Background The standard treatment for chronic viral hepatitis C (VHC) infection is peginterferon alfa 2a 180 μg or peginterferon alfa 2b 1.5 μg/kg once a week and ribavirin once a day. One of the most important side effects of the treatment is neutropenia due to peginterferon, which is sometimes a reason to discontinue the treatment.

Purpose To record the incidence of neutropenia due to the use of peginterferon in patients who are being treated for chronic VHC infection and to analyse from which neutrophil count doctors introduce neutrophil granulocyte colony-stimulating drugs, change or discontinue the treatment.

Materials and methods Retrospective observational study of patients with chronic VHC infection who were receiving treatment with peginterferon alpha 2a or peginterferon alfa 2b between January 2010 and December 2010. Demographic data such as sex, age and body weight were collected. Other data collected were the viral genotype, initial and final treatment and neutrophil count during the treatment period (neutropenia was defined as neutrophil count less than 1.5 × 10³ μL).

Results 65 patients were included, 42% women and 58% men with average age of 46.6 years. 48 patients were excluded due to being younger than 18 years or having renal disease and because some patients were lost during the follow-up period. In relation to viral genotype, 56.9%, 1.5%, 40% and 1.5% were genotype 1, 2, 3 and 4 respectively. 74% of patients were treated with peginterferon alfa 2a and 26% of patients were treated with peginterferon alfa 2b.

The incidence of neutropenia was 66% (48.8% developed grade 2 neutropenia (1.5 - 1 × 10³ μL) and 51.2% grade 3 (1 - 0.5 × 10³ μL)). Modifications of the treatment were compiled in 23% of patients who developed neutropenia: the peginterferon dose was reduced in 5 patients, filgrastim was added in 2 patients and both measures were used in 3 patients. A relationship between the neutrophil count and the type of corrective measure was not observed.

Conclusions The incidence of neutropenia during the treatment with peginterferon is significant (66%) and corrective measures were taken in 23% of the patients who developed this side effect. However there was no relationship between the neutrophil count and the decision to start a corrective measure or the type of measure taken. This suggests that symptoms of neutropenia are the most important reason to start corrective measures.

No conflict of interest.