Hepatitis C Information Central

HCV GENOTYPE and INTERFERON

GENOTYPE AND SERUM HCV RNA LEVEL ARE NEEDED BEFORE INTERFERON TREATMENT

The genotype of Hepatitis C virus (HCV) affects both the HCV RNA during interferon-a (IFN-alpha) treatment and serum HCV reduction rate RNA levels before such treatment, a study has shown.

Earlier studies have shown that the HCV genotype and pretreatment HCV RNA serum levels are significant for estimating response to IFN-alpha.

However, the rate of virologic response to such therapy relative to the actual HCV genotype is not known, noted Michinori Kohara, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan, and colleagues ("Hepatitis C Virus Genotypes 1 and 2 Respond to lnterferon-alpha with Different Virologic Kinetics," the Journal of Infectious Diseases, October 1995; 172(4):934-938).

Kohara et al. said that they studied the relationships between HCV RNA levels before treatment, the HCV genotype and rates of response to IFN-alpha therapy in patients with chronic HCV infection.

"The results of the present study indicate that the rate of reduction of HCV RNA during IFN- alpha treatment and serum HCV RNA levels before IFN-alpha treatment depend on HCV genotype," wrote Kohara et al. " HCV genotype and serum HCV RNA level (especially for genotype 1) should be determined before IFN-alpha treatment in order to provide the most effective treatment for HCV infected patients."

The findings of Kohara et al. confirm previously reported studies that have shown better response to IFN-alpha treatment in patients with low serum HCV RNA levels before treatment or with HCV genotype 2 (Lau, J.Y.N., et al., "Significance of Serum Hepatitis C Virus RNA Levels in Chronic Hepatitis C," Lancet, 1993;341:1501-1504; Kanai, K., et al, "HCV Genotypes in Chronic Hepatitis C and Response to Interferon," Lancet, 1992;339: 1543; and Yoshioka, K., et al., "Detection of Hepatitis C Virus by Polymerase Chain Reaction and Response to Interferon-alpha Therapy: Relationship to Genotypes of Hepatitis C Virus," Hepatology, 1992; 16:293- 299).

Chronic Hepatitis C virus infections: predictive value of genotype and level of viraemia on disease progression and response to interferon alpha.

Authors:

Booth JC, Foster GR, Kumar U, Galassini R, Goldin RD, Brown JL, Thomas HC Academic Department of Medicine, St Mary's Hospital Medical School, Imperial College of Science, Technology and Medicine, London. Gut 1995 Mar;36930:427-32 Article Number: UI95212969

Abstract:

The effects of Hepatitis C virus genotype and viraemia on disease outcome in patients with chronic Hepatitis C virus infection were studied.

Patients infected with genotype 1 tended to develop more severe disease, and to respond less well to interferon (IFN) treatment, but no pretreatment variable successfully predicted either the severity of the disease of the response to IFN. Failure to eliminate the virus during the first three months of therapy, however, predicted a failure to derive long term benefit from the current IFN regime. Hence pretreatment variables cannot be used to determine whether individual patients will respond to IFN, but observations during the first three months of therapy can be used to decide which patients will not respond to prolonged therapy. In these patients consideration should be given to changing the IFN dosing regime or using alternative treatments.