Clues to Alzheimer's May Reside in Spinal Fluid
Researchers may be able to predict which people with fuzzy thinking will develop the brain disorder
WEDNESDAY, June 22, 2011 (HealthDay News) -- The spinal fluid of people with mild memory problems may help identify those who will later develop Alzheimer's disease, according to new research.
In the study, researchers collected samples of cerebrospinal fluid from 58 people with mild memory (cognitive) impairment and analyzed the samples for concentrations of several proteins associated with Alzheimer's disease. After an average follow-up of three years, 21 people had developed Alzheimer's, 27 still had mild cognitive impairment, and 8 had reverted back to their normal cognitive health.
Two of the participants developed a type of dementia other than Alzheimer's and weren't included in the final results.
The spinal fluid of people who developed Alzheimer's disease had significantly higher levels of a protein called soluble amyloid precursor protein beta (sAPPβ) than the spinal fluid of those who didn't develop the brain disorder -- an average of 1,200 versus 932 nanograms per milliliter.
Predicting participants' risk of Alzheimer's was 80 percent accurate when three factors were combined -- sAPPβ, a person's age, and a known marker of brain cell damage called tau protein.
A protein called amyloid beta1-42 (Aβ1-42), previously considered a so-called "biomarker" for Alzheimer's, was not a predictive factor, according to the German researchers.
The study is published in the June 22 online edition of the journal Neurology. As many as 15 percent of people with mild memory problems develop Alzheimer's disease each year, the researchers said.
"These results suggest that sAPPβ as a biomarker [indicator] may be useful and superior to the established marker Aβ1-42 in the early diagnosis of Alzheimer's disease," study author Dr. Robert Perneczky, of the Technical University Munich, said in a journal news release.
"One possible explanation is that Aβ1-42 measures events further downstream from the initial steps that lead to the production of the amyloid plaques that accumulate in the brains of people with Alzheimer's disease," he explained.
Perneczky said that sAPPβ is a measure of the first critical step in the development of Alzheimer's and may "provide more accurate information on the core pathological events."
The U.S. National Institute of Neurological Disorders and Stroke has more about Alzheimer's disease.