Blood test for Alzheimer’s could replace costly and invasive spinal taps

A new blood test for Alzheimer’s shows high accuracy in detecting biomarkers of diseases – which reduces the need for invasive spinal cranes by more than 50%.

Study: Clinical performance of the fully automated Lumipulse Plasma P-TAU217 test for mild cognitive disorders and mild dementia. Image Credit: Pickadook / Shutterstock.com

A fully automated lumipulse plasma-fosphorylored TAU 217 (P-TAU217) test has the potential for effectively diagnosing mild cognitive disorders (MCI) and mild dementia. In a recent Alzheimer and dementia Study, researchers indicate that this method may reduce more than 50% of lumbar leaky tires that are performed for diagnostic purposes.

How is Alzheimer’s disease diagnosed?

The clinical diagnosis of Alzheimer’s disease (AD) is based on the detection of amyloid beta (AP) and Tau

Previous studies have emphasized greater benefits associated with blood-based biomarkers (BBMs) compared to CSF ​​and PET for AD diagnosis. For example, blood sampling improves the convenience of test recruitment, diagnoses and monitoring of AD progression, while CSF sampling includes invasive lumbar puncture (LP) that increases the risk of bleeding, infection and nerve damage.

Of all BBMs, P-TAU217 has the potential to differentiate AD of other neurodegenerative diseases due to the significant change and the exacerbation of cortical atrophy follows over time. Although mass spectrometry is used to quantify low-stressed plasma proteins, newer automated Immunoassay techniques are needed to accurately determine plasma P-TAU217 and AP pathology.

Previous studies have confirmed the usefulness of fully automated methods, such as Fujirebio Lumipulse, in diagnostic laboratories to reduce variability in test performance. However, the effectiveness of these tests must be validated by clinical data from practice.

About the study

The current study investigated the performance of the fully automated Fujirebio Research-Use-Alleen use (RUO) Lumipulse G Plasma P-TAU217 test to determine CSF-defined AP pathology for people who are subject to lumbar puncture (LP) for Disease diagnosis in a regional specialist memory clinic (RSMC).

RSMC performs detailed cognitive/medical assessments, neuroimaging and routine laboratory tests for 400 to 500 people every year. If necessary, patients undergo CSF ​​tests to detect ad -pathology.

Standard curves and supplied calibrators were used for optimum test performance on a Lumipulse G600 II analyzer. To estimate the Inter-assay Variation Coefficient (CV), six plasma samples were analyzed twice on two separate days.

Study findings

A total of 148 participants were recruited for the current study, of which 54.1% were female with an average age of 69.4 years. About 68% of the participants were diagnosed with MCI, while 31% had mild dementia. The average time required for the initial diagnosis to confirm was around 120 days.

CSF tests estimate 60.8% of the research cohort as AP positive. The suspected etiology of AP -negative individuals was Lewy Body Disease, Frontotemporal Dementia and Vascular Cognitive Disorders. In some people who were negative for AP, neurodegenerative etiology was not clear after diagnostic tests; However, the MCI diagnosis was diagnosed for each of these participants in the study.

Plasma monster analyzes using the Lumipulse P-TAU217 test revealed that median plasma P-TAU217 levels were four times higher in Aβ-positive study participants than Aβ-negative individuals. Plasma P-TAU217 had an area under the curve (AUC) value of 0.92 in AP-positive patients.

A two-threshold approach was used to offer stricter thresholds, including in theory, only intervening results would continue with further testing. In the current analysis, 90%, 95% and 97.5% of the sensitivity/specificity thresholds for plasma P-TAU217 may have the need for more than half of the LPS superfluous.

Fewer false positive results were generated with a specificity of 90%. These people had MCI without specific neurodegenerative etiology.

Conclusions

The current study confirmed the excellent performance of the fully automated lumipulse test in detecting AP positive in a real-world clinical cohort of patients diagnosed MCI and mild dementia. All in all, these findings show that this device can be used in laboratory environments for diagnostic purposes with higher specificity and sensitivity than current analytical approaches.

In the future, the potential impact of kidney function and vascular risk factors on the performance of Plasma P-TAU217 must be assessed on a large-scale and more diverse sample.