Freeze:

This documentation pertains to Freeze 2024_November of the Amprion - San Diego dataset.

Origin:

These plasma assays come from the laboratory of Amprion Inc.

Sample Selection:

Samples were included from observations at which at least one aliquot of CSF stored in a Sarstedt tube was available. All available observations were included for each participant.

This dataset includes 499 observations on 407 participants (205 ADRC; 202 WRAP; 264 female; 35 URG; 30 MCI and 6 Dementia at first visit; 33 MCI and 7 Dementia at last visit; 1 participant(s) are aged 90+, of those not: mean first and last ages of 65.5 and 65.9, respectively; mean first and last days since baseline of 3099 and 3282, 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 (synSAA)]

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 synSAA 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.

See Also

Biofluids Data Documentation

Document History