Minority Variants — Major or Minor Impact?

Two studies demonstrate that even very low levels of certain nonnucleoside reverse transcriptase inhibitor (NNRTI) mutations increase the risk for failure of NNRTI-based regimens. The clinical relevance of this finding remains unclear.

New technologies allow for the detection of low levels of drug-resistant HIV populations — so-called minority variants. Evidence suggests that such variants may predict nonresponse to antiretrovirals, particularly those that have a low barrier to resistance, such as NNRTIs. To explore this possibility further, investigators reanalyzed data from two AIDS Clinical Trials Group (ACTG) studies.

In ACTG 398, patients who experienced virologic failure on protease inhibitor (PI)–based regimens were randomized to receive salvage regimens containing efavirenz, abacavir, adefovir, and one or two PIs. Previous exposure to NNRTIs (delavirdine or nevirapine) was noted for 44% of patients and was highly predictive of the presence of minority NNRTI-resista…

Reviewing Author

Helmut Albrecht, MD

Disclosures

Grant / Research supportHealth Resources and Services Administration; Centers for Disease Control and Prevention

Leadership positions in professional societiesColumbia Medical Society; South Carolina Infectious Diseases Society

Helmut Albrecht, MD

Disclosures

Grant / Research supportHealth Resources and Services Administration; Centers for Disease Control and Prevention

Leadership positions in professional societiesColumbia Medical Society; South Carolina Infectious Diseases Society

Minority Variants — Major or Minor Impact?

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Reviewing Author