Detección de resistencia primaria en pacientes chilenos infectados por VIH / Detection of primary antiretroviral resistance in Chilean patients recently infected with human immunodeficiency virus (HIV)

Background: In countries with universal access to antiretroviral therapy a progressive increase in the number of patients that are infected with resistant virus, is observed. Aim To detect the presence of primary resistance to antiretroviral drugs among patients with a recent diagnosis of HIV infection. Material and methods: Twenty five male patients aged 25 to 45 years, with a diagnosis of a recent HIV infection, done between 2004 and 2005, were studied. Genotypic resistance to antiretroviral drugs was studied using the Genetic Resistance Test TRUGENE® from Bayer. Results: Resistance mutations were detected in 10 patients. All had an university title or had university studies. All lived in northeastern Santiago and had risky sexual behaviors while traveling abroad. Seven mutations were detected in reverse transcriptase. Of these, three were associated to a high resistance level and four, to an intermediate or low resistance, were also detected. Conclusions: A high frequency of genotypic resistance was detected in this group of Chilean patients recently infected with HIV. A higher socioeconomic status and lifestyle could have influenced these results.

Estudio de la funcionalidad de las células NK en el embarazo / Functionality study of pregnancy NK cells

En los últimos años, la participación del sistema inmune innato en el desarrollo de la pre-eclampsia ha sido el objetivo de numerosos estudios. Sin embargo, el rol de las células agresoras naturales (NK) en esta patología no ha sido totalmente aclarado. Las células NK, componentes del sistema inmune innato, poseen actividad citotóxica espontánea, y secretan citoquinas tales como interferón gamma (INF-y ) y Factor de Necrosis Tumoral alfa (TNF-alfa). En el presente estudio hemos analizado la actividad funcional y el inmunofenotipo de células NK obtenidas desde sangre periférica de pacientes con pre-eclampsia, mujeres sanas embarazadas y mujeres sanas no embarazadas. Se cuantificó la actividad cititóxica usando el ensayo de liberación de51cromo. La producción de citoquinas en respuesta a activadores policlonales y el inmunofenotipo (CD3-CD16+CD56+) fueron determinados por citometría de flujo. Estos parámetros no evidenciaron diferencias significativas entre los grupos estudiados; sin embargo, en las pacientes con pre-eclampsia se observa una tendencia hacia una menor citotoxicidad y menor producción de TNF-alfa en células NK estimulada sin vitro, y una proporción aumentada del subtipo celular NK CD56-CD16+ en sangre periférica en relación con los otros dos grupos estudiados.

NK cells functionality during pregnancy. During the last few years, the role of innate immune system in development of pre-eclampsia has been the focus of a number of studies. However, the role of natural killer (NK) cells in pregnancy and pre-eclampsia has not been totally clarified. NK cells, an important component of innate immune system, normally exhibit spontaneus cytolytic activity and secrete cytokines such as interferon gamma (IFN-y) and tumor necrosis factor alpha (TNF-alpha). In current paper, we studied functional activity and immunophenotype of peripheral blood NKcells obtained from patients with pre-eclampsia, healthy pregnant women and non-pregnant healthy women. For this purpose, we quantified cytolytic activity using 51chromium release assay. We determined cytokine production in response to polyclonal activators and cells immunophenotype (CD3-CD16+CD56+) by flow cytometry. We found no significant differences in these parameters among the three groups studied, however, in patients with pre-eclampsia, there is a tendency to a decreased cytotoxic activity and less production of TNF-alpha by NK cells in vitro as well as an increased proportion of the NK subset CD56-CD16+, in peripheral blood.