Exploring IL-10 and NOS3 Genetic Variants as a Risk Factor for Neonatal Respiratory Distress Syndrome and Its Outcome

Background/Objective: Neonatal respiratory distress syndrome (RDS) is a leading cause of morbidity and mortality in preterm infants. Interleukin-10 (IL-10) and endothelial nitric oxide synthase (eNOS, also known as NOS3) regulate inflammation and vascular tone, and genetic variants may influence the risk of RDS. To investigate the association between IL-10 rs1800872 (c.-149+1984T>G), IL-10 rs1800896 (c.-149+2474T>C), and NOS3 rs2070744 (c.-149+1691C>T), NOS3 rs1799983 (c.894T>G) variants and the risk of RDS in a Romanian cohort of preterm neonates. Methods: This case–control study included 340 preterm neonates (113 with RDS, 227 controls) born at <36 weeks of gestation. Genotyping was performed using TaqMan SNP assays. Logistic regression adjusted for gestational age and sex estimated odds ratios (ORs) and 95% confidence intervals (CIs). ROC analyses evaluated predictive performance. Results: No significant differences in genotype or allele distributions were observed between RDS and control groups for any variant. Haplotype analysis also revealed no association with RDS susceptibility or severity. NOS3:c.894T>G variant was associated with reduced risk of severe RDS after correction (adjusted p = 0.009), though survival analysis showed no significant genotype-specific effects. Epistatic genotype interaction was observed for the IL-10 T/G + T/C, present only in RDS (p = 0.0026). ROC analysis revealed a clinical prediction of RDS (AUC = 0.996), while the addition of genetic variants improved discrimination for severity (AUC = 0.865; 95% CI: 0.773–0.957) and mortality (AUC = 0.913; 95% CI: 0.791–1.000). Conclusions: IL-10 and NOS3 variants were not individually associated with overall RDS susceptibility. The observed epistatic interactions and the potential protective effect of NOS3:c.894T>G against severe forms can suggest modulatory roles in disease progression. Larger, ethnically homogeneous cohorts are needed to confirm these findings and assess their potential for informing personalized care for neonates.