Metabolic biomarkers for Parkinson disease

Abstract

Metabolites (molecular weight less than 1000) measurable using mass spectrometry in human blood samples are estimated to be around 500. Blood metabolites include not only components from blood cells but also those derived from systemic organs, thus depending on the overall metabolic activity of the body. Additionally, blood contains encapsulated extracellular vesicles, within which small molecule compounds such as nucleic acids, proteins, and metabolites exist, requiring caution in interpreting the metabolite concentrations.

Numerous metabolomic analyses of plasma/serum and cerebrospinal fluid have been conducted in patients with Parkinson disease (PD), revealing changes in fatty acid metabolism, steroid production, tryptophan metabolism, phenylalanine metabolism, polyamine metabolism, xanthine metabolism including caffeine, oxidative stress markers and kynurenine metabolism. This article summarizes metabolite biomarkers in plasma/serum and cerebrospinal fluid that are useful for diagnosing and understanding the pathophysiology after the onset of motor symptoms in PD.