SNP rs7770370 in HLA ‐ DPB 1 loci as a major genetic determinant of response to booster hepatitis B vaccination: Results of a genome‐wide association study

BACKGROUND AND AIM: Hepatitis B (HB) vaccination is highly effective in reducing the risk of hepatitis B virus infection. However, breakthrough and chronic hepatitis B virus infections in vaccinated subjects raised concern about its long-term efficacy. The specific aim of the study was to explore the host genetic determinants of long-term immunological memory against HB vaccination. METHODS: We conducted a case-control study nested in a cohort of HB booster recipients who had received primary HB vaccination during infancy but failed to reside an anti-HBs titers ≥ 10 mIU/mL at the age of 15-18 years. We used a genome-wide single nucleotide polymorphism (SNP) array plate to scan autosomal chromosomes and assayed the human leukocyte antigen (HLA)-DPB1 genotype by sequence-based techniques. RESULTS: We found that 10 of the 112 candidate SNPs (P-value < 5.0 × 10(-5) ) clustered within a 47-Kb region of the HLA-DP loci. All the minor alleles of these HLA-DP candidate SNPs were correlated with lower likelihoods of nonresponse to HB vaccine. There was a significant linkage disequilibrium between these HLA-DP candidate SNPs and HLA-DPB1 protective alleles. Multivariate analyses showed that rs7770370 was the most significant genetic factor. As compared with rs7770370 GG homozygotes, adjusted odds ratios were 0.524 (95% confidence interval, 0.276-0.993) and 0.095 (95% confidence interval, 0.030-0.307) for AG heterozygotes and AA homozygotes, respectively. CONCLUSION: Our results showed that rs7770370 was the most significant genetic factor of response to HB booster. The rs7770370 and nearby SNPs may also contribute to the long-term immunological memory against HB vaccination.