HLA-DQB1*03 confers susceptibility to chronic hepatitis C in Japanese: a genome-wide association study

PLoS One. 2013 Dec 20;8(12):e84226. doi: 10.1371/journal.pone.0084226. eCollection 2013.

Abstract

Hepatitis C virus (HCV) establishes a chronic infection in 70-80% of infected individuals. Many researchers have examined the effect of human leukocyte antigen (HLA) on viral persistence because of its critical role in the immune response against exposure to HCV, but almost all studies have proven to be inconclusive. To identify genetic risk factors for chronic HCV infection, we analyzed 458,207 single nucleotide polymorphisms (SNPs) in 481 chronic HCV patients and 2,963 controls in a Japanese cohort. Next, we performed a replication study with an independent panel of 4,358 cases and 1,114 controls. We further confirmed the association in 1,379 cases and 25,817 controls. In the GWAS phase, we found 17 SNPs that showed suggestive association (P < 1 × 10⁻⁵). After the first replication study, we found one intronic SNP in the HLA-DQ locus associated with chronic HCV infection, and when we combined the two studies, the association reached the level of genome-wide significance. In the second replication study, we again confirmed the association (P(combined) = 3.59 × 10⁻¹⁶, odds ratio [OR] = 0.79). Subsequent analysis revealed another SNP, rs1130380, with a stronger association (OR=0.72). This nucleotide substitution causes an amino acid substitution (R55P) in the HLA-DQB1 protein specific to the DQB1*03 allele, which is common worldwide. In addition, we confirmed an association with the previously reported IFNL3-IFNL4 locus and propose that the effect of DQB1*03 on HCV persistence might be affected by the IFNL4 polymorphism. Our findings suggest that a common amino acid substitution in HLA-DQB1 affects susceptibility to chronic infection with HCV in the Japanese population and may not be independent of the IFNL4 genotype.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Asian People / genetics*
  • Gene Frequency
  • Genetic Predisposition to Disease / genetics*
  • Genome-Wide Association Study
  • HLA-DQ beta-Chains / genetics*
  • Hepatitis C, Chronic / genetics*
  • Humans
  • Linkage Disequilibrium
  • Logistic Models
  • Polymorphism, Single Nucleotide / genetics

Substances

  • HLA-DQ beta-Chains
  • HLA-DQB1 antigen

Grants and funding

This work was partially supported by Grants-in-Aid for scientific research and development from the Ministry of Health, Labor and Welfare (http://www.mhlw.go.jp/seisakunitsuite/bunya/hokabunya/kenkyujigyou/) and Ministry of Education Culture Sports Science and Technology (http://www.mext.go.jp/a_menu/shinkou/hojyo/main5_a5.htm), Government of Japan. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.