Detection of cutaneous prion protein deposits could help diagnose GPI-anchorless prion disease with neuropathy.

BACKGROUND AND PURPOSE To investigate prion protein (PrP) deposits in cutaneous tissues of patients of glycosylphosphatidylinositol (GPI)-anchorless prion diseases with neuropathy. METHODS Cutaneous tissue samples from three patients with GPI-anchorless prion diseases were obtained, two cutaneous biopsy samples from the lower leg of Case 1 (Y162X) and Case 3 (D178fs25), and a cutaneous sample taken from the abdomen during an autopsy of Case 2 (D178fs25). We performed immunohistochemistry for PrP to look for abnormal PrP deposits. RESULTS PrP deposits were observed in the dermal papilla, the sweat glands, the hair follicles, the arrector pili muscles, and peripheral nerves of all examined cases of GPI-anchorless prion disease with neuropathy. The abnormal PrP accumulation was frequently localized at the basement membrane, and colocalized with laminin. CONCLUSION Immunohistochemical detection of PrP in cutaneous samples could be used to definitively diagnose GPI-anchorless PrP disease with neuropathy.