BREAKTHROUGH DURING RECOMBINANT INTERFERON-ALFA THERAPY IN PATIENTS WITH CHRONIC HEPATITIS-C VIRUS-INFECTION - PREVALENCE, ETIOLOGY, AND MANAGEMENT

Recombinant interferon alfa (r-IFN alpha 2) has been shown to normaliz e the aminotransferase levels in approximately 50% of patients with ch ronic hepatitis C virus (HCV). Few patients experience a relapse durin g the treatment, in spite of a complete initial response (breakthrough ). We studied 191 HCV Ab-positive patients with histologically proven chronic hepatitis. Ah of them were treated with r-IFN alpha 2 (3 MU th ree times a week), A complete response was seen in 54.4%. However, 12 of 104 responders experienced a breakthrough. At the time of breakthro ugh, neutralizing IFN antibodies were positive in 6 of 12 patients. Bi nding IFN antibodies were positive in all of these 12 patients. Contin ued treatment with r-IFN alpha 2, even at higher doses, did not restor e the previous response in any patient. All of them were then switched to natural lymphoblastoid IFN, and this rapidly restored a complete r esponse in all of the patients.