Incorporating novel virologic tests into clinical practice

Abstract

Virologic assays continue to evolve in order to meet the needs of HIV-infected patients and their health care providers. Genotypic and phenotypic assays for resistance to reverse transcriptase inhibitors, protease inhibitors, and fusion inhibitors have clear roles in disease management, with both types of assay having advantages and disadvantages. The failure of current assays to identify or measure the presence of minority resistant variants has clinical implications, since presence of such variants is associated with increased risk of virologic failure. Viral fitness may be relevant to disease management, but clinical role of available assays has not been determined. HIV coreceptor tropism assays will also be a crucial tool in the use of coreceptor antagonists, and data are emerging that will define pathways to treatment failure when using these new agents and the new integrase inhibitors. One clear finding for all antiretroviral drugs is that they select for resistance and must be used with good optimized background therapy to avoid virologic failure. This article summarizes a presentation on viral assays made by Eric S. Daar, MD, at an International AIDS Society-USA Continuing Medical Education course in Chicago in May 2007. The original presentation is available as a Webcast at www.iasusa.org.