Immunohistochemical presence of apolipoprotein D in senile plaques

Senile plaques are characteristic features of the neuropathology occurring in Alzheimer's disease and normal aging brains. These plaques have extracel lular amyloid deposits and a variety of amyloid associated molecules. Facto rs that influence amyloid deposits are incompletely understood, but some mo lecules likely play an important role. Some apolipoproteins (apolipoprotein E and J) are known to be closely associated with amyloid fibrillogenesis a nd deposition. To investigate the role of the apolipoproteins in amyloidosi s, the localization of apolipoprotein D (apo D) in senile plaques was immun ohistochemically studied. We report a novel finding: that polyclonal antibo dy to human apo D immunostained in all types of senile plaques found in nor mal aging and Alzheimer's disease. This finding implicates apo D as a poten tially relevant molecule in senile plaque pathogenesis.