Distribution of hepatitis C virus genotypes in beta-thalassaemic patients from Northern India

Multitransfused beta-thalassaemic patients constitute a population having a higher prevalence of hepatitis C virus (HCV) infection because of its transmission from infected blood collected during seronegative window period. HCV genotyping in thalassaemic patients is mainly useful for the clinical management of the patients and for facilitating decisions on therapy. Thus, the aim of the present study was to identify the genotypes that are prevalent in thalassaemic patients and to correlate these with gender, age, number of blood transfusions and the liver function test profiles. Reverse transcription-polymerase chain reaction (RT-PCR) was carried out in 80 beta-thalassaemic patients (58 men and 22 women) for detection of HCV RNA who were seronegative for hepatitis B virus or human immunodeficiency virus antibodies. HCV genotyping was carried out by restriction fragment length polymorphism (RFLP) method of Chinchai et al. Type-specific PCR followed by direct sequencing was also used to confirm the mixed-genotype infection. Among the 80 thalassaemic patients, 20 and eight patients were infected with genotypes 3 and 1, respectively, whereas two cases had infection with HCV genotype1c/5a. The serum levels of aspartate aminotransferase, alanine aminotransferase and alkaline phosphatase were found to be significantly altered between the two groups of HCV-infected and noninfected thalassaemic patients. No significant correlation was observed between genotypes when compared with gender, age and number of blood transfusions, except significantly higher level of ALP in genotype 1 than in genotype 3. Genotype 3 alone was the predominant type in beta-thalassaemic patients, with approximately 45% being infected with mixed type. Hence, detection of HCV RNA would help in decreasing the transmission of HCV-infected blood collected during the seronegative window period, whereas determination of genotypes would provide help in adoption of different treatment policies for better management of thalassaemic patients.