Quantification of Lewy body pathology by cerebrospinal fluid endpoint dilution RT-QuIC in a neuropathological autopsy cohort of clinically heterogeneous participants.

We estimated the seeding dose, yielding positive responses in 50% of replicate reactions (SD50), using the midSIN algorithm and correlated these values with postmortem synuclein pathology burden and clinical severity measures.

The SD50 values (expressed in log 10 SD/ml) differed significantly among participants at different lewy body disease stages (p < 0.0001), with those at a neocortical stage demonstrating higher values than those at a brainstem-predominant stage (p < 0.0001).