Quadruple mutation GCAC1809-1812TTCT acts as a biomarker in healthy European HBV carriers.

Kai Henrik Peiffer ,Christoph Sarrazin,Tobias Zahn,Arnold Grünweller,Michael Basic,Julia Dietz,Gert Carra,Eberhard Hildt,Alessandro Loglio,Fabian Finkelmeier,Catrina Spengler,Wiebke Obermann,Stefan Zeuzem,Johannes Vermehren,Pietro Lampertico,Mirco Glitscher,Eva Herrmann,Alica Kubesch,Christiana Graf,Lisa Kuhnhenn,Jonel Trebicka,Viola Knop,Bin Jiang ,F Facchetti

doi:10.1172/jci.insight.135833

Abstract

Many mutation analyses of the HBV genome have been performed in the search for new prognostic markers. However, the Kozak sequence preceding precore was covered only infrequently in these analyses. In this study, the HBV core promoter/precore region was sequenced in serum samples from European inactive HBV carriers. Quadruple mutation GCAC1809-1812TTCT was found with a high prevalence of 42% in the Kozak sequence preceding precore among all HBV genotypes. GCAC1809-1812TTCT was strongly associated with coexistence of basal core promoter (BCP) double mutation A1762T/G1764A and lower HBV DNA levels. In vitro GCAC1809-1812TTCT lead to drastically diminished synthesis of pregenomic RNA (pgRNA), precore mRNA, core, HBsAg, and HBeAg. Calculation of the pgRNA secondary structure suggests a destabilization of the pgRNA structure by A1762T/G1764A that was compensated by GCAC1809-1812TTCT. In 125 patients with HBV-related cirrhosis, GCAC1809-1812TTCT was not detected. While a strong association of GCAC1809-1812TTCT with inactive carrier status was observed, BCP double mutation was strongly correlated with cirrhosis, but this was only observed in absence of GCAC1809-1812TTCT. In conclusion, our data reveal that GCAC1809-1812TTCT is highly prevalent in inactive carriers and acts as a compensatory mutation for BCP double mutation. GCAC1809-1812TTCT seems to be a biomarker of good prognosis in HBV infection.

Highlights

Chronic infection with HBV affects approximately 257 million people worldwide and is a major cause for the development of advanced liver disease and hepatocellular carcinoma (HCC) [1]
GCAC1809-1812TTCT was highly prevalent in inactive carriers and strongly associated with basal core promoter (BCP) double mutation A1762T/G1764A
Besides a high prevalence of A1762T/G1764A in 61% (340 of 560) of the samples, we observed that additional mutations in the Kozak sequence at position nt1809–1812 directly preceding the precore start codon were found in 51% (283 of 560) of the samples (Figure 1A)

Summary

Introduction

Chronic infection with HBV affects approximately 257 million people worldwide and is a major cause for the development of advanced liver disease and hepatocellular carcinoma (HCC) [1]. The individual risk for disease progression and/or HCC development is variable and depends on both viral and host factors. Patients who do not fulfill treatment criteria have to be followed over a long time period because an increased risk for disease progression and HCC development remains. In addition to HBV DNA levels and quantitative surface antigen (qHBsAg) levels as established biomarkers [5,6,7,8,9], several viral polymorphisms and mutations in preS gene, precore gene, and basal core promoter (BCP), were extensively studied and found to be associated with the course of disease and treatment response [10,11,12].

Methods

Results

Conclusion