A drop of dried blood, obtained with a simple finger prick, like the one diabetics use to measure glucose, can be used to detect important markers of Alzheimer’s disease, thus avoiding more invasive tests.
The study, this Monday in Nature Medicine and which involved the Carlos III Health Institute (Madrid) and the ACE Alzheimer’s Research Center (Barcelona), detailed the new method to detect Alzheimer’s, using a drop of blood obtained from the fingertip and dried on a card.
The procedure was tested on 337 patients in seven European centers to find proteins related to Alzheimer’s and other brain changes in cerebrospinal fluid, achieving 86% accuracy in identifying changes related to the disease.
Alzheimer’s is a neurodegenerative disease that seriously affects memory and other mental functions, causing a progressive loss of neurons as it progresses. Early detection is crucial for implementing treatments that can delay or stop its progression.
Nearly one in nine people over 65 suffers of this disease, according to the Alzheimer’s Association.
Less invasive technique
Current diagnostic tests, such as cerebrospinal fluid analysis or brain imaging techniques (such as CT or PET), are often invasive, expensive or inaccessible, and they also detect the disease when it is already quite advanced.
One of the challenges of current research is improve blood tests as an early diagnosis method.
One of the practical limitations of these blood tests is the handling and storage of the samples, as well as the availability of qualified personnel to collect them.
To overcome this challenge, the present study focuses on the analysis of biomarkers from drops of blood collected from the fingertip and dried on a card. This is a test that patients can perform alone, without external help, as was the case in this study.
The authors verified that the levels of p-tau217 protein in samples obtained through fingerprints showed a high similarity with the results of conventional blood tests and allowed the identification of Alzheimer’s-related changes in cerebrospinal fluid with 86% accuracy.
Two other biomarkers associated with the disease, GFAP and NFLwere also successfully measured and presented a high degree of agreement with traditional diagnostic tests.
The researchers also cautioned that this diagnostic procedure is not yet ready for clinical use and requires further development.
However, the results suggest that this simple technique could enable large-scale diagnostics, including for people with limited resources.
