Paper Spray Ionisation Ion Mobility Mass Spectrometry of Sebum Classifies Biomarker Classes for the Diagnosis of Parkinson’s Disease

Parkinson’s disease (PD) is the second most common neurodegenerative disorder and identification of robust biomarkers to complement clinical diagnosis will accelerate treatment options. Here we demonstrate the use of direct infusion of sebum from skin swabs using paper spray ionisation coupled with ion mobility mass spectrometry (PS-IM-MS) to determine the regulation of molecular classes of lipids in sebum that are diagnostic of PD. A PS-IM-MS method for sebum samples that takes three minutes per swab was developed and optimised. The method was applied to skin swabs collected from 150 people and elucidates ~ 4200 features from each subject which were independently analysed. The data included high molecular weight lipids (>600 Da.) that differ significantly in the sebum of people with PD. Putative metabolite annotations of several lipid classes, predominantly triglycerides and larger acyl glycerides, were obtained using accurate mass, tandem mass spectrometry and collision cross section measurements.