Finding the Limits of Amyloid Clearance as a Treatment for Alzheimer ' s Disease

Alzheimer's disease is associated with a slow buildup of amyloid-β aggregates in the brain over the years of later life. The amyloid cascade hypothesis puts this process as the first step in the development of Alzheimer's disease, setting the stage for later neuroinflammation, tau aggregation, and cell death in the brain. This view of the condition has yet to lead to meaningful therapies, however. Several immunotherapy approaches have succeeded in clearing a meaningful degree of amyloid-β in human trials. Clinical improvement in those patients was very limited at best, even given a generous interpretation of the data. Now a more recent anti-amyloid immunotherapy trial has resulted in a clear slowing of the progression of Alzheimer's disease following complete or near-complete clearance of amyloid-β aggregates. While the modest slowing of progression was not the result hoped for, in the sense that it is still too little benefit for the costs involved, it is nonetheless a much less ambiguous set of data than was the case for past trial outcomes in this class of therapy. The data might be taken as a reinforcement of the view that amyloid-β is an important part of the early pre-clinical stages of Alzheimer's disease, but becomes increasingly irrelevant as the condition proceeds. Based on the research of recent years, the later stages of Alzheimer's are coming to look like a self-sustaining feedback loop between chronic inflammation, cellular senescence, immune d...
Source: Fight Aging! - Category: Research Authors: Tags: Medicine, Biotech, Research Source Type: blogs