Autoclave treatment fails to completely inactivate DLB alpha-synuclein seeding activity

Synucleinopathies are characterized by the deposition of alpha-synuclein (α-syn) aggregates in brain tissue. Pathological α-syn aggregates propagate in a prion-like manner and display prion-like biochemical properties. Using RT-QuIC, we measured α-syn seeding activity from brains of Dementia with Lewy body (DLB) patients post autoclave. Here, we show that autoclaving at 121 °C removes one to two log(10) of α-syn seeding activity but the remaining 50% seeding dose (SD(50)) is more than 107/mg tissue. DLB brain samples autoclaved at 132 °C still revealed an SD(50) of approximately 106/mg tissue. Our data suggest that DLB α-syn seeds are incompletely inactivated by standard autoclave, thus highlighting the need for evaluating laboratory procedures that fully inactivate them.