Department of Neonatology, Guangdong Women and Children Hospital, Guangzhou, China.
Department of Neonatology, Foshan fosun chancheng hospital, Foshan, China.
Ital J Pediatr. 2022 Jul 8;48(1):111. doi: 10.1186/s13052-022-01295-6.
Cathelicidin/LL-37 plays a significant role in the human immune defense reaction. Preterm human immature organs being exposed to inflammation-induced injury was the critical denominator leading to the common preterm associated complications. Previous study showed LL37 concentration in preterm neonates was lower in tracheal aspirates and breast milk as compared to term infants. An adults study showed decreased LL-37 levels was a risk factor for patients in developing severe chronic obstructive pulmonary disease (COPD). However, little is known about the regulation of human cord blood LL37 in preterm neonates and the association with preterm complications. This study was designed to investigate the concentration of LL37 in cord blood of preterm infants and correlation with preterm complications.
Singleton infants born in June 2017 to August 2021 in the study hospital were enrolled. Maternal and neonatal clinical characteristics were collected. LL37 levels, pro-inflammatory factor interleukin-6 (IL-6) and tumor necrosis factor-a (TNF-a) in cord blood and LL37 levels in serum 48-72 hours after birth were measured by enzyme-linked immunosorbent assay. The serum level of LL37 in preterm and term neonates were compared, the perinatal factors possibly affecting the LL37 levels were investigated and the relationship between LL37 level and preterm outcomes were analyzed.
Cord blood LL37 levels in preterm infants were lower than that in term neonates. Cord blood LL37 level was positively correlated with gestational age in preterm. Prenatal steroid administration in preterm neonates decreased cord blood LL37 level. LL37 level was obviously lower in patients with bronchopulmonary dysplasia (BPD). Multiple line regression analysis showed higher LL37 level in cord blood was an independent protective factor for BPD. The concentration of pro-inflammatory factor IL-6 was negatively correlated with LL37.
Cord blood LL37 levels increased during gestation and decreased after perinatal steroid usage. Very preterm infants who displayed higher cord blood LL37 level had reduced risk of developing BPD. Regulation of pro-inflammatory cytokine IL-6 may be associated with the protective effect of LL37 on BPD.
抗菌肽/LL-37 在人体免疫防御反应中发挥着重要作用。早产儿未成熟的器官暴露于炎症诱导的损伤是导致常见早产儿相关并发症的关键因素。先前的研究表明，与足月婴儿相比，早产儿的气管抽吸物和母乳中的 LL37 浓度较低。一项成人研究表明，LL-37 水平降低是患者发展为严重慢性阻塞性肺疾病（COPD）的危险因素。然而，关于早产儿脐血 LL37 的调节及其与早产儿并发症的关系知之甚少。本研究旨在探讨早产儿脐血 LL37 的浓度及其与早产儿并发症的关系。
纳入 2017 年 6 月至 2021 年 8 月在研究医院出生的单胎婴儿。收集产妇和新生儿的临床特征。采用酶联免疫吸附试验检测脐血中 LL37 水平、促炎因子白细胞介素-6（IL-6）和肿瘤坏死因子-α（TNF-α）以及出生后 48-72 小时血清中的 LL37 水平。比较早产儿和足月儿血清中 LL37 水平，探讨可能影响 LL37 水平的围生期因素，并分析 LL37 水平与早产儿结局的关系。
早产儿脐血 LL37 水平低于足月儿。早产儿脐血 LL37 水平与胎龄呈正相关。早产儿产前使用类固醇降低了脐血 LL37 水平。患有支气管肺发育不良（BPD）的患者 LL37 水平明显较低。多元线性回归分析显示，脐血中较高的 LL37 水平是 BPD 的独立保护因素。促炎因子 IL-6 的浓度与 LL37 呈负相关。
脐血 LL37 水平在妊娠期增加，在围生期使用类固醇后降低。脐血 LL37 水平较高的极早产儿发生 BPD 的风险降低。促炎细胞因子 IL-6 的调节可能与 LL37 对 BPD 的保护作用有关。
