HIV-1-infected patients with advanced disease failing a raltegravir-containing salvage regimen in São Paulo, Brazil.

Raltegravir (RAL) is the first licensed antiretroviral integrase inhibitor that may be used both for treatment-naïve human immunodeficiency virus type 1 (HIV-1) patients and for salvage therapy. The Brazilian public free access programme limits its use for salvage therapy, with scarce information regarding RAL resistance from patients failing a RAL-containing salvage regimen. This study evaluated RAL resistance mutations detected by population sequencing in 69 HIV-infected patients with advanced disease failing a RAL-containing regimen in a real-world setting.

In-vivo selection of the mutation F121Y in a patient failing raltegravir containing salvage regimen.

Raltegravir is an integrase inhibitor (INI) licensed for clinical use and other INI are in advanced stage of development. Different resistance mutations in HIV integrase from patients using these antiretroviral drugs have been described and G148H/R/K, N155H and less frequently Y143C/H/R are considered major resistant mutations to raltegravir. Both Stanford Database and Geno2Pheno list F121Y as conferring intermediate resistance "in vitro" both to raltegravir and elvitegravir.

Concordance of HIV type 1 tropism phenotype to predictions using web-based analysis of V3 sequences: composite algorithms may be needed to properly assess viral tropism.

Genotypic prediction of HIV-1 tropism has been considered a practical surrogate for phenotypic tests and recently an European Consensus has set up recommendations for its use in clinical practice. Twenty-five antiretroviral-experienced patients, all heavily treated cases with a median of 16 years of antiretroviral therapy, had viral tropism determined by the Trofile assay and predicted by HIV-1 sequencing of partial env, followed by interpretation using web-based tools. Trofile determined 17/24 (71%) as X4 tropic or dual/mixed viruses, with one nonreportable result.