Credit: Original article published here.
Researchers at Karolinska Institutet in Sweden have recently made a significant discovery that could pave the way for a simple and non-invasive screening procedure for Alzheimer’s disease (AD). The study, which was published in Alzheimer’s & Dementia: The Journal of the Alzheimer’s Association, shows that a type of sugar molecule known as bisecting N-acetylglucosamine glycan epitope is linked to tau protein, which is a key factor in the progression of advanced dementia and AD.
The research team has previously established a correlation between the levels of glycan and tau protein in individuals with AD. However, these analyses were done on cerebrospinal fluid which is difficult to obtain and can be considered invasive.
“The role of glycans, structures made up of sugar molecules, is a relatively unexplored field in dementia research,” Robin Zhou, medical student at Karolinska Institutet and lead author of the study, stated. Glycans are sugar molecules located on the surface of proteins that dictate the function and placement of these proteins in the body. By measuring blood glycan levels, the researchers found that individuals with matching levels of glycans and tau were over twice as likely to develop Alzheimer’s-type dementia.
The team of researchers conducted a study which comprised 233 individuals. Blood levels of bisecting N-acetylglucosamine and total tau were retrospectively analyzed. Progression to AD and predictive values of biomarkers were determined via Cox and logistic regression models.
Regarding the results of the study, “We demonstrate in our study that blood levels of glycans are altered early during the development of the disease. This could mean that we’ll be able to predict the risk of Alzheimer’s disease with only a blood test and a memory test,” Mr. Zhou said.
Following analysis, bisecting N-acetylglucosamine correlated with tau levels (P <0.0001) and individuals with at least an intermediate tau/bisecting N-acetylglucosamine ratio were at an increased risk of developing AD. The results of the study also suggested that “a combined model including tau/bisecting N-acetylglucosamine ratio, apolipoprotein E (APOE) ε4 status, and Mini-Mental State Examination score predicted future AD.”
Both practicality and cost-effectiveness are crucial requirements for the development of non-invasive screening techniques for AD. Markers in blood are preferable, as taking samples of the cerebrospinal fluid is more difficult, and brain imaging is expensive, according to co-author Sophia Schedin Weiss, PhD.
The team is now looking to the future, eyeing studies further expanding on biomarkers related to AD and dementia. “We’re collaborating with researchers in primary care in Sweden to evaluate different biomarkers for dementia at primary health care centers. We hope that glycans in the blood will prove to be a valuable complement to current methods of screening people for Alzheimer’s disease that will enable the disease to be detected early,” Dr. Weiss shared.
