Exam can detect disease 10 years earlier – science

The appearance of characteristic Alzheimer’s symptoms, such as decreased memory and aggressiveness, usually indicates that the patient is no longer in an early stage of the disease. Establishing approaches that help detect this neurodegenerative process at an early stage is, in the opinion of scientists and other professionals in the field, essential for developing mechanisms capable of stopping it. Researchers from the Karolinska Institutet in Sweden are betting that a blood test can provide this strategic information.

In an article published in the journal Brain, they show how biomarkers in the blood indicate early pathological changes in an inherited form of the disease. The researchers noticed changes in the glial fibrillary acid protein (GFAP) about 10 years before the first symptoms of Alzheimer’s disease appeared.

“They were followed by an increase in the concentration of P-tau181 (tau protein) and, by extension, NfL (neural filament light protein), which, as we already know, is directly related to the extent of neuronal damage in the Alzheimer’s brain,” details Caroline Graff, one of the study’s authors and professor. in the Department of Neuroscience, Science and Care Society at the Swedish Institute.

To come to its conclusion, 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 was collected between 1994 and 2018, and the analysis indicated “clear changes” in the concentrations of various blood proteins in carriers of the mutations ten years before the onset of symptoms.

In the team’s evaluation, the results were promising for the development of novel approaches against the disease. “In the future, the results of the study could be used as a non-invasive biomarker for the early activation of immune cells such as astrocytes in the central nervous system, which could be valuable for developing new drugs and diagnosing cognitive diseases,” notes Charlotte Johansson, a member of the group of researchers.

silent

Alzheimer’s disease is the most common type of dementia – data from the Swedish Brain Foundation shows it corresponds to 60% to 70% of cases – and begins to develop silently. According to the authors of the article, biological changes in the brain begin 20 to 25 years before memory loss and other cognitive symptoms.

Neurons in the area deteriorate as a result of the abnormal buildup of beta-amyloid and tau proteins. The scientists explained that as more neurons in the brain are damaged, this manifests in an imbalance in cognitive functions such as memory and speech. The sooner complications are detected, the higher the chances of encountering them. “This is one of the many reasons why more research is needed on accurate and easy methods for early diagnosis,” they noted in a note.

The investigation “affects” the disease

Cognitive and behavioral neuroscientist Carlos Enrique Uribe says the strategy of looking for signs and markers that predict a person’s risk of developing Alzheimer’s disease has rallied 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 investigation directly “affected” the disease.

For Uribe, this may be a pathway for strategies to treat the disease. “By trying to find the root of the problem, it is possible to change its natural history. This strategy works to reach a healing procedure, to change the pathophysiological mechanism of the disease. In medicine, we call this disease-modifying therapy, which does not yet exist in Alzheimer’s disease,” he says. Says.

Uribe expresses reservations. He recalls that the study analyzed Alzheimer’s patients linked to genetic factors. “Because it is not the most common condition, these findings must be carefully evaluated, because a genetically determined disease is a model for studying sporadic diseases (without genetic factors). Sometimes things just don’t work out with such a direct relationship,” he explains.

Extended analysis

Cognitive neuroscientist and dementia syndrome specialist Arthur Gattob says some biomarkers for early Alzheimer’s disease are available, but not for the general population. “The diagnosis today, for most patients, is made through clinical and neuropsychological evaluation and brain imaging tests (magnetic resonance imaging of the skull),” he says.

The doctor expects that in the future, this type of analysis will be more available and will cover many biological indicators of increased risk. “I believe that in the next few years, we will be able to have a blood test with a range of biomarkers for Alzheimer’s disease, such as beta-amyloid protein, tau, GFAP and NfL. This will help us in early diagnosis of the disease.”

“The interesting thing about this methodology of using people with genetically determined Alzheimer’s disease is that they’re more likely to have symptoms. That’s why so many studies in this area are done in this kind of population. You know the problem is going to happen. So, you’re watching. And you determine what the marker is and you think of an intervention that could change that outcome. So the results are important.”

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Pathology has four stages

The clinical picture of the stages of Alzheimer’s disease is divided into four stages, according to the Ministry of Health. In the first case, there are usually changes in memory, personality, and visual and spatial skills. The second is difficulty speaking, performing simple tasks, coordinating movements, restlessness, and restlessness. Then resistance to performing daily tasks, urinary and fecal incontinence, difficulty eating and progressive motor impairment. Finally, dumbness, swallowing pain, and cross-infections.