Metabolomic Study Using Time-of-Flight Mass Spectrometry Reveals Novel Urinary Biomarkers for Gaucher Disease Type 1

Gaucher disease (GD) is a lysosomal storage disorder resulting from a biallelic mutation in the gene GBA1, leading to deficiencies in the enzyme beta-glucocerebrosidase (Gcase). Inabilities of the Gcase to catabolize its substrate result in the accumulation of sphingolipids in macrophages, which impairs the cell functions and ultimately leads to multisystemic clinical manifestations. Important variability in symptoms and manifestations may lead to challenging diagnosis and patient care. Plasma glucosylsphingosine (lyso-Gb(1)) is a biomarker frequently used for prognosis, monitoring, and patient follow-up. While lyso-Gb(1) appears to be a valid biomarker, few studies have investigated other matrices for potential GD biomarkers. The main objective of this study was to investigate the urine matrix as a potential source of new GD biomarkers by performing a metabolomic study using time-of-flight mass spectrometry. Our study highlighted a significant increase of eight urinary lyso-Gb(1) analogues. Moreover, a novel class of biomarkers, named polycyclic lyso-Gb(1) analogues, was identified. These four new molecules were more elevated than lyso-Gb(1) and related analogues in urine specimens of GD patients. Further investigations are warranted to validate the efficiency of these newly found biomarkers on a larger cohort of Gaucher patients and to compare them with plasma biomarkers currently quantified in clinical laboratories.