Freeze

This documentation pertains to Freeze 2023_May of the Quanterix/Alzpath - Gothenburg dataset.

Origin

These plasma assays come from the laboratory of Henrik Zetterberg and Kaj Blennow. 


Sample Selection

Samples were included from observations at which at least one aliquot of EDTA plasma was available for participants who had also had at least one amyloid PET scan or at least one lumbar puncture. All available observations were included for each participant.
This dataset includes 1250 observations on 422 participants (0 ADRC; 283 female; 19 URG; 10 MCI and 1 Dementia at first visit; 14 MCI and 2 Dementia at last visit; mean first and last ages of 61.8 and 66.7, respectively). Per data sharing agreements with the Oneida nation, data from Native American participants are not included in this dataset.

Analytes:

• Amyloid beta 40 [Quanterix Simoa assay]
• Amyloid beta 42 [Quanterix Simoa assay]
• Glial fibrillary acidic protein [Quanterix Simoa assay]
• Neurofilament light-chain [Quanterix Simoa assay]
• Phosphorylated tau 231 [in-house Simoa assay; Ashton et al., 2021]
• Phosphorylated tau 181 [Quanterix V2; V1 is documented in Karikari et al., 2020, but absolute levels for V2 differ]
• Phosphorylated tau 217 [AlzPath]

Detection Limits:

• Ab40: functional LLOQ = 4.08 pg/mL
• Ab42: functional LLOQ = 1.51 pg/mL
• GFAP: functional LLOQ = 11.6 pg/mL
• NfL: functional LLOQ = 1.6 pg/mL
• pTau181: functional LLOQ = 0.338 pg/mL
• pTau231: LLOQ = 2 pg/mL
• pTau217: Not yet available

Methods

A description of V1 for the pTau181 assay is in this article; however, the absolute levels for V2 are different.
Karikari TK, Pascoal TA, Ashton NJ, et al. Blood phosphorylated tau 181 as a biomarker for Alzheimer’s disease: a diagnostic performance and prediction modeling study using data from four prospective cohorts. Lancet Neurol. 2020;19(5):422-433. https://doi.org/doi:10.1016/S1474-4422(20)30071-5

A full description of the methods for the pTau231 assay can be found here:
Ashton NJ, Pascoal TA, Karikari TK, et al. Plasma p-tau231: a new biomarker for incipient Alzheimer's disease pathology. Acta Neuropathol. 2021;141(5):709-724. https://doi.org/doi:10.1007/s00401-021-02275-6

Data Sheets

Quanterix 4-plex (Ab40, Ab42, GFAP, NfL):

https://www.quanterix.com/wp-content/uploads/2020/12/Neurology-4-Plex-E-Data-Sheet-HD-X.pdf

Quanterix pTau171 V2:

https://www.quanterix.com/wp-content/uploads/2021/03/pTau-181-V2-Data-Sheet-HD-1-and-HD-X-Rev03.pdf

Data Dictionary

Funding / Acknowledgments

Papers including data obtained from these assays should acknowledge NIH R01 AG027161 (the Wisconsin Registry for Alzheimer's Prevention).