Immunochemical and morphometric features of astrocyte reactivity vs. plaque location in Alzheimers disease.

ABSTRACT

The quantitative relationship between glial fibrillary acidic protein (GFAP) hyper-reactivity and beta-amyloid protein (betaAP) deposition was investigated by double immunoperoxidase labeling of hippocampal and entorhinal cortex sections from five Alzheimers disease (AD) cases and five age-matched controls. betaAP plaques, which were absent in controls, were found in all AD samples, without significant differences in number or perimeter according to their location among the regions studied. In contrast, the mean number of GFAP (+) cells was significantly greater in the hippocampus than in the entorhinal cortex from AD cases (49 vs.39). Although at lower values (30 vs. 20), predominance of astrocyte hyperplasia in hippocampus as compared with entorhinal cortex was also found in control samples. Concomitant astrocyte hypertrophy, as defined by surface density (Sv) values of GFAP-immunoreactive material exceeding those of control means, affected a similar proportion of cells in the hippocampus (73