Associations of ITPA gene polymorphisms with outcomes among chronic hepatitis C patients treated with Peg-interferon/ribavirin: A 5-year follow-up study

To investigate associations between inosine triphosphatase (ITPA) gene polymorphisms and long-term outcomes among chronic hepatitis C (CHC) patients in Northeast China treated with Peg-interferon (IFN)/ribavirin (RBV). CHC patients who received Peg-IFN-2a/RBV treatment during between 2011 and 2013 at 5 hepatitis centers in Northeast China were enrolled. ITPA single nucleotide polymorphisms rs1127354 and rs7270101 from all patients were detected and their associations with 5-year outcomes were analyzed. A total of 635 patients, including 421 infected with hepatitis C virus (HCV) genotype 1 and 214 infected with non-genotype 1 were included. No significant differences were observed in the distribution frequencies of ITPA rs1127354 variants and ITPase activity between patients with HCV genotype 1 and non-genotype 1. In patients who received more than 80% of the planned RBV dose, the 5-year virological response rate and the improvement in liver fibrosis were higher in those with ITPA rs1127354 non-CC with ITPase activity <25% compared with these outcomes in patients with ITPA rs1127354 CC with 100% ITPase activity. Multiple regression analysis revealed that HCV genotype non-1, low baseline HCV ribose nucleic acid (RNA) levels (≤4 × 10(5) IU/mL), interleukin-28B rs12979860 CC genotype, low baseline liver fibrosis (Fibroscan 0-2), and ITPA rs1127354 non-CC genotype were independent predictors for a high long-term virological response rate, whereas interleukin-28B rs12979860 CC genotype, ITPA rs1127354 non-CC genotype, and low baseline liver fibrosis were independent predictors for improvement of liver fibrosis. ITPA rs1127354 polymorphisms is predictors of long-term outcomes in CHC patients treated with Peg-IFN/RBV.