The assessment of HIV-1 tropism is needed before starting treatment with a CCR5-antagonist. Several phenotypic and genotyping tropism tests have been developed in the recent years. Phenotypic assays (i.e. TrofileTM and ES-TrofileTM) have been used.in most clinical trials. Genotypic tropism testing, however, is easier, cheaper and faster than phenotypic methods, and can be performed in a local HIV laboratories.~Viral RNA amplification is difficult in subjects with HIV-1 RNA levels <500-1000 copies/mL. In these cases, the optimal source of genetic material is peripheral blood mononuclear cell (PBMC)-associated proviral DNA. Whereas genotypic tropism testing in proviral DNA is technically feasible, it has not been validated as a tool to predict sustained virological response to CCR5-antagonist therapy in subjects with undetectable viremia.~As of today, maraviroc is the only CCR5-antagonist approved for HIV treatment. It has few drug interactions and a good security profile, particularly in terms of lipid and glucose metabolism. Therefore, it might be an adequate alternative for HIV-1-infected individuals with suppressed viremia who experience antiretroviral-related toxicity or metabolic problems.~This study will evaluate 48-week virological outcomes in aviremic subjects with an R5 virus by proviral genotypic tropism testing who switch the third drug of their regimen to maraviroc.
CCR5 antagonists might be an adequate alternative for HIV-1-infected individuals with suppressed viremia who experience antiretroviral-related toxicity. The assessment of HIV-1 tropism in proviral DNA could be helpful to inform in which of these subjects CCR5 antagonists could be efficacious.