Use of pegylated interferons is associated with an increased incidence of infections during combination treatment of chronic hepatitis C: a side effect of pegylation?

Standard interferon treatment is known to increase the risk of infections; this risk also needs to be evaluated in clinical practice for pegylated interferon. To this end, we studied 255 patients treated with standard (103) or pegylated (152) interferon, in combination with ribavirin, for hepatitis C. Overall, 31 anti-hepatitis C virus treatment-related infections were observed. Neutropenia (neutrophil counts below 1x10(3) cells/ml) was observed in a significantly higher proportion of patients treated with pegylated interferons (48% vs 9%; P=0.0009). Of the 31 infections, eight were respiratory infections and were observed only in patients with neutropenia. None of the non-respiratory infections was observed in patients with neutropenia. Multivariate analysis, using Cox's proportional hazards regression model, found a higher risk of all infections associated with both use of pegylated interferons [hazard ratio (HR) 4.6] and neutropenia (HR 2.46). However, neutropenia was independently associated with acute respiratory infections only and use of pegylated interferons with non-respiratory infections. In summary, use of pegylated interferon appears to increase the risk of non-respiratory infections independently from neutropenia.

Severe hepatotoxicity during combination antiretroviral treatment: incidence, liver histology, and outcome.

OBJECTIVES: To assess incidence, risk factors, histology, and outcome of severe hepatotoxicity (SH) during antiretroviral treatment (ART). METHODS: Seven hundred fifty-five HIV-seropositive patients consecutively prescribed new ART were selected. Liver function tests were assessed at baseline, after 1 month, and every 4 months thereafter. Liver biopsy was recommended in case of SH (i.e., increase in liver enzymes >/=10 times the upper limit of normal or 5 times baseline if markedly abnormal). RESULTS: Twenty-six cases of SH were observed with an incidence of 4.2% person-years. Liver failure (LF) was rarely seen (1.1 per 100 person-years). Liver damage was invariably observed in patients with chronic viral hepatitis. Liver histology showed exacerbation of viral hepatitis in all 16 patients for whom a liver biopsy was available at the time of SH. A direct correlation was found between alanine aminotransferase increase and increase in CD4 T-cell count in patients with SH (r = 0.53, p <.001). Death occurred during follow-up in 7 of 26 (27%) patients, all of whom showed LF and baseline CD4+ count less than 200 cells/mm(3) (7/7 patients = 100% vs. 8/19 patients without LF; p <.01). Relapse of SH was observed after ART was recommenced in 7 of 17 (41%) patients. Five of these 7 patients did not show further SH relapse after treatment with interferon. CONCLUSIONS: This study provides estimates of SH and LF in a large population-based setting where hepatitis C virus coinfection is highly prevalent and provides indications that liver damage may be caused by immune reconstitution and related exacerbation of viral hepatitis. A strict follow-up for hepatotoxicity is mandatory when ART is initiated in patients with <200 CD4+ T cells/mm(3). Antihepatitis pre- or comedication could be an effective preventive or curative measure.