A metabolomic-based biomarker discovery study for predicting phototherapy duration for neonatal hyperbilirubinemia.

Background: Phototherapy is a recommended method for the treatment of neonatal hyperbilirubinemia. However, biomarkers for predicting the more effective duration of phototherapy prior to treatment are lacking. Therefore, we aimed to determine novel predictors for the timing of phototherapy from the perspective of metabolomics. Methods: A total of 12 newborns with neonatal hyperbilirubinemia were recruited on the day of admission. The infants were divided into a short-duration (<30 hours) phototherapy group and a long-duration (≥30 hours) phototherapy group based on the length of phototherapy treatment. Metabolites in serum samples were then explored using an untargeted metabolomics strategy. Results: In total, 59 of 1,073 significantly different metabolites were identified between the short-duration and long-duration phototherapy groups, including 18 upregulated and 41 downregulated metabolites. The results of metabolomic analysis showed that the differentially expressed metabolites were enriched in glycerophospholipid metabolism, which is closely associated with the excretion of bilirubin. Moreover, the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis revealed that the metabolites were also enriched in alpha-Linolenic acid metabolism and fatty acid elongation. Spearman correlation hierarchical clustering analysis demonstrated that 9 metabolites were negatively correlated with the duration of phototherapy. Metabolites, especially phosphatidylethanolamine (PE) (22:1(13Z)/15:0), phosphatidylcholine (PC) (18:1(9Z)/18:1(9Z)), phosphatidylserine (PS) (22:0/15:0), 5,6-dihydrouridine, and PE (MonoMe(11,3)/MonoMe(13,5)), had better predictability for the duration of phototherapy [area under curve (AUC): 1; 95% confidence interval (CI): 1-1] than total serum total bilirubin and direct bilirubin (AUC: 0.806; 95% CI: 0.55-1), as revealed by receiver operating characteristic analysis. Conclusions: Our research found that the differential metabolites were associated with the duration of neonatal jaundice and that glycerophospholipid metabolism might have played a role in this biological process. Moreover, metabolites such as PE (22:1(13Z)/15:0), PC (18:1(9Z)/18:1(9Z)), PS (22:0/15:0), 5,6-dihydrouridine, and PE (MonoMe(11,3)/MonoMe(13,5)) could be used as predictors for phototherapy duration in neonatal hyperbilirubinemia and assist with decision-making.