The biology of Alzheimer's disease

The pathological hallmarks of Alzheimer's disease (AD) are amyloid angiopathy (AA), neutritic plaques (NP), and neurofibrillary tangles (NFT). This article will provide an update on Alzheimer's disease as well as discuss the key elements of a proposed multi-step pathogenic pathway. In an attempt to simplify this complex process, the focus will be on the production of NP/AA and NFT and the mechanisms of disease underlying their formation. In particular, this review will explore the possibility that AD is in part an inflammatory or immunological process, the potential role of oxidative DNA damage from oxygen free radical metabolites, and/or the putative role of excitotoxicity or ischemic neurological injury. Several genes have been identified as causative of AD and the evidence supports multiple mechanisms of disease. Alzheimer's disease may represent a final common pathway of different disease processes.