RESUMO
BACKGROUND: Breastmilk is a dynamic fluid whose initial function is to provide the most adapted nutrition to the neonate. Additional attributes have been recently ascribed to breastmilk, with the evidence of a specific microbiota and the presence of various components of the immune system, such as cytokines and leukocytes. The composition of breastmilk varies through time, according to the health status of mother and child, and altogether contributes to the future health of the infant. Obesity is a rising condition worldwide that creates a state of systemic, chronic inflammation including leukocytosis. Here, we asked whether colostrum, the milk produced within the first 48 h post-partum, would contain a distinct leukocyte composition depending on the body mass index (BMI) of the mother. METHODS: We collected peripheral blood and colostrum paired samples from obese (BMI > 30) and lean (BMI < 25) mothers within 48 h post-partum and applied a panel of 6 antibodies plus a viability marker to characterize 10 major leukocyte subpopulations using flow cytometry. RESULTS: The size, internal complexity, and surface expression of CD45 and CD16 of multiple leukocyte subpopulations were selectively regulated between blood and colostrum irrespective of the study groups, suggesting a generalized cell-specific phenotype alteration. In obesity, the colostrum B lymphocyte compartment was significantly reduced, and CD16+ blood monocytes had an increased CD16 expression compared to the lean group. CONCLUSIONS: This is the first characterization of major leukocyte subsets in colostrum of mothers suffering from obesity and the first report of colostrum leukocyte subpopulations in Latin America. We evidence various significant alterations of most leukocyte populations between blood and colostrum and demonstrate a decreased colostrum B lymphocyte fraction in obesity. This pioneering study is a stepping stone to further investigate active immunity in human breastmilk.
Assuntos
Colostro , Leucócitos , Leite Humano , Obesidade , Feminino , Humanos , Lactente , Recém-Nascido , Gravidez , Colostro/citologia , Estudos Transversais , Leite Humano/citologia , MãesRESUMO
Both transient tachypnea of the newborn and neonatal respiratory distress syndrome have been associated with changes in gene expression of aquaporine-5 (AQP5) and the ß subunit of the epithelial sodium channel (ß-ENaC) in the respiratory epithelium. Gastric aspirate (GA) obtained immediately after birth could represent a new source for gene expression analysis for these respiratory diseases. The aims of this study were to determine the feasibility of estimating AQP5 and ß-ENaC gene expression in exfoliated respiratory epithelial cells from the GA of term neonates, and to compare the values with those found in scraped nasal epithelial cells, previously validated as a surrogate for distal lung epithelium in terms of ionic channel activity. The study had a cross-sectional, proof-of-concept design. Immediately after birth, we obtained GA and nasal mucous membrane scrapings from term newborns, in which total RNA and RT-qPCR assays for AQP5 and ß-ENaC genes were performed. AQP5 gene expression was greater in GA than in nasal scrapings, and ß-ENaC gene expression was at least as great in GA as that obtained in nasal scrapings. Amplification of samples from the two sites was comparable. AQP5 gene expression was greater in babies delivered by cesarean section; ß-ENaC gene expression was greater in babies delivered vaginally, but only in the nasal samples. Quantitation of the expression of AQP5 and of ß-ENaC genes in GA, obtained shortly after birth from term newborns is feasible. If confirmed in preterm neonates, this approach could aid in the differential diagnosis of neonatal respiratory diseases.