Analysis of HCV Genotype with Low Titer of HCV RNA Using the Methods of Concentration

Abstract

Analysis of HCV genotypes can help identify infection routes and the development of treatment methods. However, in some samples with a low titer of HCV RNA, it is difficult to analyze their genotypes. In our previous study about HCV genotyping, we could not identify 12 cases among the 175 HCV NAT reactive samples due to their low titer. In this study, we adopted three different kinds of virus concentration methods to identify the genotypes of the 12 unidentified cases and compared their efficacy. The three virus concentration methods were automatic nucleic acid extraction, polyethyleneimine-magnetic bead-based extraction, and sucrose cushion ultracentrifugation. After virus concentration using every three methods, we analyzed HCV RNA genotypes using the concentrated sample of the best efficacy. Among the 12 cases, six were identified as 1b, four as mixed types, and two were unidentified. Here we could validate that the sample concentration method is useful to identify the HCV genotypes, especially in samples with low HCV RNA titers. Furthermore, considering the convenience, high efficacy, and time-saving, automatic nucleic acid extraction is considered the most useful concentration method for samples with titer lower than 50 IU/mL. (Korean J Blood Transfus 2021;32:43-48)