APOLIPOPROTEIN-E GENOTYPE AND AMYLOID LOAD IN ALZHEIMER-DISEASE AND CONTROL BRAINS

We investigated the effect of apolipoprotein E (apoE) genotype on amyl oid load in the frontal and cerebellar cortices of 24 patients with de finite Alzheimer disease (AD) and 19 controls. Amyloid load was examin ed by using two methods: 1) acid-extractable amyloid beta-protein (A b eta) and insoluble A beta levels of frontal and cerebellar cortices we re measured by using enzyme-linked immunosorbent assay, and 2) all typ es of amyloid plaques and neurofibrillary tangles (NFT) in the frontal cortices were counted after sliver staining. Acid-extractable A beta and insoluble A beta levels were higher in AD brains than controls, al though there was an overlap between the groups. Acid-extractable A bet a and insoluble A beta levels were higher from AD and controls with th e apoE epsilon 4 alleles than those without such alleles. However, the differences did not reach statistical significance in AD group. There was no correlation between acid-extractable A beta or insoluble A bet a levels and the number of amyloid plaques in AD and control brains. H owever, insoluble A beta revels correlated positively with the number of NFT in AD brains. Our results show that although apoE epsilon 4 inf luences the accumulation of A beta, multiple processes may be involved in deposition of A beta in the brain. Copyright (C) 1996 Elsevier Sci ence Inc.