Posted on 01/11/2023 06:00
(Credit: KIRSTY WIGGLESWORTH)
The occurrence of characteristic Alzheimer’s symptoms such as poor memory and aggressiveness usually indicates that the patient is no longer in an early stage of the disease. According to scientists and other professionals in the field, the creation of approaches that help to discover this neurodegenerative process at an early stage is essential to develop mechanisms that can stop it. Researchers at the Karolinska Institute in Sweden are betting that a blood test could provide this strategic information.
In an article published in the journal Brain, they show how biomarkers in the blood indicate the presence of early pathological changes in an inherited form of the disease. The researchers noticed changes in glial fibrillary acidic protein (GFAP) about 10 years before the onset of symptoms of Alzheimer’s.
“This was followed by increased levels of Ptau181 (tau protein) and subsequently NfL (neurofilament light protein), which we already know are directly related to the extent of neuronal damage in the Alzheimer’s brain,” explains Caroline Graff , one of the authors of the study and a professor in the Department of Neurobiology, Science and Society of Care at the Swedish institute.
To arrive at the result, the group analyzed 164 blood plasma samples from 33 people with a mutation that increases susceptibility to Alzheimer’s disease and 42 relatives without the inherited pathogen predisposition. The data were collected between 1994 and 2018, and the analysis showed “significant changes” in various blood protein concentrations in the mutation carriers a decade before the onset of symptoms.
In the team’s evaluation, the results are promising for the development of new approaches against the disease. “The study results could be used in the future as a noninvasive biomarker for the early activation of immune cells such as astrocytes in the central nervous system, which could be valuable for the development of new drugs and for the diagnosis of cognitive diseases,” says Charlotte Johansson, a member of the research group , on.
Quiet
Alzheimer’s is the most common type of dementia data from the Swedish Brain Foundation shows it accounts for 60% to 70% of cases and it starts to develop quietly. According to the authors of the article, biological changes in the brain begin 20 to 25 years before memory loss and other cognitive symptoms become apparent.
Nerve cells in the region degenerate as a result of abnormal accumulation of betaamyloid and tau proteins. When more brain neurons are damaged, it manifests itself in dysfunction of cognitive functions like memory and language, the scientists explain. The earlier the complication is discovered, the greater the chances of encountering it. ‘This is one of the many reasons why more research is needed on accurate and simple methods of early detection,’ they emphasize in a statement.
cure
Cognitive and behavioral neurology expert Carlos Enrique Uribe says the strategy of looking for markers and signs that anticipate a person’s risk of Alzheimer’s has mobilized scientists for many years. In the case of the Swedish work, published in the latest issue of Brain, the originality lies in the fact that the research directly “affected” the disease.
For Uribe, this could be a route to strategies that will cure the disease. “By trying to find the source of the problem, it is possible to change its natural course. This strategy works to arrive at a healing process that alters the pathophysiological mechanism of the disease. In medicine, we call these diseasemodifying treatments, and Alzheimer’s didn’t exist before,” he says.
Reserved Uribe. He recalls that the study analyzed patients with Alzheimer’s related to genetic factors. “Because it is not the most common case, these results need to be evaluated carefully, since the genetic disease is a model for studying sporadic diseases (without hereditary factors). Sometimes it doesn’t work with that direct connection,” he explains.
Advanced Analysis
Cognitive neurology and dementia syndromes specialist Arthur Jatobá says some biomarkers are available for early detection of Alzheimer’s, but not for the general population. “Today, most patients are diagnosed by clinical, neuropsychological examination and brain imaging (cranial magnetic resonance imaging),” he says.
The doctor expects that in the future this type of analysis will be more accessible and will cover several biological indicators of increased risk. “I believe that in the next few years we will be able to do a blood test with a panel of multiple Alzheimer’s disease biomarkers such as amyloid beta protein, tau, GFAP and NfL. This will help us in the early detection of the disease,” it said.
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Cognitive and Behavioral Neurology Specialist, Carlos Enrique Uribe. Photo: Personal archive
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Caroline Graff, Professor, Department of Neurobiology, Nursing Science and Society, Karolinska Institutet. Photo: Karolisnka Institutet
even more vulnerable
“The interesting thing about this method of using people with genetic Alzheimer’s disease is that they are at a much higher risk of developing symptoms. Therefore, many studies in this field are conducted in this type of population. You know the problem will arise. So you monitor, identify what the marker was, and think of an intervention that can change that outcome. So the results are important.”
Carlos Enrique Uribe, specialist in cognitive and behavioral neurology
the internships
According to the Ministry of Health, the clinical picture of the stages of Alzheimer’s disease is divided into four stages. The first usually involves changes in memory, personality, and visual and spatial abilities. In the second case, difficulty speaking, performing simple tasks, coordinating movements, restlessness and insomnia. Then resistance to performing everyday tasks, urinary and fecal incontinence, difficulty eating, and progressive motor impairment. Finally mutism, painful swallowing and intercurrent infections.