Abstract:
Chronic Hepatitis B (CHB) is an importance health problem. At present, the major drug for CHB is pegylated interferon (PEG-IFN). Several evidences indicated that host genetic factors associated with response to PEG-IFN treatment. This study aims to demonstrate the association between single nucleotide polymorphisms (SNPs) and PEG-IFN treatment response in CHB patients. The SNPs rs3077 in the Human leukocyte antigen-DPA1 (HLA-DPA1) gene and ss469415590 in the Interferon lambda 4 (IFNL4) gene were identified by TaqMan probe real-time PCR, whereas the SNPs G-201A in the promoter region of IFN-γ induces protein 10 (IP-10) gene and rs12979860 in the Interleukin-28B (IL28B) gene were identified by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). We retrospectively analyzed data of Thai patients with CHB treated with PEG-IFN for 48 weeks. Virological response (VR) for HBeAg-positive CHB was defined as HBeAg seroconversion plus HBV DNA level <2,000 IU/mL at 24 weeks post treatment. VR for HBeAg-negative CHB was defined as HBV DNA level <2,000 IU/mL at 48 weeks post treatment. A total 254 patients (107 HBeAg-positive and 147 HBeAg-negative) were enrolled in the study. In HBeAg-positive CHB, the GG genotype of G-201A in IP-10 was significantly associated with VR and pretreatment serum IP-10 level, whereas the other SNPs were not associated with VR. In HBeAg-negative CHB, the GG genotype of rs3077 in HLA-DPA1 was significantly associated with VR and HBsAg clearance. Besides, the GG genotype of G-201A in IP-10 was associated with baseline serum Alanine Aminotransferase (ALT) level but not associated with VR. There was no significant correlation between the IL28B or IFNL4 SNP genotypes and VR in both groups of patients. Therefore, these findings provided important evidence that SNP G-201A in IP-10 was associated with VR in HBeAg-positive CHB patients and SNP rs3077 in HLA-DPA1 was associated with VR in HBeAg-negative CHB patients and may help to identify predictors of treatment outcome, which will in turn significantly reduce the cost/effect of PEG-IFN therapy.