Abstract:

Objective To investigate the relationship between miR-15b-5p，miR-29a-3p，miR-146a and the severity of neonatal respiratory distress syndrome（NRDS）in preterm infants，as well as their value in prognosis assessment. Methods A total of 243 preterm infants with NRDS in the Second Affiliated Hospital of Xingtai Medical College from March 2021 to May 2025 were enrolled（NRDS group）. They were classified into mild group（71 cases），moderate group（98 cases）and severe group（74 cases）. The clinical data were collected，and serum miR-15b-5p，miR-29a-3p and miR-146a relative expression levels were determined. According to the survival status within 7 d after birth，they were classified into survival group（198 cases）and death group（45 cases）. Pearson correlation analysis was used to evaluate the correlation between serum miR-15b-5p，miR-29a-3p and miR-146a expression levels in preterm infants with the 5 min Apgar score. Multivariate Logistic regression analysis was used to evaluate the influencing factors of the prognosis of preterm infants with NRDS. Receiver operating characteristic（ROC）curve was used to analyze the efficacy of single and combined determinations of each index in judging the 7 d death of preterm infants with NRDS. Clinical decision curve analysis was used to evaluate the clinical applicability of the combined determination in judging the 7 d death of preterm infants with NRDS. Results The relative expression levels of serum miR-15b-5p，miR-146a in mild group，moderate group and severe group were increased successively（P<0.05），while the relative expression level of serum miR-29a-3p and the 5 min Apgar score were decreased successively（P<0.05）. The relative expression levels of miR-15b-5p，miR-146a in death group were higher than those in survival group（P<0.05），and the relative expression level of serum miR-29a-3p and the 5 min Apgar score were lower than those in survival group（P<0.05）.The expression levels of miR-15b-5p and miR-146a in the serum of death group were negatively correlated with the 5 min Apgar score （r=-0.669 and -0.528，P<0.05），while the expression level of miR-29a-3p in the serum was positively correlated with the 5 min Apgar score （r=0.501，P<0.05）. Increased expression of miR-15b-5p，miR-146a and decreased expression of miR-29a-3p were independent risk factors for 7 d death in preterm infants with NRDS（P<0.05）. The areas under curves（AUC）of single and combined determinations of serum miR-15b-5p，miR-29a-3p，miR-146a in judging the death of preterm infants with NRDS were 0.826，0.850，0.838 and 0.956，respectively. Within the risk threshold range of 0.06 to 0.98，the net benefit of combined determination was higher than those of single determinations of miR-15b-5p，miR-29a-3p and miR-146a，and the maximum net benefit value was 0.85. Conclusions In preterm infants with NRDS，serum miR-15b-5p and miR-146a show high expression，while miR-29a-3p shows low expression. These expressions are related to the severity of NRDS. The combined determination has high clinical value in the short-term prognosis assessment of preterm infants with NRDS.

Key words: MicroRNA-15b-5p, MicroRNA-29a-3p, MicroRNA-146a, Neonatal respiratory distress syndrome, Preterm infant