Researchers at the Hospital del Mar, in Barcelona, ??have identified a new marker that predicts the evolution, faster or slower, of Alzheimer’s disease and other dementias. This is the degree of deterioration of the blood-brain barrier, a relatively easy value to determine using simple tests.
Alzheimer’s tends to progress slowly and gradually worsens patients’ condition over the years, but the rate of deterioration is different for each person. One of the reasons for the disparity in this evolution lies in the state of the blood-brain barrier. This system is a network of blood vessels and tissue made up of closely connected cells, located along most of the capillaries that supply the brain. Its function is to regulate exchanges between the blood and the brain in order to prevent harmful substances from entering the brain.
In order to check whether the state of this filter acts as a predictor of the evolution of Alzheimer’s, researchers have monitored more than 300 patients for four years. These are people diagnosed with mild cognitive impairment or dementia caused by different neurodegenerative diseases. The diagnosis is based on data from a lumbar puncture, magnetic resonance imaging and neuropsychological assessment.
The results indicate that patients who are detected by lumbar puncture with higher levels of albumin (a protein produced by the liver that is mostly found in the bloodstream and helps keep blood from leaking into other tissues) experience a more accelerated disease evolution. The risk of rapid progression increases by 8% for every 10% increase in the level of albumin in the cerebrospinal fluid, the study found.
“The initial hypothesis of the research is that in recent years there is more and more evidence that cardiovascular risk factors are also risk factors for cognitive impairment”, explains researcher Albert Puig-Pijoan, assistant doctor at the service, to La Vanguardia of neurology at the Hospital del Mar. “In the blood-brain barrier, whose main function is to regulate the passage of substances between the blood and the brain and vice versa, an increase in permeability indicates a worse functioning of this structure”.
The marker of the level of permeability is the quotient between the concentration of albumin in the cerebrospinal fluid and the blood. And it is not difficult to measure. It is an accessible test for laboratories. “It is enough to have a lumbar puncture, which nowadays is a common practice in the diagnosis of Alzheimer’s, especially in the initial stages, and a blood analysis, done simultaneously, which does not have any complications”, explains the doctor .
According to Puig-Pijoan, due to this simplicity the method can have an impact on clinical practice and would be valid for different causes of cognitive impairment. “On the other hand, it is inferred that cardiovascular health is of great importance both in the prevention and in the evolution of cognitive impairment, and that therapies aimed at preserving or restoring the function of the blood-brain barrier could play a key role in the future”.
Led by the Mar Research Institute hospital, the research has been published in Alzheimer’s
According to Puig-Pijoan, the work will continue with other cohorts of patients, larger and more specific, in order to validate the marker for different pathologies and refine the variables that allow predicting the evolution of people diagnosed with some type of dementia.
