Cuestionario de reacciones vasovagales a la donación de sangre en una institución de salud / Questionnaire of vasovagal reactions to blood donation in a health institution

Resumen: Objetivo: Identificar mediante un cuestionario de signos y síntomas vasovagales a donadores de sangre, con el fin de registrar los antecedentes que aumentan la probabilidad de presentar reacciones vasovagales. Materiales y Métodos: Se aplico un cuestionario a donadores de sangre, durante tres meses, en el banco de sangre en una institución de salud de tercer nivel. Resultados: El 100% de los donadores respondió negativamente a las preguntas del cuestionario, pero el 1.3% de ellos presentaron reacción vasovagal, siendo el mareo, palidez y náusea el signo y síntomas más frecuentemente mostrados. Al comparar dos grupos con y sin reacción vasovagal pareados por sexo, edad e índice de masa corporal, no hubo diferencias entre ellos. Conclusiones: Los donadores en nuestro país son fundamentalmente de reemplazo, por lo que se debe considerar esta circunstancia además de sus motivaciones, para el diseño de encuestas dirigidas a esta población.

Abstract: Objective: Identify, trough a vasovagal signs and symptoms questionnaire, blood donors in order to record the antecedents that increases the probability of presenting vasovagal reactions. Materials and Methods: A questionnaire was applied to blood donors, for three months, in the blood bank in a third-level health institution. Results: 100% of the donors answered negatively to the questions in the questionnaire, but 1.3% of them presented vasovagal reaction, with dizziness, pallor and nausea being the most frequently shown sing and symptoms. When comparing two groups with and without vasovagal reaction matched by sex, age and body mass index, there were no differences between them. Conclusions: Donors in our country are fundamentally replacement donors, so this circumstance plus their motivations should be considered for the design of surveys aimed at this population.

The Type of Trypanosoma Cruzi Strain (Native or Non-Native) Used as Substrate for Immunoassays Influences the Ability of Screening Asymptomatic Blood Donors.

BACKGROUND: The origin (native or non-native) of Trypanosoma cruzi strains used as substrate for immunoassays may influence their performance. OBJECTIVE: To assess the performance of an immunoassay based on a native T. cruzi strain compared to another based on non-native T. cruzi strains, in asymptomatic blood donors from Mexico. METHODS: Serum samples from a tertiary referral center were tested by both ELISA-INC9 (native) and Chagatest (non-native) assays. All reactive serum samples were further analyzed by indirect immunofluorescence. RESULTS: Sera from 1,098 asymptomatic blood donors were tested. A 4.3 and 0.7% serum reactivity prevalence was observed using ELISA-INC9 and Chagatest, respectively (kappa = 0.13; -0.11 to 0.38). Subsequently, indirect immunofluorescence analyses showed higher positivity in serum samples reactive by ELISA-INC9 compared to those reactive by Chagatest (79 vs. 62.5%; p < 0.001). Furthermore, out of the 47 positive samples by both ELISA-INC9 and indirect immunofluorescence, only four (8.5%) were reactive in Chagatest assay. Meanwhile, four (80%) out of the five positive samples by both Chagatest and indirect immunofluorescence were reactive using ELISA-INC9. CONCLUSION: Immunoassays based on a native T. cruzi strain perform better than those based on non-native strains, highlighting the need to develop and validate screening assays in accordance to endemic T. cruzi strains.

SFRP5 hepatic expression is associated with non-alcoholic liver disease in morbidly obese women.

BACKGROUND AND AIMS: Secreted frizzled-related protein 5 (SFRP5) was recently described as a new adipokine protective for hepatic steatosis and other obesity-related complications in the mouse model. To date, SFRP5 expression in non-alcoholic fatty liver disease (NAFLD) has not been fully assessed in humans. We measured circulating SFRP5 levels and its expression in liver and adipose tissue, and evaluated its association with NAFLD in morbidly obese women. MATERIAL AND METHODS: Fifty-four morbidly obese women undergoing bariatric surgery were included in the study. Liver biopsies were used for histology and hepatic triglyceride content quantification. Circulating SFRP5 levels were measured through enzyme-linked immunoabsorbent assay, and SFRP5 expression was performed in hepatic and adipose tissue (subcutaneous and visceral). RESULTS: Although circulating SFRP5 levels showed a tendency to decrease with NAFLD progression, no significant differences were observed among non-alcoholic steatosis, steatohepatitis, and control subjects. Hepatic SFRP5 expression showed a negative correlation with hepatic triglyceride content (r = -0.349, P = 0.016 for mRNA and r = -0.291, P = 0.040 for SRFP5 protein) and ALT serum levels (r = -0.437, P = 0.001 for SRFP5 protein). In addition, hepatic SFRP5 protein levels were significantly lower in NASH than in control subjects (P = 0.006). CONCLUSION: This is the first study reporting an association of hepatic SFRP5 expression with NAFLD in humans.

Helminth excreted/secreted antigens repress expression of LPS-induced Let-7i but not miR-146a and miR-155 in human dendritic cells.

MicroRNAs have emerged as key regulators of immune responses. They influence immune cells' function and probably the outcome of several infections. Currently, it is largely unknown if helminth parasites and their antigens modify host microRNAs expression. The aim of this study was to explore if excreted/secreted antigens of Taenia crassiceps regulate LPS-induced miRNAs expression in human dendritic cells. We found that these antigens repressed LPS-let-7i induction but not mir-146a or mir-155 and this correlates with a diminished inflammatory response. This let-7i downregulation in dendritic cells constitutes a novel feature of the modulatory activity that helminth-derived antigens exert on their host.

Association of the I148M/PNPLA3 variant with elevated alanine transaminase levels in normal-weight and overweight/obese Mexican children.

BACKGROUND AND AIMS: Non-alcoholic fatty liver disease (NAFLD) and elevated alanine transaminase (ALT) levels are common in obese Hispanic adults and children. Recently, a PNPLA3 gene variant (I148M) was strongly associated with NAFLD and higher ALT levels in obese adults, including Hispanics. The aims of this study were to estimate the frequency of elevated ALT levels, and to address the influence of obesity and PNPLA3/I148M on ALT levels in a general population sample of Mexican school-aged children. METHODS: A total of 1037 non-related Mexican children aged 6 to 12 years were genotyped for the I148M variant. Anthropometric, clinical and metabolic parameters were collected from all participants. RESULTS: Elevated ALT levels (>35 U/L) were more frequent in obese (26.9%) and overweight (9.3%) than in normal weight children (2.2%). The M148M genotype was significantly associated with elevated ALT levels in this population (OR=3.7, 95% CI 2.3-5.9; P=3.7×10(-8)), and children carrying the M148M genotype showed significantly lower HDL cholesterol levels and BMI z-core (P=0.036 and 0.015, respectively). On stratifying by BMI percentile, this genotype conferred a much greater risk of elevated ALT levels in normal weight (OR=19.9, 95% CI 2.5-157.7; P=0.005) than overweight and obese children (OR=3.4, 95% CI 1.3-8.9; P=0.014 and OR=3.1, 95% CI 1.7-5.5; P=1.4 x10(-4), respectively). CONCLUSIONS: The I148M PNPLA3 variant is strongly associated with elevated ALT levels in normal weight and overweight/obese Mexican children. Thus, the M148M genotype may be considered as an important risk factor for liver damage in this population.

Cestode antigens induce a tolerogenic-like phenotype and inhibit LPS inflammatory responses in human dendritic cells.

Pathogens have developed strategies to modify Dendritic Cells (DCs) phenotypes and impair their functions in order to create a safer environment for their survival. DCs responses to helminths and their derivatives vary among different studies. Here we show that excretory/secretory products of the cestode Taenia crassiceps (TcES) do not induce the maturation of human DCs judged by a lack of increment in the expression of CD83, HLA-DR, CD80 and CD86 molecules but enhanced the production of IL-10 and positively modulated the expression of the C-type lectin receptor MGL and negatively modulated the expression of DC-SIGN. Additionally, these antigens were capable of down-modulating the inflammatory response induced by LPS in these cells by reducing the expression of the maturation markers and the production of the inflammatory cytokines IL-1ß, TNF, IL-12 and IL-6. The effects of TcES upon the DCs responses to LPS were stronger if cells were exposed during their differentiation to the helminth antigens. All together, these findings suggest the ability of TcES to induce the differentiation of human DCs into a tolerogenic-like phenotype and to inhibit the effects of inflammatory stimuli.