Interferon-Containing Regimens in Patients with Hepatitis C Associated with Reduction in Lung Function

Interstitial lung disease (ILD) is a known rare side effect of interferon treatment. Investigators confirmed the low incidence if ILD in patients with hepatitis C receiving interferon, but also recorded reductions in lung function in almost half of treated patients.

Foster et al published a recent article on reports of declining pulmonary function in patients with hepatitis C virus (HCV) receiving treatment with interferons and ribavirin. Investigators split 391 patients into 4 treatment groups receiving 24 weeks of therapy. Three groups received ribavirin and albinterferon alfa-2b at 3 different dosage levels and the 4th group received ribavirin with peginterferon alfa-2a. At baseline, 12 weeks, 24 weeks, and 6 months, investigators measured lung function with spirometry, chest x-ray, and diffusing capacity of the lung for carbon monoxide.

In each of the 4 groups, 3% to 7% of patients withdrew from the study before completion. This study was powered to detect a 2% incidence of interstitial lung disease. A confounding factor in the analysis was that almost one-third (29%) of patients were smokers.

Lung diffusion capacity declined in almost half (48%) of patients. A patient taking albinterferon at the highest dose experienced a case of serious restrictive pulmonary disease 1 month after starting therapy. Three months after starting therapy, the patient’s lung problem led to hospitalization. Although the patient had features of interstitial lung disease, including interstitial tissue abnormalities on a chest x-ray, the diagnosis was not confirmed because the patient did not receive a lung biopsy.

Interstitial lung disease is a known rare side effect of interferon alfa and pegylated interferon alfa. This study shows that the incidence of interstitial lung disease is very likely lower than 2%, but the incidence of clinically relevant reductions in lung function may extend to almost half of patients receiving a standard regimen of interferons for HCV. In addition to the known side effects of interferons, including flu-like symptoms, the risk of interstitial lung disease and reduced lung function may prompt some patients with HCV to wait for approval of an interferon-free regimen before seeking treatment.