🧠 FDA Clears First Blood-Based Diagnostic Test for Alzheimer’s Pathology

Fujirebio has received FDA 510(k) clearance for its Lumipulse® G pTau 217/β-Amyloid 1-42 Plasma Ratio test—the first blood-based in vitro diagnostic (IVD) test in the U.S. to aid in identifying amyloid pathology associated with Alzheimer’s disease. This test offers a less invasive, more accessible alternative to PET imaging or lumbar puncture for diagnosing Alzheimer’s-related changes.

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🔬 Key Highlights

Biomarker Innovation:

The test measures plasma levels of phosphorylated tau 217 (pTau 217) and β-amyloid 1-42, calculating their ratio to assess the likelihood of amyloid plaque presence—one of the core pathological features of Alzheimer’s disease.

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Strong Clinical Performance:

In a validation study of 499 cognitively impaired patients over age 50, the test achieved a 92% positive predictive value and 97% negative predictive value, demonstrating high diagnostic reliability.

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Laboratory-Ready Integration:

Designed for use on the LUMIPULSE® G1200 automated platform, the test is compatible with clinical lab workflows, supporting real-world scalability and adoption.

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Earlier, Easier Diagnosis:

By enabling Alzheimer’s-related pathology screening from a simple blood sample, the test facilitates earlier intervention, patient counseling, and potential trial enrollment for disease-modifying therapies.

1. 🧪 Blood-Based Biomarkers for Alzheimer’s: Clinical Utility and Limitations

Recent advances have made it possible to detect amyloid and tau pathology through plasma-based assays, offering a scalable alternative to CSF analysis and amyloid PET. Neurologists should understand the analytical performance, target populations, and appropriate clinical use cases—screening, differential diagnosis, and research eligibility.

2. 🧬 The pTau217/β-Amyloid 1-42 Ratio: What It Detects and Why It Matters

This ratio reflects both amyloid plaque burden and tau pathology, two hallmarks of Alzheimer’s disease. Compared to other biomarkers (like total tau, neurofilament light, or pTau181), the pTau217/β-amyloid ratio has shown high concordance with PET and autopsy-confirmed AD—a crucial distinction for disease-specific diagnosis.

3. 🧠 How Blood Tests Fit into the AT(N) Framework for AD Diagnosis

The NIA-AA “AT(N)” research framework classifies AD biomarkers by pathology: A = amyloid, T = tau, N = neurodegeneration. This test provides direct “A” and “T” evidence from blood. Neurologists should understand how to integrate this test with cognitive assessments, imaging, and functional evaluations in both primary and specialty care.

4. 🔄 Implications for Early Diagnosis and Access to Disease-Modifying Therapies

FDA-cleared blood tests enable earlier identification of AD pathology, which may be required for eligibility for new anti-amyloid monoclonal antibody treatments (e.g., lecanemab, donanemab). They also support referral triage and patient selection for clinical trials, streamlining access to personalized therapies.

5. ⚙️ Lab Readiness, Reimbursement, and Clinical Workflow Integration

While technically robust, tests like Lumipulse require specific platforms (e.g., G1200), CLIA-certified labs, and consistent protocols. Neurologists will benefit from understanding where and how the test can be ordered, expected turnaround times, payer policies, and how to explain results to patients in a diagnostic conversation.

📚 References

1. Fujirebio. (2025). Fujirebio Receives FDA Clearance for Lumipulse® G pTau 217/β-Amyloid 1-42 Plasma Ratio Test.​
   ​https://www.fujirebio.com/en/news-events/fujirebio-receives-marketing-clearance-for-lumipulser-g-ptau-217bamyloid-142-plasma​
2. Palmqvist, S., et al. (2020). Discriminative Accuracy of Plasma Phospho-tau217 for Alzheimer Disease vs Other Neurodegenerative Disorders.JAMA, 324(8), 772–781.
3. Mattsson-Carlgren, N., et al. (2021). Aβ and tau biomarkers in plasma predict development of Alzheimer’s pathology and dementia in cognitively unimpaired individuals.Brain, 144(6), 1693–1706.
4. Jack, C. R., et al. (2018). NIA-AA Research Framework: Toward a biological definition of Alzheimer’s disease.Alzheimer’s & Dementia, 14(4), 535–562.
5. Hampel, H., et al. (2021). Blood-based biomarkers for Alzheimer disease: mapping the road to the clinic.Nature Reviews Neurology, 17(11), 715–733.
6. Thijssen, E. H., et al. (2023). Plasma biomarkers for Alzheimer’s disease: Toward clinical implementation.Lancet Neurology, 22(1), 66–77.
7. Cummings, J., et al. (2023). Alzheimer’s disease drug development pipeline: 2023.Alzheimer’s & Dementia, 19(7), 2763–2780.
8. Janelidze, S., et al. (2022). Head-to-head comparison of 10 plasma phospho-tau assays in Alzheimer’s disease.Brain, 145(2), 484–500.
9. Snyder, H. M., et al. (2021). The changing landscape of Alzheimer’s disease diagnostics: moving toward earlier detection.Neuron, 109(19), 3124–3128.
10. US FDA. (2024). 510(k) Summary: Lumipulse G pTau 217/β-Amyloid 1-42 Plasma Ratio Test.​
    ​https://www.fda.gov (search: “Fujirebio 510k Alzheimer’s test”)