Comparative Evaluation of the ViroSeq™ HIV-1 Genotyping System and an In-House Method for Analysis of HIV-1 Drug-Resistance Mutations in China

Background and Objective: With the introduction of the ViroSeq (TM) HIV-1 Genotyping System (ViroSeq (TM) assay) into China, it is important to evaluate the impact of the diversity of HIV-1 genotypes found in China on the performance of the ViroSeq (TM) assay compared with an in-house method. Materials and Methods: A total of 318 plasma samples, collected from 206 HIV-1-infected patients receiving antiretroviral therapy and 112 treatment-naive HIV-1-infected patients, were used for evaluating the concordance of genotypes, genotypic resistance mutations, and phenotypic resistance between the ViroSeq (TM) assay and an in-house method for analyzing HIV-1 drug resistance in China. Results: A concordance of genotypes between the ViroSeq (TM) assay and the in-house method was observed for the 313 samples (98.4%), using the Stanford University HIV Drug Resistance Database (Version 6.0.5). The overall concordances of drug-resistance-related mutations (DRRMs) in the HIV-1 protease (PR) and reverse transcriptase (RT) coding sequences within the HIV-1 pol gene, scored by the ViroSeq (TM) assay and the in-house method, were 99.5% and 98.1%, respectively. Discrepancies between the two methods were found in 38 samples assayed for protease inhibitor (PI) DRRMs, 36 samples assayed for nucleoside reverse transcriptase inhibitor (NRTI) DRRMs, and 72 samples assayed for non-nucleoside reverse transcriptase inhibitor (NNRTI) DRRMs, and 100%, 88.9%, and 87.5% of the samples with discrepancies for PI, NRTI, and NNRTI DRRMs, respectively, were genotyped as subtype B. One NNRTI mutation (the RT mutation Y318F) was reported only by the ViroSeq (TM) assay, and this discrepancy resulted from the difference in the pol gene lengths generated by the two systems. Furthermore, the overall concordance of phenotypic resistance was 94.7% (301/318) between the two methods. Conclusion: The ViroSeq (TM) assay will be a useful tool for monitoring clinical drug resistance and for better management of HIV-1 patients receiving antiretroviral therapy in China.