1. Determination of HIV-1 susceptibility to reverse transcriptase (RT) inhibitors by a quantitative cell-free RT assay.
- Author
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Greene RA, Japour AJ, Brewster F, Joseph RA, Chung PH, Kasila PA, and Chatis PA
- Subjects
- Cell-Free System, Drug Resistance, HIV-1 drug effects, Humans, Reproducibility of Results, Sensitivity and Specificity, Zidovudine pharmacology, Didanosine pharmacology, HIV Reverse Transcriptase antagonists & inhibitors, HIV-1 enzymology, Reverse Transcriptase Inhibitors pharmacology
- Abstract
Background: Mutations in the human immunodeficiency virus type 1 (HIV-1) reverse transcriptase (RT) gene confer resistance to antiviral drugs acting on RT. Current methods employed to detect such resistance require time-consuming culture techniques during which selective pressures may affect the outcome of the test., Objectives: We sought to determine whether drug-susceptible and drug-resistant HIV-1 derived from clinical specimens could be distinguished by the effects of the active form of the drug on the enzyme activity in a quantitative, cell-free RT assay., Study Design: Polyethylene glycol (PEG)-precipitated virus was obtained from 7-day culture supernatants. RT activity in the lysed viral extracts was measured in the presence of increasing concentrations of the active form of the drug being tested. IC50 (50% inhibitory concentration) values were determined by application of the median effect equation., Results: Assays from nine post-nevirapine therapy isolates gave IC50 values at least 2 logs greater than pre-nevirapine isolates. The method also correctly distinguished between isolates sensitive and resistant to 2',3'-dideoxyinosine (ddI), but not between the ZDV-sensitive and ZDV-resistant isolates tested. The results agreed with data obtained by sequencing and by culture-based susceptibility assays.
- Published
- 1996
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