Diagnosis of Creutzfeldt-Jakob disease by Western blot identification of marker protein in human brain tissue.

We tested purified preparations of brain tissue from 39 patients with Creutzfeldt-Jakob disease, Gerstmann-Sträussler-Scheinker syndrome, or kuru, and from 32 patients with a variety of nonspongiform degenerative diseases, with the use of Western blots against an antiserum to a similarly purified fraction made from scrapie-infected hamster brain. Positive reactions occurred in 81 percent of the 31 specimens from the patients with Creutzfeldt-Jakob disease (and in all of the 7 specimens that were stored frozen for less than one year), in 3 of the 4 specimens from the patients with kuru, in 3 of the 4 specimens from the patients with Gerstmann-Sträussler-Scheinker syndrome, and in none of the specimens from the patients with other neurologic degenerative disorders, including familial or sporadic Alzheimer's disease; dementia associated with myoclonus, motor neuron disease, or parkinsonism; and acquired-immunodeficiency-syndrome encephalopathy. Immunologic testing has thus begun to provide a useful and rapid adjunct to neuropathological examinations and animal-transmission experiments for the diagnosis of the spongiform encephalopathies.