The US Food and Drug Administration cleared Fujirebio Diagnostics' Lumipulse blood assay for use in evaluating adults aged 55 or older who show signs of cognitive decline. It was the first FDA-cleared in-vitro blood test intended to help clinicians diagnose Alzheimer's disease, potentially reducing reliance on brain scans and spinal-fluid collection.
The device measures pTau217 and beta-amyloid 1-42 in plasma, then calculates the ratio between them. That result correlates with whether amyloid plaques are present in the brain. Plaques are associated with Alzheimer's, although they can occur in other conditions, so the result must be considered alongside symptoms, history and other clinical findings.
Until this clearance, clinicians could assess amyloid through positron-emission tomography or tests using cerebrospinal fluid. PET imaging is expensive, takes time and involves radiation. Cerebrospinal-fluid sampling requires a lumbar puncture. A routine blood draw is less invasive and could make this stage of evaluation easier to access.
The FDA reviewed a multicentre study using plasma from 499 cognitively impaired adults. Among people whose Lumipulse result was positive, 91.7% also had amyloid detected by PET or a cerebrospinal-fluid test. Of those with a negative blood result, 97.3% were negative on the comparison methods. Fewer than one in five samples produced an indeterminate outcome.
Those figures do not make the assay a population-screening tool. The agency specified that it is intended for symptomatic patients evaluated in specialist care and is neither a stand-alone diagnosis nor a basis by itself for treatment. Clinical assessment or further testing may still be necessary, especially after an uncertain result.
False positives could lead to distress, unnecessary therapy, expense and delay in identifying the actual cause of a patient's symptoms. False negatives could postpone an effective diagnosis or prompt additional testing. The FDA highlighted both risks when explaining why clinicians must interpret the ratio in context.
The agency used its 510(k) pathway, finding the plasma test substantially equivalent to an authorised Fujirebio assay that measures a different beta-amyloid ratio in cerebrospinal fluid. Lumipulse had also received Breakthrough Device designation, which is intended to speed work on tools for serious or irreversibly debilitating conditions.
With nearly seven million Americans living with Alzheimer's and the figure projected to approach 13 million, the clearance represented a practical diagnostic advance. Its value lies in helping specialists identify amyloid pathology more conveniently, not in replacing a full medical evaluation.
Alzheimer’s progressively damages memory, reasoning and eventually basic daily functioning. Amyloid can accumulate before clear symptoms appear, which is why pathology tests can support a diagnosis. The clearance addresses that diagnostic process; it does not establish that treating or removing plaques will reverse an individual patient’s decline.
