Neutropenia (low white blood cell levels) is a common complication of treatment with PegIFN/RBV for hepatitis C virus infection. Because research had not addressed whether this neutropenia promotes infection in people with HCV and HIV, researchers in Madrid conducted this prospective cohort study from 2000 through 2012.
The investigators defined serious infections as those requiring hospital admission, requiring discontinuation of PegIFN/RBV, or causing death. They defined severe neutropenia as a white cell count below 500 cells/μL, while nonsevere neutropenia meant a count between 500 and 1500 cells/μL.
The study involved 418 people receiving PegIFN/RBV for 3928 person-weeks. The researchers recorded 149 infections in 123 people (29%) for an infection incidence of 3.8 per 100 person-weeks of therapy, meaning almost 4 of every 100 people got an infection every week. Almost half of infections (47%) involved the upper respiratory tract and were minor.
To identify factors associated with infection, the researchers conducted a logistic regression analysis adjusted for age, gender, CD4 count, AIDS, antiretroviral therapy, cirrhosis, neutrophil count, type of PegIFN, and granulocyte colony-stimulating factor use. None of these factors was independently associated with infection.
Twenty study participants (4.8%) had a serious infection. Serious infections were more frequent in people with severe neutropenia (8.6%) than in those with nonsevere neutropenia (4.8%) or without neutropenia (3.6%), but these differences were not statistically significant (P = 0.28). Multivariate analysis identified no factors independently associated with increased risk of serious infection.
“In this large prospective cohort of HIV/HCV-coinfected patients treated with peg-IFN plus RBV,” the researchers conclude, “serious infections were uncommon, nonfatal, and unrelated to peg-IFN-induced severe neutropenia.”
Source: Sergio Serrano-Villar, Carmen Quereda, Ana Moreno, María Jesús Pérez-Elías, José Luis Casado, Ana Royuela, Fernando Dronda, Enrique Navas, José Manuel Hermida, Santiago Moreno. Neutropenia during therapy with peginterferon and ribavirin in HIV-infected subjects with chronic hepatitis C and the risk of infections. Clinical Infectious Diseases. 2013; 57: 458-464.