Taken together, these data suggest that the extracellular ratios of pT73-Rab10 to total Rab10 in serum can be sensitive to genetic variants that stimulate LRRK2 activity (e.g., R1441C-Lrrk2 or VPS35 mutation), acute inflammation (e.g., sepsis), as well as chronic inflammation found in a progressive iPD α-synuclein transgenic model. Here, VPS35 is linked to Sepsis.