HLA DPB1 15:01 Allele Predicts Spontaneus Hepatitis B Surface Antigen Seroconversion

Aim : Chronic hepatitis B (CHB) is a global health problem. Recent genome-wide association studies (GWAS) exposed signifi- cant association between the human leukocyte antigen (HLA) class II region, including both DP and DQ loci, and chronic hepatitis B. Previous research also indicated the involvement of adaptive immune system in Hepatitis B seroconversion. The aim of this study is to investigate possible polymorphisms in the HLA-DP locus that can contribute to immune response to Hepatitis B virus (HBV). Methods : We enrolled 94 chronic hepatitis B (CHB) patients and a control group of 85 spontaneous seroconverted healthy subjects and genotyped HLA-DPB1 alleles by polymerase chain reaction followed by restriction length polymorphism (PCR-RFLP) and Sanger sequencing. Results : Among the 19 DPB1 alleles analyzed in this study, DPB1*15:01 allele was more frequent in the spontaneous sero- converted control group compared to CHB patients (15.3% vs. 1.1%, ?2 = 12.5, OR = 0.06, 95% CI = 0.08-0.046 P < 0.001, Pcorrected < 0.001). DPB1*02:01 and DPB1*10:01 were the other alleles observed more frequently in the control group (38.8% vs. 22.3% P = 0.02 and 16.5% vs. 5.3% P = 0.02, respectively). However associations of these two alleles were lost their significance after Bonferoni's correction (Pcorrected = 0.4 for all). Conclusions : In conclusion, this study demonstrates that HLA alleles may participate in spontaneous HBsAg seroconversion which is the ultimate target in CHB in Turkish CHB patients. (Acta gastroenterol. belg., 2017, 80, 351-355).