For many years, the diagnosis of Alzheimer’s has been based on the characterization of amyloid plaques and tau tangles in the brain, typically after a person dies. An inexpensive and widely available blood test for the presence of plaques and tangles would have a profound impact on Alzheimer’s research and care. According to the new study, measurements of phospho-tau217 (p-tau217), one of the tau proteins found in tangles, could provide a relatively sensitive and accurate indicator of both plaques and tangles—corresponding to the diagnosis of Alzheimer’s—in living people.
“The p-tau217 blood test has great promise in the diagnosis, early detection, and study of Alzheimer’s,” said Oskar Hansson, MD, PhD, Professor of Clinical Memory Research at Lund University, Sweden, who leads the Swedish BioFINDER Study and senior author on the study who spearheaded the international collaborative effort. “While more work is needed to optimize the assay and test it in other people before it becomes available in the clinic, the blood test might become especially useful to improve the recognition, diagnosis, and care of people in the primary care setting.”
Researchers evaluated a new p-tau217 blood test in 1,402 cognitively impaired and unimpaired research participants from well-known studies in Arizona, Sweden, and Colombia. The study, which was coordinated from Lund University in Sweden, included 81 Arizona participants in Banner Sun Health Research Institute’s Brain Donation program who had clinical assessments and provided blood samples in their last years of life and then had neuropathological assessments after they died; 699 participants in the Swedish BioFINDER Study who had clinical, brain imaging, cerebrospinal fluid (CSF), and blood-based biomarker assessments; and 522 Colombian autosomal dominant Alzheimer’s disease (ADAD)-causing mutation carriers and non-carriers from the world’s largest ADAD cohort.
- In the Arizona (Banner Sun Health Research Institute) Brain Donation Cohort, the plasma p-tau217 assay discriminated between Arizona Brain donors with and without the subsequent neuropathological diagnosis of “intermediate or high likelihood Alzheimer’s” (i.e., characterized by plaques, as well as tangles that have at least spread to temporal lobe memory areas or beyond) with 89% accuracy; it distinguished between those with and without a diagnosis of “high likelihood Alzheimer’s” with 98% accuracy; and higher ptau217 measurements were correlated with higher brain tangle counts only in those persons who also had amyloid plaques.
- In the Swedish BioFINDER Study, the assay discriminated between persons with the clinical diagnoses of Alzheimer’s and other neurodegenerative diseases with 96% accuracy, similar to tau PET scans and CSF biomarkers and better than several other blood tests and MRI measurements; and it distinguished between those with and without an abnormal tau PET scan with 93% accuracy.
- In the Colombia Cohort, the assay began to distinguish between mutation carriers and non-carriers 20 years before their estimated age at the onset of mild cognitive impairment.
In each of these analyses, p-tau217 (a major component of Alzheimer’s disease-related tau tangles) performed better than p-tau181 (another component of tau tangles and a blood test recently found to have promise in the diagnosis of Alzheimer’s) and several other studied blood tests.
Other study leaders include Jeffrey Dage, PhD, from Eli Lilly and Company, who developed the p-tau217 assay, co-first authors Sebastian Palmqvist, MD, PhD, and Shorena Janelidz, PhD, from Lund University, and Eric Reiman, MD, Banner Alzheimer’s Institute, who organized the analysis of Arizona and Colombian cohort data.
In the last two years, researchers have made great progress in the development of amyloid blood tests, providing valuable information about one of the two cardinal features of Alzheimer’s. While more work is needed before the test is ready for use in the clinic, a p-tau217 blood test has the potential to provide information about both plaques and tangles, corresponding to the diagnosis of Alzheimer’s. It has the potential to advance the disease’s research and care in other important ways.
“Blood tests like p-tau217 have the potential to revolutionize Alzheimer’s research, treatment and prevention trials, and clinical care,” said Eric Reiman, MD, Executive Director of Banner Alzheimer’s Institute in Phoenix and a senior author on the study. “While there’s more work to do, I anticipate that their impact in both the research and clinical setting will become readily apparent within the next two years.”
Alzheimer’s is a debilitating and incurable disease that affects an estimated 5.8 million Americans age 65 and older. Without the discovery of successful prevention therapies, the number of U.S. cases is projected to reach nearly 14 million by 2050.
Publication in the Journal of the American Medical Association (JAMA)
“Discriminative accuracy of plasma phospho-tau217 for Alzheimer disease vs other neurodegenerative disorders” Sebastian Palmqvist, Shorena Janelidze, Yakeel T. Quiroz, Henrik Zetterberg, Francisco Lopera, Erik Stomrud, Yi Su, Yinghua Chen, Geidy E. Serrano, Antoine Leuzy, Niklas Mattsson-Carlgren, Olof Strandberg, Ruben Smith, Andres Villegas, Diego Sepulveda-Falla, Xiyun Chai, Nicholas K. Proctor, Thomas G. Beach, Kaj Blennow, Jeffrey L. Dage, Eric M. Reiman och Oskar Hansson.
- Clinical Memory Research Unit, Lund University
Lund University was founded in 1666 and is ranked among the world’s top 100 universities. The University has 40000 students and 8160 staff based in the cities of Lund, Helsingborg and Malmö in Sweden. Based on the strong tradition of neuroscience at Lund University, the Clinical Memory Research Unit has built a creative and multi-disciplinary research team led by Prof. Oskar Hansson. The research team is one of the leading international research groups when it comes to development and validation of biomarkers for Alzheimer’s and Parkinson’s diseases, and has established the Swedish BioFINDER Study (www.biofinder.se).
- Banner Alzheimer’s Institute
Since its inception in 2006, Banner Alzheimer’s Institute (BAI) has sought to find effective Alzheimer’s disease prevention therapies without losing another generation, establish a new model of dementia care for patients and family caregivers, and forge new models of collaboration in biomedical research. It has made groundbreaking contributions to the unusually early detection, tracking, diagnosis and study of Alzheimer’s, and aims to find an effective prevention therapy by 2025. It includes the pioneering Alzheimer’s Prevention Initiative (API), an extensive profile of research studies and clinical trials, comprehensive clinical, family and community service programs, a leading brain imaging research program, and strategic partnerships with numerous public and private research organizations around the world.
- Banner Sun Health Research Institute
Located in the nation’s most concentrated community of senior citizens, Banner Sun Health Research Institute (BSHRI) has played leading roles in the effort to find answers for Alzheimer’s disease, Parkinson’s disease, other age-related brain disorders, and the promotion of healthy aging. Its Brain and Body Donation Program provides the world’s most extensively shared resource of high-quality brain tissue and related clinical and neuropathological data in the fight against Alzheimer’s, Parkinson’s, and related disorders. It includes numerous research studies and clinical trials, memory and movement disorders clinics, comprehensive family and community service programs, and close working relationships with other research organizations inside and outside of Arizona.
- Eli Lilly and Company
Lilly is a global health care leader that unites caring with discovery to create medicines that make life better for people around the world. We were founded more than a century ago by a man committed to creating high-quality medicines that meet real needs, and today we remain true to that mission in all our work. Across the globe, Lilly employees work to discover and bring life-changing medicines to those who need them, improve the understanding and management of disease, and give back to communities through philanthropy and volunteerism. To learn more about Lilly, please visit us at lilly.com and lilly.com/newsroom.
- Grupo de Neurociencias de Antioquia
Grupo de Neurociencias de Antioquia (GNA), at the University of Antioquia in Medellín, is ranked as one of the leading research programs in Colombia. For more than three decades, it has characterized the world’s largest number of persons with autosomal dominant Alzheimer’s disease and other neurogenetic disorders. Its research cohorts, studies, and collaborations have had a major impact on the early detection and tracking of Alzheimer’s and the accelerated evaluation of prevention therapies.
- Massachusetts General Hospital
Massachusetts General Hospital, founded in 1811, is the original and largest teaching hospital of Harvard Medical School. The MGH Research Institute conducts the largest hospital-based research program in the nation, with an annual research budget of more than $1 billion and comprises more than 8,500 researchers working across more than 30 institutes, centers and departments. In August 2019 the MGH was once again named #2 in the nation by U.S. News & World Report in its list of "America’s Best Hospitals."