CD55 Variant Associated with Pegylated-interferon ? Therapy Response in HBeAg-positive Chronic Hepatitis B Patients

Background and Aims: Only a small percentage of chronic hepatitis B (CHB) patients effectively respond to treatment with pegylated-interferon alpha (PegIFN alpha) or nucleos(t)ide analogues (NUCs). We aimed to detect the correlations of complement regulators-associated single-nucleotide polymorphisms (SNPs) with treatment response of hepatitis B e antigen (HBeAg)-positive CHB patients. Methods: A total of 1,763 HBeAg-positive CHB patients were enrolled, 894 received PegIFN alpha for at least 48 weeks and were followed up for 24 weeks, and 869 received NUCs for 104 weeks. For each patient, nine SNPs in genes encoding for complement regulators were determined and genotyped. To assess the cumulative effect of numerous SNPs, a polygenic score (PGS) was utilized. The correlations of SNPs and PGS with the levels of combined response (CR) and hepatitis B s antigen (HBsAg) loss were also investigated. Results: In PegIFN alpha-treated patients, an intronic SNP of CD55, rs28371597, was strongly related to CR, and the CR rate in rs28371597_GG genotype carriers was only approximately half that of rs28371597_GT/ TT genotype carriers (20.29% vs. 37.10%, p=2.00 x 10-3). A PGS incorporating CD55_rs28371597 and two additional SNPs, CFB_rs12614 and STAT4_rs7574865, which had been considered as predictors for PegIFN alpha treatment response before, was strongly correlated with the levels of CR (ptrend=7.94x10-6) and HBsAg loss (p-trend=9.40x10-3) in PegIFN alpha-treated patients. In NUCs-treated individuals, how ever, none of the nine SNPs were shown to be significantly linked to CHB treatment response. Conclusions: CD55_ rs28371597 is a promising biomarker for predicting CHB pa-tients' responsiveness to PegIFN alpha therapy. The updated PGS may be used for optimizing CHB treatment