Prevalence of thrombophilia-associated genetic risk factors in blood donors of a regional hospital in southern Brazil

ABSTRACT Introduction: Thromboembolic events occur due to an imbalance in the hemostasis and some factors associated with this condition can be inherited. In order to evaluate the frequency of genotypes considered to be common hereditary risk factors for thrombophilia associated with venous thrombosis (g.1691G>A and g.20210G>A) and hyperhomocysteinemia (g.677C>T and g.1298A>C), samples from voluntary healthy blood donors at the Hospital de Clínicas de Porto Alegre were tested. Methods: We examined 325 blood samples from blood donors collected from October 2017 to July 2018. Blood was collected on filter paper and the DNA was extracted for single nucleotide polymorphisms (SNPs) analysis using the qualitative real time polymerase chain reaction. Results: The calculated frequencies of each genetic variant in heterozygosity were 4% for the FV gene (g.1691G> A), 4% for the F2 gene (g.20210G> A) and 42% and 39% for methylenetetrahydrofolate reductase (MTHFR), g.677C>T and g.1298A>C, respectively. Only the genetic variants of MTHFR were found in homozygosity, with frequencies of 14% and 6% (g.677C>T and g.1298A>C), respectively. Discussion: Altogether, these results describe the frequencies of genetic variants associated with venous thrombosis and hyperhomocysteinemia in the analyzed group and are important to enhance our current knowledge about the genetic profiles of Brazilian blood donors.

Quantification of peripheral blood CD34+ cells prior to stem cell harvesting by leukapheresis: a single center experience

ABSTRACT Background: Due to laboratory logistic issues, our center has traditionally scheduled peripheral blood stem cell harvests based on timing from the start of mobilization. This has proved to be useful in some cases, but also resulted in many fruitless harvests due to poor mobilization. In order to improve the efficiency of collections and compare the effectiveness of peripheral blood CD34+ cells as a predictor with data from other reports, this study analyzed the implementation of this routine. Methods: Peripheral blood and leukapheresis samples were quantified by flow cytometry and the association between these parameters was assessed. Results: Sixty-six consecutive leukapheresis samples were collected from 34 patients after the collection of peripheral blood samples for CD34+ quantification. A moderate positive correlation was observed between peripheral blood CD34+ cell count and total CD34+ cell count/kg (r = 0.596; p-value < 0.001). A multivariable regression model also confirmed this association and allowed the estimation that for every increase in five CD34+ cells/µL in the peripheral blood, a mean increase of 0.38 × 106 CD34+ cells/kg could be predicted. Demographic characteristics, baseline comorbidities and mobilization regimen did not influence final CD34+ cell count in this sample. Conclusions: As observed in other centers, quantification of peripheral blood CD34+ progenitor cells is a strong predictor of effectiveness to guide stem cell harvesting. Due to the results of this study, a modification in the peripheral blood stem cell harvesting logistics was implemented at our center in order to incorporate this routine.

Blood transfusion-related immunomodulation

The phenomenon of transfusion-related immunomodulation (TRIM) has been studied since the observation of a higher kidney allograft survival in patients who had received a higher number of transfusions. Conversely, it has been suggested as one of the possible causes related to the development of infections in patients with multiple blood transfusions and/or after a major surgery, and has been also associated with a decreased function of natural killer cells (NK) and antigen-presenting cells (APCs), reduced cell-mediated immunity, and increased regulatory T cells (Tregs). This review aimed to conceptualize TRIM and discuss some aspects related to its mechanisms and the prevention of immunomodulatory events.

Níveis de hematócrito e hemoglobina e estado nutricional em crianças de 7 a 12 anos em um bairro de baixa renda de Porto Alegre, RS / Levels of hematocrit and hemoglobin and nutritional status in children from 7 to 12 years old in a low income population district of Porto Alegre

O presente trabalho avaliamos 128 crianças de 7 a 12 anos quanto a níveis de hematócrito e hemoglobina, prevalência de valores baixos de hematócrito e hemoglobina, estado nutricional conforme critérios de Seoane Lathan. A populaçäo era de baixa renda com um salário médio mensal entre 1 e 2 salários mínimos, que correspondem a US$50 e US4100 respectivamente. Os níveis médios de hematócritos e hemoglobina encontrados foram de 36.37 (+/- 2.58) e 10.87 (+/- 1.28) respectivamente. A prevalência de hematócrito menor que 34% de hemoglobina menor que 11 g/dl foi de 10,9% e 53.9% respectivamente. Da populaçäo, 89,1% apresentavam algum tipo de desnutriçäo conforme critérios de Seoane Lathan, sendo a mais freqüente Desnutriçäo Crônica Atual