A new study from Johns Hopkins University Bloomberg School of Public Health suggests the development of dementia is associated with abnormal levels of plasma proteins, and these proteins may be predictive of dementia up to five years before a patient receives a diagnosis.
A new study from Johns Hopkins University Bloomberg School of Public Health suggests the development of dementia is associated with abnormal levels of plasma proteins, and these proteins may be predictive of dementia up to five years before a patient receives a diagnosis.
The findings provide new hints for the pathway in which Alzheimer’s disease develops, as many of the proteins identified in this study were not previously known to be associated with dementia.
Over six million people in the U.S. are believed to have Alzheimer’s disease, the most common type of dementia. Alzheimer’s disease is currently an irreversible and fatal condition, despite decades of research that has been employed to identify effective treatments to slow disease progression. Most experts in the field of aging and neuroscience believe the most optimal time to manage Alzheimer’s disease is prior to the development of dementia symptoms.
Scientists have focused mainly on two features of brain pathology involved in Alzheimer’s disease – tangles of tau protein and amyloid beta protein clumps (plaques). Brain imaging studies suggest that plaques and blood or cerebrospinal fluid amyloid beta or tau levels may have some advanced predictive value for Alzheimer’s disease.
In the most recent study published in Nature Aging, researchers analyzed blood specimens from more than 10,000 middle aged and elderly participants. Samples from these participants were obtained and stored during Phase III trials conducted ten or more years ago.
An initial analysis conducted by the researchers included blood samples from 4,800 late- to -middle-aged participants in a large epidemiological study of heart disease. The Atherosclerosis Risk in Communities (ARIC) study has been running since 1985. The findings were verified in a larger sample of patients from other studies.
Overall, a total of 38 proteins that were abnormally found in the study participants’ blood were associated with higher risks of Alzheimer’s disease within a five-year period. Out of these proteins, up to 16 were considered predictive of participants’ risk of dementia at approximately 20 years in advance.
High levels of SVEP1, one of the proteins identified in the study, appeared to be a likely causative factor associated with Alzheimer’s disease development. To date, the normal functions of SVEP1 in humans have remained somewhat elusive. But recent research has linked the protein with atherosclerosis, suggesting the protein has an underlying propensity toward deleterious health outcomes.
Several key immune proteins were also associated with dementia risk in this new study, which is broadly consistent with findings from other Alzheimer’s disease studies performed over the years.
Senior study author, Josef Coresh, MD, PhD, MHS, a George W. Comstock Professor at the Bloomberg School, said in a statement that this study “is the most comprehensive analysis of its kind to date, and it sheds light on multiple biological pathways that are connected to Alzheimer’s” disease.
“Some of these proteins we uncovered are just indicators that disease might occur, but a subset may be causally relevant, which is exciting because it raises the possibility of targeting these proteins with future treatments,” Dr. Coresh added.
According to Dr. Coresh and his research colleagues, there are plans to continue analyzing these proteins in blood samples from long-term research studies. The hope is that the investigators will identify possible pathways responsible for triggering Alzheimer’s disease while finding a viable approach to develop targeted treatments for the condition.
