Identification of a Reliable Biomarker Profile for the Diagnosis of Gaucher Disease Type 1 Patients Using a Mass Spectrometry-Based Metabolomic Approach

Abstract

Gaucher disease (GD) is a rare autosomal recessive multisystemic lysosomal storage disorder presenting a marked phenotypic and genotypic variability. GD is caused by a deficiency in the glucocerebrosidase enzyme. The diagnosis of GD remains challenging because of the large clinical spectrum associated with the disease. Moreover, GD biomarkers are often not sensitive enough and can be subject to polymorphic variations. The main objective of this study was to perform a metabolomic study using an ultra-performance liquid chromatography system coupled to a time-of-flight mass spectrometer to identify novel GD biomarkers. Following the analysis of plasma samples from patients with GD, and age- and gender-matched control samples, supervised statistical analyses were used to find the best molecules to differentiate the two groups. Targeted biomarkers were structurally elucidated using accurate mass measurements and tandem mass spectrometry. This metabolomic study was successful in highlighting seven biomarkers associated with GD. Fragmentation tests revealed that these latter biomarkers were lyso-Gb1 (glucosylsphingosine) and four related analogs (with the following modifications on the sphingosine moiety: -C2H4, -H2, -H2+O, and +H2O), sphingosylphosphorylcholine, and N-palmitoyl-O-phosphocholineserine. Based on the plasma biomarker distribution, we suggest the evaluation of this GD biomarker profile, which might facilitate early diagnosis, monitoring, and follow-up of patients.

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

“…Biomarker with m/z 462.3422 was confirmed to be lyso-Gb 1 based on the fragmentation pattern and its relative retention time 23 (Figure S4A). In addition to the molecular ion, the fragment corresponds to the loss of one water molecule (m/z 444), the loss of the sugar unit (m/z 300), and the following losses of one (m/z 282) and two (m/z 264) water molecules were observed.…”

“…The chromatographic separation method used for this study was developed to efficiently separate lyso-Gb 1 from its structural isomer galactosylsphingosine (psychosine). Considering that psychosine levels are increased in Krabbe disease, 23 which is another sphingolipidosis, it was important to be able to adequately separate these compounds. As shown in Figure S2, the method described herein achieved this goal, allowing the use of retention time as an indicator when fragmentation tests were inconclusive (i.e., 2 molecules with identical fragmentation profiles).…”

Quantitation of a Urinary Profile of Biomarkers in Gaucher Disease Type 1 Patients Using Tandem Mass Spectrometry

“…Considering the nature of the disease and associated clinical manifestations, the blood matrix was mostly investigated as a source of biomarkers related to the disease, potentially overlooking biomarkers found in other matrices such as urine. Recently, metabolomic studies performed by our research group in plasma and urine highlighted several different metabolites increased in each matrix [ 22 , 23 ]. More specifically, N-palmitoyl-O-phosphocholine serine, sphingosylphosphorylcholine, lyso-Gb 1 as well as lyso-Gb 1 analogs −28, −2, +14, and +18 Da were targeted as potential biomarkers in plasma specimens.…”

“…Indeed, some lyso-Gb 1 analogs were more abundant than lyso-Gb 1 itself in urine [ 22 ]. Moreover, analogs +44, +32, +30, +2, and −26 Da were not detected in plasma [ 23 ]. Additionally, the metabolomic study performed in urine specimens highlighted a novel class of GD biomarkers called polycyclic lyso-Gb 1 analogs.…”

Biomarkers in Rare Diseases

“…Several articles focus on lysosomal storage disorders, with the interesting metabolomic study of Menkovic and co-workers recommending a biomarker panel rather than a single biomarker to overcome some of the diagnostic challenges and heterogeneous presentation of Gaucher disease [ 1 ]. In the second article from this group, Boutin and colleagues demonstrate a diurnal variation of disease biomarkers in the urine of patients with Fabry disease and recommend a morning collection of urine specimens for longitudinal evaluations [ 2 ].…”