Background/aims: To determine whether the initial response to interferon (IFN) therapy predicts the long-term response, monitoring of HCV RNA level in the early phase of IFN therapy was performed.
Methodology: Sixty-seven patients with chronic hepatitis C virus (HCV) infection were investigated. Patients received 6 MU of human lymphoblastoid IFN daily for 2 weeks and then three times weekly for 22 weeks (total dose; 480 U). These were 34 complete responders (CR) and 33 non-responders (NR). Serum levels of HCV RNA were assayed before therapy and at weeks 1 and 2, using the AMPLICOR HCV Monitor kit.
Results: Serum levels of HCV RNA were below the detection limit in 33 (97.1%) of 34 CR compared with 13 (39.4%) of 33 NR at week 1, and in 100% of CR compared with 17 (51.5%) of NR at week 2 (P < P0.05). These observations were independent with viral genotypes.
Conclusion: A complete response to IFN therapy results primarily from a rapid decrease in the serum levels of HCV RNA and a further decrease to below the detection limit by week 2 of the therapy. In spite of a viral genotype, early monitoring of serum levels of HCV RNA during IFN therapy are predictive of a subsequent long-term response to IFN in patients with chronic HCV infection.