By measuring cerebrospinal fluid (CSF) concentrations of two of the disease’s biochemical hallmarks – amyloid beta42 peptide and tau protein – the test also predicted whether a person’s mild cognitive impairment would convert to Alzheimer’s disease over time.
Researchers were able to detect this devastating disease at the earliest stages, before dementia symptoms appeared and widespread irreversible damage occurred. The findings hold promise in the search for effective pharmaceutical therapies capable of halting the disease.
Honing in on a previously suggested pathological CSF biomarker signature, a team of Penn Medicine researchers led by Leslie M. Shaw, PhD, Co-Director of the Penn Alzheimer’s Disease Neuroimaging Initiative (ADNI) Biomarker Core, found evidence of neuron degeneration – marked by an increase in CSF concentration of tau proteins – and plaque deposition, indicated by a decrease in amyloid beta42 concentration.
In addition, people with two copies of the genetic risk factor for Alzheimer’s disease, APOE ε4 , had the lowest concentrations of amyloid beta42, compared to those with one or no copies. The study appears in the online edition of the Annals of Neurology.
“With this test, we can reliably detect and track the progression of Alzheimer’s disease,” said Dr. Shaw.
“Validated biomarker tests will improve the focus of Alzheimer’s clinical trials, enrolling patients at earlier stages of the disease to find treatments that can at least delay –and perhaps stop– neurodegeneration. In addition, prevention trials can test methods to delay or block mild cognitive impairment from converting to full-blown Alzheimer’s.”
Further validation studies of this research test system are underway. Additional work is needed to develop additional biomarkers, as well as identify more genetic risk factors that will help distinguish Alzheimer’s from other neurodegenerative diseases characterized by cognitive impairments.
“Thanks to the dedicated researchers and volunteers who participated in this and other Alzheimer’s disease studies through the Penn Alzheimer’s Disease Core Center and at ADNI trial sites around the US and Canada, we have validated a test where a safe, simple lumbar puncture can provide information to confirm suspected Alzheimer’s disease and predict the onset of the disease,” said John Q. Trojanowski, MD, Ph.D, Director of the Penn Alzheimer’s Disease Core Center.
“Using this technique, we will further our understanding of how the disease progresses and what we can do to stop Alzheimer’s disease before it starts.”