Application of Six Hepatitis C Virus Genotyping Systems to Sera from Chronic Hepatitis C Patients in the United States

Abstract

Serum samples from 139 US patients with chronic hepatitis C virus (HCY) infection were studied using six different genotyping systems, including both molecular and serologic methods, to determine the applicability of these approaches and the prevalence of various HCY subtypes. The concordance of genotyping results based on the various systems (except for core polymerase chain reaction genotyping) was good (93.5%). Subtypes la and Ib were prevalent (37.4%). Subtypes 2a (2.2%), 2b (8.6%), and 3a (5.8%) were less common. HCY genotypes could not be determined in 3.4%-16.5% of samples depending on the method used. HCY type 2 was associated with greater histologic activity but lower serum HCY RNA levels (P < .05), whereas type 3 was associated with lower serum alanine aminotransferase levels (P < .05). These data demonstrate a high concordance between HCY genotyping systems and provide a foundation for comparison of genotyping data between studies using different systems. HCY types 1a and 1bare both prevalent in the United States.