In recent studies, researchers have identified chemical changes that occur in Alzheimer’s disease, opening the door to a possible skin test to diagnose Alzheimer’s in the not too distant future.
Although only an autopsy can prove the presence of Alzheimer’s disease, the clinical diagnosis is usually accurate. The current approach to establishing the cause of memory loss involves ruling out some potential causes and finding evidence to confirm the presence of others.
Once other conditions, such as depression, Huntington’s disease, or hypothyroidism, have been ruled out, the diagnosis of Alzheimer’s is made by accumulating information on the individual’s history, mental status exams, and interviews with the patient, family members, and friends over a period of several weeks.
What’s on the horizon?
Researchers have identified chemical changes that occur in Alzheimer’s disease but not in other forms of dementia. Because the specific chemical signals can be detected in both brain and skin cells of Alzheimer’s patients, this opens the door to a possible skin test for Alzheimer’s.
In the study, which was reported in the Proceedings of the National Academy of Sciences (Volume 103, page 13203), researchers compared human skin cells from a tissue bank with autopsy samples from people who had Alzheimer’s disease.
As it turned out, the skin tissues from the Alzheimer’s patients were distinguished by changes in two related enzymes that are involved in inflammatory signaling pathways. Inflammation is believed to play an important role in the development of Alzheimer’s disease.
A skin test would have many advantages over a spinal tap or brain scan - -- two tests currently used to aid doctors in the diagnosis of Alzheimer’s disease. If such a test is eventually developed, it could be administered on an outpatient basis, in a clinic or physician’s office.
More important, it could be given early in the course of Alzheimer’s, when it is often difficult to determine whether a person has Alzheimer’s or another degenerative neurological condition. The earlier an accurate diagnosis of Alzheimer’s is obtained, the earlier treatment can begin. That’s important because current medications are effective only when given early in the disease process.
