"Dynamic range" of inferred phenotypic HIV drug resistance values in clinical practice.

ABSTRACT: 'Virtual' or inferred phenotypes (vPhenotypes) are commonly used to assess resistance to antiretroviral agents in patients failing therapy. In this study, we provide a clinical context for understanding vPhenotype values.All HIV-infected persons enrolled in the British Columbia Drug Treatment Program with a baseline plasma viral load (pVL) and follow-up genotypic resistance and pVL results were included up to October 29, 2008 (N?=?5,277). Change from baseline pVL was determined as a function of Virco vPhenotype, and the "dynamic range" (defined here by the 10th and 90th percentiles for fold-change in IC?? amongst all patients) was estimated from the distribution of vPhenotye fold-changes across the cohort.The distribution of vPhenotypes from a large cohort of HIV patients who have failed therapy are presented for all available antiretroviral agents. A maximum change in IC?? of at least 13-fold was observed for all drugs. The dideoxy drugs, tenofovir and most PIs exhibited small "dynamic ranges" with values of <4-fold change observed in > 99% of samples. In contrast, zidovudine, lamivudine, emtricitabine and the non-nucleoside reverse transcriptase inihibitors (excluding etravirine) had large dynamic ranges.We describe the populational distribution of vPhenotypes such that vPhenotype results can be interpreted relative to other patients in a drug-specific manner.

SUBMITTER: Swenson LC 

PROVIDER: S-EPMC3044728 | biostudies-other | 2011 Feb

REPOSITORIES: biostudies-other