RESUMEN
There are few data on drug resistance-associated mutations in the former Soviet Union since, studies have usually been focused on the env or gag genes for subtype information. This study examines the prevalence and patterns of resistance-associated mutations to reverse transcriptase and protease inhibitors (RTI, PRI) in 278 HIV-1-infected treatment-naïve subjects from countries of Eastern Europe, and defines characteristic polymorphisms of RT and PR sequences in HIV-1 subtype A viruses. Blood samples were collected between 1997 and 2004. Plasma RNA was used for PR-RT amplification by reverse transcription coupled with nested PCR and sequencing. Phylogenetic analysis was done with neighbor-joining trees and bootscanning. Analysis of drug resistance mutations, with Stanford University HIV Drug Resistance Database's algorithm, resulted in an overall prevalence of 12.9% resistance to RTI and 3.9% to PRI. The most frequent substitutions in the RT region were at positions 62 and 236. V77I substitution in PR was found in 47.8% of samples. Polymorphisms in subtype A sequences were identified. This is the first study reporting the prevalence and patterns of both PRI and RTI resistance-associated mutations in naïve HIV-1 infected patients from the former Soviet Union. These data underline the importance of genotypic resistance testing of chronically HIV-1-infected patients before initiating treatment, in order to select the most suitable drug regimen.
Asunto(s)
Farmacorresistencia Viral/genética , Infecciones por VIH/tratamiento farmacológico , VIH-1/clasificación , VIH-1/efectos de los fármacos , Mutación , Adulto , Fármacos Anti-VIH/farmacología , Femenino , Infecciones por VIH/epidemiología , Infecciones por VIH/virología , Proteasa del VIH/genética , Inhibidores de la Proteasa del VIH/farmacología , Transcriptasa Inversa del VIH/genética , VIH-1/genética , Humanos , Masculino , Pruebas de Sensibilidad Microbiana , Polimorfismo Genético , Prevalencia , ARN Viral/sangre , Recombinación Genética , Inhibidores de la Transcriptasa Inversa/farmacología , U.R.S.S./epidemiologíaRESUMEN
BACKGROUND: The natural occurrence of primary resistance mutations in reverse transcriptase (RT) and protease (PR) genes of HIV-1 isolates from untreated patients has been reported and it may have important implications for the response to drug treatment. It is predictable that the same occurs in the HR1 region of gp41 sequence from patients who have never received T20 therapy, and in this regard it would be important to know not only the mutation frequencies at HR1 region but also the natural polymorphisms at resistance-associated positions present in the absence of this drug. OBJECTIVES: The objectives of this study are to investigate the existence of natural resistance-associated mutations to T20 in HR1 gp41 region corresponding to different HIV-1 genetic forms from T20 naive patients and to determine their prevalence. STUDY DESIGN: Two hundred HIV-1 gp41 sequences were included: subtype B: 164 (81.3%); subtype A: 15 (8.2%); subtype G: 10 (4.6%); subtype F: 6 (3.5%); subtype C: 3 (1.8%); subtype K: 1 (0.6%); and subtype D: 1 (0.6%). We analyzed the resistance-associated mutations previously described: Q32H/R, G36D/S, I37V, V38A/M, Q39R/H, Q40H, N42T/D/Q/H, N43D/S/K/Q, L44M, L45M, R46M and V69I. RESULTS: Natural resistance mutations to T20 were found at a high frequency: 10.5%, corresponding to 9.1% in subtype B and 16.7% in non-B subtype samples. Polymorphisms were more frequent in non-B and recombinant forms than in subtype B (p<0.001). Different substitutions were related to subtypes: N42S in subtypes A, B, G and C, but not in F, Q56R in subtype A from CRF02_AG, and L54M in subtype B from CRF14_BG. CONCLUSIONS: To our knowledge this is the first study describing natural-resistance to T20 among different HIV-1 subtypes, warranting a study of the biological significance of this mutations and their clinical relevance. The detection of differences between subtypes may have an influence on the rate and patterns of resistance in patients undergoing T20 treatment.
Asunto(s)
Fármacos Anti-VIH/uso terapéutico , Proteína gp41 de Envoltorio del VIH/genética , Infecciones por VIH/virología , VIH-1/genética , Mutación , Fragmentos de Péptidos/uso terapéutico , Polimorfismo Genético , Secuencia de Aminoácidos , ADN Complementario/química , ADN Complementario/aislamiento & purificación , ADN Viral/química , ADN Viral/aislamiento & purificación , Farmacorresistencia Viral/genética , Enfuvirtida , Frecuencia de los Genes , Proteína gp41 de Envoltorio del VIH/uso terapéutico , VIH-1/aislamiento & purificación , Humanos , Datos de Secuencia Molecular , ARN Viral , Alineación de Secuencia , Análisis de Secuencia de ADN , EspañaRESUMEN
OBJECTIVES: To determine the prevalence of drug resistance and to analyze the subtyping in HIV-1 samples from Cuba. METHODS: From an estimated total number of 1,950 HIV-1-infected persons in Cuba, a sample of 103 patients were studied, 76 of whom had received drug treatment for HIV and 27 who had not. The RNA plasma viral load was measured, and automated sequencing was used to assess resistance mutations to reverse transcriptase inhibitors (RTIs) and to protease inhibitors (PIs). Subtyping in the V3 region was performed using heteroduplex mobility assay (HMA). In order to corroborate the HMA results, sequencing of env (C2-V3-C3) was done with one-third of the samples in each of the subtype groups detected by HMA. RESULTS: Out of the 103 samples, 81 of them (78.6%) were classified as subtype B, 19 (18.5%) as subtype A, and 3 (2.9%) as subtype C. The prevalence of resistance mutations was 26.2% to RTIs, none to PIs alone, and 3.9% to both categories of drugs. The prevalence of resistance to nucleoside RTIs (NRTIs) was 27.6% in treated patients and 7.4% in the untreated patients, and for nonnucleoside RTIs (NNRTIs) it was 5.3% and 0%, respectively. Among treated patients a low frequency (2.6%) of dual resistance to zidovudine (ZDV) plus lamivudine (3TC) and abacavir (ABC) was detected, and multidrug resistance to NRTIs was not found. In relation to PIs together with RTIs, the prevalence of resistance was 5.3% for treated patients and 0% for untreated patients. CONCLUSIONS: Even though Cuba is generally considered an area where subtype B is dominant, we detected a high proportion of non-B subtype viruses. The low prevalence of resistance mutations to RTIs and PIs reflects the delay in introducing these drugs to Cuba. Multidrug resistance to RTIs was not found, so, as of now, the use of these drugs continues to be an option for Cuban patients.
Asunto(s)
Fármacos Anti-VIH/uso terapéutico , Farmacorresistencia Viral , VIH-1/efectos de los fármacos , VIH-1/genética , Cuba , Genotipo , Humanos , Mutación , PrevalenciaRESUMEN
BACKGROUND: The HIV-1 epidemics in Western Europe are dominated by B subtype viruses. Non-B subtype is largely restricted to individuals infected outside of Europe and to their direct contacts and is generally acquired by the heterosexual route. METHODS: Protease and a segment of reverse transcriptase were amplified and sequenced from plasma RNA in 451 individuals from seven cities of Galicia, north-western Spain. Subtype sequence homologies were determined using the BLAST algorithm. Non-B sequences were examined by phylogenetic analysis and intersubtype recombination by bootscanning. The env V3 region was analysed in all non-B and in 38 B subtype viruses. RESULTS: Ten different non-B genetic forms were identified in 20 (4.4%) individuals. Subtypes were concordant between pol and V3 in five viruses; 14 (70%) infections were with intersubtype recombinant viruses, and one individual had a dual B+G infection. Seven recombinant viruses were phylogenetically related to five reported recombinant forms. Three non-recombinant G and six recombinant BG viruses formed a monophyletic cluster for pol. All but three individuals with non-B infections were native Spanish. Only 6 of 16 individuals referred to sexual contacts with sub-Saharan Africans. Twelve (60%) non-B subtype infections, including all with G and BG viruses, were in injecting drug users (IDU). CONCLUSIONS: Non-B subtype viruses were identified in 4.4%, with a high diversity of genetic forms, including 70% infections with intersubtype recombinant viruses. The majority of individuals with non-B infections were IDU, most of them without known contacts with non-European sources, and among whom BG recombinant viruses are circulating.
Asunto(s)
Proteína gp120 de Envoltorio del VIH/genética , Infecciones por VIH/virología , VIH-1/genética , Fragmentos de Péptidos/genética , Abuso de Sustancias por Vía Intravenosa/virología , Adulto , Femenino , Genes pol/genética , Variación Genética , Genotipo , Infecciones por VIH/epidemiología , Proteasa del VIH/genética , Transcriptasa Inversa del VIH/genética , Humanos , Masculino , Persona de Mediana Edad , Epidemiología Molecular , Filogenia , ARN Viral/análisis , Recombinación Genética , Análisis de Secuencia de ARN , España/epidemiología , Abuso de Sustancias por Vía Intravenosa/complicacionesRESUMEN
OBJECTIVES: To describe the prevalence of genotypic resistance mutations, including single and multidrug resistance (MDR) to reverse transcriptase (RT) and protease (PR) inhibitors in treated and untreated patients from two geographical areas in Spain (Madrid and Galicia). STUDY DESIGN/METHODS: Resistance mutations to RT inhibitors were studied by line probe assay (LiPA) or by automated sequencing in 468 patients (Madrid, 268; Galicia, 200), and resistance mutations to PR inhibitors were studied by automated sequencing in 295 patients (Madrid, 85; Galicia, 210). RESULTS: The proportion of resistance mutations in treated and untreated patients results were higher by the LiPA method than by sequencing. By sequencing, we detected resistance mutations to nucleoside analogue RT (NRT) inhibitors and NRT inhibitors plus nonnucleoside RT (NNRT) inhibitors in 35.4% and 17.2% of treated patients, respectively. We also detected MDR to zidovudine plus lamivudine in 13.9% of treated patients from Galicia, in 1.7% from Madrid (p < 0.001), and in 1.5% of untreated patients from Galicia. Also, we detected MDR to NRT inhibitors in 3.8% and to NNRT inhibitors in 9.1%. We found resistance mutations to PR inhibitors in 38.1% of treated patients and in 0.9% of untreated patients. CONCLUSIONS: These findings reinforce the usefulness of testing for resistance mutations in some cases to evaluate their prevalence in a given population and in the follow-up of treated patients.
Asunto(s)
Infecciones por VIH/virología , VIH-1/efectos de los fármacos , VIH-1/genética , Inhibidores de Proteasas/farmacología , Inhibidores de la Transcriptasa Inversa/farmacología , Estudios de Cohortes , ADN Viral/análisis , Farmacorresistencia Microbiana , Resistencia a Múltiples Medicamentos , Quimioterapia Combinada , Infecciones por VIH/tratamiento farmacológico , Infecciones por VIH/epidemiología , Humanos , Lamivudine/farmacología , Lamivudine/uso terapéutico , Mutación , Mutación Puntual , Inhibidores de Proteasas/uso terapéutico , Provirus , ARN Viral/genética , Inhibidores de la Transcriptasa Inversa/uso terapéutico , España/epidemiología , Zidovudina/farmacología , Zidovudina/uso terapéuticoAsunto(s)
Infecciones por VIH/epidemiología , Infecciones por VIH/virología , Transcriptasa Inversa del VIH/genética , VIH-1/genética , Recombinación Genética , Adulto , Argentina/epidemiología , Femenino , Genes Virales , Proteasa del VIH/genética , VIH-1/clasificación , Humanos , Masculino , Filogenia , Reacción en Cadena de la PolimerasaRESUMEN
OBJECTIVES: We attempted to define optimal conditions for amplification of low copy number HIV-1 RNA sequences in plasma samples, applying improved conditions for nucleic acid extraction and amplification. METHODS: Several methodologic parameters were evaluated, including methods of RNA extraction, volumes of plasma samples, proportion of extracted RNA used as a template for amplification, and reverse transcriptase-DNA polymerase enzyme combination employed in cDNA synthesis and polymerase chain reaction amplification. RESULTS: With this improved assay, we were able to obtain sufficient amounts of amplified material for direct sequencing in 97% of all plasma samples in our study, including 88% of samples with viral loads <80 copies/mL, 78% of samples with viral loads <50 copies/mL, and even 2 (67%) of 3 samples with <20 copies/mL. CONCLUSIONS: This procedure could be useful for testing resistance mutations in patients undergoing highly active antiretroviral therapy, in which the viral load is commonly <400 copies/mL, and even if it is <20 RNA copies/mL.