Freeze

This documentation pertains to the May 2025 Freeze of the CSF Amprion - San Diego dataset.

Origin

These CSF assays come from the laboratory of Amprion Inc - San Diego.

Sample Selection

Samples stored in Sarstedt cryovials were prioritized. Additional samples stored in other tube types were then analyzed. 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 834 observations on 568 participants (338 ADRC; 230 WRAP; 345 female; 87 URG; 70 MCI and 64 Dementia at first visit; 69 MCI and 68 Dementia at last visit; <5 participant(s) are aged 90+, of those not: mean first and last ages of 65.4 and 66.5, respectively; mean first and last days since baseline of 2176 and 2614, respectively).

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

Analytes

Alpha synuclein [Amprion alpha synuclein seed amplification assay (aSyn SAA)]

Detection

Samples were run in triplicate. Samples in which no seeding reaction occurred are classified as Not Detected. Those in which a seeding reaction occurred in all replicates are subdivided into Detected-1 (profile consistent with neuronal synuclein disease) and Detected-2 (profile consistent with multiple system atrophy). Samples in which a seeding reaction occurred in only two of the three replicates are classified as Indeterminate. Samples lacking sufficient quantity are classified as QNS.

Methods

A full description of the methods for the aSyn SAA assay can be found here:

Concha-Marambio L, Pritzkow S, Shahnawaz M, Farris CM, Soto C. Seed amplification assay for the detection of pathologic alpha-synuclein aggregates in cerebrospinal fluid. Nat Protoc. 2023;18(4):1179-1196. doi:10.1038/s41596-022-00787-3. Epub 2023 Jan 18. PMID: 36653527; PMCID: PMC10561622.

A description of the present algorithm for classifying results can be found here:

Bellomo G, Toja A, Paolini Paoletti F, et al. Investigating alpha-synuclein co-pathology in Alzheimer's disease by means of cerebrospinal fluid alpha-synuclein seed amplification assay. Alzheimers Dement. 2024;20(4):2444-2452. doi:10.1002/alz.13658. Epub 2024 Feb 7. PMID: 38323747; PMCID: PMC11032521.

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 based on this work has been published. This paper investigated the relationship between aSyn SAA and concurrent AD biomarkers, clinical characteristics, and cognitive trajectories.

Jonaitis EM, MacLeod K, Lamoureux J, et al. Misfolded a-synuclein co-occurrence with Alzheimer's disease proteinopathy. Alzheimers Dement. 2025;21(5):e70205. doi:10.1002/alz.70205.

For further details or questions, please contact Rachel Studer or Ramiro Rea Reyes.

See Also

Biofluids Data Documentation

Document History