Can Ribavirin-related anemia predict a sustained viral response in chronic hepatitis C treated with Peginterferon plus Ribavirin?

Introduction: Ribavirin (RBV) synergistically enhances the antiviral activity and the sustained viral response (SVR) rate of interferon-based treatment in pts with chronic hepatitis C (CHC), but may also lead to dose-dependent hemolytic anemia as a major side-effect. The interindividual RBV bioavailability is highly variable, and in some pts treated with the recommended doses of pegylated interferon (PEG-IFN) + RBV neither RBV-related anemia nor SVR can be experienced, suggesting a lower-than-optimal RBV effect.

Aim: To assess whether the lack of anemia or a negligible fall in hemoglobin (hb) level during PEG-IFN + RBV therapy can predict a lack of SVR in pts with CHC. Patients: 174 consecutive CHC pts treated with PEG-IFN + RBV (89 PegIntron + Rebetol and 85 Pegasys + Copegus) for at least 16 weeks, with laboratory controls every 4 weeks. All were abstainers and free from coinfections with human immunodeficiency or hepatitis B virus. None of them received erythropoietin for anemia correction.

Results: In this group of unselected pts, the overall SVR rate was 40.2%. The initial hb level was 144±13g/l (mean±SD). At the end of the 12th week, the average fall in hb was 28.6g/l (20%; range:-13 to 65g/l). Thirty one pts (17,8%) had experienced a ≥30%, and 33 (18.9%) a ≤10% fall in hb, respectively. No range of hb alteration exhibited any statistically significant correlation with the attainment of SVR. There was no statistically significant difference in the fall in hb level between the pts with an SVR, non-respone or relapse.

Conclusions: The results demonstrate that the hb-lowering effect of RBV does not correlate with the antiviral potency of PEG-IFN + RBV combination therapy, and thus the assessment of hb changes cannot substitute the monitoring of circulating RBV concentration in attempting an antivirally more optimal dosing of the drug.