beta-amyloid load, astroglia and microglia in Alzheimer's disease: association with apoE genotype

In addition to beta-amyloid (A beta) aggregates and neuronal degeneration s een as neurofibrillary tangles (NFT), a glial response is a prominent patho logical feature in Alzheimer's disease (AD). In this clinically and neuropa thologically verified post-mortem material of 43 demented subjects we have demonstrated that the presence of an apoE epsilon 4 allele cause a slight b ut not significant increase in the neocortical A beta load, the number of G FAP expressing astrocytes and HLA DR expressing microglia. A beta load corr elated significantly with astrogliosis and the counts of NFT's correlated s ignificantly with the number of activated microglia. Furthermore, the corre lation between activated microglia and neuronal degeneration (NFT scores) w as influenced by the apoE genotype since it was not present in individuals carrying an apoE epsilon 4 allele. Moreover, multiple linear regression ana lysis revealed a significant influence of the gender an microglial activati on. Our results indicate that the glial reaction is indeed a phenomenon ass ociated with the histopathological lesions of AD whereas the extent of the microglia activation seems to be related not only to the neuronal degenerat ion but also to the gender of the patient.