Resistance-associated mutations in reverse transcriptase at week 8 after interruption of NNRTI-based ART, according to the interruption modality, HIV-1 RNA load at interruption, and NNRTI concentrations at week 4 post-interruption.

Each row gives data for a single patient.aResistance-associated mutations (RAMs) in reverse transcriptase (RT) were detected by Sanger sequencing, allele-specific PCR (AS-PCR) and ultra-deep sequencing (UDS). AS-PCR targeted the NNRTI-RAMs K103N, Y181C, Y188L and G190A (the latter only in samples with K103N), and the following NRTI-RAMs: thymidine analogue mutations (M41L, D67N, K70R, L210W, T215Y/F, K219Q), K65R, Q151M, and 184V/I. Mutation-specific cut-offs ranging between 0.3% and 1% were used for AS-PCR interpretation as previously described [15]. UDS targeted the RT amino acid region 100–190; a detection limit of 1% was chosen to avoid the high probability of technical artifacts below this threshold [19]. RAMs detected by sensitive testing but not by Sanger sequencing are indicated in bold; RAMs detected by RT100–190UDS but not by AS-PCR are underlined; where RT100–190UDS results were obtained the frequency (%) of the mutant is given in brackets. Only samples with NNRTI-RAMs are shown; an additional 15 samples had NRTI-RAMs only, without NNRTI-RAMs. NNRTI = non-nucleoside reverse transcriptase inhibitor; ART = antiretroviral therapy; ZDV = zidovudine; 3TC = lamivudine; NVP = nevirapine; TDF = tenofovir; FTC = emtricitabine; EFV = efavirenz; D4T = stavudine; ABC = abacavir; DDI = didanosine; IDV = indinavir; NFV = nelfinavir; LPV/r = lopinavir/ritonavir; NA = not available.