November 21, 2007
Factors Involved in Potential Use of beta-amyloid as a Blood Test for Alzheimer's Disease
The Roskamp Institute scientists are currently working towards finding treatments for Alzheimer's disease, determining potential usefulness of beta-amyloid in screening of individuals at risk of developing Alzheimer's disease and monitoring response to disease modifying treatments.
Alzheimer's disease is clinically characterized by progressive cognitive decline accompanied by the presence of amyloid plaques and neurofibrillary tangles in the brain of Alzheimer's patients. Beta-amyloid is a key protein shown to play a central role in Alzheimer's disease etiology. A fragment of beta-amyloid with 42 amino acids is shown to deposit earlier in the disease process than the slightly shorter form (40 amino acid fragment).
Previous clinical studies of beta-amyloid have shown that blood and cerebrospinal fluid levels of beta-amyloid may be helpful in diagnosis of Alzheimer's disease. Furthermore, current research suggests that the disease process in Alzheimer's begins long before the presence of palpable symptoms and wide-spread pathological changes in the brain. Therefore, use of beta-amyloid seems promising in identification of individuals at-risk for Alzheimer's disease. However, it is not clear if these amyloid levels change over a short time period and whether presence of this short-term fluctuation may be an impediment in potential use of beta-amyloid as a diagnostic marker for Alzheimer's disease. The Roskamp Institute scientists Dr. Daniel Paris and Laila Abdullah showed that higher levels of the 40 amino acid beta-amyloid fragment were associated with the diagnosis of Alzheimer's disease. Also, the ratio of these two beta-amyloid fragments was significantly lower in Alzheimer's disease patients than individuals with no memory problems. Increase in beta-amyloid was also associated with older age and low scores on a standard memory test (Mini Mental Status Examination) routinely used in screening of dementia.
Now for the first time, these Roskamp Institute scientists show presence of higher fluctuations in both serum and plasma beta-amyloid levels in normal individuals than in Alzheimer's disease patients. Therefore, due to this, beta-amyloid can be a useful biomarker for Alzheimer's disease only on individual basis where fluctuations within a person are monitored overtime to determine onset of Alzheimer's disease among at-risk individuals. These scientific findings are published in the journal Neuroscience Letters (also see Articles). Although, validity of beta-amyloid's use in monitoring response to disease modifying medications for Alzheimer's disease is currently being investigated and its potential usefulness in this is yet to be determined.
The Roskamp Institute is a not-for-profit Institute and has clinical arms located both in Sarasota and Tampa, Florida. The Roskamp Institute Memory Clinics offer comprehensive cognitive and medical assessment towards differential diagnosis of Alzheimer's disease and offer treatment and disease management options once the diagnostic evaluation is completed. This and other blood based biomarker discovery programs are currently ongoing at the Roskamp Institute. To find out information about participating in these studies or obtaining additional information on biomedical research being conducted at the Roskamp Institute, please visit www.rfdn.org or call 941-752-2949.
The Roskamp Institute is currently funded by the National Institutes of Health, the Department of Defense, the Counter-drug Technology Assessment Center, the Veterans Administration and private donations from the Robert and Diane Roskamp Foundation.
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