Exploratory Metabolomic Profiling of Plasma and Cerebrospinal Fluid in a Pilot Study of Children with Acute Lymphoblastic Leukemia.

Acute lymphoblastic leukemia (ALL) is the most common pediatric malignancy and is associated with profound metabolic reprogramming. This exploratory study aimed to characterize the metabolomic profiles of plasma and cerebrospinal fluid (CSF) in children with newly diagnosed pre-B-cell acute lymphoblastic leukemia (pre-B ALL) prior to therapy. Metabolomic analyses were performed using mass spectrometry-based platforms combined with multivariate statistical approaches (PCA, OPLS-DA, SVM-RFE, EBAM). In plasma, we identified 41 significantly altered metabolites (FDR < 0.011), revealing a distinct signature that differentiated pre-B ALL patients from healthy controls. Specifically, patients exhibited elevated levels of hypoxanthine, xanthine, and phosphatidylcholine derivatives, alongside reduced concentrations of L-cysteine and prasterone sulfate, indicating systemic dysregulation of purine, lipid, and amino acid metabolism. In CSF, we observed a distinct metabolic profile characterized by coordinated disturbances in purine degradation, phospholipid metabolism, and sphingolipid pathways. Notably, correlation analysis between the two matrices suggested that systemic metabolic shifts, particularly in purine metabolism (e.g., hypoxanthine and xanthine levels), are mirrored within the central nervous system microenvironment. These findings indicate that children with pre-B ALL exhibit specific metabolic alterations in both compartments before treatment. This work serves as a proof-of-concept for applying metabolomics in pediatric oncology, highlighting the necessity for further validation in larger, prospective cohorts to assess the clinical utility of these profiles.