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Basic Characteristics of Mutations
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Mutation Site
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A128T |
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Mutation Site Sentence
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Some secondary integrase mutations associated with resistance to EVG and/or RAL were detected as natural integrase polymorphisms, most often at very low frequencies (0.5–1%: V72T, L74M, A128T, and G163R) with few exceptions (19%: M50I; 59%: S119P/G/T/R; and 3.8%: E157Q). |
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Mutation Level
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Amino acid level |
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Mutation Type
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Nonsynonymous substitution |
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Gene/Protein/Region
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IN |
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Standardized Encoding Gene
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gag-pol:155348
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Genotype/Subtype
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HIV-1 B |
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Viral Reference
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HIV-1NL4-3
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Functional Impact and Mechanisms
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Disease
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HIV Infections
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Immune
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- |
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Target Gene
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-
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Clinical and Epidemiological Correlations
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Clinical Information
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- |
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Treatment
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- |
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Location
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Multi-country study |
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Literature Information
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PMID
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28212411
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Title
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Lack of impact of pre-existing T97A HIV-1 integrase mutation on integrase strand transfer inhibitor resistance and treatment outcome
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Author
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Abram ME,Ram RR,Margot NA,Barnes TL,White KL,Callebaut C,Miller MD
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Journal
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PloS one
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Journal Info
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2017 Feb 17;12(2):e0172206
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Abstract
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T97A is an HIV-1 integrase polymorphism associated with integrase strand transfer inhibitor (INSTI) resistance. Using pooled data from 16 clinical studies, we investigated the prevalence of T97A (pre-existing and emergent) and its impact on INSTI susceptibility and treatment response in INSTI-naive patients who enrolled on elvitegravir (EVG)- or raltegravir (RAL)-based regimens. Prior to INSTI-based therapy, primary INSTI resistance-associated mutations (RAMs) were absent and T97A pre-existed infrequently (1.4%; 47 of 3367 integrase sequences); most often among non-B (5.3%) than B (0.9%) HIV-1 subtypes. During INSTI-based therapy, few patients experienced virologic failure with emergent INSTI RAMs (3%; 122 of 3881 patients), among whom T97A emerged infrequently in the presence (n = 6) or absence (n = 8) of primary INSTI RAMs. A comparison between pre-existing and emergent T97A patient populations (i.e., in the absence of primary INSTI RAMs) showed no significant differences in EVG or RAL susceptibility in vitro. Furthermore, among all T97A-containing viruses tested, only 38-44% exhibited reduced susceptibility to EVG and/or RAL (all of low magnitude; <11-fold), while all maintained susceptibility to dolutegravir. Of the patients with pre-existing T97A, 17 had available clinical follow-up: 16 achieved virologic suppression and 1 maintained T97A and INSTI sensitivity without further resistance development. Overall, T97A is an infrequent integrase polymorphism that is enriched among non-B HIV-1 subtypes and can confer low-level reduced susceptibility to EVG and/or RAL. However, detection of T97A does not affect response to INSTI-based therapy with EVG or RAL. These results suggest a very low risk of initiating INSTI-based therapy in patients with pre-existing T97A.
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Sequence Data
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-
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