HLA-DPB1 and anti-HBs titer kinetics in hepatitis B booster recipients who completed primary hepatitis B vaccination during infancy.

Previously we reported significant associations of the human leukocyte antigen (HLA)-DPB1 05:01 with memory against hepatitis B (HB) vaccination. However, the effects of HLA-DPB1 on antibodies to hepatitis B surface antigen (anti-HBs) kinetics were not explored. We followed up a cohort of 1974 HB booster recipients and quantified their 1-month and 1-year post-booster anti-HBs titers. A total of 681 subjects were randomly selected and typed for HLA-DPB1. We found that male subjects, undetectable pre-booster titers, and 05:01 homozygotes led to significantly lower post-booster anti-HBs titers. The geometric means (95% confidence interval (CI)) of 1-month post-booster anti-HBs titers were 4.68 (2.69-8.12), 23.01 (14.96-35.40) and 50.06 (27.20-92.13) mIU ml(-1) for subjects carrying two, one and no HLA-DPB1 05:01 allele. The corresponding figures for 1-year post-booster anti-HBs titers were 1.26 (0.73-2.18), 4.72 (3.08-7.25) and 7.32 (3.75-13.56) mIU ml(-1). There were significant associations of post-booster anti-HBs titers with the number of HLA-DPB1 risk and protective alleles. Among booster responders, anti-HBs decay rates were significantly reduced in subjects who had detectable pre-booster anti-HBs titers and the HLA-DPB1 05:01 allele. Our results indicated that HLA-DPB1 influences the kinetics of anti-HBs. The long-term memory against hepatitis B surface antigen (HBsAg) and the residual serum titers of anti-HBs after HB vaccination may be influenced by different mechanisms as evidenced by their inverse trend of associations with the 05:01 allele.