Abstract: Several previously defined LPV mutations were found to have a stronger than average effect (e.g., M46I/L, I54V/T, V82A/F), and new variants at known positions (e.g., I54A/M/S, V82S) were identified.
HIV-1 reverse transcriptase and protease resistance mutations selected during 16-72 weeks of therapy in isolates from antiretroviral therapy-experienced patients receiving abacavir/efavirenz/amprenavir in the CNA2007 study.
Abstract: Mutations D30N, G48V, N88D/S, L90M and 154V were de-selected, and mutations I50V, I or V to 54M/L, I84V, M46I/L, L33F, I47V as well mutations at position 10 were observed in 20/49 (41%) isolates.
HIV-1 phenotypic susceptibility to lopinavir (LPV) and genotypic analysis in LPV/r-naive subjects with prior protease inhibitor experience.
PMID: 12869832
2003
Journal of acquired immune deficiency syndromes (1999)
Abstract: Current PI therapy (P = 0.002) and indinavir administration (P < 0.001), >5 LPV/r mutations (P < 0.0012), and detection of L10FIRV, K20MR, M46IL, I54VL, A71VT, G73SA, V82AFTS, I84V, and M90L were associated with LPV resistance in univariate analysis.
Emergence of resistance to protease inhibitor amprenavir in human immunodeficiency virus type 1-infected patients: selection of four alternative viral protease genotypes and influence of viral susceptibility to coadministered reverse transcriptase nucleoside inhibitors.
PMID: 11850255
2002
Antimicrobial agents and chemotherapy
Abstract: These mutations fell into four distinct categories, characterized by the presence of either I50V, I54L/I54M, I84V, or V32I+I47V and often included accessory mutations, commonly M46I/L.
Low prevalence of primary mutations associated with drug resistance in antiviral-naive patients at therapy initiation.
Abstract: Primary mutations associated with substantial resistance to protease inhibitors were found in only five of 347 patients (1.4%) (M46V/L, I54V, V82A/I); all the other patients carried only secondary mutations (L10F/I/V, M36I, L63P, A71T/V, V77I).
Changes in human immunodeficiency virus type 1 Gag at positions L449 and P453 are linked to I50V protease mutants in vivo and cause reduction of sensitivity to amprenavir and improved viral fitness in vitro.
Abstract: Sequential plasma samples from one patient revealed a transition from I50V M46L P453L viruses at early time points to I50V M46I L449F viruses in later samples.
Virologic rebound on HAART in the context of low treatment adherence is associated with a low prevalence of antiretroviral drug resistance.
PMID: 12131564
2002
Journal of acquired immune deficiency syndromes (1999)
Abstract: In the viremic group, substitutions in HIV protease were detected most frequently in the following positions in subjects on indinavir (IDV): L10I/V (35.7%), M46I/L (35.7%), A71T/V (35.7%), V82A (42.9%); and for subjects on nelfinavir (NFV): D30N (50.0%), V77I (56.3%), N88D (37.5%).
Nelfinavir-resistant, amprenavir-hypersusceptible strains of human immunodeficiency virus type 1 carrying an N88S mutation in protease have reduced infectivity, reduced replication capacity, and reduced fitness and process the Gag polyprotein precursor aberrantly.
Abstract: Addition of mutation M46L to a strain harboring mutations L63P, V77I, and N88S resulted in a reduction of fitness and infectivity without changing Gag-processing efficiency, while amprenavir hypersusceptibility was further diminished.
Abstract: The ratio of reverse transcriptase activity to p24 protein was reduced in this strain compared to that in the other variants, suggesting that the M46L effect on fitness occurred through a mechanism different from a Gag-processing defect.
Persistence of earlier HIV-1 drug resistance mutations at new treatment failure.
Abstract: In contrast, after changing from indinavir to saquinavir or nelfinavir, the M46I/L and/or V82A/F/ST disappeared in only 9 of 21 occasions at the new treatment failure.