title: Non-invasive screening of HLA-DPA1 and HLA-DPB1 alleles for persistent hepatitis B virus infection: susceptibility for vertical transmission and toward a personalized approach for vaccination and treatment.
abstract: BACKGROUND
  Polymorphisms in the major histocompatibility complex (MHC) and non-MHC genes were recently reported to be associated with persistent hepatitis B virus (HBV) infection and host response to hepatitis B vaccine in Asian populations. We aimed to confirm the associations in Chinese population and develop a non-invasive screening method for the risk loci.
  
  
  METHODS
  We genotyped 2 risk alleles on the MHC loci, HLA-DPA1 (rs3077) and HLA-DPB1 (rs9277535), and 1 risk allele near a non-MHC gene, FOXP1 (rs6789153) using high-resolution melting curve analysis. With minimal processing steps and time, salivary DNA was extracted with a modified protocol of a blood kit. We compared the genotyping fidelity between peripheral blood DNA and salivary DNA.
  
  
  RESULTS
  Both rs3077 and rs9277535, but not rs6789153, are significantly associated with CHB in Chinese population (p-value<0.001). High genotype concordance between different sources of genomic DNA was obtained.
  
  
  CONCLUSIONS
  Genotyping salivary DNA using our modified methods provides a non-invasive fast screening for host susceptibility loci. The transmission mechanism of hepatitis B can now be modified by adding genetic susceptibility to the traditional vertical transmission model of hepatitis B.
authors.affiliation: Department of Pathology, The University of Hong Kong, Queen Mary Hospital, Hong Kong, China.
authors.forename: Kin-Chong
authors.initials: KC
authors.lastname: Lau
authors.forename: Ching-Wan
authors.initials: CW
authors.lastname: Lam
authors.forename: Chun-Yiu
authors.initials: CY
authors.lastname: Law
authors.forename: Sik-To
authors.initials: ST
authors.lastname: Lai
authors.forename: Tak-Yin
authors.initials: TY
authors.lastname: Tsang
authors.forename: Carol Wai-Kwan
authors.initials: CW
authors.lastname: Siu
authors.forename: Wing-Kin
authors.initials: WK
authors.lastname: To
authors.forename: Ka-Fai
authors.initials: KF
authors.lastname: Leung
authors.forename: Chloe Miu
authors.initials: CM
authors.lastname: Mak
authors.forename: Wing-Tat
authors.initials: WT
authors.lastname: Poon
authors.forename: Paul Kay-Sheung
authors.initials: PK
authors.lastname: Chan
authors.forename: Yan-Wo
authors.initials: YW
authors.lastname: Chan
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000483:Alleles; D005260:Female; D056426:Genetic Loci / Q000235:genetics; D005820:Genetic Testing / Q000379:methods*; D059867:HLA-DP alpha-Chains / Q000235:genetics; D059868:HLA-DP beta-Chains / Q000235:genetics; D006515:Hepatitis B virus / Q000472:pathogenicity; D019694:Hepatitis B, Chronic / Q000235:genetics* / Q000517:prevention & control / Q000628:therapy / Q000635:transmission*; D006801:Humans; D018445:Infectious Disease Transmission, Vertical; D008297:Male; D008875:Middle Aged; D057285:Precision Medicine / Q000379:methods*; D014611:Vaccination / Q000379:methods*; D055815:Young Adult
chemical_list: D059867:HLA-DP alpha-Chains; D059868:HLA-DP beta-Chains; C071172:HLA-DPA1 antigen; C071170:HLA-DPB1 antigen