African Americans with genotype 1 treated with interferon for chronic hepatitis C have a lower end of treatment response than Caucasians

African Americans as a group have a higher incidence of chronic hepatitis C (CHC) than Caucasians but are often under-represented in clinical trials u sed to define response rates to interferon therapy. The aim of this study w as to compare African Americans with Caucasians with respect to end-of-trea tment response to interferon. This retrospective study had 61 African Ameri cans and 49 Caucasians with CHC. All patients were treated for at least 12 weeks with interferon-alpha 2b (Intron A) thrice weekly. End-of-treatment r esponse was defined as three consecutive nondetectable HCV RNA measurements at least 1 month apart. Sustained response was defined as a negative serum HCV RNA 6 months after end of treatment. Of the 110 patients, 19 achieved an end-of-treatment response (17%) but only four achieved a sustained respo nse (4/110=4%). Of the patients achieving a sustained response, one was gen otype 1 (male Caucasian), three were genotype 2/3 with four patients having no follow-up information. The end-of-treatment response was 7% for patient s with genotype 1 and 71% for genotype non-1 (P < 0.005 for genotype non-1) . The end-of-treatment response was significantly higher in Caucasians (14/ 49=31%) compared with African Americans (5/61=8%; P < 0.05). A lower respon se rate in African Americans with genotype 1 in contrast to Caucasians was the primary reason for the difference in end-of-treatment response (1/45=2% vs. 5/33=15%, P < 0.05). Hence, interferon treatment resulted in a poor su stained response rate in the group of patients representative of the urban populations with the highest prevalence of hepatitis C. A genotype other th an type 1 was the strongest predictor of end-of-treatment response in patie nts treated but over 86% of patients in this urban clinic were genotype 1. Caucasians were more likely to respond than African Americans, especially i n patients with genotype 1.