A simple skin test that would allow detection of Alzheimer's disease appears to be a realistic possibility in the future.
According to scientists at the Blanchette Rockefeller Neurosciences Institute (BRNI), substances in skin cells may provide doctors with a quick and accurate yes-or-no answer when they suspect a patient is showing early signs of the disease.
They say the test could be performed easily by a nurse or medical technician in a doctor's office or outpatient clinic.
The researchers at BRNI have apparently found a biomarker that can accurately distinguish between Alzheimer's disease and other forms of dementia during the first one to two years of the disease's progression.
The biomarker showed high rates of accuracy when it was tested with human skin cells from a tissue bank, as well as for samples obtained in a previous, unpublished study of patients with autopsy-confirmed diagnoses.
The biomarker also has the potential to be used with blood samples.
Dr. Daniel L. Alkon, M.D., scientific director of BRNI and coauthor of the study, along with with Tapan K. Khan, Ph.D., assistant professor, say that in the initial stages Alzheimer's disease is often difficult to distinguish from other dementias or mild cognitive impairment, but treatments for Alzheimer's are most effective before the devastating and widespread impairment of brain function that inevitably develops after four or more years.
Other scientists have found that Alzheimer's effects are found throughout the body and not just in the brain, but the BRNI team has located a biomarker for the disease by testing for signs of Alzheimer's-related inflammation in skin cells called fibroblasts, without the need for invasive tests previously required, such as a lumbar tap.
It seems that when Alzheimer's disease occurs it stimulates a change indicated by a steep imbalance in the ratio of the two forms of the enzyme, MAP kinase Erk, in skin cells that are exposed to bradykinin, an inflammation-related molecule.
That particular imbalance is not seen in cells of people without dementia or those with other forms of dementia, such as Parkinson's disease, multiple infarct dementia and Huntington's chorea.