(Bret Stetka/ Scientific American) — For the most part, clinical trials in Alzheimer’s disease have been woefully disappointing—failed drug after failed drug. Even colossal drugmaker Pfizer announced earlier this month that it will stop pursuing treatments for the disorder out of scientific and financial frustration. Yet a Japanese study published Jan. 31 in Nature reports on a screening test that could improve the success of Alzheimer’s drug research.
The new findings suggest a simple blood test can accurately predict levels of a protein called amyloid beta in the brain that begins appearing early in the course of the disease before symptoms appear. Amyloid buildup is a key pathological feature of Alzheimer’s, and determining the degree to which someone’s brain is riddled with the molecule is essential for designing effective clinical trials.
At the moment the only way to accurately measure amyloid in a living person is either via costly positron emission tomography imaging (PET scan) or by sampling cerebrospinal fluid (CSF) with a lumbar puncture, or spinal tap. A blood test would offer a cheaper, far less invasive means of determining a patient’s amyloid status. This could encourage more patients to enter clinical trials. It could also help researchers distinguish people with brewing Alzheimer’s from those with other forms of dementia.
Senior study author Katsuhiko Yanagisawa, director general of the National Center for Geriatrics and Gerontology in Japan, is convinced that enough amyloid penetrates the blood–brain barrier to make its way into the bloodstream to be a useful measure of cognitive function.
“We think amyloid blood tests could replace costly, invasive amyloid tests, especially when it comes to detecting preclinical Alzheimer’s,” he says. “We hope our biomarker better facilitates clinical trials for [Alzheimer’s] by improving enrollment of participants.” (…)