Development of a cost-effective assay for genotyping of HIV-1 non-B subtype for drug resistance

Highly Active Antiretroviral Therapy (HAART) is the most effective way to control HIV-1 replication in infected patients. Prior to the start of therapy, genotyping of HIV-1 for mutations that confer resistance to potential drug candidates is crucial for it allows formulating an effective regimen. Ineffective drugs are excluded and potentially effective ones are included. A number of diagnostic kits are commercially available for this purpose but are tailored for HIV-1 subtype-B, a strain chiefly found in AIDS patients of Europe and America. However, AIDS patients of South-East Asia including Thailand are predominant infected with HIV-1 subtype non-B. In this study, an inexpensive assay was developed that genotypes HIV-1 non-B for drug resistance and tested it on 99 Thai AIDS patients. Results showed that 98 were infected with HIV-1 subtype non-B (or CRF01_AE) and one with subtype-B. Within the HIV-1 polymerase (pol), reverse transcriptase (RT) gene, the assay identified 18 codon mutations associated with resistance to Nucleoside/Nucleotide Reverse Transcriptase Inhibitors (NRTIs) and 17 Non-Nucleoside Reverse Transcriptase Inhibitors (NNRTIs). Employing a commercially available kit, parallel genotyping of patient samples confirmed results providing validation of the assay. This method approximately costs 100 US dollars compared to $300 for a commercially available test. In Thailand, the burden of cost for treating HIV-infections is high not only for the average citizen but the country's health care systems. Therefore the low cost and yet effective genotyping test for HIV-1 subtype non-B is a practical and viable solution to expensive genotyping platforms.