Combining untargeted and targeted metabolomics to identify diagnostic biomarkers of adenoid hypertrophy.

Adenoid hypertrophy (AH) is a common condition among pediatric and adolescent populations. The clinical diagnosis primarily relies on rhinoscopy, with a notable absence of noninvasive early diagnostic methods. This study sought to identify potential biomarkers to facilitate the early diagnosis of AH. Ultra-high-performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UHPLC-Q-TOF-MS/MS) was employed to analyze and compare urine samples from 40 patients with AH and 30 healthy controls. To validate and enhance the findings from untargeted metabolomics, targeted metabolomics was conducted using ultra-high-performance liquid chromatography coupled with triple quadrupole mass spectrometry (UHPLC-QqQ-MS/MS), aiming to elucidate the relationship between AH and metabolic pathways. The untargeted metabolomics analysis, utilizing multivariate techniques, identified significant differences in the levels of 20 endogenous metabolites in urine samples between the AH and healthy groups. Further investigation of metabolic pathways indicated that sphingolipid and riboflavin metabolism are implicated in the pathogenesis of AH. Riboflavin and phytosphingosine were identified as potential biomarkers using targeted metabolomics. In this study, a comprehensive approach involving both untargeted and targeted metabolomics was employed to investigate diagnostic biomarkers of AH. The abnormal expression levels of riboflavin and phytosphingosine may be related to inflammation, oxidative damage, and immunomodulatory dysfunction in the pathogenesis of AH. The results showed that the identified biomarkers may serve as a novel tool for early diagnosis and tracking of disease progression.