A simple test for a complex disease: Alzheimer’s – Prof. Antonio Giordano

A new line of research is opening very different scenarios: a single drop of blood might be enough to obtain precise information on the disease

Diagnosing Alzheimer’s has never been simple.

Until today, to have a reliable confirmation of the disease, it is often necessary to resort to expensive or invasive tests, such as PET brain scans or the withdrawal of cerebrospinal fluid through a lumbar puncture. Effective procedures, certainly, but not always easily accessible or acceptable to patients.

A new line of research, however, is opening very different scenarios: a single drop of blood might be enough to obtain equally precise information. An idea that, if confirmed, would have an enormous impact on Alzheimer’s diagnosis.

The test is based on the detection of p-tau217, a protein considered a fundamental biomarker of the disease. Its presence in the blood is strictly linked to the accumulation of amyloid plaques in the brain, one of the hallmarks of Alzheimer’s. In practice, by analyzing this protein, it is possible to detect the biological changes that occur well before symptoms become evident.

Sample collection is extremely simple: a finger prick, similar to the one used daily by people with diabetes to check blood sugar. Not only that: samples can be stored at room temperature and shipped by mail, making this test potentially accessible even to those who live far from specialist centers or in rural areas.

In the studies conducted so far, the results have been surprising. The test has succeeded in distinguishing with great accuracy people affected by Alzheimer’s from healthy subjects, showing performance comparable to that of traditional blood tests performed in a clinical setting.

The true value of this innovation, however, lies in early diagnosis.

Being able to identify the disease in its initial phases is crucial for several reasons. New-generation drugs, such as those based on monoclonal antibodies, in fact seem to be more effective when administered before brain damage is advanced. Furthermore, a simple and inexpensive test would allow large-scale screening programs, reducing costs and facilitating the recruitment of participants for research on new therapies.

Despite the enthusiasm, experts urge caution. This test cannot yet replace a complete clinical evaluation, and further studies are needed to verify its reliability on different populations and in the context of primary care.

One fundamental fact remains, however: this progress marks a possible paradigm shift. We move from an Alzheimer’s diagnosis based predominantly on symptoms to one founded on molecular biology, opening the way to a future in which the disease could be recognized – and perhaps treated – well before it manifests evidently.

This article was originally written for the “Terra Medica” column written by Prof. Antonio Giordano for “La voce di New York“.