Clade-specific HIV-1 integrase polymorphisms do not reduce raltegravir and elvitegravir phenotypic susceptibility

The contribution of clade-specific polymorphisms in the HIV-1 integrase gene towards integrase inhibitor phenotypic susceptibility was tested on 137 clinical isolates, of which 60 were non-clade B strains. Control Q148R mutant virus showed fold change values of 17.85 +/- 2.77 and 88.94 +/- 9.02 for raltegravir and elvitegravir, respectively, whereas the average fold change for the clinical samples was 0.91 +/- 0.40, and 0.84 +/- 0.37. Phenotypic testing proved that clade-specific integrase polymorphisms do not contribute to reduced susceptibility towards integrase inhibitors.