The Alzheimer’s Disease Neuroimaging Initiative (ADNI) began in October 2004 as a landmark study with a public-private partnership that gathered and analyzed thousands of brain scans, genetic profiles and biomarkers in blood and cerebrospinal fluid (CSF). Although the original goal was to define biomarkers for use in clinical trials to determine the best way to measure treatment effects of Alzheimer’s disease (AD), the goal has been expanded to using biomarkers to identify AD at a pre-dementia stage. ADNI involves scientists at 59 research centers, 54 in the U.S. and five in Canada. There are over 800 participants comprised of 200 with AD, 400 with mild cognitive impairment (MCI) and 200 with normal cognition.
Some of the leading-edge technologies under study are brain-imaging techniques, such as positron emission tomography (PET), including FDG-PET (which measures glucose metabolism in the brain); PET using a radioactive compound (PiB) that measures brain beta-amyloid; and structural MRI. Brain scans are showing scientists how the brain’s structure and function change as AD starts and progresses.
Biomarkers in cerebrospinal fluid are revealing other changes that could identify which patients with MCI will develop Alzheimer’s. Scientists are looking at levels of beta-amyloid and tau in cerebrospinal fluid. (Abnormal amounts of the amyloid and tau proteins in the brain are hallmarks of Alzheimer’s disease.)
The next step is to scan and analyze the brains of people with early mild cognitive impairment (eMCI). With a generous grant from American Recovery and Reinvestment Funds ADNI researchers will be able to study people with eMCI. This new grant expands the scope of ongoing research under ADNI by allowing for the enrollment of participants at an earlier stage of MCI, when symptoms are milder.
Furthermore, the funding for this new grant will allow ADNI investigators to extend the length of the original study to better assess changes in individuals over time. All of the participants will have neuroimaging scans and blood and cerebrospinal fluid analyses to look for changes in the brain.
The overall impact of the added funding will be increased knowledge of the sequence and timing of events leading to MCI and AD, development of better clinical and imaging/fluid biomarker methods for early detection and for monitoring the progression of these conditions. This will facilitate clinical trials of treatments to slow disease progression and will ultimately contribute to the prevention of AD.
In 2009, ADNI made a significant step forward in developing a test to help diagnose the beginning stages of AD sooner and more accurately by measuring levels of two biomarkers–tau and beta-amyloid proteins–in cerebrospinal fluid.
For more information on the clinical research sites taking part in ADNI and that are looking for study participants, go to http://www.adcs.org/Studies/ImagineADNI.aspx
