Newswise — PHILADELPHIA—Alzheimer’s disease and related diseases can still only be confirmed in deceased patients’ brains via autopsy. Even so, the development of biomarkers can give patients and their families answers during life: 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. In 2018, a new framework suggested combining three Alzheimer’s disease biomarkers in CSF – pathologic amyloid plaques (A), tangles (T), and neurodegeneration (N), collectively called ATN. According to recent research from the Perelman School of Medicine at the University of Pennsylvania, the ATN framework can be extended to detect another neurodegenerative condition: frontotemporal degeneration.

Patients with frontotemporal degeneration can experience a range of symptoms, including behavioral changes, executive dysfunction, and language impairments. Distinguishing frontotemporal degeneration from Alzheimer’s disease can be a challenge for clinicians: the symptoms of frontotemporal degeneration can sometimes overlap with Alzheimer’s disease, 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. But like a pregnancy test, biomarkers for Alzheimer’s disease can provide false negatives or positives,” said lead investigator Katheryn A.Q. Cousins, PhD, a research associate in the Frontotemporal Degeneration Center in the Department of Neurology at Penn Medicine. “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 findings, published in Alzheimer’s and Dementia: The Journal of the Alzheimer’s Association, show that ATN incorporating neurofilament light chain (NfL) may provide a more accurate and precise diagnosis for patients with frontotemporal degeneration. NfL is a protein abundant in the brain, whose levels increase as degeneration progresses. Cousins’ work shows that 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. 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,” said Cousins. “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.”

This study was funded by the Swedish Research Council (2018-02532); the European Research Council, (681712); Swedish State Support for Clinical Research (ALFGBG-720931); the Alzheimer Drug Discovery Foundation (201809-2016862); the Swedish Alzheimer Foundation, (AF-742881); European Union Joint Program for Neurodegenerative Disorders (JPND2019-466-236); and the Alzheimer’s Association Research Fellowship (AARF-16-44368).

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Penn Medicine is one of the world’s leading academic medical centers, dedicated to the related missions of medical education, biomedical research, and excellence in patient care. Penn Medicine consists of the Raymond and Ruth Perelman School of Medicine at the University of Pennsylvania (founded in 1765 as the nation’s first medical school) and the University of Pennsylvania Health System, which together form a $8.9 billion enterprise.

The Perelman School of Medicine has been ranked among the top medical schools in the United States for more than 20 years, according to U.S. News & World Report's survey of research-oriented medical schools. The School is consistently among the nation's top recipients of funding from the National Institutes of Health, with $496 million awarded in the 2020 fiscal year.

The University of Pennsylvania Health System’s patient care facilities include: the Hospital of the University of Pennsylvania and Penn Presbyterian Medical Center—which are recognized as one of the nation’s top “Honor Roll” hospitals by U.S. News & World Report—Chester County Hospital; Lancaster General Health; Penn Medicine Princeton Health; and Pennsylvania Hospital, the nation’s first hospital, founded in 1751. Additional facilities and enterprises include Good Shepherd Penn Partners, Penn Medicine at Home, Lancaster Behavioral Health Hospital, and Princeton House Behavioral Health, among others.

Penn Medicine is powered by a talented and dedicated workforce of more than 44,000 people. The organization also has alliances with top community health systems across both Southeastern Pennsylvania and Southern New Jersey, creating more options for patients no matter where they live.

Penn Medicine is committed to improving lives and health through a variety of community-based programs and activities. In fiscal year 2020, Penn Medicine provided more than $563 million to benefit our community.

Journal Link: Alzheimer’s and Dementia: The Journal of the Alzheimer’s Association