Arai Hirokazu, Ito Tomoo, Adachi Hiroyuki, Goto Ryoji, Takahashi Tsutomu
Department of Pediatrics, Akita University Graduate School of Medicine, Akita, Japan.
Pediatr Pulmonol. 2014 Sep;49(9):905-10. doi: 10.1002/ppul.22910. Epub 2013 Oct 24.
Funisitis reflects the fetal systemic inflammatory response in premature infants. Macrophages and neutrophils have been identified as key elements in the inflammatory process of the lungs, and secrete proteases that cause the destruction of the extracellular matrix (ECM). Fibronectin (FN) is the major constituent of the pulmonary ECM and exists in multiple isoforms arising from alternative RNA splicing. Extra domain A (EDA) is the major alternatively spliced segment, and the expression of EDA containing FN (EDA + FN) in the lungs is associated with distal pulmonary cell proliferation during alveolar formation.
To study the relationship between the presence of funisitis and EDA + FN levels in the tracheal aspirate fluid (TAF) of infants of less than 28 weeks' gestation.
The subjects included in this study were 26 extremely premature infants of <28 weeks' gestation at <24 hr of age, from whom the TAF was collected. These preterm infants were divided into two groups according to placental histology. The funisitis (+) group (n = 9) was compared with the funisitis (-) group (n = 17). The TAF supernatants were analyzed for IL-1β, IL-6, IL-8, neutrophil elastase, and EDA + FN using enzyme-linked immunosorbent assay (ELISA).
There were no significant differences in gestational age or birthweight between these groups. The funisitis (+) group had a significantly higher ventilator setting (inspired O(2) × mean airway pressure) at Day 28 than the funisitis (-) group. In the TAF, the concentrations of IL-1β were significantly higher in the funisitis (+) group than in the funisitis (-) group, as were the concentrations of neutrophil elastase. The concentrations of EDA + FN were significantly lower in the funisitis (+) group than in the funisitis (-) group.
Decreased EDA + FN in TAF might be one of the risk factors leading to respiratory distress in extremely premature infants with funisitis.
脐带炎反映了早产儿的胎儿全身炎症反应。巨噬细胞和中性粒细胞已被确定为肺部炎症过程中的关键因素，并分泌导致细胞外基质（ECM）破坏的蛋白酶。纤连蛋白（FN）是肺ECM的主要成分，以多种由可变RNA剪接产生的异构体形式存在。额外结构域A（EDA）是主要的可变剪接片段，肺中含EDA的FN（EDA+FN）的表达与肺泡形成过程中远端肺细胞增殖有关。
研究胎龄小于28周婴儿的气管吸出液（TAF）中脐带炎的存在与EDA+FN水平之间的关系。
本研究纳入26例胎龄小于28周、出生后<24小时的极早产儿，收集其TAF。这些早产儿根据胎盘组织学分为两组。将脐带炎（+）组（n=9）与脐带炎（-）组（n=17）进行比较。使用酶联免疫吸附测定（ELISA）分析TAF上清液中的IL-1β、IL-6、IL-8、中性粒细胞弹性蛋白酶和EDA+FN。
两组之间的胎龄或出生体重无显著差异。脐带炎（+）组在第28天的呼吸机设置（吸入氧浓度×平均气道压）显著高于脐带炎（-）组。在TAF中，脐带炎（+）组的IL-1β浓度显著高于脐带炎（-）组，中性粒细胞弹性蛋白酶浓度也是如此。脐带炎（+）组的EDA+FN浓度显著低于脐带炎（-）组。
TAF中EDA+FN降低可能是导致患有脐带炎的极早产儿呼吸窘迫的危险因素之一。
