Impact of HIV-1 Genetic Diversity in China on the Measurement of Viral Load

In this study, 190 HIV-positive samples were collected from different regions of China. The HIV clades of 153 samples were determined successfully based on env sequencing. Specifically, 48, 5, 87, and 13 isolates belonged to clades B 0 , B, BC, and AE, respectively. The viral loads in all samples were measured using three commercial assays, Amplicor HIV-1 monitor v1.5, Nuclisens HIV-1 QT and NucliSens EasyQ HIV-1 assays. The differences and linear correlations for individual assays were compared, with expected 1:1 relationships. Significant differences were found for the following viral loads: clade BC measured by any two assays (P <0.001); clade AE between Amplicor 1.5 and Easy Q (P ¼0.005); clade B 0 between Amplicor 1.5 and Nuclisens QT (P ¼ 0.002); clade AE between Amplicor 1.5 and Nuclisens QT (P ¼0.025); and clade B 0 between Amplicor 1.5 and EasyQ (P ¼0.04). The largest mean difference in the log10 values was 0.9518, which was found between Amplicor 1.5 and Nuclisens QT. However, the viral loads for clades AE and B 0 measured by EasyQ and Nuclisens QT,