alpha 2-macroglobulin polymorphism is not associated with AD or AD-type neuropathology in the Japanese

Background: alpha 2-Macroglobulin (A2M) forms the complex with amyloid beta -protein (A beta) and is associated with degradation of A beta. It has been reported that the A2M gene (A2M) exon 18 splice acceptor deletion polymorp hism influences the development of AD, regardless of apolipoprotein E-epsil on 4 (APOE-epsilon 4) status. Objective: To determine the effect of A2M pol ymorphism on the development of AD and AD-type neuropathologic changes. Met hods: The authors examined the A2M and APOE genotypes, the densities of the senile plaques (SPs), SPs with dystrophic neurites (NPs), and neurofibrill ary tangles (NFTs) in the brains of 62 postmortem-confirmed sporadic AD and 90 nondemented patients from an autopsy series of elderly Japanese subject s. Results: There was no association of the A2M polymorphism with AD, age a t onset, or duration of illness in AD. The A2M polymorphism was not associa ted with the SPs, NPs, or NFTs in AD or nondemented patients. The results r emained insignificant, even when the A2M genotype groups were divided into subgroups by APOE-epsilon 4 status. Conclusion: The A2M polymorphism does n ot affect the development of sporadic AD or formation of AD-type neuropatho logic changes.