Association of HLA Class II Alleles with Outcome of Hepatitis C Virus Infection: A Systematic Review and Meta-analysis

Context: Hepatitis C Virus (HCV) infection is a major cause of chronic cirrhosis and hepatocellular carcinoma. Approximately 30% of infected persons with HCV spontaneously clear the viral infection; but, some of the remaining patients develop chronic HCV. StudiesshowthatHLAmolecules playanimportant role in theoutcomeof HCVinfection by influencing the efficiency of the antiviral immune response to HCV infection. It is now known that polymorphisms in HLA loci are associated with HCV susceptibility or clearance. The purpose of the present study was to systematically review the studies that reported the association of HLA class II alleles (HLA-DQ and HLA-DR) with the outcome of HCV infection. Evidence Acquisition: Studies were identified by searching electronic databases, including PubMed and Scopus. A total of 12,265 relevant studies were identified by the electronic search, of which a total of 19 eligible papers were identified that were metaanalyzed for the association between HLA class II alleles and the outcome of HCV infection. Results: Subjects carrying HLA-DQB1*0301, HLA-DQB1*0501, HLA-DRB1*1303, HLA-DRB1*1201, HLA-DRB1*0401, HLA-DRB1*0101, and HLADRB1* 1101 alleles were significantly associated with higher spontaneous clearance of HCV infection. Conclusions: The data from the current study confirm that several polymorphisms in HLA-DQ and HLA-DR loci are correlated with the clearance of HCVinfection. Identifying thesepolymorphismsmaycontribute to a better understanding of immunemechanisms of HCV clearance or persistence.