RESUMO
NRAMP1 and VDR gene polymorphisms have been variably associated with susceptibility to tuberculosis (TB) amongst populations having different genetic background. NRAMP1 and VDR gene variants' association with susceptibility to active infection by Mycobacterium tuberculosis (Mtb) was analyzed in the Warao Amerindian population, an ethnic population from Venezuela's Orinoco delta region. Genomic DNA was extracted from individuals with and without TB to evaluate genetic polymorphism by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Four NRAMP1 gene polymorphisms were analyzed: D543N (rs17235409), 3' UTR (rs17235416), INT4 (rs3731865), and 274C/T (rs2276631), and one VDR gene polymorphism: FokI (rs2228570). The results showed that the genotypes D543N-A/A, 3'UTR-TGTG+/+, INT4-C/C, and 274C/T-T/T of known polymorphism in the NRAMP1 gene, as well as the genotypes FokI-F/f and FokI-f/f in the VDR gene were most often found in indigenous Warao with active TB. Binomial logistic regression was used for evaluating associations between polymorphisms and risk of contracting TB, an association between NRAMP1-D543N-A/A genotype distribution and TB susceptibility was found in Warao Amerindians. Regarding Venezuelan populations having different genetic backgrounds; statistically significant TB associations concerning NRAMP1-D543N-A/A, INT4-C/C and 3'UTR-TGTG+/+ variant genotype distributions in Warao Amerindians (indigenous) compared to Creole (admixed non-indigenous population) individuals were found. In conclusion, the results thus indicated that the association between NRAMP1-D543N-A/A genotype and TB in Warao Amerindians could support such allele's role in host susceptibility to Mtb infection.
Assuntos
Proteínas de Transporte de Cátions , Tuberculose , Humanos , Regiões 3' não Traduzidas/genética , Venezuela , Predisposição Genética para Doença , Proteínas de Transporte de Cátions/genética , Tuberculose/genética , Genótipo , Estudos de Casos e ControlesRESUMO
Delta Amacuro asienta la mayor población indígena de la etnia Warao en comunidades de difícil acceso y limitadas condiciones de vida. En 2007, la Cruz Roja venezolana diagnosticó los primeros casos de infección por VIH en este estado; posteriormente, diversas publicaciones han reportado que la prevalencia de infección por VIH en comunidades de la etnia Warao es 10 veces mayor a la prevalencia mundial. El objetivo de la investigación fue evaluar factores de riesgo para infección por VIH en indígenas del municipio Antonio Díaz, Estado Delta Amacuro durante octubre diciembre 2015. Los factores de riesgo fueron agrupados en: características socioeconómicas, estatus migratorio, hábitos psicobiológicos y conocimiento sobre la enfermedad. Se realizó un estudio analítico de tipo casos y controles. Se evaluaron 50 pacientes VIH positivo de 7 comunidades y 100 controles del mismo sexo, comunidad y edad. A todos se les realizó una entrevista directa. Se compararon los resultados utilizando pruebas Chi cuadrado y se determinaron los Odds Ratio. La inestabilidad en la pareja sexual, las prácticas de hombres que tienen sexo con hombres, las relaciones sexuales fortuitas y durante viajes, el inicio precoz de relaciones sexuales, el sexo oral, sexo anal y el no uso de métodos de barrera constituyeron factores de riesgo para infección por VIH en la población estudiada. El desconocimiento de la forma de trasmisión y prevención resultaron también estadísticamente significativos. La falta de conocimiento, movimientos migratorios frecuentes y las prácticas sexuales de riesgo pueden explicar la elevada prevalencia de infección por VIH en esta población.
In Delta Amacuro state is established the biggest Amerindian community belonging to the Warao ethnic. This people live in difficult access communities with precarious life conditions. In 2007 the Venezuelan Red Cross diagnosed the first HIV infection cases in the state. Later, many publications have reported HIV prevalence in Waraos communities ten times higher than worldwide prevalence. The main objective was to evaluate risk factors for HIV infection in Waraos Amerindians who live in Antonio Diaz municipality, Delta Amacuro state between October and December 2015. Risk factors were grouped in: socioeconomic conditions, migratory status, sexual and psychobiologic habits and disease knowledge. An analytic case-control study was conducted. Fifty HIV patients from seven communities and 100 controls were evaluated. The information from cases and controls was collected through a direct interview. The results were compared using chi square test, odds ratios were calculated. No stability in sexual partners, men who have sex with other men, casual sex, sex during trips, early sexual initiation, oral sex and anal sex and lacking in use of barrier contraceptive methods were risk factors for HIV infection in the study group. Lack of knowledge about transmission and prevention of the disease were also statistically significant risk factors. Lack of knowledge, frequent migratory movements and risk sexual behavior may explain the high prevalence of HIV infection in this population.