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Abstract

Background

The adoption of Alzheimer's disease (AD) biomarkers in clinical practice is expected to increase following recent approval of disease-modifying therapies. Fully automated immunoassays, Elecsys platform, offer convenience and enhanced reliability.

Objective

This study was performed to evaluate the performance of the Elecsys assay in a Korean clinical setting, comparing its effectiveness to ELISA for detecting amyloid-PET positivity.

Methods

Cerebrospinal fluid (CSF) Aβ₄₂, pTau₁₈₁, tTau, pTau₁₈₁/Aβ₄₂, and tTau/Aβ₄₂ were evaluated using Elecsys kits on a Cobas e 411 analyzer and manual Innotest ELISA with paired frozen samples (n = 118) from subjects with cognitive status ranging from unimpaired to mild cognitive impairment and dementia.

Results

Strong linear correlations were observed between Elecsys- and ELISA-measured Aβ₄₂, pTau₁₈₁, and tTau levels. Receiver operating characteristic-based cutoff points for pTau₁₈₁/Aβ₄₂ (0.0252) and tTau/Aβ₄₂ (0.258) in Elecsys demonstrated the highest areas under the curve (0.97 and 0.96) and predictive values (96.6% for both) for detecting amyloid-PET abnormalities. No cases of abnormal amyloid PET status were found without concurrent abnormal CSF biomarkers when considering Elecsys Aβ₄₂ and the pTau₁₈₁/Aβ₄₂ ratio simultaneously. In addition, previously established cutoffs for combined ratios effectively differentiated amyloid PET status in our samples.

Conclusions

This study demonstrated the utility of Elecsys-measured CSF AD biomarkers in agreement with amyloid-PET classification in the Korean population. The pTau₁₈₁/Aβ₄₂ and tTau/Aβ₄₂ ratios were the most accurate in detecting amyloid-PET (+), with Elecsys showing higher accuracy than ELISA. The study also supported the applicability of common cutoffs from Western countries for these biomarkers in our samples.

Keywords

Alzheimer's disease amyloid PET biomarkers cerebrospinal fluid cutoffs Elecsys ELISA method comparison

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Comparative analysis of Elecsys and ELISA for differentiating amyloid-PET status in a Korean memory clinic based on cerebrospinal fluid biomarkers

Abstract

Background

Objective

Methods

Results

Conclusions

Keywords

Get full access to this article

References

Supplementary Material