Evaluation of the Applied Biosystems™ TaqPath™ Seq HIV-1 Genotyping Kit for HIV-1 drug resistance testing from dried...

Monitoring HIV drug resistance is crucial for HIV treatment success. Logistical challenges restrict the use of liquid venous blood specimens for HIV drug resistance (HIVDR) testing, but dried blood spots (DBS) offer a more accessible alternative. This study evaluates the performance of TaqPath™ Seq HIV-1 Genotyping Kit (TaqPath kit) for detecting resistance-associated mutations in the protease (PR), reverse transcriptase (RT), and integrase (INI) regions of HIV-1 pol gene using DBS specimens.

A total of 79 DBS samples collected from ART-naive and ART-experienced individuals with viral loads ranging from 2830 to 9,095,161 copies/mL and HIV-1 subtypes A, B, C, F, and CRF01_AE were genotyped with TaqPath kit. Performance was assessed using the WHO HIVDR assay validation criteria.

The assay met the amplification sensitivity criterion, achieving 95.7 % for PR/RT and 92.7 % for INI in high viral load samples. However, lower viral load samples between 2000 and 5000 copies/mL demonstrated reduced sensitivity of 50 % and 30 % for the PR/RT and INI regions respectively. Intra- and inter-assay agreement exceeded 99 % and mutation detection showed strong correlation with the reference assay, identifying over 95 % of reference mutations.

The TaqPath kit met the WHO acceptance criteria for HIVDR assay validation, except in the INI region at low viral loads, where amplification sensitivity was below the required threshold. Dried blood spot specimens are compatible with TaqPath kit for baseline and treatment-failure HIVDR genotyping, offering a reliable alternative to plasma in resource-constrained and remote settings.