Effects of etravirine on HIV-1 reverse transcriptase, recovered from plasma of HIV-1 infected patients.

*Two recombinant reverse transcriptase, (BH10)-wild-type (WT) and its mutant form L100I, were used as references. Based on the IC50 value of BH10-wild-type (1.0±0.18 µM), which was included in every run, the IC50 value and the fold-difference in susceptibility of each isolate were determined. A fold-difference of <5 was considered as sensitive, between 5–15 as decreased susceptibility, and above 15 as resistant. Abbreviations: NA, not applicable; IC50, inhibitory effect; ETR etravirine. **Genotype result was obtained six months earlier. The results of three genotypic scoring systems (Stanford, Monogram Weighted Score, Tibotec Weighted Genotype Score) predicting ETR susceptibility are presented. s: sensitive; i: intermediate; r: resistant. A Stanford score of 0-<15, ≥15-<60 and ≥60 are defined as susceptible, intermediate and resistant. Tibotec weighted genotypic score of 0–2, 2.5–3.5 and ≥4 are predictive of susceptible, intermediate and reduced response. Monogram defines a weighted score of 0–3 as susceptible and ≥4 as resistant.