Creutzfeldt-Jakob disease with amyloid angiopathy: diagnosis by immunological analyses and transmission experiments.

It was difficult to make a definite pathological diagnosis in a 73-year-old man with Creutzfeldt-Jakob disease (CJD) due to extensive amyloid angiopathy which lacked any severe spongiform changes. Immunostaining using anti-prion protein (PrP) antibody revealed fine granular deposits in the gray matter, after hydrolytic autoclaving pretreatment on tissue sections. Western blotting also revealed an abnormal isoform of PrP, but PrP gene analysis did not show any abnormalities. The primary transmission experiments were repeated three times and induced spongiform encephalopathy in a few mice after a long incubation period.