Patient characteristics associated with peglyated interferon alfa-2a induced neutropenia in chronic hepatitis C patients.

Neutropenia is a haematologic disorder commonly reported in patients with chronic hepatitis C virus (HCV) infection treated with pegylated interferon alfa-2a (PEG-IFN alpha-2a). The objective of the present project is to identify patient characteristics associated with neutropenia in hepatitis C patients. Demographic, clinical, and genetic data from 715 patients with chronic HCV infection treated with PEG-IFN alpha-2a and ribavirin. The outcome variable was the development of grade 3 or 4 neutropenia, defined as the decrease in neutrophil counts below 110(9)/L anytime during study. Predictors of neutropenia were identified using a 2-stage approach. First, univariate analysis was performed to identify possible predictors of neutropenia. T test was used for continuous variables and Fisher's exact test was used for categorical variables. Second, multiple logistic regression with stepwise addition was then performed using predictors identified in the univariate analysis step to produce final model containing independent predictors at P < .05. Logistic regression identified female gender, absolute neutrophils counts, and cholesterol level as the main predictors of neutropenia. Female gender increases the odds of experiencing neutropenia by 86% compared to male gender. A 1 unit (mmol/L) increase in cholesterol level decreases the odds of developing neutropenia by 13%. A 55% reduction in the likelihood of developing neutropenia for a 1 unit (10(9)/L) increase in the absolute neutrophils counts. Patients with high risk of developing neutropenia can be identified. Identification of this cohort allows early intervention to prevent neutropenia. Possible intervention is to administer drugs that raise neutrophil count such as filgrastim before neutropenia occurs.