Spinal Fluid Biomarkers Detect Neurodegeneration, Alzheimer’s Disease in Living Patients
July 20, 2021

Alzheimer’s disease can be accurately detected via peptides and proteins in a patient’s cerebrospinal fluids (CSF), which can be collected through a lumbar puncture and tested while the patient is alive, according to a study published in Alzheimer’s and Dementia: The Journal of the Alzheimer’s Association.

In 2018, a new framework suggested combining 3 Alzheimer’s disease biomarkers in CSF -- pathologic amyloid plaques (A), tangles (T), and neurodegeneration (N) -- collectively called ATN. The current study showed that the ATN framework can be extended to detect frontotemporal degeneration.

Distinguishing frontotemporal degeneration from Alzheimer’s disease can be a challenge for clinicians because the symptoms can sometimes overlap, and a subset of patients can even have both pathologies. Biomarkers can fill the gap by providing evidence of whether Alzheimer’s pathology underlies a patient’s symptoms.

“CSF biomarkers work similarly to a pregnancy test, offering a simple positive or negative result when enough of a substance is detected,” said Katheryn A.Q. Cousins, PhD, Frontotemporal Degeneration Center, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania. “But like a pregnancy test, biomarkers for Alzheimer’s disease can provide false negatives or positives. Alzheimer’s is a diverse disease, and it is common for other conditions to also be present in the brain. The ATN framework may provide a more complete look at a person’s diagnosis and give us a much richer understanding of not only Alzheimer’s disease, but other co-occurring neurodegenerative conditions. However, to accomplish this, additional biomarkers that can detect other neurodegenerative conditions are critically needed.”

The study showed that ATN incorporating neurofilament light chain (NfL) may provide a more accurate and precise diagnosis for patients with frontotemporal degeneration. CSF NfL may be a more accurate marker of neurodegeneration for patients with frontotemporal degeneration, including for Alzheimer’s disease.

“While the ATN framework is very exciting and offers much opportunity for patients with Alzheimer’s disease, these biomarkers don’t capture every case of the disease,” said Dr. Cousins. “We want to be able to detect and treat every patient with neurodegenerative disease as early as possible, and more research is needed to fully understand how biofluids track with the disease process. I am eager to conduct additional research into which patients might be missed by these markers, what they have in common, and what causes the pathological and clinical differences in the disease.”

Reference: https://alz-journals.onlinelibrary.wiley.com/doi/10.1002/alz.12233

SOURCE: University of Pennsylvania School of Medicine