Differences between interferon-alpha and -beta treatment for patients withchronic hepatitis C virus infection

To compare virological, biochemical, and immune responses to human lymphobl astoid interferon (IFN-alpha) and human fibroblast interferon (IFN-beta) in patients with chronic hepatitis C virus (HCV) infection, 120 patients were randomly assigned to three groups (group A, 60 patients receiving IFN-alph a, 6 million units (MU) once a day, daily for one month and thrice weekly f or five months; group B, 40 patients receiving 6 MU IFN-beta once a day dai ly for two months; and group C, 20 patients receiving 3 MU IFN-beta twice a day (6 MU/day) daily for two months). Serum soluble interleukin-2 receptor (sIL-2R) and interleukin-6 (IL-6) Levels were measured by enzyme-linked im munosorbent assay. Patients with sustained clearance of serum HCV RNA detec ted by polymerase chain reaction (PCR) at six months after IFN treatment we re defined as having complete response to IFN treatment. A row level of HCV RNA (less than or equal to 10(4) copies/50 mu l, measured by competitive P CR) and HCV RNA of genotype 2a were favorable factors for a complete respon se to both IFNs. Complete response in group A treatment was strongly associ ated with early HCV RNA clearance, in contrast with group B. A significantl y higher HCV RNA negativity at the second week from start of treatment was noted in group C (80.0%), compared with groups A (41.6%) and B (27.5%). sIL -2R levels rose in each group during IFN administration. In group C, alanin e aminotransferase (ALT) and IL-6 levers were remarkably elevated. These fi ndings indicate that timing of serum HCV RNA negativity in sustained respon se differs between IFN-alpha and IFN-beta administrations and that early HC V RNA clearance was induced by twice-a-day IFN-beta treatment.