The brains of Alzheimer’s disease patients may be differentiated from healthy volunteers on brain scans with a novel radioactive compound. This makes such images available beyond facilities that can manufacture their own radioactive compounds. The research conducted by Johns Hopkins University School of Medicine may lead to better ways to distinguish Alzheimer’s from other types of dementia, track disease progression and develop new therapeutics to fight the memory-ravaging disease.
The brain of Alzheimer’s patients was formerly observed through autopsy or with the help of another radioactive compound Pittsburgh that is usually used in scans or radiotracer. Pittsburgh is drawn to a protein beta-amyloid that gathers strangely in the brains of Alzheimer’s patients. However half of this substance deteriorates every 20 minutes after it is made. Probably due to this function very few well equipped hospitals or academic centers manufacture it.
A new radiotracer known as 18F-AV-45 was examined by researchers to solve this problem. This compound based on radioactive isotope fluorine-18 is seemingly drawn to beta-amyloid similarly like Pittsburgh. However this compound has a half life of 110 minutes that makes it portable to distances far off from manufacturing facilities.
In order to test the compound for the first time researchers enlisted 26 volunteers. Among these 11 were previously detected with Alzheimer’s disease and 15 healthy subjects had performed well on cognitive tests. They were injected with florbetapir and then received a PET scan of their brains. Researchers were able to observe the uptake of florbetapir in the brain as the brain scans acquired over a 90-minute period.
They observed that florbetapir had gathered greatly in the Alzheimer’s patients brains compared to healthy participants. According to previous analysis accumulation in the brain region was expected to be greater in beta-amyloid deposits. By 30 minutes after injection of florbetapir AD patients were easily evident from healthy participants and it continued for 90 minutes. None of the participants suffered any ill effects from florbetapir and displayed normal signs, electrocardiograms and blood-work post scan.
Dean F. Wong, M.D., Ph.D., a professor of radiology and psychiatry at the Johns Hopkins University School of Medicine shares, “We could easily tell apart the two groups of patients. Those without Alzheimer’s disease retained much less of the compound, and those with Alzheimer’s disease retained much more of it. This is the first time we’ve been able to get results like this with a compound that can travel beyond the confines of a major academic medical center to the majority of the U.S. population.”
In addition he says that florbetapir’s portability may lead to many applications for this compound. For example imaging with florbetapir may resolve tricky cases in which patients might have other forms of dementia. In order to solve other problems, such as which patients are most likely to progress from mild cognitive impairment to full-blown Alzheimer’s disease the compound may help in further studies. It may also be useful in trials of new experimental Alzheimer’s therapeutics in order to measure its success for which the compound is being used limitedly.
These results were reported in the June Journal of Nuclear Medicine.