A team of neuroscientists led by a University of Pittsburgh School of Medicine scientist has developed a blood test to detect a new marker for Alzheimer’s disease neurodegeneration. Brain, a journal that publishes the results of this study, has published them. According to the authors of the study, the blood test can identify a new biomarker known as BD-tau-derived tau.
According to the reports, current diagnostic tests aren’t effective enough to detect this biomarker for Alzheimer‘s disease neurodegeneration. BD-tau, which is specific for Alzheimer’s disease, is linked to Alzheimer’s neurodegeneration indicators (CSF) in the cerebrospinal liquid (CSF). Dr. Thomas Karikari, the senior author of this study, stated that neuroimaging is currently used to diagnose Alzheimer’s disease. These scans can be expensive and time-consuming. He stated that many patients, including those in the US, do not have access either to MRI scanning or PET scanners. This is a significant concern.
At present, healthcare professionals use guidelines that were set in 2011 to diagnose. These guidelines that are also known as AT(N) Framework have been suggested by the National Institute on Aging and the Alzheimer’s Association. As per these guidelines, the detection of three different elements of Alzheimer’s pathology such as tau tangles, neurodegeneration in the brain, and the presence of amyloid via imaging or CSF sample analysis is required for the diagnosis of Alzheimer’s disease.
Regrettably, both methods have certain economical and practical limitations, it shows that there is a need for the development of suitable and consistent AT(N) biomarkers in blood samples and the collection of blood samples is negligibly invasive and does not require a lot of resources as well. The lead author of the study has said that developing simple tools that can identify symptoms of Alzheimer’s disease in the bloodstream with utmost accuracy is a vital step forward in the initiative of improving access to medical care for marginalized people.
Dr. Thomas Karikari has said that The usage of blood biomarkers will make people’s life easy and enhance medical accuracy and risk calculation in the diagnosis of Alzheimer’s disease. Health experts have said that blood diagnostic approaches that are currently available can identify irregularities in plasma amyloid beta and the phosphorylated type of tau, which are two of the three required biomarkers to accurately diagnose Alzheimer’s disease.
According to the authors of the study, it was difficult to apply the AT(N) Framework in blood samples as it is difficult to detect neurodegenerative biomarkers that are connected to the brain. It is also not affected by potentially misleading toxins that may be generated elsewhere in the body.
The researchers found that neurofilament light levels and a protein indicator of nerve cell damage are elevated in Alzheimer’s and Parkinson’s diseases. This shows that the AT(N) Framework does not work well while experts attempt to differentiate Alzheimer’s disease and other dementia-related problems.
It has been shown that total tau levels in bloodstreams are more useful than checking their levels in CSF fluids. Dr. Thomas Karikari and others from the University of Gothenburg (Sweden) have devised a method to separately identify BD Tau. This avoids free-floating “big tau”, proteins that are generated by cells in the brain. The unique antibody only attaches BD-tau making it easy to detect in the blood sample.
They included blood samples taken from more than 600 patients across five cohorts. They also examined blood samples of patients who had been diagnosed with Alzheimer’s after their deaths. Tests on blood from these patients revealed that levels of BD–tau in blood samples were similar to levels in CSF of Alzheimer’s patients. Also, consistent Alzheimer’s disease signs such as tau tangles and amyloid buildup in brain tissue have also been detected.
The study authors believe that keeping track of blood levels might help improve the design and testing of medical trials, as well as aid enrollment and testing of patients from individuals who have not yet been enrolled in the study.