This study confirms that polymorphisms in the ITPA gene are associated with protection from RBV-induced anemia in HIV/HCV-coinfected patients but not improved clinical outcomes.
Thus, genotyping information about single IL28B or ITPA variants is reproducibly and statistically significantly associated with hepatitis C therapy outcomes; however, the clinical predictive utility of single variants can be increased by combinations of genotypes.
Genome-wide association studies have recently identified genetic variants, most notably IL28B and ITPA, which will enhance the ability of clinicians to personalize antiviral therapy for HCV infection.
IL28B but not ITPA polymorphism is predictive of response to pegylated interferon, ribavirin, and telaprevir triple therapy in patients with genotype 1 hepatitis C.
An association between a single nucleotide polymorphism (SNP) in the inosine triphosphate pyrophosphatase (ITPA) gene and reduction of hemoglobin during peg-interferon plus ribavirin combination therapy for patients with chronic hepatitis C virus (HCV) infection has been reported.
Two functional variants in the inosine triphosphatase (ITPA) gene causing inosine triphosphatase (ITPase) deficiency protect against ribavirin (RBV)-induced hemolytic anemia and the need for RBV dose reduction in patients with genotype 1 hepatitis C virus (HCV).
Hepatitis C virus (HCV)-encoded nonstructural protein 3 (NS3) possesses protease, NTPase, and helicase activities, which are considered essential for viral proliferation.