A Biomarker Study in Patients with GBA1-Parkinson's Disease and Healthy Controls

Area of Science:

• Biochemistry
• Neuroscience
• Genetics

Background:

• Glucocerebrosidase (GCase) related molecules are investigated as biomarkers for GBA1-associated Parkinson's disease (GBA-PD).
• GBA-PD is a genetic subtype of Parkinson's disease linked to mutations in the GBA1 gene.

Purpose of the Study:

• To assess the variability of glycosphingolipids (GSLs) in plasma, peripheral blood mononuclear cells (PBMCs), and cerebrospinal fluid (CSF).
• To compare GSL levels across GBA-PD patients, idiopathic PD (iPD) patients, and healthy volunteers (HVs).
• To identify potential GSL biomarkers for GBA-PD.

Main Methods:

• Combined data from five studies analyzing GSLs (glucosylceramide, lactosylceramide, glucosylsphingosine, galactosylsphingosine), GCase activity, and GCase protein.
• Measured GSLs in plasma, PBMCs, and CSF from GBA-PD, iPD, and HVs.
• Utilized principal component analysis to explore patterns in GSLs and clinical data.

Main Results:

• Within-subject variability was lower in plasma than in PBMCs.
• Extracellular glucosylceramide levels were slightly higher in GBA-PD plasma compared to iPD and HVs.
• GBA-PD was distinguishable from iPD and HVs primarily based on plasma glucosylceramide levels.

Conclusions:

• Glucosylceramide is a stable biomarker in plasma and PBMCs, suitable for clinical trials targeting GBA-PD.
• Glucosylceramide levels in plasma can differentiate GBA-PD from iPD and HVs.
• GSLs in plasma, PBMCs, and CSF did not correlate, highlighting matrix-specific utility.