Natural History of Anemia Associated with Interferon/Ribavirin Therapy for Patients with HIV/HCV Coinfection

The natural history of anemia related to interferon/ribavirin (IFN/RBV) treatment in patients with human immunodeficiency virus/hepatitis C virus (HIV/HCV) coinfection is not completely understood. The current 8-week, multicenter, observational study characterized anemia over the course of HCV treatment in patients with HIV/HCV coinfection. Eligible HIV/HCV coinfected patients were receiving care in community-based and academic institutions and were on stable antiretroviral therapy and initiating IFN/RBV therapy. Hb, sEPO, reticulocytes, transfusions, laboratory values (e.g., total bilirubin), and IFN and RBV dosages were monitored weekly. Ninety-one patients were analyzed (mean age, 46 years; 71% on HAART) and 53 patients completed the study. Mean Hb decreased significantly (5.0 g/dl) within 1 week of initiating IFN/RBV therapy (p = 0.0002); Hb nadir occurred at a median of 37 days. Maximum Hb decreases of ≥2.0 g/dl occurred in 56 (62%) patients and ≥3.0 g/dl occurred in 45 (49%) patients. Reticulocyte count increased within the first 2 weeks and sEPO peaked at week 3. Mean increase from baseline to week 2 in reticulocyte count and sEPO, respectively, was 1.3% (n = 74) and 45.0 mIU/ml (n = 80) (p < 0.0001 for each parameter), and from baseline to week 8 was 0.9% (n = 48) and 41.0 mIU/ml (n = 52) (p ≤ 0.0001 for each parameter). Adverse events (AEs) were the most common reason for study discontinuation (66% of discontinuing patients). Among the 25 patients who discontinued due to AEs, 84% discontinued due to anemia (n = 21). Significant decreases in Hb were observed in HIV/HCV-coinfected patients within 1 week of initiating IFN/RBV therapy. sEPO and reticulocyte increases were blunted in response to anemia; Hb levels did not return to baseline values and anemia was a frequent reason for discontinuing the study.