title: Role of HLA-DP polymorphisms on chronicity and disease activity of hepatitis B infection in Southern Chinese.
abstract: OBJECTIVE
  The association between HLA-DP single nucleotide polymorphisms (SNPs) and chronic hepatitis B virus (HBV) infection varies between different populations. We aimed to study the association between HLA-DP SNPs and HBV infection and disease activity in the Chinese population of Hong Kong.
  
  
  METHODS
  We genotyped SNPs rs3077 (near HLA-DPA1) and rs9277378 and rs3128917 (both near HLA-DPB1) in 500 HBV carriers (hepatitis B surface antigen [HBsAg]-positive), 245 non-HBV infected controls (HBsAg- and antibody to hepatitis B core protein [anti-HBc]-negative), and 259 subjects with natural HBV clearance (HBsAg-negative, anti-HBc-positive). Inactive HBV carriers state was defined by HBV DNA levels <2,000 IU/ml and persistently normal alanine aminotransferase level for least 12 months.
  
  
  RESULTS
  Compared to the non-HBV infected subjects, the HBV carriers had a significantly lower frequency of the rs3077 T allele (p = 0.0040), rs9277378 A allele (p = 0.0068) and a trend for lower frequency of rs3128917 T allele (p = 0.054). These alleles were associated with an increased chance of HBV clearance (rs3077: OR = 1.41, p = 0.0083; rs9277378: OR = 1.61, p = 0.00011; rs3128917: OR = 1.54, p = 0.00017). Significant associations between HLA-DP genotypes and HBV clearance were also found under different genetic models. Haplotype TAT was associated with an increased chance of HBV clearance (OR = 1.64, p = 0.0013). No association was found between these SNPs and HBV disease activity.
  
  
  CONCLUSIONS
  HLA-DP SNPs rs3077, rs9277378 and rs3128917 were associated with chronicity of HBV disease in the Chinese. Further studies are required to determine whether these SNPs influence the disease endemicity in different ethnic populations.
authors.affiliation: Department of Medicine, The University of Hong Kong, Queen Mary Hospital, Hong Kong.
authors.forename: Danny Ka-Ho
authors.initials: DK
authors.lastname: Wong
authors.forename: Tsunamasa
authors.initials: T
authors.lastname: Watanabe
authors.forename: Yasuhito
authors.initials: Y
authors.lastname: Tanaka
authors.forename: Wai-Kay
authors.initials: WK
authors.lastname: Seto
authors.forename: Cheuk-Kwong
authors.initials: CK
authors.lastname: Lee
authors.forename: James
authors.initials: J
authors.lastname: Fung
authors.forename: Che-Kit
authors.initials: CK
authors.lastname: Lin
authors.forename: Fung-Yu
authors.initials: FY
authors.lastname: Huang
authors.forename: Ching-Lung
authors.initials: CL
authors.lastname: Lai
authors.forename: Man-Fung
authors.initials: MF
authors.lastname: Yuen
mesh_terms: D044466:Asian People / Q000235:genetics*; D005260:Female; D006682:HLA-DP Antigens / Q000235:genetics*; D006239:Haplotypes; D019694:Hepatitis B, Chronic / Q000235:genetics*; D006723:Hong Kong / Q000453:epidemiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D020641:Polymorphism, Single Nucleotide; D015995:Prevalence
chemical_list: D006682:HLA-DP Antigens