Accumulation of amyloid precursor protein in brain lesions of patients with Pick disease.

The expression of amyloid precursor protein (APP) was examined immunohistochemically in Pick disease brain using several antibodies to various segments of APP. Some neurons, including ballooned neurons, were intensely stained with antibodies to all but the N-terminal APP segment. However, Pick bodies were labeled with the antibody to that segment as well as the antibody to intermediate segment of APP. The pattern was similar to that previously observed for Alzheimer neurofibrillary tangles. These data provide additional evidence that Pick bodies and neurofibrillary tangles share some immunohistochemical characteristics.