Perfil de citocinas nas primeiras três horas de vida de recém-nascidos prematuros: utilização de amostras coletadas em papel filtro e relação com desfechos desfavoráveis prevalentes nesta população

Abstract

thProcedures performed on preterm neonates within the first hours of birth may trigge systemic inflammatory responses and boost the development of unfavorable outcomes, in addition to immediate and late complications. Objective: This study aimed to look into the correlations between levels of Interleukin (IL) 2, 4, 6, 8, 10, Interferon gamma (IFN-·), tumor necrosis factor alpha (TNF-·), and granulocytemacrophage colony-stimulating factor (GM-CSF) in neonates withinree hours of birth and the main unfavorable outcomes observed in this population.Method: This prospective observational study was carried out at the Unimed-B Unidade Grajaú Maternity Hospital. Thirty-four preterm neonates with gestational ages ranging between 28 and 32 weeks seen from July 2012 to December 2014 were enrolled in the study. Cytokine levels were measured from samples collected on filter paper within 10 minutes, one hour, and three hours of birth. Results: Cytokine levels were measured from blood spots collected on filter paper. A correlation was found between TNF- serum levels within one hour of birth and theoccurrence of sepsis in the studied population. Increased levels of GM-CSF were observed in patients with hypothermia upon admission to the neonatal care unit. IL-6, IL-8, IL-10, IFN-, TNF-, and GM-CSF were detected in the blood samples taken within three hours of birth, with statistically significant differences between each of the sample collection times for cytokines IL-6, IL-8, and IFN-. IL-2 and IL-4 were notdetected in any of the tests. No correlation was found between the expression of cytokines at the sample collection times and the occurrence of bronchopulmonary dysplasia, retinopathy of prematurity, periventricular/intraventricular hemorrhage, o death, even after the studied population was divided into groups of individuals weighing less than 1,500 grams or 1,500 grams and more. Conclusion: The detection of cytokine levels from blood spots on filter paper proved to be a viable testing method. Its advantages include easier sample collection,storage, and transportation, in addition to the low volume of blood required to perform the tests. The study findings suggested that TNF- might be used as an early marker for sepsis. The correlation between increased GM-CSF levels and hypothermia indicates the potentially harmful nature of hypothermia in preterm neonates within thefirst hours of birth, and the relevance of providing effective preventive thermal control measures. More studies are needed to confirm and clarify these correlations an underline the impact early intervention may have on cytokine expression patterns.