Liver damage favors the eliminations of HBV integration and clonal hepatocytes in chronic hepatitis B

Gang Hu,Chong J Gan,Xiao M Peng,Ming X Huang,Wei Y Li,Wen X Dong

doi:10.1007/s12072-020-10125-y

Abstract

BackgroundHBV integration is suspected to be an obstinate risk factor for hepatocellular carcinoma (HCC) in the era of antiviral therapy. Integration events start to occur in the immunotolerance phase, but their fates in the immune clearance phase have not yet been clarified. Here, we report the influences of liver damage on HBV integration and clonal hepatocyte expansion in patients with chronic hepatitis B (CHB).MethodsHBV integration breakpoints in liver biopsy samples from 54 CHB patients were detected using a modified next-generation sequencing assay.ResultsA total of 3729 (69 per sample) integration breakpoints were found in the human genome, including some hotspot genes and KEGG pathways, especially in patients with abnormal transaminases. The number of breakpoint types, an integration risk parameter, was negatively correlated with HBV DNA load and transaminase levels. The average, maximum and total frequencies of given breakpoint types, parameters of clonal hepatocyte expansion, were negatively correlated with HBV DNA load, transaminase levels and liver inflammation activity grade score. The HBV DNA load and inflammation activity grade score were further found to be positively correlated with transaminase levels. Moreover, nucleos(t)ide analog (NUC) treatment that normalized transaminases nonsignificantly reduced the types, but significantly increased the average frequency and negated the enrichments of integration breakpoints.ConclusionLiver damage mainly removed the inventories of viral integration and clonal hepatocytes in CHB. NUC treatment may have reduced HBV integration but clearly increased clonal hepatocyte expansion, which may explain why HCC risk cannot be ruled out by NUC treatment.

Highlights

Hepatitis B virus (HBV) infection is the major cause of hepatocellular carcinoma (HCC) regardless of current antiviral therapy with nucleos(t)ide analogs (NUCs)
The number of breakpoint types and the average, maximum and total frequencies of given breakpoint types were not significantly different when patients were stratified by age, sex, viral genotype, hepatitis B surface antigen (HBsAg) persistence, albumin (ALB) and alpha fetoprotein (AFP) (Table 1)
The number of breakpoint types was positively correlated with the time of HBsAg persistence, but the average, maximum and total breakpoint frequencies were all negatively correlated with ALT, AST, HBV DNA load and hepatitis B e antigen (HBeAg) (Fig. S3)

Summary

Introduction

Hepatitis B virus (HBV) infection is the major cause of hepatocellular carcinoma (HCC) regardless of current antiviral therapy with nucleos(t)ide analogs (NUCs). The HCC risk still exists among those patients outside current treatment criteria or even exists in individuals with HBV that has been functionally cleared [6, 7] These above findings suggest that there are some obstinate HCC-driving factors other than viral replication and hepatitis. The subsequent fates and evolution of early viral integration in the immune clearance phase (chronic hepatitis) are important parts of hepatocarcinogenesis. We report the influences of liver damage on HBV integration and clonal hepatocyte expansion in patients with chronic hepatitis B (CHB). The average, maximum and total frequencies of given breakpoint types, parameters of clonal hepatocyte expansion, were negatively correlated with HBV DNA load, transaminase levels and liver inflammation activity grade score. NUC treatment may have reduced HBV integration but clearly increased clonal hepatocyte expansion, which may explain why HCC risk cannot be ruled out by NUC treatment

Methods

Results

Conclusion