Background: Treatment with sphingosine-1-phosphate (S1P) agonists confers neuroprotective effects in animal models of Parkinson's disease (PD).
Objectives: We assessed the association of serum S1P levels with motor and cognitive symptoms in patients with PD.
Methods: S1P concentrations were analyzed with liquid chromatography-tandem mass spectrometry (LC-MS/MS) in serum of 196 PD patients and in 196 age- and sex-matched controls.