The evolving role of antiretroviral drug resistance testing in HIV-infected individuals.

Scientific advances have made HIV resistance testing routinely available to clinicians and other HIV caregivers. However, interpretation of HIV resistance results is complicated by the lack of knowledge of the clinical consequences of specific genotypic and phenotypic results for most antiretroviral agents. Limitations of viral genotype and phenotype HIV resistance testing include factors such as lack of uniform quality assurance, turn around time, cost, and insensitivity to those mutant strains present in less than 20% to 30% of the viral population. Since there are currently no multicenter prospective data that compare and support the use of one type of resistance testing over another, clinicians who are caring for HIV-infected individuals should become familiar with the pros and cons of the available assays. Clinicians will need to watch for new developments in HIV resistance testing that are on the horizon and will become available in years to come.