PREDICTION OF RESPONSE DURING INTERFERON-ALFA 2B THERAPY IN CHRONIC HEPATITIS-C PATIENTS USING VIRAL AND BIOCHEMICAL CHARACTERISTICS - A COMPARISON

Patients with chronic hepatitis C (n = 103) were treated for 24 weeks with interferon alfa 2b and followed up for 24 weeks after cessation o f therapy (week 48). When hepatitis C virus (HCV) RNA at week 48 was u sed to assess interferon response, 15 (14.6%) were virological complet e responders, and all have remained HCV RNA negative for a mean of 3 y ears. At week 48, 3 of 15 virological complete responders had elevated alanine transaminase (ALT) values. When serum ALT level was used at w eek 48 to determine response to interferon, 20 (19.4%) were biochemica l complete responders. However, 8 of the 20 patients with normal ALT l evels were HCV RNA positive at week 48, and 7 of these individuals hav e had a recurrence of elevated ALT levels within 3 years after cessati on of treatment. These findings indicate that measurement of HCV RNA w as more accurate than ALT in determining true responses to interferon therapy. Identification of nonresponders early during the course of in terferon treatment showed that an elevated ALT level at week 12 was 92 % predictive (odds ratio 3.7) but misidentified 33% (5 of 15) of the p atients who were virological complete responders at week 48. In contra st, a positive HCV RNA at week 12 of treatment was 98% predictive (odd s ratio 35.5) and misidentified only 6.7% (1 of 15) of the virological complete responders. Thus, positive HCV RNA at week 12 of therapy was more accurate in identifying eventual virological nonresponders than measurement of ALT at this time. Termination of interferon therapy in patients who were HCV RNA positive at week 12 would result in a 27% re duction in the direct medical costs and keep patients from undergoing unnecessary treatment. Therefore, testing for HCV RNA at week 12 to id entify nonresponders and then discontinuing their treatment is practic al, cost-efficient and beneficial both to patients and to third-party payers.