BETA-PP PARTICIPATES IN PRP-AMYLOID PLAQUES OF GERSTMANN-STRAUSSLER-SCHEINKER DISEAE, INDIANA KINDRED

Gerstmann-Straussler-Scheinker disease in the Indiana kindred is pathologically characterized by deposits of PrP-amyloid, neurofibrillary tangles and degenerating neurites. The aim of this study was to investigate seven patients of different ages for betaPP and Abeta immunoreactivities associated with PrP-amyloid deposits and degenerating neurites. In one asymptomatic individual with PrP-amyloid deposits, Alz50 and Abeta immunoreactivities were absent. In six symptomatic patients, the degenerating neurites surrounding PrP-amyloid deposits were labeled by Alz50 and by antibodies to synaptophysin, ubiquitin and the N- and C-terminal domains of betaPP. In one symptomatic, senile patient, Abeta immunoreactivity was present in the extracellular space, often in association with PrP-amyloid deposits. The analysis of the immunohistochemical findings suggested that in the Indiana kindred the intracellular accumulation of betaPP, synaptophysin and ubiquitinated material most probably revealed a reaction of neurites to PrP-amyloid, whereas the extracellular deposition of Abeta was likely an age-related phenomenon.