Portuguese scientists have managed to identify two distinct subgroups of Alzheimer's disease.
This discovery could help improve clinical trials, which are fundamental to understanding and treating this disease that still has no cure.
The team is international, but led by specialists from the University of Lisbon and the University of Coimbra.
The study was carried out to better understand the biochemical profiles of patients diagnosed with mild cognitive impairment with markers of Alzheimer's disease (DCL-DA).
Daniela Moutinho
The many clinical trials carried out over the last 10 years have not brought comprehensive solutions to the disease - and this may be related to the fact that “we are dealing with a patient population that is considered homogeneous, when biochemically they are heterogeneous, as proven in this study,” analyzes one of the study's authors, Bruno Manadas.
Now, the researchers have managed to show “the presence of biochemical subgroups within a well-defined clinical group of individuals with mild cognitive impairment with Alzheimer's biomarkers, which may point to the existence of different mechanisms of origin and progression of the disease”, quotes the University of Coimbra in a statement sent to ZAP.
This study also shows that there are more proteins - in addition to beta-amyloid and tau - that make it possible to distinguish between patients with DCL-DA and patients with mild cognitive impairment (DCL) without markers of Alzheimer's disease.
These advances could lead to clinical trials with higher efficacy rates, as they provide new information on the different biochemical profiles of the disease.
To reach this conclusion, the 262 participants were assessed to identify whether they had mild cognitive impairment; in the patients, cerebrospinal fluid (CSF, the fluid that circulates around brain structures) was collected and then molecularly characterized. This was used to determine who had markers for Alzheimer's disease.
The protein profiles of the cerebrospinal fluids were then analyzed. This phase revealed that the patients could be classified into two subgroups: the immune dysfunction and blood-brain barrier impairment group; and the hyperplasticity-related protein alterations group.
In other words, there are at least two profiles of early-stage Alzheimer's patients that can be considered in clinical trials. They could be divided up according to their biochemical profile, rather than assessed as a single group.
The next stage is to try to understand “whether we are looking at a new classification of Alzheimer's patients in their early stages”, concludes Bruno Manadas.
