Freeze

This documentation pertains to the May 2025 Freeze of the plasma Fujirebio Lumipulse pTau217/Amyloid Beta - Madison dataset.

Origin

These plasma assay results come from the University of Wisconsin ADRC Biomarker Lab and were analyzed using the Fujirebio Lumipulse G2100 platform.

Sample Selection

Samples are collected on an ongoing basis, starting May 3, 2021. Samples stored in Sarstedt cryovials were prioritized. Additional samples stored in other tube types were then analyzed. Samples were stored in varying tube types depending on the study and date of collection.
For detailed information, refer to the WRAP and/or ADRC pre-analytic protocols for CSF and plasma collection, available on the Wisconsin Alzheimer's Program KnowledgeBase.

Sample and Participant Characteristics

This dataset includes 1773 observations on 1241 participants (495 ADRC; 746 WRAP; 813 female; 241 URG; 81 MCI and 17 Dementia at first visit; 71 MCI and 32 Dementia at last visit; 8 participant(s) are aged 90+, of those not: mean first and last ages of 67.8 and 68.3, respectively; mean first and last days since baseline of 3909 and 4086, respectively).

Per data sharing agreements with the Oneida nation, data from Native American participants are not included in this dataset. 

Analytes

• Phosphorylated tau 217 (pTau217)
• Amyloid beta 42 (AB42)
• Amyloid beta 40 (AB40)

All the concentrations reported for these analytes are in pg/mL.

Methods

This analysis is part of an ongoing two-year collaboration with Fujirebio. Sample analysis was performed between Dec 12, 2024 and June 17, 2025. The assay used in this study was received prior to its commercial release, and as such, documentation was initially limited. However, the assay is now FDA-approved for in vitro diagnostics, and additional information is expected to become available.

All analyses were conducted following the manufacturer's instructions. Samples, calibrators, and controls were thawed to room temperature over the course of one hour. Calibrators and controls were then prepared as directed and analyzed prior to sample loading. Plasma samples were centrifuged at 2000 x g for five minutes before being loaded into the sample racks. Once acceptable calibrator and control results were confirmed according to manufacturer specifications, the samples were analyzed in single measure. For samples contained in tube types incompatible with the sample rack, the contents were transferred to 0.5 mL Sarstedt cryovials (Sarstedt Part #72.730.005) for analysis. Each batch consisted of 78 samples.

To assess reproducibility, a pooled in-house plasma sample was analyzed at both the start and end of each run. The within-batch percent coefficient of variation (%CV) was 4.0% for pTau217 (range: 0.0%-17.2%), 2.9% for AB42 (range: 0.0%-8.9%), and 3.3% for AB40 (range: 0.0%-9.6%). The between-batch %CV was 8.2% for pTau217, 6.6% for AB42, and 7.7% for AB40.

Samples were analyzed across multiple reagent, calibrator, and control lots. A formal crosswalk has not yet been performed due to limited reagent availability and the ongoing nature of the study.

Code Availability

The entire processing pipeline is available on the SMPH GitLab. For any questions, please contact Ramiro Rea Reyes(rreareyes@medicine.wisc.edu).

Funding/Acknowledgments

Papers including data obtained from these assays should acknowledge NIH R01 AG027161 (the Wisconsin Registry for Alzheimer's Prevention) and/or NIH P30 AG062715 (the Wisconsin Alzheimer's Disease Research Center).

A manuscript is currently under development under the guidance of Sterling Johnson and Henrik Zetterberg.

For further details or collaboration inquiries, please contact Julie Oomens or Ramiro Rea Reyes.

See Also

Biofluids Data Documentation

Document History