Lumipulse Blood Biomarker Test for Diagnosis of Alzheimer Disease

The Lumipulse G pTau217/beta-amyloid 1–42 plasma ratio assay (Fujirebio Diagnostics, Sweden) is a blood test used to assist in the diagnosis of Alzheimer disease. The Lumipulse assay was approved by the US Food and Drug Administration (FDA) in May 2025 as the first blood test to aid in the detection of amyloid plaques in patients 55 years and older with early signs of Alzheimer disease.¹ FDA approval was based on the test being deemed substantially equivalent to the Lumipulse G beta-amyloid ratio cerebrospinal fluid (CSF) assay, which was approved in 2022 for the same indication.^2,3

The Lumipulse blood assay was evaluated in a cross-sectional study in Sweden, which included 1,213 individuals recruited from primary care and specialty dementia care settings from 2020 to 2024.⁴ Participants were experiencing varying degrees of memory loss ranging from subjective concerns to major cognitive impairment. The study used predefined blood biomarker cutoff values to evaluate whether blood testing could aid in the diagnosis of Alzheimer disease compared with CSF testing.

Samples were collected initially as a single batch and then biweekly to assess consistency and stability of measurements. The investigators used two cutoff approaches: a single positive or negative cutoff set at 90% specificity, and two cutoffs set with an upper and lower limit between which results were deemed uncertain. As previously determined, a CSF amyloid-beta biomarker cutoff value of 0.072 pg/mL or tau biomarker cutoff of 11.42 pg/mL indicates amyloid plaque. Diagnosis of Alzheimer disease pathology required a positive result on Lumi-pulse CSF testing or a positron emission tomography (PET) scan showing amyloid plaques for those unable to undergo a lumbar puncture. The secondary outcome was detection of clinical Alzheimer disease in conjunction with a positive finding on Alzheimer blood biomarker testing or PET scan.

The study showed that clinical diagnosis in the primary and secondary care settings was significantly more accurate when combined with the Lumipulse blood assay result (Table 1).⁴ Data from the Lumipulse blood assay (single batch and the biweekly results) were analyzed with a logistic regression model, demonstrating areas under the curve of 0.96 and 0.97 for primary and secondary care, respectively. This shows the ability of the Lumipulse blood assay to predict the presence of amyloid plaques on a PET scan, which was the basis for FDA approval.