Detection of prions in skin punch biopsies of Creutzfeldt-Jakob disease patients.

Prion real-time quaking-induced conversion (RT-QuIC) is an ultrasensitive assay detecting pathological aggregates of misfolded prion protein in biospecimens. We studied 71 punch biopsy skin samples of 35 patients with Creutzfeldt-Jakob disease (CJD), including five assessed in vitam. The results confirmed the high value of skin prion RT-QuIC for CJD diagnosis (89% sensitivity and 100% specificity) and support its use in clinical practice. Preliminary data based on a limited number of cases suggest that prion-seeding activity in the skin varies according to the prion strain, being higher in sporadic CJD subtypes linked to the V2 strain (VV2 and MV2K) than in typical CJDMM1.