Early diagnosis of Alzheimer’s disease has eluded researchers and physicians alike for many years. This has led many to pursue development of improved tests to detect the mind-crippling condition before its clinical symptoms show.
A recent study by University of Washington (UW) researchers demonstrates a way to catch the abnormal proteins that were so far found only in advanced stages in people having Alzheimer’s.
The researchers caught the proteins through a simple blood test that they developed. This test may now be refined to routinely enable diagnosis of Alzheimer’s much earlier than at present.
One of the hallmarks of Alzheimer’s is the presence of protein clumps in the brain that have evaded detection until the condition has advanced. The clumps are made of a protein called amyloid-beta, whose structure gets altered and leads to the formation of amyloid beta oligomers. These toxic oligomers are typically seen in later stages of Alzheimer’s when they lead to the death of brain cells.
Damage undetected for 10-20 years
“Toxic oligomers are estimated to be doing damage for 10-20 years before the advent of symptoms” senior author of the study, Valerie Daggett, a professor of bioengineering at UW, tells Happiest Health.
While there is no solution yet to stop or reverse conditions such as Alzheimer’s, efforts are being made to detect the problem early so that effective interventions can be used to slow the progression of Alzheimer’s.
“The process to diagnose a patient and get referrals to dementia experts can take years. It’s important to provide a timely diagnosis and equally important to be able to rule out Alzheimer’s disease so that other potential cases of cognitive impairment can be investigated and potentially treated,” says Daggett.
Spot on with control group
For their study, the researchers designed a laboratory test called SOBA or soluble oligomer binding assay. It detected the presence of toxic oligomers in the blood of people diagnosed with Alzheimer’s as well as in individuals in the control group who did not show cognitive impairments.
In a follow-up a few years later, 10 individuals in the control group in whom SOBA had detected toxic oligomers showed cognitive impairments consistent with early signs of Alzheimer’s disease.
“What clinicians and researchers have wanted is a reliable diagnostic test for Alzheimer’s disease — one that can detect signs of the disease before cognitive impairment happens. That’s important for individuals’ health and for all the research into how toxic oligomers of amyloid beta go on and cause the damage that they do,” says Dr Daggett. “What we show here is that SOBA may be the basis of such a test.”
Caught in a `bind’
The SOBA test works by using the properties of amyloid beta oligomers to form a structure called an alpha sheet. This novel structure is not something that occurs in nature and binds itself to other alpha sheet structures.
Dr Daggett and team decided to make a synthetic form of the alpha sheet so that it could bind itself to oligomers found in blood and cerebrospinal fluid.
“We believe that SOBA could aid in identifying individuals at risk or incubating the disease, as well as serve as a readout of therapeutic efficacy to aid in development of early treatments for Alzheimer’s disease,” Dr Daggett says in a statement.
Test may benefit other conditions
She adds that the potential for a test like SOBA lies in helping people to get access to drugs like Lecanemab. This is an investigational drug which has been showing encouraging results in delaying cognitive decline in Alzheimer’s cases. Dr Daggert says it might be available to people with Alzheimer’s in the not-too-distant future.
Dr Daggett and her team are currently working with a company to develop SOBA as a diagnostic test for Parkinson’s, Type 2 diabetes and other conditions that show similar formation of the alpha structure.
Their goal is to neutralise the toxic oligomers and provide immediate treatments that can modify the conditions early.