The glial fibrillary acidic protein (GFAPfor its acronym in English) is a very precise biomarker for diagnosing the initial stages of Alzheimer’s disease in the blood, as revealed by a study carried out by researchers from the Barcelonaβeta Brain Research Center (BBRC), a research center of the Foundation Pasqual Maragall.
He Dr. Marc Suárez-Calvetprincipal investigator of the study and head of the BBRC Biomarkers in Fluids and Translational Neurology group, highlights that this finding “will allow improve the diagnostic accuracy of the preclinical phase of Alzheimer’s through a blood testcombining the detection of the GFAP biomarker with others recently discovered”.
GFAP is a specific brain protein astroglia cellsinvolved in different functional processes, such as giving support the activity of neurons and in the regulation of the blood-brain barrier. When some type of brain damage occurs, a reaction of these cells takes place, called astrogliosis, which tries to contain the brain damage and increases the expression of GFAP and other markers.
Dr. Marc Suárez-Calvet is the principal investigator of this study
In the case of Alzheimer’s disease, GFAP is a biomarker that was usually measured in the cerebrospinal fluid after performing a lumbar puncture on the patient. The novelty of this study is that it shows that GFAP measured in blood plasma is better than that measured in cerebrospinal fluid to determine, with more precision and in a less invasive way, at what point in Alzheimer’s disease the affected person is.
Marta Milà-Alomastudy investigator and member of the BBRC Biomarkers in Fluids and Translational Neurology group, points out that “We have seen that the GFAP biomarker levels are higher in people who are in the asymptomatic phase of Alzheimer’sand that allow us to differentiate individuals with or without amyloid pathology in the brain, which is the stage prior to the disease”.
900 participants from three cohorts
The results of the study have been confirmed in people who are in different phases of the Alzheimer’s disease continuum. The assay results have been validated in about 900 participants from three cohorts dedicated to Alzheimer’s prevention research. One of the cohorts is Alpha Studiopromoted by the ‘la Caixa’ Foundation in Barcelona.
First, the researchers looked at the blood samples from 387 people without cognitive alterations and with some risk of developing Alzheimer’s, from Estudio Alfa, promoted in 2013 in Barcelona by the Pasqual Maragall Foundation and the ‘la Caixa’ Foundation. They also investigated the plasma of 300 asymptomatic people with cognitive impairment that are part of the TRIAD study, led at McGill University in Montreal. And, finally, they analyzed the samples of 187 patients with cognitive impairment from the Lariboisière Hospital in Paris. All tests in the assay were analyzed in the University of Gothenburgand quantified with high-precision technology (Simoa HD-X) using commercially available immunoassays.
The research has been published in the journal JAMA Neurologyand has enjoyed the collaboration of researchers from the University of Göteborg, McGill University in Montreal, the University of Paris, the Lariboisière Fernand-Widal Hospital in Paris, the Hospital del Mar and the Hospital del Mar Medical Research Institute (IMIM ), the CIBER for Fragility and Healthy Aging (CIBERFES) and the CIBER for Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN).
New findings in blood biomarkers to detect Alzheimer’s
The results of this international study add to those latest findings of blood biomarkers to detect Alzheimer’s disease. In November 2020, the same team led by Dr. Suárez-Calvet in the identified other biomarkers, in this case of the tau protein, to detect the initial phases.
As explained by Dr. Suárez-Calvet, who now leads a prestigious in this ambit, “In just two years, research in the field of Alzheimer’s biomarkers in the blood is advancing at such a rate that we are convinced that in the near future we can detect the silent changes that occur in the brain with a simple blood test requested by the GP. This will allow us to test treatment before neuronal damage is irreversible.”
Currently, the is setting up a translational laboratory equipped with technologies such as the one used in this study, in order to be able to bring to Spain tools for next generation in Alzheimer’s disease research and put them at the service of the scientific community and patients.