Study on identification of a three-microRNA panel in serum for diagnosing neonatal early onset sepsis

Comparing with other diseases, early onset sepsis (EOS) is a global health concern in neonatal period for its high morbidity and mortality rates. In recent years, many studies have contributed to the figure out the expression patterns of circulating micro-RNAs (miRNAs) in different diseases and progressions, which could function as diagnostic biomarkers for EOS. The purpose of this study was to analyze the expression patterns of selected miRNAs and evaluate their diagnostic value for early detection and treatment.

This was a prospective cross-sectional study conducted from 1 July 2021 to 30 June 2022. We collected surplus peripheral blood and demographic statistics of septic neonates and non-infected neonates during the first 24 h after delivery and obtained 11 candidate miRNAs by literature screening. First, we extracted the candidate miRNAs from the serum of selected neonates and analyzed their expression levels, and then the receiver operating characteristic (ROC) curve was used to select the differentially expressed miRNAs. We analyzed their sensitivity and specificity and obtained the best diagnostic panel. Finally, with the help of differentially expressed miRNAs, we performed gene ontology (GO) enrichment and protein-protein interaction (PPI) analyses by their target genes.

In patients with EOS, three miRNAs (mir-223-3p, mir-15a-5p, and mir-17-5p) in serum were significantly downregulated, and mir-146a-5p, mir-1-3p, and mir-16-5p were upregulated. The diagnostic value of these miRNAs (miR-15a-5p, AUC = 0.67; miR-223-3p, AUC = 0.72; miR-16-5p, AUC = 0.68; miR-17-5p, AUC = 0.70; miR-1-3p, AUC = 0.69; miR-146a-5p, AUC = 0.72) was moderate, and the diagnostic panel constructed by miR-15a-5p, miR-223-3p, and miR-16-5p possessed a comparatively higher diagnostic value (AUC = 0.85, sensitivity: 74.6%, specificity: 86%), indicating that their combined application may be a promising biomarker for clinical diagnosis of EOS. According to GO enrichment analysis, most proteins encoded by target genes were located in the cytosol as for cellular component (CC), for molecular function (MF), most proteins acted as regulators in protein binding, and for biological process (BP). Most genes function in positive or negative regulation of transcription from RNA polymerase II promoter, and the top 10 hub genes were CDKN1A, YAP1, CCNE1, CCND1, CKK6, ERBB4, CHEK1, DICER1, VEGFA, and APP by rank degree after PPI construction.

The three-miRNA panels (miR-15a-5p, miR-223-3p, and miR-16-5p) may be a novel noninvasive biological marker for EOS screening.