Antimicrobial skin peptides in premature infants: Comparison with term infants and impact of perinatal factors

Front Immunol. 2023 Feb 27:14:1093340. doi: 10.3389/fimmu.2023.1093340. eCollection 2023.

Abstract

Introduction: 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.

Materials and methods: 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) via 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.

Results: 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.

Discussion: 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.

Keywords: antimicrobial peptides; chorioamnionitis; premature infants; sepsis; skin barrier.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antimicrobial Peptides*
  • Epidermis
  • Female
  • Humans
  • Infant
  • Infant, Newborn
  • Infant, Premature*
  • Pregnancy
  • Prospective Studies
  • S100 Calcium Binding Protein A7

Substances

  • S100 Calcium Binding Protein A7
  • Antimicrobial Peptides

Grants and funding

This work was supported by the Department of Pediatrics, University Hospital of Schleswig-Holstein, Campus Lübeck; and by the Department of Dermatology, Venerology and Allergology, Quincke Research Center, University-Hospital Schleswig-Holstein, Campus Kiel. The study sponsors had no involvement on study design, the collection, analysis, and interpretation of data; the writing of the report; and the decision to submit the manuscript for publication. Individual participant data reported in this article are available on reasonable request. Proposals may be submitted up to 36 months following article publication.