A controversial vaccine that was the subject of a halted trial to prevent cognitive decline in Alzheimer's patients could have the potential to be reformulated to eliminate its toxicity while retaining the benefits. In a Practice Point article in the December issue of Nature Clinical Practice Neurology, Thomas Wisniewski considers how this could be achieved, while commenting on the recently published trial results.
Despite evidence that an amyloid beta vaccine can reduce brain amyloid deposits and improve cognitive function in patients with Alzheimer's disease, the clinical trial was stopped owing to the development of encephalitis in a small proportion of patients. Wisniewski points out that the positive and negative effects of the vaccine are attributable to different components of the immune response. Improvements in cognitive function were linked to an antibody-mediated response, whereas encephalitis was associated with a cell-mediated response. Antibodies that are engineered to avoid the cell-mediated response while retaining the antibody-mediated response could be the way forward, he argues.
The ability to image amyloid plaques in the living brain is important both for the diagnosis of Alzheimer's disease and for increasing our knowledge of the underlying disease mechanisms. In a Technology Insight Review article, Dan Huddleston and Scott Small review recent progress using positron emission tomography (PET scanning) in humans, and consider whether some promising results using magnetic resonance imaging in animals might be translated into the clinical setting.
Author contact details:
Thomas Wisniewski (New York University School of Medicine, New York, NY, USA)
Scott A Small (Columbia University College of Physicians and Surgeons, New York, NY, USA)
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