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ICAAC 2012: Infections are Common among HIV/HCV Coinfected Patients on Interferon

Life-threatening infections occur frequently among people with HIV and hepatitis C virus (HCV) coinfection during treatment with pegylated interferon plus ribavirin, but this does not appear to be a consequence of neutropenia, or loss of white blood cells, according to a poster presented at the 52nd Interscience Conference on Antimicrobial Agents and Chemotherapy (ICAAC 2012) this month on San Francisco.

Neutropenia and other blood cell deficiencies are well-known potential side effects of interferon-based therapy. Loss of pathogen-fighting neutrophils increases the risk of bacterial and other types of infections. People with HIV/HCV coinfection may fare worse because they also have impaired T-cell function.

Sergio Serrano-Villarfrom Hospital Universitario Ramón y Cajal in Madrid and colleagues conducted a prospective study that included 418 HIV positive patients with chronic hepatitis C who started treatment with pegylated alfa-2a (Pegasys) or alfa-2b (PegIntron) plus ribavirin between 2000 and 2011.

The participants had a median age of 41 years and most (88%) had a history of injection drug use. They had well-preserved immune function at baseline, with a median CD4 T-cell count close to 500 cells/mm³ (ranging from 342 to 696 cells/mm³).

Results

• About one-third of study participants (30%) developed at least 1 infection during interferon treatment.
• 163 infections were observed in 122 patients, indicating that several people had more than 1.
• The median time to the first infection was 12 weeks.
• The largest proportion -- about one-third -- were respiratory tract infections, including 8 cases of pneumonia.
• In addition, 12% people herpes simplex virus (HSV) or varicella zoster virus (VZV) infection, 6% had dental or gingival (gum) infections, and 6% developed acute gastroenteritis.
• 4% of all infections were classed as severe, including 1 case of Fournier gangrene.
• Nearly half of participants developed serious grade 3 or 4 neutropenia, or the World Health organization classification of < 1000 neutrophils/mL.
• Risk of infection, however, was the same for patients with and without neutropenia (69.6% vs 69.8%, respectively).
• 15% of patients with neutropenia received granulocyte colony-stimulating factor (G-CSF) to promote white blood cell production, which successfully raisedneutrophil counts.
• In a multivariate analysis adjusting for age, sex, presence of neutropenia, CD4 count, and use of antiretroviral therapy and G-CSF, none of these variables were significant predictors of infection risk.

"Infections are a common complication of treatment with [pegylated interferon/ribavirin] in HIV/HCV coinfected patients," the researchers concluded. "Most infections take place within the first 12 weeks of treatment and are exceptionally life-threatening." However, they added, pegylated interferon-induced neutropenia was not associated with the risk of infection."

9/28/12

Reference

S Serrano-Villar, CQuereda, A Moreno, et al. Neutropenia During Therapy with PegIFN and RBV and the Risk of Infections in HIV-infected Subjects with Chronic Hepatitis C (CHC). 52nd Interscience Conference on Antimicrobial Agents and Chemotherapy (ICAAC 2012). San Francisco. September 9-12, 2012. Abstract H-217.