A team of researchers at the Institut national de la recherche scientifique (INRS) team has identified two early markers in plasma that can detect Alzheimer’s disease five years before its onset.
The results of the recent study led by doctoral student Mohamed Raâfet Ben Khedher and postdoctoral student Mohamed Haddad, directed by Professor Charles Ramassamy, have been published in the prestigious scientific journal Alzheimer’s & Dementia: Translational Research & Clinical Interventions (TRCI).
Alzheimer’s diagnoses are usually based on a series of psychometric tests assessing cognitive function, brain imaging and cerebrospinal fluid analysis explain the researchers, but those tests have their limitations. “The lumbar puncture is invasive, while brain imaging is expensive and not 100% reliable. This complicates regular follow-up,” says Ramassamy, adding that people with the disease are often being diagnosed at a late stage of the disease. “We need to find more and more early markers so we can act as soon as possible. When the disease is symptomatic, there is little, if any, way back.”
The research team took up the challenge by discovering two markers detectable through a blood test, enabling them to follow the disease’s progression. The markers are found in plasma extracellular vesicles, pockets released by all cells in the body that circulate in the bloodstream.
The research was carried out by analyzing blood samples collected as part of the Canadian Study of Health and Aging (CSHA), from a population of patients with cognitive problems, but not suffering from dementia, and only some of whom developed Alzheimer’s disease. The team focused specifically on the “sporadic” Alzheimer’s disease, the most common type. It stems mainly from the presence of a certain gene. Patients with this gene who developed the disease five years later had markers present that varied with the progression of the disease.
Ramassamy hopes to analyze a larger population with pre- and post-disease samples, permitting him to determine the progression of markers after the onset of symptoms. The research on markers located in the vesicles opens up the possibility for studying other diseases such as vascular dementia.