Minority HIV Drug–Resistance Mutations and Virologic Failure

HIV drug–resistance mutations that are present in less than 10% to 20% of the viral population — minority variants — may not be detected on commercial assays but can be found using more-sensitive testing. The presence of pretreatment nonnucleoside reverse transcriptase inhibitor (NNRTI) minority variants was previously shown to predict an increased risk for virologic failure in patients who initiate this drug class (JW AIDS Clin Care May 16 2011). Now, the authors of that study have assessed whether pretreatment minority variants expand to become the predominant viral population in patients who fail NNRTI-based antiretroviral therapy (ART).

The investigators combined data from seven studies involving treatment-naive HIV-infected patients who…