A drop of blood from the finger could be used to detect Alzheimer's

BarcelonaA new step forward in the fight against Alzheimer's. A drop of dried blood obtained with a simple finger prick, like the ones people with diabetes use to measure their glucose, could be used to detect key markers of this disease. This is described in a study conducted by the ACE Alzheimer's Research Center in Barcelona and the Carlos III Health Institute in Madrid, published this Monday in the journal Nature Medicine. The research is progressing with a method – blood extraction – that has long been studied to predict the disease. It is now especially relevant that the detection could be done by the patient simply and quickly.

The procedure has been tested on 337 patients from seven European centers. The aim was to find proteins related to Alzheimer's and other brain changes in cerebrospinal fluid. The drop of blood obtained is then dried on a card, and the results can be obtained in this way. With this new method, more invasive tests could be avoided, and the disease could be detected earlier. In fact, current diagnostic tests, such as cerebrospinal fluid analysis or brain imaging techniques (such as CT or PET scans), are often invasive, expensive, or inaccessible, and, moreover, detect the disease when it is already in a more advanced stage.

Patient autonomy

One of the practical limitations of blood-based screening methods to date has been the handling and storage of samples and the availability of qualified personnel to collect them. To address this challenge, this study focuses on analyzing biomarkers from drops of blood obtained from the soft tissue of a finger and dried on a card. This is a test that patients can perform themselves without external assistance. This is what makes the study relevant: this simple technique could enable large-scale diagnoses, including for people with limited resources.

The authors found that p-tau217 protein levels in samples obtained via finger prick closely matched the results of standard blood tests and allowed for the identification of Alzheimer's-related changes in cerebrospinal fluid with 86% accuracy. Two other biomarkers associated with the disease, GFAP and NFL, were also successfully measured, showing a high degree of agreement with traditional diagnostic tests. However, researchers caution that this diagnostic procedure is not yet ready for clinical use and requires further development.

One of the challenges of current research is to advance blood testing as a method of early diagnosis. The study announced this Monday goes further, detecting the disease using a simple drop of dried blood obtained with a finger prick. In fact, these advances in Alzheimer's detection using blood samples also bear a Catalan stamp. For example, a study with the participation of the Barcelona Beta Brain Research Center of the Pasqual Maragall Foundation It was demonstrated that a blood test based on the p-tau217 biomarker (a protein) effectively identifies individuals without cognitive impairment but with beta-amyloid accumulation, one of the main brain alterations characteristic of Alzheimer's disease. A team of researchers from the Sant Pau Research Institute (IR Sant Pau) also reached similar conclusions.