surface antigen (HBsAg) level in serum is a complementary marker for intrahepatic HBV DNA and covalently closed circular DNA (cccDNA). Sortilin-1 (SORT1) has been reported to be involved in the post-Golgi vesicle trafficking of Apo lipoproteins degradation pathways. This study was designed to evaluate the hepatic and serum expression of HBsAg and its association with hepatic SORT1 gene expression in patients with chronic HBV. Thirty chronic hepatitis B patients with histological examination results were enrolled in this study. Liver biopsies were analyzed for hepatic HBsAg and SORT1 gene expression by immunohistochemistry and quantitative real time PCR (qRT-PCR), respectively. Twenty seven out of 30 (90%) liver biopsies had positive staining for HBsAg and showed a significant inverse association with hepatic SORT1 fold change gene expression (β = -0.5, P = 0.042). There was significant association between HBV DNA levels and HBsAg expression in hepatocyte or serum titer of HBsAg (r = 0.39, P = 0.029; r = 0.39, P = 0.032 respectively). Serum ALT was also correlated with hepatic activity index (HAI) score (β = 0.6, P = 0.001). Inverse association between hepatic SORT1 gene expression and hepatic HBsAg expression indicates the possible role of sortilin in HBsAg particle formation.