Department of General Pediatrics, University Children's Hospital Muenster, Muenster, Germany.
Institute of Medical Biometry and Statistics, University of Luebeck, Luebeck, Germany.
Front Immunol. 2023 Feb 27;14:1093340. doi: 10.3389/fimmu.2023.1093340. eCollection 2023.
Preterm infants have an immature epidermis barrier function that may lead to an increased permeability to pathogens. On the surface of the human skin, antimicrobial peptides (AMPs) are important molecules of the innate immune system, have broad antimicrobial properties, and provide an essential role in integrity of the microbiome. Given the marked susceptibility of preterm infants to infection, we hypothesize a decreased expression of AMPs on the skin of preterm infants.
In a prospective single-center study with 35 preterm and 20 term infants, we analyzed skin rinsing probes for the presence of the AMPs psoriasin (S100A7) and ribonuclease 7 (RNase 7) enzyme-linked immunosorbent assay. Samples were taken from preterm infants < 34 0/7 weeks gestational age (mean ± SD gestational age, 28.8 ± 2.4 weeks) on days 0, 7, 14, and 28 after birth. Term infants (> 36 6/7 weeks) (controls) were washed on days 0 and 28.
Psoriasin and RNase 7 were both expressed on skin of preterm and term infants and increased in concentration significantly over time. RNase 7 was more expressed in term infants on day 0 [preterm = 1.1 (0.7-2.9) vs. term = 2.0 (1.1-3.4) ng/ml, p = 0.017]. On day 28, premature infants showed higher values of psoriasin [preterm = 10.9 (5.6-14.2) vs. term = 6.3 (3.4-9.0) ng/ml, p < 0.001]. Notably, preterm infants with infectious or inflammatory context driven by histological proof of chorioamnionitis and early-onset or late-onset sepsis had higher concentrations of psoriasin as compared with non-affected preterm infants. After exclusion of infants with inflammatory hit, median concentrations of RNase 7 and psoriasin did not differ between preterm and full-term infants on days 0 and 28.
Psoriasin and RNase 7 concentrations increase over time on the skin of newborn infants and seem to play a role in the first defense against infection. This is of particularly interest as the role of AMPs on a maturing skin microbiome and its possible new prevention strategies is unclear and needs to be determined.
早产儿的表皮屏障功能不成熟，这可能导致其对病原体的通透性增加。在人体皮肤表面，抗菌肽（AMPs）是先天免疫系统的重要分子，具有广泛的抗菌特性，并为微生物组的完整性提供了重要作用。鉴于早产儿对感染的明显易感性，我们假设早产儿皮肤中 AMPs 的表达减少。
在一项具有 35 名早产儿和 20 名足月产儿的前瞻性单中心研究中，我们通过酶联免疫吸附试验分析了皮肤冲洗探针中存在的抗菌肽（S100A7）和核糖核酸酶 7（RNase 7）。在出生后第 0、7、14 和 28 天，从胎龄<34 0/7 周（平均±标准差胎龄，28.8±2.4 周）的早产儿中采集样本。在第 0 天和第 28 天对胎龄>36 6/7 周的足月产儿（对照组）进行清洗。
抗菌肽和 RNase 7 均在早产儿和足月儿的皮肤中表达，并随着时间的推移浓度显著增加。RNase 7 在第 0 天的表达在足月产儿中更高[早产儿=1.1（0.7-2.9）vs. 足月产儿=2.0（1.1-3.4）ng/ml，p=0.017]。在第 28 天，早产儿的 psoriasin 值较高[早产儿=10.9（5.6-14.2）vs. 足月产儿=6.3（3.4-9.0）ng/ml，p<0.001]。值得注意的是，与未受影响的早产儿相比，具有组织学证明的绒毛膜羊膜炎和早发性或晚发性败血症驱动的感染或炎症背景的早产儿，其 psoriasin 浓度更高。排除具有炎症影响的婴儿后，在第 0 天和第 28 天，早产儿和足月儿的 RNase 7 和 psoriasin 浓度在中位数上没有差异。
psoriasin 和 RNase 7 的浓度在新生儿皮肤随时间推移而增加，似乎在抗感染的第一道防线中发挥作用。这一点尤其重要，因为 AMPs 在成熟皮肤微生物组中的作用及其可能的新预防策略尚不清楚，需要进一步确定。
