Table 2

Tissue and fluid biomarkers for PD

SourceMediumMain techniquesCandidate markersInvasivenessCostSuitability for screening
Cerebrospinal fluidFluidAssay, electrophoresis, mass-spect-α-syn, p-α-syn, t-tau, p-tau, NFL+++++++
BloodFluidAssay, electrophoresis, mass-specUric acid, inflammatory markers, IGF-1, ApoA1, DJ-1++++++
SalivaFluidAssay, electrophoresis, mass-specα-syn, DJ-1+++++
GutTissue biopsyImmunohistochemistryt-α-syn, p-α-syn+++++++++
Salivary glandTissue biopsyImmunohistochemistryt-α-syn, p-α-syn++++++++
SkinTissue biopsyImmunohistochemistryt-α-syn, p-α-syn++++++++
  • Invasiveness, cost and suitability for screening are estimated semiquantitatively on a four-point relative scale with + lowest and ++++ highest.

  • ApoA1, apolipoprotein A1; IGF-1, insulin like growth factor 1; NFL, neurofilament light chain; p-α-syn, phosphorylated α synuclein; t-α-syn, total α synuclein.