Imaging Agent Could Help Diagnose Alzheimer’s Disease

WASHINGTON (Reuters) - A new imaging agent that homes in on the amyloid plaque that characterizes the brains of Alzheimer’s patients may allow earlier diagnosis of the disease, researchers said on Wednesday.

The agent, a radioactive dye called Pittsburgh Compound B, can also be used to test new drugs being developed to fight Alzheimer’s disease, which affects an estimated 4 million Americans, the researchers said.

Using the new agent, “we will likely be able to follow the progression of the disease and speed the development of promising new therapies aimed at halting the build-up of amyloid in the brain,” Dr. William Klunk of the University of Pittsburgh, who led the study, said in a statement.

Writing in the Annals of Neurology, Klunk and colleagues said the imaging agent allowed the use of positron emission tomography PET) to view the plaque in the brains of 16 Alzheimer’s disease patients. They also used the method on nine healthy volunteers.

“We will not only find out when plaques begin to form, we will be able to see directly if a medication is preventing or reversing plaque formation over the long term,” Klunk said.

The Alzheimer’s Association, which helped fund the study, said it was an important step forward.

“We now have a tool to detect one of the hallmarks of Alzheimer’s disease in the brains of living patients. Until now, this could only be shown at autopsy or by brain biopsy,” said the Association’s William Theis.

Chet Mathis, a chemist and professor of radiology who worked on the study, said the imaging compound uses a dye that homes in on plaque, attached to a radioactive carbon tag.

The dye, a modified version of the dye used by pathologists to detect Alzheimer’s disease in brain tissue from dead patients, is harmless, Mathis said. “In 2 hours it is gone from the body,” he said in a telephone interview.

He said the compound, patented by the university, had been licensed to Amersham, a British healthcare firm that makes imaging agents. General Electric is about to take over Amersham.

Source: SOURCE: Annals of Neurology, 2004. [ Google search on this article ]

MeSH Headings:Isotope Labeling: Investigative Techniques: Analytical, Diagnostic and Therapeutic Techniques and EquipmentCopyright © 2002 Reuters Limited. All rights reserved. Republication or redistribution of Reuters content, including by framing or similar means, is expressly prohibited without the prior written consent of Reuters. Reuters shall not be liable for any errors or delays in the content, or for any actions taken in reliance thereon. Reuters and the Reuters sphere logo are registered trademarks and trademarks of the Reuters group of companies around the world.

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