NEW YORK (Reuters Health) - The PhenoSense HIV phenotypic drug susceptibility assay appears to help provide consistent and reliable indications of subtle variations in antiretroviral drug resistance, researchers report in the February issue of Antimicrobial Agents and Chemotherapy.
Dr. Neil T. Parkin of ViroLogic Inc, South San Francisco and colleagues used HIV wild-type viruses from the company’s phenotype-genotype database to determine drug susceptibility biological cutoffs for the PhenoSense assay.
The researchers note that “the biological cutoff reflects both natural variations in viral susceptibility and inherent assay variability. Thus, such cutoffs may differ among assays that have different intrinsic variabilities.”
In fact, the investigators found that the biological cutoffs for the variety of drugs tested were lower than those reported for other phenotype assays. They were also lower than clinically relevant cutoffs previously defined for the PhenoSense assay.
To investigate further, the team tested 10 reference viruses with different drug susceptibility patterns 8 to 30 times each. The results, they say, “strongly suggest” the “observed differences in wild-type virus susceptibility to the different drugs is related to intrinsic virus variability rather than assay variability.”
Overall, the researchers express certain reservations, but as Dr. Parkin told Reuters Health, “the availability of a phenotypic assay with improved accuracy and precision allows more confident assessment of subtle changes in drug susceptibility.”
Source: Antimicrob Agents Chemother 2004;48:437-443. [ Google search on this article ]
MeSH Headings:Biological Phenomena: Biological Phenomena, Cell Phenomena, and Immunity: Biological Sciences: Biology: Drug Resistance, Microbial: Genetics: Genetics, Microbial: Microbiologic Phenomena: Pharmacogenetics: Anti-HIV Agents: Biological SciencesCopyright © 2002 Reuters Limited. All rights reserved. Republication or redistribution of Reuters content, including by framing or similar means, is expressly prohibited without the prior written consent of Reuters. Reuters shall not be liable for any errors or delays in the content, or for any actions taken in reliance thereon. Reuters and the Reuters sphere logo are registered trademarks and trademarks of the Reuters group of companies around the world.