Early detection of Alzheimer’s disease remains a major challenge, given that symptoms appear late, when brain damage is already present. A new study suggests that a simple procedure performed in the nasal cavity could identify biological changes associated with the disease before memory and thinking disorders appear.
Duke Health researchers have demonstrated in a clinical trial that an outpatient nasal swab can detect cellular changes associated with Alzheimer’s disease in the early stages.
The procedure involves harvesting nerve and immune cells from the upper part of the nasal cavity, where the neurons involved in the sense of smell are located.
After applying an anesthetic spray, the doctor inserts a fine brush into this area and collects the cells. They are then analyzed to identify active genes, an indicator of the biological processes taking place in the brain at that time.
The analysis included samples from 22 participants and assessed the activity of thousands of genes in hundreds of thousands of individual cells, generating millions of data.
Researchers have identified distinct patterns that differentiate people with early or diagnosed Alzheimer’s disease from those without the disease. The method detected early changes in nerve and immune cells, including in people without symptoms, but with signs suggestive of Alzheimer’s, detected in the laboratory.
A combined score, based on gene activity in nasal tissue, was able to differentiate early and clinical Alzheimer’s cases from healthy people in about 81% of cases, according to a report published by Nature Communications.
The authors of the study emphasize in a statement that the goal is to confirm the disease as early as possible, before brain damage accumulates. They believe that an early diagnosis could allow the initiation of therapies capable of preventing the appearance of clinical forms of the disease.
Compared to existing blood tests, which identify markers that appear later in the course of the disease, this method directly analyzes the activity of living nerve and immune cells. Thus, it could provide an earlier and more direct picture of the processes associated with the disease.
The authors of the study, who filed a patent application for this method in the US, note that much of the current knowledge about Alzheimer’s comes from studies on tissues obtained post-mortem. The new approach allows studying living neural tissue, which opens new directions for diagnosis and treatment.
The Duke team, in collaboration with the Duke & UNC Alzheimer’s Disease Research Center, is currently expanding the study to larger groups of participants and investigating whether the test can be used to monitor treatment response.
