Immunohistochemical verification of senile and kuru plaques in Creutzfeldt-Jakob disease and the allied disease.

We investigated paraffin-embedded brain sections from 41 patients with Creutzfeldt-Jakob disease (CJD) and from 9 with Gerstmann-Sträussler syndrome (GSS) using anti-human prion protein (PrP) antisera (anti-GSS kuru plaque cores and anti-PrP synthetic peptide) and anti-beta protein antiserum. The anti-human PrP antiserum reacted with the plaques in CJD and GSS, with or without degenerative neurites (neuritic components). In addition, the anti-beta protein antiserum immunolabeled kuru plaque-like compact plaques in some cases of CJD. Therefore, previous morphological classifications of the plaques may not always be valid. Senile plaques labeled with anti-beta protein antiserum were evident in 65% of the CJD brains and 50% of GSS brains from patients in their 60s, and in 73% of brains from CJD patients in their 70s, but not in brains from patients under 60 years of age. The incidence of the senile plaques was compatible with the normal aging process and was apparently not accelerated by the disease process of CJD or GSS. These immunostaining approaches using anti-human PrP and anti-beta protein antisera allow classification of plaque types and increase the reliability of the pathological diagnosis in persons with dementia.