Background and aim: Conventional hepatitis C treatment using pegylated interferon (PEG-IFN) and ribavirin is associated with significant side effects. IL28B polymorphism can predict response to treatment, with CC genotype having a better response. ITPA gene deficiency protects against clinically significant anaemia induced by treatment. The purpose of this study was to determine IL28B polymorphism and ITPA variation among hepatitis C genotype 1 patients who have undergone therapy with PEG-IFN and ribavirin and their association with sustained viral response (SVR). Methods: All hepatitis C genotype 1 patients who had been treated with PEG-IFN and ribavirin over the past 10 years were identified by available medical records and were contacted by letter of invitation to participate in the study. Blood samples for IL28B and ITPA genotyping were obtained. Medical records were reviewed for verification of treatment response, development of anaemia and if treatment reduction was required during the treatment. Results: A total of 61 patients with hepatitis C genotype 1 were treated with PEG-IFN and ribavirin, of whom 42 agreed to participate in the study. Mean age was 45.6±12.9 years at time of treatment, and 83.3% of patients were males. Thirty-three (78.6%) had IL28B CC genotype, of whom 25 (75.8%) obtained SVR compared with only 3 of 9 (33.3%) non C/C genotype patients who achieved SVR (P=0.041). Eleven (26.1%) patients had ITPA AC genotype, and 30 (71.4%) had CC genotype. There was no statistically significant difference between ITPA AC and CC genotypes in predicting clinically significant anaemia (45.5% vs 63.3%, P=0.302). Even among patients who developed anaemia, 70.8% still managed to achieve SVR. Treatment reduction also had no impact on SVR. Conclusion: Hepatitis C genotype 1 patients should be informed of the response rate for treatment with PEG-IFN and ribavirin in a population with favourable IL28B genotype before consideration of newer therapeutic options.
Keywords: IL28B polymorphism; hepatitis C; pegylated interferon; sustained viral response.