Induction of inosine triphosphatase activity during ribavirin treatment for chronic hepatitis C

Abstract

BackgroundRibavirin (RBV) is an antiviral agent and the primary component for chronic hepatitis C (CHC) therapy. Hemolytic anemia is limitation for RBV treatment. Inosine triphosphatase (ITPA) activity has been associated with severity of RBV-induced anemia. However, changes in ITPA activity during CHC therapy are unknown. The aim of this study was to measure the time-dependent change in ITPA activity over the RBV treatment. MethodsForty-two patients with CHC were evaluated for ITPA activity over the course of RBV treatment. ResultsThe median value of ITPA activity at start of RBV treatment was 134.2 μmol/h/g hemoglobin (Hb; range, 26.3–251.0 μmol/h/g Hb). The ITPA activity values at 4, 8, and 12 weeks during RBV treatment were 143.2, 202.2, and 225.7 μmol/h/g Hb, respectively, and these ITPA values were significantly elevated compared with the start of treatment (p < 0.001). In patients with ITPA variants, patients with anemia (Hb < 10 g/dL) had greater elevated ITPA activities compared with patients without anemia at 12 weeks. ConclusionOur findings indicate that ITPA activities are elevated with RBV therapy, and this elevation may be a risk of anemia in late therapeutic phase in patients that began with low ITPA activity.