Immunohistochemical and histopathologic correlates of Alzheimer's disease-associated Alz-50 immunoreactivity quantified in homogenates of cerebral tissue.
Alz-50 is a monoclonal antibody that immunoreacts with neurofibrillary tangles and neurites in brains with Alzheimer's disease (AD). In addition, the levels of Alz-50 immunoreactivity in brain, measured by either enzyme-linked immunosorbent assay or ALZ-enzyme-linked immunosorbant assay (EIA), are increased in AD relative to age-matched controls. The current study compares the distribution and extent of Alz-50 immunostaining with quantified levels of Alz-50 immunoreactivity measured in adjacent frozen blocks of tissue by ALZ-EIA. The brain tissue studied was obtained from individuals with AD, AD + Down's syndrome (AD + DN), Parkinson's disease with dementia (PD), or AD + PD, and from nondemented aged controls. In AD, AD + DN, and AD + PD, there were significantly higher densities of Alz-50-immunoreactive (AFI) neurons, more abundant diffuse AFI neurites, and higher ALZ-EIA values than in aged controls. In PD, the overall mean density of AFI neurons was significantly lower than in AD and AD + DN, but AFI neurites were as abundant as they were in brains with an AD diagnosis. However, PD was readily distinguished from AD and AD + DN by significantly lower mean ALZ-EIA values, and significantly lower densities of neurofilament-immuno-reactive AD lesions. Multiple-regression analysis demonstrated significant correlations between ALZ-EIA levels and the severity of AD lesions, and the density of AFI neurites, but not with the density of AFI neurons. Therefore, ALZ-EIA levels may represent only a portion of the Alz-50 immunoreactivity detectable by immunohistochemical staining.
de la Monte
S M
SM
Massachusetts General Hospital Alzheimer's Disease Research Center, Boston.
Spratt
R A
RA
Chong
J
J
Ghanbari
H A
HA
Wands
J R
JR
D000544:Alzheimer Disease / Q000378:metabolism* / Q000473:pathology; D000941:Antigens / Q000032:analysis* / Q000235:genetics / Q000378:metabolism; D002540:Cerebral Cortex / Q000737:chemistry* / Q000378:metabolism; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D007150:Immunohistochemistry; D016501:Neurites / Q000737:chemistry / Q000473:pathology; D012044:Regression Analysis; D014158:Transcription, Genetic
C056167:Alzheimer's disease antigen; D000941:Antigens