Early Predictors of Anemia in Patients with Hepatitis C Genotype 1 Treated with Peginterferon Alfa-2a (40KD) Plus Ribavirin

Objective: Adherence to ribavirin is one factor that is critically important in the treatment of hepatitis C virus infection. However, ribavirin can be associated with clinically significant hemolytic anemia resulting in dose modifications in up to one-quarter of patients. Currently, baseline predictors of considerable anemia are not sufficiently discriminating for routine therapeutic intervention. The objective of this analysis was to elucidate baseline and on-treatment factors predictive of a considerable hemoglobin drop at week 4.

Methods: Multivariate logistic regression analysis was used to explore possible predictors for considerable hemoglobin decline (> or =2.5 g/dL) at week 4 among patients receiving peginterferon alfa-2a (40KD) and ribavirin (1,000/1,200 mg/day).

Results: A total of 555 patients were included in this analysis. At week 4, 236 patients exhibited a > or =2.5 g/dL decrease in hemoglobin. By regression analysis the most important independent variables associated with a decrease in hemoglobin of > or =2.5 g/dL were baseline creatinine clearance (P= 0.0003) and a rapid decline in hemoglobin of > or =1.5 g/dL at week 2 (P < 0.0001). Considerable hemoglobin decreases at week 4 were also significantly associated with early ribavirin dose reductions and a lower cumulative daily dose of ribavirin.

Conclusion: Patients with impaired renal function may be at an increased risk of ribavirin-related anemia and should be monitored accordingly. Furthermore, a hemoglobin drop of > or =1.5 g/dL by week 2 was an excellent early predictor for subsequent considerable hemoglobin decreases and might be used to identify candidates for early intervention against anemia in order to help maintain ribavirin dosing and avoid suboptimal exposure.