Dynamics of drug-resistant HIV-1 in plasma and peripheral blood cells in patients during and after enfuvirtide therapy.

Genetic analysis of HIV-1 gp41 in plasma and peripheral blood mononuclear cell (PBMC) compartments was performed longitudinally in 10 HIV-infected patients treated with enfuvirtide. The appearance of enfuvirtide resistance mutations in PBMCs (DNA) generally occurred after (from 23 to 157 weeks) being recognizable in plasma (RNA). The disappearance of drug-resistant HIV-1 mutations to enfuvirtide in seven patients who discontinued the drug was directly dependent of the exposure time failing enfuvirtide, being associated mainly with the selection of secondary/compensatory mutations recognizable in proviral DNA.