A revolutionary blood test could detect the beginnings of Alzheimer's disease quicker than has ever been possible before. The test detects a toxic protein in the blood which appears well before other symptoms.
Currently, patients can only receive a diagnosis of Alzheimer's after they suffer from memory loss or other symptoms. But at this point, the only treatment options available can only slow the progress of the disease.
But the new study suggests that signs of Alzheimer's appear years before memory loss occurs. During the early stages of the illness, amyloid beta proteins misfold, clump together and form something called oligomers.
It is thought that these toxic oligomers develop into Alzheimer's. Scientists at the Univesity of Washington have now designed a blood test that can detect these oligomers. This test is known as SOBA, which stands for soluble oligomer binding assay.
Senior author Valerie Daggett, a UW professor of bioengineering and faculty member in the UW Molecular Engineering & Sciences Institute, said: “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.”
She added: “What clinicians and researchers have wanted is a reliable diagnostic test for Alzheimer’s disease – and not just an assay that confirms a diagnosis of Alzheimer’s, but one that can also 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. “What we show here is that SOBA may be the basis of such a test.”
The study was able to detect oligomers in the blood of patients with Alzheimer's but not in most of the healthy members of the public. However, of those in the healthy group, 11 people tested positive for the proteins.
When the researchers carried out follow-up checks on those patients, 10 of them were diagnosed years later with mild cognitive impairment or brain pathology consistent with Alzheimer’s disease. It suggests that the blood test diagnosed the disease early.
The findings are published in the Proceedings of the National Academy of Sciences.
