Think of the night sky when you look up through the smog of the city. Then, think of that same sky on a clear night in a rural area.
That’s the difference between two images of a 90-year-old man’s brain, after he passed away and donated his body to Alzheimer’s disease research. Both scans are dark blue, with points of light showing plaques consistent with the disease. But the sharper image uses a new compound developed by researchers at Washington University in St. Louis.
“We really want to challenge our molecule for sensitivity. Can it detect what has been missed by the other agents?” said the study’s senior author, Vijay Sharma, PhD.
The imaging agent, called fluselenamyl, showed an improved clarity in PET scans of mice and human brain tissue by binding more effectively to the main components of amyloid plaques, a sign of Alzheimer's. The researchers are applying for federal approval to test low doses of the agent in humans.
Outside of clinical trials, Alzheimer’s disease is generally diagnosed by ruling out other potential causes of memory loss. By improving PET scans for patients experiencing symptoms, the scientists hope to avoid “false negative” tests, which could give a family unfounded hope, and to test new medications and therapies.
“With a more sensitive or better PET tracer, we could have the ability to detect the earlier stages of amyloid accumulation in the brain, and also a better tool to measure response to treatments,” said Dr. Paul Kotzbauer, a WashU neurologist and co-author of the paper.
Kotzbauer said the tracer’s application doesn’t stop at Alzheimer’s—buildups of amyloid plaques have been found in the brains of patients with Parkinson’s disease as well.
According to the paper, fluselenamyl is about 2 to 10 times more effective than tracers currently approved by the FDA.
“To reach this level, I have no words for it,” said G.S.M Sundaram, PhD, the paper’s primary author.
The findings appear in the journal Scientific Reports.
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