Association between Chronic Hepatitis B Virus Infection and HLA Gene rs3077 and rs9277535Polymorphisms in the Turkish population

DOI: 10.5176/2251-2489_BioTech16.9

Authors: Ersin Akgöllü, Ramazan Bilgin, Hikmet Akkız, Yakup Ülger, Berrin Yalınbaş Kaya

Abstract: Background: Hepatitis B virus (HBV) affects approximately 360 million people worldwide. 10–15{6e6090cdd558c53a8bc18225ef4499fead9160abd3419ad4f137e902b483c465} of chronic carriers develop liver cirrhosis (LC), liver failure and hepatocellular carcinoma (HCC). Chronic HBV infection or HBV clearance is influenced by both viral and host factors. In genome-wide association studies (GWAS), the human leukocyte antigen (HLA) gene polymorphisms rs3077 and rs9277535 were identified to be associated with chronic hepatitis B. HLA genes have been linked to immune response to infectious agents, but genetic variants in HLA genes influence HLA mRNA expression which might also affect antigen presentation. We evaluated the association between HLA gene polymorphisms and the risk for persistent HBV infection. Methods: HLA gene polymorphisms were investigated in a case–control study of 294 chronic HBV carriers and 234 persons with HBV natural clearance by using a real-time polymerase chain reaction (RT-PCR). Results: There was a significant association between the control and the case groups for rs9277535 allele frequencies (P=0.05), but not significant for rs3077, in the Turkish subjects examined. Additionally, the AG haplotype block which showed a protective effect against the risk of persistent HBV infection (for the rs3077 A/rs9277535 G, OR=0.52; 95{6e6090cdd558c53a8bc18225ef4499fead9160abd3419ad4f137e902b483c465} 0.34-0.80, P=0.003). Conclusions: Our results demonstrate for the first time that HLA-DPB1 gene rs9277535 A allele, especially in male, has a major effect on the risk of persistent HBV infection, but not for rs3077. Further independent studies are necessary to clarify the association of these polymorphisms with persistence or natural clearance of HBV infection in Caucasian populations. This study was supported by a grant from THE SCIENTIFIC AND TECHNOLOGICAL RESEARCH COUNCIL OF TURKEY (TUBITAK113S560).

Keywords: HLA polymorphism rs9277535