Identification of components of immunoglobulins in senile plaques by means of fluorescent antibody technique.

Using a fluorescent antibody technique, sections of the brains of patients with senile dementia or Alzheimer's disease containing senile plaques were treated with rabbit antihuman immunoglobulins labelled with FITC (fluorescein isothiocyanate, BBL). The senile plaques and the cerebral amyloid angiopathy (drusige Entartung, Scholz, 1938) in the brains of patients with senile dementia or Alzheimer's disease showed specific fluorescence. Control sections from the brains of a girl who died from carcinoma of the stomach and of a female schizophrenic who died from lung abscess, showed only slight fluorescence in a few vessel walls. The presence of components or fragments of immunoglobulins in a senile plaques may mean that immunological factors are involved in their pathogenesis and probably also in that of senile dementia and Alzheimer's disease.