No abstract

Introduction: The HIV-exposed seronegative (HESN) status is for individuals who remain seronegative despite repeated exposure to HIV. One of the main cohorts within this group is men who have sex with men (MSM). Studies of this cohort have revealed different immunological and genetic mechanisms that can explain the phenomenon of natural HIV resistance. NK cells' higher effector capacity is related to natural resistance to HIV. Besides, a new population of NK cells with adaptive features was described recently. These cells are increased in some HESN cohorts and appear to be involved in better control of viral replication in primarily HIV-infected subjects. The present study evaluated the role of NK cells in the natural resistance to HIV-1 infection in MSM. Methodology: Phenotypic and functional features were evaluated in NK cells from two groups of MSM, at different risks of HIV infection, according to the number of sexual partners. The production of IFN-γ and β-chemokines was included in the analysis, as well as the cytotoxic capacity and adaptive NK cell frequency. Genetic features, such as HLA and KIR allele frequencies, were also explored. Results: High-risk MSM exhibit an increased frequency of fully mature and CD57 + /NKG2C high NK cells. These individuals also show higher cytotoxic capacity and IFN-γ production in response to K562 stimuli. NK cells with a CD107a + /IFN-γ + functional profile were found more frequently and displayed higher IFN-γ production capacity among high-risk MSM than among low-risk MSM. The protective allele HLA-B * 18 was only present in the high-risk MSM group as well as HLA-B * 39. The protective phenotype KIR3DL1/S1-HLA-B * Bw4, in a homozygous state, was particularly abundant in the high-risk population. Notably, some of these functional features were related to higher frequencies of mature and CD57 + /NKG2C high NK cells, which, in turn, were associated with a higher number of sexual partners. Conclusion: The changes observed in the NK cell compartment can be driven by the magnitude of sexual exposure and immunological challenges of high-risk individuals, which could influence their resistance/susceptibility to HIV infection.

No abstract

Human immunodeficiency virus (HIV) infection still represents a major public health problem worldwide, and its vaccine remains elusive. The study of HIV-exposed seronegative individuals (HESN) brings important information about the natural resistance to HIV, allows a better understanding of the infection, and opens doors for new preventive and therapeutic strategies. Among HESN groups, there are some men who have sex with men (MSM) with high-risk sexual behaviors, who represent an adequate cohort for HESN study because of their major HIV exposure without infection. This study aimed to compare the immunological profile of Colombian seronegative MSM with different risk sexual behaviors. This study included 60 MSM at high-risk (n = 16) and low-risk (n = 44) of HIV-1 acquisition. No sex worker nor homozygous delta 32 mutation subjects were included. All participants were negative for anti-HIV-1/2 antibodies and HIV-1 proviral DNA. A higher frequency of sexual partners in the last 3 months before the study participation (median, 30 vs. 2), lifetime sexual partners (median, 1,708 vs. 26), and unprotected anal intercourse (median 12.5 vs. 2) was determined in high-risk MSM than low-risk MSM. High-risk MSM also showed a quiescent profile of T cells and natural killer (NK) cells, with a significantly lower percentage of CD4+CD38+, CD4+HLADR−CD38+, CD4+Ki67+ T cells, and NKG2D+ NK cells (CD3−CD16+CD56+), a significantly higher percentage of CD4+HLADR−CD38−, and a tendency to show a higher percentage of CD8+HLADR+CD38− T cells than the low-risk group. Likewise, they showed higher mRNA levels of Serpin A1 from PBMCs. The results suggest that this MSM cohort could be HESN individuals and their resistance would be explained by a quiescent profile of T cells and NK cells and an increased Serpin A1 expression. Further study on MSM at high risk of exposure to HIV-1 is necessary to better understand the natural resistance to HIV.

No abstract

Introducción: la detección del género Corynebacterium en flujo vaginal representa un reto para el estudio de su posible papel patogénico en el tracto genital femenino. La coloración de Gram es la técnica recomendada para la detección de corinebacterias en muestras clínicas; no obstante, algunas características biológicas de estas bacterias dificultan la identificación por medio de esta. Objetivo: evaluar el desempeño de la coloración de Albert para la identificación de Corynebacterium spp. en muestras de flujo vaginal. Materiales y métodos: se evaluó la tinción de Albert como prueba diagnóstica para la identificación de Corynebacterium spp. en 451 flujos vaginales en comparación de la coloración de Gram. Se calculó la sensibilidad, la especificidad, los valores predictivos, las razones de verosimilitud y el índice J de Youden con el software Epidat 3.1. Resultados: la coloración de Albert presentó sensibilidad y especificidad de 61,5% y 74,6%, respectivamente, valor predictivo positivo de 78,3%, valor predictivo negativo de 56,5%, razón de verosimilitud positiva de 2,4 y negativa de 0,5 y un Índice de Youden de 0,4. Conclusiones: la tinción de Albert no mostró un mejor rendimiento que la coloración de Gram en la identificación del género Corynebacterium en muestras de flujo vaginal. Por lo tanto, se recomienda el uso en conjunto de las coloraciones de Gram y Albert para la identificación de corinebacterias en flujo vaginal.

HIV infection still represents a major public health problem worldwide, and a vaccine remains elusive. The study of HIV-exposed seronegative individuals (HESN) brings important information about the natural resistance to HIV, allows a better understanding of the infection and opens doors for new preventive and therapeutic strategies. Among HESN groups there are some men who have sex with men (MSM) with high-risk sexual behaviors, who represent an adequate cohort for the study of HESN because of their major exposure to HIV in the absence of infection. This study aimed to compare the immunological profile of Colombian seronegative MSM with different risk sexual behaviors. Sixty MSM at high-risk (n=16) and low-risk (n=44) of HIV-1 acquisition were included. No sex worker nor homozygous delta 32 mutation subjects were included. All the participants were negative for anti-HIV-1/2 antibodies and HIV-1 proviral DNA. The high-risk MSM presented a higher frequency of sexual partners in the last 3 months previous to the enrollment in the study (Median 30 vs. 2), lifetime sexual partners (Median 1708 vs. 26), and unprotected anal intercourse (Median 12.5 vs. 2) than low-risk MSM. This group also showed a quiescent profile of T cells and NK cells, with a significantly lower percentage of CD4+CD38+, CD4+HLADR-CD38+, CD4+Ki67+ T cells, NKG2D+ NK cells (CD3-CD16+CD56+), a significantly higher percentage of CD4+HLADR-CD38- and a tendency to show a higher percentage of CD8+HLADR+CD38- T cells, than the low-risk group. Likewise, they showed higher mRNA levels of Serpin A1 from PBMCs. The results suggest that this cohort of MSM could be HESN individuals and their resistance would be explained by a quiescent profile of T cells and NK cells, and increased expression of Serpin A1. It is necessary to continue the study of MSM at high-risk of exposure to HIV-1 to better understand the natural resistance to HIV.

Introducción: Corynebacterium spp. está presente en flujo vaginal de mujeres asintomáticas, pero se ha encontrado asociado a procesos patológicos, generando confusión al momento de clasificarlo como flora normal o patógena. Nuestro objetivo fue determinar la prevalencia de Corynebacterium spp. y explorar su asociación con características clínicas y hábitos sexuales. Materiales y Métodos: Estudio descriptivo transversal en 511 mujeres del Valle de Aburrá durante 2012 y 2013. Los datos demográficos, clínicos y de comportamiento sexual se obtuvieron mediante encuestas; la información sobre el perfil microbiológico genital se obtuvo de muestra de flujo vaginal. El análisis descriptivo se hizo con frecuencias y medidas de resumen; para el análisis bivariado se usó Chi Cuadrado, Prueba exacta de Fisher, U de Mann Whitney y se usó Regresión Logística para el análisis multivariado; los análisis se realizaron en el programa estadístico IBM SPSS Statistics versión 22. Resultados: La prevalencia de Corynebacterium spp. fue 59%. Referente al comportamiento sexual durante el último mes previo a la toma de muestra, encontramos que las participantes tuvieron sexo con una persona en promedio (rango de 0 a 3 personas distintas); respecto a las prácticas durante el coito en el mismo mes, se observó que el 58% de las mujeres tuvo sexo sin preservativo, al 61% le practicaron sexo oral y al 10% sexo anal. Se encontró asociación de Corynebacterium spp. con reacción leucocitaria. Conclusiones: La prevalencia de Corynebacterium spp. fue 59% y se encontró asociado a reacción leucocitaria; no se asoció a comportamientos sexuales específicos ni sintomatología ginecológica.