Prevalence and predictors of antiretroviral drug resistance in newly diagnosed HIV-1 infection.

Objectives: To determine prevalence and predictors of antiretroviral drug resistance in newly diagnosed individuals with HIV-1 infection, using a systematic approach to avoid selection bias.

Methods: Plasma samples from all persons diagnosed HIV-1 seropositive at a large London centre between April 2004 and February 2006 underwent sequencing of HIV-1 reverse transcriptase (RT) and protease genes. Subtype was assigned by phylogenetic analysis.

Theoretical rationale for the use of sequential single-drug antiretroviral therapy for treatment of HIV infection.

Background: Subpopulations of HIV with mutations associated with resistance to antiretroviral drugs often have reduced replicative capacity, so virus with resistance mutations for all existing and new antiretroviral drugs is likely to be appreciably impaired. Issues of toxicity, quality of life and economics mean that the simultaneous use of all these drugs in combination is unrealistic. We aimed to explore the use of sequential monotherapy regimens using a mathematical model of quasi-species dynamics, to see if these could take advantage of the poor replicative capacity of highly resistant virus.

Human immunodeficiency virus rebound after suppression to <400 copies/mL during initial highly active antiretroviral therapy regimens, according to prior nucleoside experience and duration of suppression.

This study evaluated 1433 human immunodeficiency virus (HIV)-infected patients starting highly active antiretroviral therapy (HAART), 409 (28%) of whom had prior nucleoside experience and achieved an HIV load of <400 copies/mL by 24 weeks of therapy. Three hundred seven patients experienced virus rebound during a total of 2773.3 person-years of follow-up.