Gaucher disease is a rare inherited disorder caused by a deficiency of the lysosomal acid beta-glucocerebrosidase enzyme. Metabolomic studies by our group targeted several new potential urinary biomarkers. Apart from lyso-Gb1, these studies highlighted lyso-Gb1 analogs -28, -26, -12 (A/B), +2, +14, +16 (A/B), +30, and +32 Da, and polycyclic lyso-Gb1 analogs 362, 366, 390, and 394 Da. The main objective of the current study was to develop and validate a robust UPLC-MS/MS method to study the urine distribution of these biomarkers in patients.
Method: Urine samples were purified using solid-phase extraction. A 12 min UPLC-MS/MS method was developed.
Results: Validation assays revealed high precision and accuracy for creatinine and lyso-Gb1. Most lyso-Gb1 analogs had good recovery rates and high intra- and interday precision assays. Biomarker-estimated LOD and LOQ levels ranged from 56-109 pM to 186-354 pM, respectively. Comparison between GD patients and healthy controls showed significant differences in most biomarker levels. Typically, treated GD patients presented lower biomarker levels compared to untreated patients.
Conclusions: These data suggest that the metabolites investigated might be interesting GD biomarkers. More studies with a larger cohort of patients will be needed to better understand the clinical significance of these GD biomarkers.
Keywords: Gaucher disease type 1; biomarkers; glucosylsphingosine; lyso-Gb1; lyso-Gb1 analogs; polycyclic lyso-Gb1 analogs; tandem mass spectrometry; ultra-performance liquid chromatography; urine.