Comparison of in-house HIV-1 genotypic drug resistant test with commercial HIV-1 genotypic test kit.

Background: The use of combination antiretroviral therapy (cART) has become a standard of care in the treatment of HIV infection. However, antiretroviral drug resistance occurs in a substantial number of patients. In resourcelimited settings, genotypic resistance assay using a commercial kit is costly. Objective: Focus on the validation of an in-house HIV-1 specific genotypic drug resistance assay in Thai patients failing cART. Materials and methods: Results of HIV-1 genotypic drug resistance assay was evaluated by comparing an inhouse method to a commercial test. The TRUGENE HIV-1 genotyping kit was used in 79 plasma specimens (49 from HIV patients failing cART therapy and 30 from proficiency testing panels). Results: The results from the in-house assay were comparable to those obtained from the TRUGENE HIV-1 genotyping kit with >99.0% codon-to-codon agreement. The lower limit of detection by the in-house assay was approximately 100 copies/mL of HIV-1 RNA. In addition, this in-house assay would allow testing of samples from patients infected with HIV-1 subtype other than B. Conclusion: The in-house HIV-1 genotypic drug resistance assay may be used as an alternative to commercial kits, particularly in resource limited settings.

Frequencies of IL10 SNP genotypes by multiplex PCR-SSP and their association with viral load and CD4 counts in HIV-1-infected Thais.

Background: Interleukin (IL)-10 is an immuno-regulatory cytokine, levels of which can be influenced by single nucleotide polymorphisms (SNPs) in the promoter. Some, but not all previous studies have shown associations of IL10 SNPs with HIV-1 disease progression, using markers such as viral load or CD4 count. There are few data on IL10 SNP frequencies and HIV-1 disease in regions where non-B HIV-1 subtypes predominate. Objective: To determine genotypes, haplotypes, allele frequencies and associations with markers of HIV-1 disease progression of IL10 SNPs. Methods: A new multiplexed PCR-SSP assay to detect IL10 SNPs at positions -1082, -819 and -592 was developed and used to determine genotypes and haplotypes in 244 HIV-1 CRF01_AE-infected northern Thais having a median time since HIV-1 infection of 2.7 years. Results: At position -1082 of IL10, AA genotype and A allele were the most common (87.3% and 93.2%, respectively). The -819 CT and -592 CA genotypes were the most prevalent (44.3%), and -819T and -592A were the most prevalent alleles (64.8%). The ATA/ATA was the most common genotype (42.6%) with the most prevalent haplotype of ATA (64.7%). No associations of any of the three IL10 SNPs with CD4+ or CD8+ T cell counts or with viral load were found. Conclusions: This first report of IL10-1082A, -819T and the IL10-592A allele frequencies in HIV-1-infected Thais shows the highest frequencies in HIV-1-infected persons worldwide. The lack of association of IL10 SNPs with CD4+ T cell count and viral load suggest that other genes may influence these markers in HIV-1-infected Thais.