Serum LRG1 as a diagnostic marker of necrotizing enterocolitis in preterm infants.

Objective: Necrotizing enterocolitis (NEC) remains a leading cause of morbidity and mortality in preterm infants; however, early diagnosis is limited by the lack of reliable circulating biomarkers. This study aimed to evaluate the diagnostic value of serum leucine-rich Methods: LRG1 was identified through an integrative bioinformatics analysis by intersecting differentially expressed genes from two Gene Expression Omnibus datasets (GSE46619 and GSE64801) with the Secreted Protein Database. A nested case-control study was subsequently conducted in preterm infants (<32 weeks' gestation). Serum LRG1 levels were measured using ELISA, and their associations with clinical and laboratory parameters were analyzed. Machine learning approaches were applied for feature selection, followed by multivariable logistic regression. Diagnostic performance was evaluated using receiver operating characteristic curve analysis. Results: Serum LRG1 levels were significantly elevated in infants with NEC compared with controls. LRG1 was positively correlated with C-reactive protein and neutrophil count, and negatively correlated with plateletcrit. Higher LRG1 levels were independently associated with NEC. In the predictive model, LRG1 demonstrated moderate diagnostic performance (area under the curve = 0.811). Conclusion: Serum LRG1 is a candidate adjunctive biomarker associated with NEC in preterm infants. However, these findings remain exploratory and require validation in larger, multicenter studies.