Les mutations de résistance pour une molécule sont produites avant que la molécule en question ne soit utilisée, et c’est sous « pression de sélection » que la souche résistante va être sélectionnée. Des données récentes montrent que des variants résistants minoritaires (VRMs) peuvent être une source d’échec virologique. Les nouvelles techniques de séquençage sont bien plus sensibles que les techniques classiques de séquençage et permettent la détection des VRMs. Afin d’évaluer l’intérêt de l’utilisation de ces techniques, nous avons étudié les prélèvements de patients en situation d’échec virologique après traitement par deux combinaisons antirétrovirales très utilisées (tenofovir/emtricitabine/efarirenz et tenofovir/emtricitabine/rilpivirine). De nombreux variants de résistance supplémentaires ont été détectés, touchant principalement la classe des Inhibiteurs Nucléosidiques de la Transcriptase Inverse (INTIs), avec un impact potentiel sur le choix du traitement de relais. Nous avons également étudié la prévalence des mutations de résistance transmise sur le gène de la protéase et de la transcriptase inverse chez des patients naïfs chroniquement infectés, chez deux groupes de transmission : des patients hommes ayant des rapports avec d’autres hommes (HSH), et des patients hétérosexuels. Nous avons retrouvé une prévalence plus élevée de mutations touchant les INTIs dans le groupe des patients hétérosexuels. Parmi les patients HSH, ceux infectés par un virus de sous-type B étaient plus fréquemment infectés par un virus résistant. Cette thèse met en avant la puissance des ces techniques, dont les conditions d'utilisation ne sont pas encore complètement définies. / Resistance mutations for a given molecule are produced before the molecule is used, and it is under "selection pressure" that the resistant strain will be selected. Recent data show that minority resistant variants (MRV) can be a source of virologic failure. New sequencing techniques are much more sensitive than conventional sequencing techniques and allow MRV detection. To assess the value of these new techniques, we studied samples from patients experiencing virologic failure after treatment with two antiretroviral combinations widely used (tenofovir/emtricitabine/efarirenz et tenofovir/emtricitabine/rilpivirine). Many additional resistance variants affecting the class of nucleoside reverse transcriptase inhibitors (NRTIs) were detected, with a potential impact on the choice of the subsequent regimen. We also studied the prevalence of transmitted resistance mutations in the protease and reverse transcriptase genes among naive patients chronically infected, among two groups of transmission: patients of men who have sex with men (MSM) and heterosexual patients. We found a higher prevalence of NRTI mutations among the heterosexual group. Among MSM patients, those infected with subtype B viruses were more frequently infected with a resistant virus. This thesis highlights the power of these techniques, the conditions of use are not yet fully defined.

Faculdade Christus / Introduction: Genotypic testing for HIV-1 drug resistance is useful for selecting antiretroviral drugs for patients developing treatment failure. O melhor entendimento da sua interpretaÃÃo facilitarà sua utilizaÃÃo como ferramenta mÃdica na terapÃutica do HIV. The optimal understanding of its interpretation will give an important tool for HIV treatment. Objective: To identify common combinations of resistance mutations and antiretroviral resistance profile. Methods: Between April 2002 and March 2004, 101 protease and reverse transcriptase (RT) sequences were determined for HIV-1 isolates from patients who were failing antiretroviral therapy. Resistance profile was obtained by Stanford program. Results: male were 76.2%, median age 38 years, CD4 media was 279.21 cells/mm3 and Viral load 4.49 log. Total of 31 mutational patterns were detected to protease inhibitor (IP), 49 to nucleoside RT inhibitor (NRTI), and 17 to nonnucleoside RT inhibitor (NNRTI). K65R was detected in 5.9% isolates. The most frequent mutations were L90M, M184V and K103N to IP, NRTI and NNRTI respectively. The main mutational patterns accounted for 49% of mutant sequences to IP, 38.5% to ITRN accounted and 40,9% to NNRTI. Patients with three or more therapeutic failure had worst resistance profile to all IP except for Lopinavir, and NRTI except for Tenofovir. High resistance to Lamivudine and NNRTI were independent of failure quantity. Conclusion: The best susceptibility was found to Lopinavir at IPâs class and to Tenofovir at ITRNâs. The main mutational patterns to IP, ITRN and NNRTI represented almost half of all patterns found. / A Genotipagem està sendo usada como mÃtodo para guiar a seleÃÃo de antiretrovirais em pacientes com falha terapÃutica. O melhor entendimento da sua interpretaÃÃo facilitarà sua utilizaÃÃo como ferramenta mÃdica na terapÃutica do HIV. Objetivo: Avaliar o perfil de resistÃncia aos antiretrovirais e identificar padrÃes mutacionais das seqÃÃncias de protease e TR do HIV-1. MÃtodos: Foram estudadas as sequÃncias de genes da protease e TR isoladas de 101 amostras de pacientes com HIV-1 em falha terapÃutica, entre abril/2002 a marÃo/2004, atravÃs de Genotipagem realizadas no CearÃ. O Banco de dados de Stanford foi utilizado para avaliaÃÃo de resistÃncia e SPSS versÃo 11 e Epi Info versÃo 6 para anÃlise estatÃstica. Resultados: Sexo masculino 76,2%, mediana de idade 38 anos, CD4 mÃdio de 279,21 cells/mm3 e Carga Viral 4.49 log. Na classe de Inibidores de Protease (IP) 31 padrÃes mutacionais foram encontrados, nos inibidores da transcriptase reversa anÃlogos de nucleosÃdeos (ITRN) 49 e para inibidores da transcriptase reversa nÃo anÃlogos de nucleosÃdeos (ITRNN) 17. As mutaÃÃes mais frequentes foram L90M, M184V e K103N para IP, ITRN e ITRNN espectivamente. A K65R foi detectada em 5,9% dos isolados. TrÃs ou mais falhas terapÃuticas apresentaram maior perfil de resistÃncia para todos os IPs exceto para Lopinavir, e para todos os ITRNs exceto para Tenofovir. Os seis principais padrÃes mutacionais para IPs equivaleram a 49% das sequÃncias, para ITRNs a 38,5%, e para ITRNNs os dois principais padrÃes corresponderam a 40,9%. Foram encontrados altos Ãndices de resistÃncia para ITRNNs independente da quantidade de falhas terapÃuticas. ConclusÃo: Nos IPs a menor resistÃncia encontrada foi ao Lopinavir e nos ITRNs ao Tenofovir. Os principais padrÃes mutacionais para IPs, ITRNs e ITRNNs representaram quase metade de todos os padrÃes de resistÃncia encontrados.