WCPGHAN in Montreal 2016.10.7

The same genetic factors in human leukocyte antigen (HLA)-DP are important for both hepatitis B vaccine response and the clinical outcomes of hepatitis B infection Aiko Sakai1 MD, Takashi Fukushima1, Manabu Tagawa1, Kazuo Imagawa1, Hiroko Fukushima1, Atsushi Iwabuchi1, Emiko Noguchi2, Mika Sasaki3, Ryo Sumazaki1 Child Health, University of Tsukuba1, Human Genetics, University of Tsukuba2, Tsukuba, Ibaraki, Japan; Pediatrics, Iwate Medical University3, Morioka, Iwate, Japan.

Aiko Sakai has documented no financial relationships to disclose or Conflict of Interest (COIs) to resolve.

BACKGROUND Hepatitis B virus (HBV) vaccine ・Containing hepatitis B surface antigen (HBsAg) ・The mainstay of HBV prevention ・5–10% of recipients have no response Class II Human leukocyte antigen (HLA) loci: HLA-DP, DQ, DR HLA-DQ and -DR : identified as candidate host genetic factors for the vaccine response

Question1: less evidence for HLA-DP loci HLA-DP SNP (rs3077, rs9277535) were associated with both (1) HBV vaccine response (2) Chronic hepatitis B susceptibility Question2: Underlying mechanism ?

OBJECTIVE For Question1：less evidence for HLA-DP loci • To define the effects of HLA-DP alleles and SNPs on the primary HBV vaccine response For Question2：Underlying mechanism ? • To compare the findings with the genetic factors reported for chronic hepatitis B susceptibility • To consider the underlying mechanism

DESIGN/METHODS We performed a case-control association study between HBV vaccine response and HLA-DP alleles. ●Participants • 578 HBV vaccine recipients • Healthy Japanese university students • Never had HBV vaccine before • Not infected with HBV • Gender: male 268, female 310 • Age: median 20 years old (range 19-38)

●Vaccination • 10μg/dose recombinant hepatitis B vaccine • 3 times of subcutaneous administration • Schedule: 0, 1, 6-12 month after the first dose ●Evaluation of Vaccine response Examine anti-hepatitis B surface antigen antibody (HBsAb) 1-2 months after the final dose Poor responders

HBsAb（mIU/mL) < 100

(n = 156)

Sufficient responders ≥ 100 (n = 422)

●Genotyping • HLA-DPA1 : Direct sequencing • HLA-DPB1 : PCR-SSOP method (Sequence Specific Oligonucleotide Probe)

HLA-DP molecule Antigen-binding site α chain (DPA1)

β chain (DPB1)

• SNPs:TaqMan PCR

●Statistical analysis • Fisher’s exact test using the allelic model. • Total of 3 HLA-DPA1 alleles and 15 HLA-DPB1 alleles were genotyped. • Thresholds for statistical significance considering multiple testing: 0.05/3 for DPA1 and 0.05/15 for DPB1

RESULT: Alleles and SNPs in HLA-DP and HBV vaccine response A total of 3 DPA1 alleles and 15 DPB1 alleles were genotyped. Protective Risk DPA1

DPA1*01:03 Alleles DPA1*02:02 DPB1 DPB1*04:02 Alleles DPB1*05:01 SNPs rs3077 A rs3077 G rs9277535 A rs9277535 G

Allele frequency

Poor

Sufficient

(2n = 312)

(2n = 844)

% 39.9 44.0 9.9 39.4 39.9 60.1 39.7 60.3

% 31.7 52.9 4.5 50.3 31.7 68.3 28.5 71.5

% 42.9 40.8 12.0 35.3 42.9 57.1 43.8 56.2

Fisher’s exact test

P value 0.0006 0.0002 0.0001