Imagine being able to detect the early stages of Alzheimer's by swabbing your skin with a specially prepared pad; waiting, then finding out after laboratory assessment if you have the Disease.
Published this week in the Proceedings of the National Academy of Sciences; resarchers investigated 70 subjects. The BRNI biomarker (named after an institute affiliated with Univ. of West Virgina) showed high accuracy when tested with human skin cells from a tissue bank, as well as for samples obtained in a previous, unpublished study of patients with autopsy-confirmed diagnoses.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 could also potentially be used with blood samples.
"When it begins, Alzheimer's disease is often difficult to distinguish from other dementias or mild cognitive impairment," says Daniel L. Alkon, M.D., scientific director of BRNI and coauthor of the study with Tapan K. Khan, Ph.D., assistant professor. "Potential treatments of Alzheimer's, however, are likely to have their greatest efficacy before the devastating and widespread impairment of brain function that inevitably develops after four or more years."
Some researchers have noted the systemic effects of Alzheimer's on the body, encompassing circulatory and other body systems in addition to the brain. By testing for signs of Alzheimer's-related inflammation in skin cells called fibroblasts, the BRNI team has located a biomarker for the disease that can be tested without the invasive tests previously required.
The researchers found that Alzheimer's disease stimulates a change in the enzyme, MAP Kinase Erk 1/2. When fibroblasts are tested by exposing them to Bradykinin, a common inflammatory signal, the Erk 1/2 response in skin cells of Alzheimer's patients was sharply distinguished from the results in cells from age-matched controls. It was also differentiated from the skin cells from patients with non-Alzheimer's dementias, such as Parkinson's disease, multiple infarct dementia and Huntington's chorea.
A possible 'skin' test for human use, assuming the results are replicable; is five to ten years away.