Mayo Clinic Laboratories > Neurology > Alzheimer’s disease

Alzheimer’s disease

Accurate answers to guide care

The swift pace of research and discovery around Alzheimer’s disease has yielded new treatments that, more than ever before, give patients a reason to hope. Early, accurate diagnosis is important to access FDA-approved medications and improve patient care.

Our complete menu of innovative Alzheimer's disease evaluations includes both blood and cerebrospinal fluid (CSF) biomarkers to achieve a high concordance with amyloid positron emission tomography (PET) scans. Using the most up-to-date methodology — automated immunoassay with innovative instrumentation — these tests are clinically validated in our lab and optimized to reduce pre-clinical variability. Offering precision measurements and a fast time to results, our Alzheimer’s assays deliver accurate answers that can improve access to Alzheimer’s disease treatments.

6.7M

6.7 million individuals diagnosed with Alzheimer’s disease in 20231

12.7M

12.7 million individuals estimated to be diagnosed by 20501

1 in 3

1 in 3 seniors die with Alzheimer’s or other dementia1

Alzheimer’s disease Test menu

Plasma biomarker testing Plasma biomarker testing
Cerebrospinal fluid biomarker testing Cerebrospinal fluid biomarker testing

Plasma biomarker testing

Alzheimer’s disease remains a challenge to diagnose, however, heightened understanding of the role of blood biomarkers has enabled the development of noninvasive blood tests that provide a diagnostic tool to aid in the evaluation of patients presenting with mild cognitive impairment or early dementia. Our plasma-based assay evaluates for phosphorylated Tau 217 (p-Tau217), which provides the highest diagnostic accuracy and specificity for the detection of amyloid pathology.  

Key testing

Advantages

  • Noninvasive blood test with a rapid time to result (1–5 days).
  • Assesses pathological accumulation of beta amyloid in the brain by measuring the amount of phosphorylated Tau 217 (p-Tau217) in plasma.
  • Provides high diagnostic accuracy for the detection of brain amyloid pathology as assessed by amyloid PET imaging.
  • Test interpretation cutpoints have been optimized to obtain an overall 92% sensitivity and 96% specificity for the detection of abnormal amyloid pathology based on amyloid-PET positivity.
  • Uses a two-cutpoint model of result interpretation, which maximizes the overall testing accuracy.
    • A positive result is consistent with the presence of amyloid pathology and supports an Alzheimer’s disease diagnosis; a negative result indicates a reduced likelihood that an individual has neuropathological changes associated with Alzheimer’s disease; and an intermediate result cannot accurately differentiate between the presence or absence of neuropathological changes associated with Alzheimer’s disease.
    • In the case of an intermediate result, additional testing, such as amyloid PET or CSF pTau181/Aβ42 or CSF Aβ42/Aβ40 ratio, is recommended.
  • Promotes increased access to dementia evaluation and potential treatment.
  • Recommended for patients age 50 and older who present with symptoms of mild cognitive impairment or early dementia.
  • This test is NOT intended for asymptomatic patients.
  • Note: Patients with advanced chronic kidney disease may have elevated levels of p-Tau217. In these instances, careful evaluation of a positive result is required.

Mayo Clinic Laboratories also offers the following C2N Diagnostics tests

Advantages

  • Noninvasive blood test with turnaround time of 5–10 days.
  • Measures core biomarkers of Alzheimer’s disease to assess the presence of amyloid pathology in the brain.
  • Uses highly accurate liquid-chromatography-tandem mass spectrometry (LC-MS/MS), a leading analytical platform for protein quantitation,1,2 to measure Aβ42, Aβ40, p-Tau217 and non-phosphorylated Tau217 (np-Tau217).3
  • Combines two ratios — Aβ42/40 and %p-Tau217(p-Tau217/non-p-Tau217) — into a clinically and analytically validated algorithm to generate the Amyloid Probability Score 2 (APS2).
    • Analyte ratios may help mitigate differences in race and comorbidities, including chronic kidney disease.4,5
  • APS2 algorithm achieves superior performance in distinguishing amyloid PET status compared to individual biomarkers or certain biomarker ratios considered separately.3
    • Single APS2 cutpoint optimized to obtain an overall 88% sensitivity and 89% specificity. At an observed disease prevalence of 53%, the test achieves 88% overall accuracy, 90% PPV, and 87% NPV.3
  • APS2 numeric scores that approach 0 or 100 correlate with higher NPVs and PPVs, respectively.3
  • A positive result (APS2: 48–100) is consistent with a positive amyloid PET scan; it reflects a high likelihood of brain amyloid plaques, one of the neuropathological findings of Alzheimer’s disease (AD).
  • A negative result (APS2: 0–47) is consistent with a negative amyloid PET scan.3
  • Intended for patients age 55 and older with signs and symptoms of MCI or dementia.
  • This test is NOT intended for asymptomatic patients.
  • Also available with reflex to Precivity-ApoE™ test, using Mayo ID: AD2AR.

Advantages

  • Noninvasive blood test with turnaround time of 5–10 days.
  • Measures core biomarkers of Alzheimer’s disease to assess the presence of amyloid pathology in the brain.
  • Uses highly accurate liquid-chromatography-tandem mass spectrometry (LC-MS/MS), a leading analytical platform for protein quantitation,1,2 to measure amounts of Aβ42 and Aβ40 and determine the presence of apolipoprotein E (ApoE)-specific peptides to establish the APOE genotype.7
  • Combines Aβ42/40, APOE genotype, and patient age into a clinically and analytically validated algorithm to calculate the Amyloid Probability Score (APS).
  • APS algorithm achieves high diagnostic accuracy in determining amyloid PET status.7
    • Two cutpoints optimized to obtain an overall 92% sensitivity, and 77% specificity, excluding 14% of individuals in the intermediate category. At an observed prevalence of 60%, the test achieves 86% overall accuracy, 86% PPV, and 86% NPV.7
    • A high result (APS: 58–100) is consistent with a positive amyloid PET scan, and thus, a high likelihood of brain amyloid plaques.
    • A low result (APS: 0–35) is consistent with a negative amyloid PET scan.
    • An intermediate result (APS: 36–57) cannot accurately distinguish between the presence or absence of amyloid plaques.7
      • In the case of an intermediate result, additional testing, such as amyloid PET or CSF pTau181/Aβ42 or CSF Aβ42/Aβ40 ratio, is recommended.
  • Intended for patients age 55 and older with signs and symptoms of MCI or dementia.
  • This test is NOT intended for asymptomatic patients.

Highlights

Innovative Alzheimer’s disease diagnostic tool unveiled

Mayo Clinic Laboratories has marked a significant advancement in the fight against Alzheimer's disease with the introduction of an innovative diagnostic test. This noninvasive blood test accurately detects the p-Tau217 biomarker, indicative of amyloid beta accumulation in the brain. This test is set to transform the approach to Alzheimer's disease management, offering a convenient and less invasive alternative to traditional diagnostic methods.

Learn more
Noninvasive plasma biomarker testing provides faster answers: Alicia Algeciras-Schimnich, Ph.D. 

Alicia Algeciras-Schimnich, Ph.D., discusses Mayo Clinic Laboratories’ new noninvasive plasma biomarker assay for Alzheimer’s disease, an accessible, highly accurate testing option for individuals age 50 and above who are experiencing mild cognitive impairment or early dementia. Positive test results can confirm amyloid beta pathology and facilitate access to disease-modifying therapies.

Learn more

Cerebrospinal fluid biomarker testing

The results from our CSF evaluations are based on ratios of p-Tau and AB42 (Mayo ID: ADEVL) and AB42 and AB40 (Mayo ID: AMYR), which allow for greater than 90% diagnostic accuracy compared to standard assessments. We also use low-binding tubes, resulting in fewer falsely abnormal results for patients.

Key testing

Advantages

  • Uses the most up-to-date methodology (automated immunoassay).
  • Evaluates multiple biomarkers and ratios.
  • Aligns with consensus research diagnostic criteria for Alzheimer’s disease, mild cognitive impairment (MCI), and pre-clinical Alzheimer’s disease as proposed by the National Institute on Aging and Alzheimer’s Associate Research Framework.2
  • AMYR is an FDA-approved evaluation.
  • Positive result enables access to FDA-approved medications.

When to consider testing

  • For the differential diagnosis of Alzheimer’s disease versus other causes of cognitive impairment.
  • When patients present with atypical dementia symptoms.
  • To assess Alzheimer’s disease pathology in a mixed diagnosis.
  • To allow for eligibility into clinical trials.

More information

Clear results that guide treatment decisions

A diagnosis of Alzheimer’s disease can change patients' lives. Receiving a fast, definitive answer from a healthcare institution they trust can provide hope and a plan for their future. Whether it is the right treatment for symptom management, confirmation of diagnosis, or eligibility for clinical trials, we are here to provide the highest quality of care. 

Fast, cost-effective answers when you need them the most

A differential diagnosis can change treatment and improve patient care. With our testing, a patient receives the answers they need in as little as one day. They don’t have to wait weeks or months to be placed on the right treatment and start planning for their future.

A complementary solution to assist with diagnosis

Standard assessment of suspected Alzheimer's disease patients through clinical and cognitive assessment is 70%–80% accurate. By adding our Alzheimer's disease evaluations, physicians can increase diagnostic accuracy by 12%–22% to ensure they are providing the correct diagnosis and treatment for patients.

Confirm neuronal damage

For patients suspected of having Alzheimer’s disease, testing for neurofilament light chain (NfL), a generic marker of neurodegeneration, can confirm a neurodegenerative disease process. Mayo Clinic Laboratories has developed an innovative assay to test for elevated levels of NfL in the blood. Positive test results not only confirm neuronal damage but can offer insights on disease progression and prognosis to guide therapeutic decision-making.

Highlights

New Panels Help Find Cause of Rapidly Progressive Dementia: Gregg Day, M.D.

Rapidly progressive dementia (RPD) is an umbrella term covering many devasting conditions, including Creutzfeldt-Jakob disease (CJD). Gregory (Gregg) Day, M.D., explains how Mayo Clinic Laboratories' unique RPD evaluation and new CJD test help pinpoint diagnosis, to guide prognosis and treatment decisions.

Learn more
Alzheimer’s Disease and Testing Innovations: Bill Morice, M.D., Ph.D.

In this episode of “Answers From the Lab,” host Bobbi Pritt, M.D., chair of the Division of Clinical Microbiology at Mayo Clinic, is joined by William Morice II, M.D., Ph.D., CEO and president of Mayo Clinic Laboratories. They discuss testing innovations for Alzheimer’s disease and cognitive impairments, and how laboratorians can responsibly help shape the future of healthcare.

Learn more
Innovative Alzheimer’s disease diagnostic tool unveiled

Mayo Clinic Laboratories has marked a significant advancement in the fight against Alzheimer's disease with the introduction of an innovative diagnostic test. This noninvasive blood test accurately detects the p-Tau217 biomarker, indicative of amyloid beta accumulation in the brain. This test is set to transform the approach to Alzheimer's disease management, offering a convenient and less invasive alternative to traditional diagnostic methods.

Learn more
FDA-approved test expands options for Alzheimer’s disease

Joshua Bornhorst, Ph.D., describes the new, FDA-approved Alzheimer's disease (AD) test and how it differs from Mayo Clinic Laboratories' existing AD evaluation. The laboratory will offer both tests, to ensure flexibility and options for managing clinical care.

Learn more
The Role of CSF in Alzheimer’s Disease

This "Specialty Testing" webinar will discuss Cerebrospinal fluid (CSF), which has been used in research on Alzheimer's disease for decades. Only recently, have platforms been developed to standardize measurements across laboratories.

Learn more
References
  1. Pan S, Aebersold R, Chen R, et al. Mass spectrometry based targeted protein quantification: methods and applications. J Proteome Res. 2009;8(2):787-797. doi:10.1021/pr800538n
  2. Bravo-Veyrat S, Hopfgartner G. Mass spectrometry based high-throughput bioanalysis of low molecular weight compounds: are we ready to support personalized medicine? Anal Bioanal Chem. 2022;414(1):181-192. doi:10.1007/s00216-021-03583-2
  3. Meyer MR, Kirmess KM, Eastwood S, et al. Clinical validation of the PrecivityAD2 blood test: A mass spectrometry-based test with algorithm combining %p-tau217 and Aβ42/40 ratio to identify presence of brain amyloid. Alzheimers Dement. 2024;20(5):3179-3192. doi:10.1002/alz.13764
  4. Schindler SE, Karikari TK, Ashton NJ, et al. Effect of Race on Prediction of Brain Amyloidosis by Plasma Aβ42/Aβ40, Phosphorylated Tau, and Neurofilament Light. Neurology. 2022;99(3):e245-e257. doi:10.1212/WNL.0000000000200358
  5. Pichet Binette A, Janelidze S, Cullen N, et al. Confounding factors of Alzheimer's disease plasma biomarkers and their impact on clinical performance. Alzheimers Dement. 2023;19(4):1403-1414. doi:10.1002/alz.12787
  6. Janelidze S, Barthélemy NR, He Y, Bateman RJ, Hansson O. Mitigating the associations of kidney dysfunction with blood biomarkers of Alzheimer disease by using phosphorylated tau to total tau ratios [published correction appears in JAMA Neurol. 2023 Aug 1;80(8):873]. JAMA Neurol. 2023;80(5):516-522. doi:10.1001/jamaneurol.2023.0199
  7. Hu Y, et al. (2022) Assessment of a plasma amyloid probability score to estimate amyloid positron emission tomography findings among adults with cognitive impairment. JAMA Network Open. (PMID: 35446396)
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