Ribavirin induced hemolysis is haptoglobin dependent

Abstract

sponsive to or relapsing after a minimum of 12 weeks of TIW interferon were enrolled in the North American RIBAHEP Study Group. Study subjects were randomized into the following treatment groups: DTIW received 1000 mgm ribavirin daily with 3 million units (MU) Intron A for 28 days followed by Intron A 3 MU for 44 additional weeks or TIW received 1000 mgm ribavirin daily with 3 MU Intron A TIW for 48 weeks. Results: Two hundred nine (209) of the enrolled patients have competed 48 weeks of treatment. Eighty-one (81) patients were HCV RNA negative at end of treatment week 12 (WI2R) and remained so at end of treatment week 48. Of this group twenty-five patients have completed follow-up week 24 with a sustained response rate (SR) of 80% (20/25). Twelve (12) patients who were HCV RNA positive at end of week 12 were negative at end of week 48 (LR). Eight (8) of these patients have completed follow-up week 24 with an SR of 50% (4/8). The following table compares characteristics of the above mentioned groups. Table: Observation: Comparison of week 12 responders and late responders suggests that LRs are more likely than WI2Rs to be patients with genotype I, who were not treated with daily interferon induction and/or who had no reduction of ribavirin dose. Though the number of patients evaluated for SR is small, it appears that LRs are less likely than WI2Rs to sustain their non-detectable HCV RNA status. Conclusions: eWeek 24 HCV RNA level is a better marker than week 12 HCV RNA level to identify patients who will clear HCV RNA after 48 weeks of combination therapy. eThe cumulative doses of interferon andlor ribavirin appear to be critical determinants in HCV RNA clearance, particularly in difficult to treat patients (i.e. those who are previous treatment non-responders or have HCV genotype I). elndividualization of treatment protocols based on the above observations may improve the individual outcome and over-all cost effectiveness of interferonlribavirin treatment.