Alzheimer’s disease/Dementia Screening Profile Blood Test

What is the Alzheimer’s Disease/Dementia Screening Profile - Blood Test?

The Alzheimer’s disease/dementia screening profile is a blood test that looks for specific proteins in your bloodstream that are linked to brain changes associated with Alzheimer’s disease. It measures two key markers, plasma p-Tau 217 and beta-amyloid 1-42, along with their ratio. Together, these reflect the presence of amyloid plaques and neurofibrillary tangles in the brain, which are the defining biological features of Alzheimer’s disease.

This test is indicated for adults aged 50 years and older who are experiencing signs of cognitive decline and are being evaluated for Alzheimer’s disease. The combined ratio of p-Tau 217 and beta-amyloid 1-42 has demonstrated more than 90% accuracy in distinguishing Alzheimer’s disease from other types of dementia, and shows strong agreement with amyloid PET imaging results.

A small blood sample drawn from a vein in your arm is all that is needed. Compared to a spinal tap or a PET brain scan, this blood test offers a far more accessible and less invasive way to support early assessment of Alzheimer’s disease.

What Does the Alzheimer’s Disease/Dementia Screening Profile - Blood Test Measure?

This profile measures three closely related markers that together provide a more complete and accurate picture of Alzheimer’s-related brain changes:

• Plasma p-Tau 217: This measures the level of phosphorylated tau protein circulating in your blood. Elevated p-Tau 217 levels are strongly linked to the formation of neurofibrillary tangles in the brain, one of the hallmark changes seen in Alzheimer’s disease.
• Beta-Amyloid 1-42: This measures the concentration of a specific amyloid protein fragment. When amyloid begins to accumulate as plaques in the brain, its level in the blood tends to fall. Lower beta-amyloid 1-42 levels in the blood are therefore associated with Alzheimer’s disease pathology.
• Plasma p-Tau 217/Beta Amyloid 1-42 Ratio: The ratio of these two markers together delivers greater diagnostic accuracy than either marker measured alone. A higher ratio points to a stronger likelihood of Alzheimer’s disease-related changes in the brain and aligns closely with what is seen on amyloid PET scans.

Alzheimer’s Disease/Dementia Screening Profile - Blood Test: Who Needs It and Why It’s Done

What Symptoms May Call for an Alzheimer’s Disease/Dementia Screening Profile - Blood Test?

Your doctor may recommend this test if you or a family member is showing signs of cognitive decline or memory-related changes:

• Progressive memory loss, such as repeatedly forgetting recent conversations, events, or appointments
• Difficulty finding words or following a conversation
• Confusion about time, date, or familiar places
• Trouble making decisions, solving everyday problems, or planning tasks
• Unexplained changes in mood, behaviour, or personality
• Increasing difficulty managing day-to-day activities independently

Who Should Get an Alzheimer’s Disease/Dementia Screening Profile - Blood Test?

• Adults aged 50 years and above who are experiencing signs or symptoms of cognitive decline
• Individuals currently undergoing a formal assessment for Alzheimer’s disease or related dementia
• People whose doctor needs to distinguish Alzheimer’s disease from other forms of dementia
• Patients with a family history of early-onset Alzheimer’s disease who are now showing early symptoms
• Individuals for whom more invasive investigations such as a spinal tap or PET scan are not suitable or accessible

Why is an Alzheimer’s Disease/Dementia Screening Profile - Blood Test Done?

This test gives your doctor a reliable, non-invasive way to assess whether Alzheimer’s-related brain changes are likely to be contributing to your symptoms. With over 90% accuracy in differentiating Alzheimer’s disease from other dementias, the results support earlier clinical decisions and more personalised care planning for you or your loved one.

Importance of Alzheimer’s Disease/Dementia Screening Profile - Blood Test

Alzheimer’s disease is a progressive condition, and early identification of its underlying pathology can significantly influence the course of care. Symptoms of Alzheimer’s often overlap with those of other dementias, making accurate differentiation essential for the right treatment approach.

The plasma p-Tau 217/Beta Amyloid 1-42 ratio offers clinicians one of the most powerful blood-based tools currently available for Alzheimer’s assessment. Its performance outstrips standalone biomarkers and shows strong concordance with amyloid PET imaging, which is among the most reliable but expensive and radiation-based methods for detecting Alzheimer’s brain changes.

For patients and families, this means a meaningful step forward in assessment is now possible through a simple blood draw at a diagnostic laboratory. Early results can guide timely referrals, enable personalised disease risk assessment, and help families plan ahead with greater clarity and confidence.

Alzheimer’s Disease/Dementia Screening Profile - Blood Test Booking and Reports – Metropolis Healthcare

How to Book the Alzheimer’s Disease/Dementia Screening Profile - Blood Test and Get Your Reports?

1. Simple Online Booking
   Booking can be done through the Metropolis Healthcare App or website. Select the Alzheimer’s Disease/Dementia Screening Profile - Blood Test, choose a convenient time slot, and provide your address for a blood test at home. You can also visit the nearest Metropolis Lab if you prefer to give the sample directly at the Lab.
2. Safe Home Sample Collection
   Our trained phlebotomists ensure timely collection of your sample while strictly following all safety and hygiene protocols.
3. Sample Tracking Updates
   Stay informed at every step. From collection to testing, you can track your sample directly through the Metropolis Healthcare website.
4. Accurate Laboratory Testing
   Your sample is processed at our NABL and CAP accredited laboratories, where expert technicians ensure accurate results.
5. Quick and Easy Reports
   Receive your test reports promptly via email, WhatsApp, or by downloading them directly from the Metropolis Healthcare website or app.

Is Home Sample Collection for Alzheimer’s Disease/Dementia Screening Profile - Blood Test Available Near You?

Yes, Metropolis Healthcare offers home sample collection for the Alzheimer’s Disease/Dementia Screening Profile - Blood Test. Our trained phlebotomists visit your home at a time that suits you, following strict safety and hygiene protocols throughout. This means you can avoid the effort of a hospital visit while ensuring professional and reliable sample collection from the comfort of your home.

In How Much Time Will I Get the Alzheimer’s Disease/Dementia Screening Profile - Blood Test Report?

Reports are usually available same day once the sample reaches the lab.
Note: Reporting time may vary based on your location.

Where Can I See or Get Alzheimer’s Disease/Dementia Screening Profile - Blood Test Results?

Test results from Metropolis Healthcare can be accessed through multiple convenient channels. You can log in to the Metropolis website using your credentials or use the Metropolis Healthcare App to view and download your reports. Additionally, test reports are sent via email or WhatsApp and you also have the option to collect a physical copy directly from the lab.

How Should You Prepare for an Alzheimer’s Disease/Dementia Screening Profile - Blood Test?

This test requires minimal preparation. Follow these steps before your appointment to help ensure accurate results:

• No fasting required: You can eat and drink normally before the test.
• Bring your medical history: Clinical history is essential for accurate result interpretation. Bring a written summary of your symptoms, any previous cognitive assessments, and relevant medical records.
• Medication review: Inform your doctor about all medicines, supplements, and over-the-counter treatments you are currently taking, as certain medications may affect biomarker levels.
• Normal hydration: Drink water as you normally would. Staying adequately hydrated is good practice before any blood test.
• Advance appointment only: Walk-in testing is not available for this profile. Please book your appointment through the Metropolis website, app, or call centre before your visit.

How Is an Alzheimer’s Disease/Dementia Screening Profile - Blood Test Done? (Step-by-Step Procedure)

The test is performed using a simple, standard blood collection process:

• Preparation: A tourniquet is tied around your upper arm to make the vein more visible.
• Cleaning: The puncture site is cleaned with an antiseptic solution.
• Sample Collection: A sterile needle is used to draw 3 ml of blood into an EDTA tube.
• Completion: The needle is removed, and a bandage is applied to the site.
• Processing: The plasma is separated and analysed using Chemiluminescence Immunoassay (CLIA) to measure p-Tau 217, beta-amyloid 1-42, and their ratio.

Conditions That May Affect Alzheimer’s Disease/Dementia Screening Profile - Blood Test Accuracy

Several factors may influence the accuracy or interpretation of your results:

• Kidney function: Impaired kidney function can affect the clearance of tau and amyloid proteins from the blood, potentially altering biomarker levels independent of any brain disease.
• Other neurological conditions: Conditions such as Parkinson’s disease, traumatic brain injury, or frontotemporal dementia can also affect tau and amyloid levels, making clinical context essential for accurate interpretation.
• Age: Biomarker levels naturally change with age. Your doctor will always interpret results in relation to your age and overall clinical picture.
• Current medications: Certain medicines may influence biomarker concentrations in the blood. Always provide a full and accurate list of your medications before the test.
• Incomplete clinical history: Because result interpretation depends heavily on your clinical context, an incomplete or inaccurate medical history may affect how your results are assessed.

Diseases That an Alzheimer’s Disease/Dementia Screening Profile - Blood Test Can Help Detect

• Alzheimer’s Disease: The primary condition this test is designed to assess. An elevated p-Tau 217/Beta Amyloid 1-42 ratio supports the likelihood of Alzheimer’s disease pathology in adults with cognitive decline.
• Mild Cognitive Impairment due to Alzheimer’s Disease: Identifies individuals in the early stages of cognitive change where underlying Alzheimer’s pathology may already be developing, even before full dementia sets in.
• Non-Alzheimer’s Dementias: Helps your doctor distinguish Alzheimer’s disease from other dementias such as frontotemporal dementia or Lewy body dementia, enabling more targeted diagnosis and care.
• Neurodegenerative Disease Monitoring: Assists in tracking biological changes over time in individuals who are at high risk of neurodegeneration or have already been diagnosed with a cognitive condition.