Clinical

Serum ribavirin level impacts outcome in HCV-HIV coinfection

Last Updated: 2008-10-08 15:53:43 -0400 (Reuters Health)

NEW YORK (Reuters Health) - The serum concentration of ribavirin influences the outcome of treatment of hepatitis C virus (HCV) genotype 1 or 4 infection in HIV-positive patients, results of a study indicate.

A ribavirin concentration of 2,300 ng/mL or less is a "strong predictor of nonresponse" in this patient population, the study team notes in the September issue of the Journal of Medical Virology.

Measuring serum ribavirin concentrations in these "difficult-to-treat patients could be used to optimize the ribavirin dose and so increase the probability of success," Dr. Florence Nicot from INSERM, Toulouse, France and colleagues conclude.

They investigated the relationship between serum ribavirin and pegylated interferon concentrations 3 and 6 months after the start of treatment, and treatment outcome in 35 HCV-HIV coinfected patients.

The serum levels of interferon were similar at 3 and 6 months, as were levels of ribavirin, although levels varied widely between patients.

Results showed no influence of the pegylated interferon concentration on treatment outcome, which is in keeping with a recent study, the authors note.

The ribavirin concentrations, on the other hand, tended to be higher in responders (2,322 ng/mL) than nonresponders (1,833 ng/mL). Moreover, responders infected with HCV genotype 1 or 4 had significantly higher ribavirin concentrations (2,672 ng/mL) than did similarly infected nonresponders (1,758 ng/mL).

"The ribavirin concentration could be important for predicting treatment outcome in patients infected with HIV and HCV genotype 1 or 4," Dr. Nicot and colleagues conclude.

In their study, a ribavirin concentration of 2,300 ng/mL was the best threshold for predicting a nonresponse in these patients, they note, adding that 86% of the patients with a concentration below this threshold were nonresponders.

J Med Virol 2008;80:1523-1529.