Abstract: TH-PO406
Reproducibility of the SOMAscan Proteomic Assay in CKD: A Pilot Study in the Chronic Renal Insufficiency Cohort (CRIC) for the CKD Biomarkers Consortium
Session Information
- CKD: Risk Scores and Translational Epidemiology
November 07, 2019 | Location: Exhibit Hall, Walter E. Washington Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: CKD (Non-Dialysis)
- 2101 CKD (Non-Dialysis): Epidemiology, Risk Factors, and Prevention
Authors
- Dubin, Ruth F., UCSF, San Francisco, California, United States
- Deo, Rajat, University of Pennsylvania, Philadelphia, Pennsylvania, United States
- Ren, Yue, University of Pennsylvania, Philadelphia, Pennsylvania, United States
- Shou, Haochang, University of Pennsylvania, Philadelphia, Pennsylvania, United States
- Feldman, Harold I., University of Pennsylvania, Philadelphia, Pennsylvania, United States
- Rhee, Eugene P., Massachusetts General Hospital, Newton, Massachusetts, United States
- Coresh, Josef, Welch Center for Prevention, Epidemiology & Clinical Research, Baltimore, Maryland, United States
- Kimmel, Paul L., National Institute of Diabetes and Digestive Kidney Diseases (NIDDK), Bethesda, Maryland, United States
- Ganz, Peter, University of California, San Francisco, San Francisco, California, United States
Background
The Slow Off-rate Modified Aptamer proteomic assay (SOMAscan) is a transformative tool used increasingly in medical research as it affords the opportunity to measure 4,933 unique proteins in 150µl of plasma. In prior studies, mostly outside of the setting of chronic kidney disease (CKD), these assays have low levels of analytical variability, with median inter- and intra-assay coefficients of variation (CV) of 4–6%. Whether the biochemical alterations present in CKD impact the assay’s precision is unknown. We examined the reproducibility of these assays in participants with CKD.
Methods
Cryopreserved blinded split duplicate plasma samples from 24 CRIC participants were assayed at SomaLogic (Boulder, CO). Among these 24, 8 were from each of CKD Stages IIIa, IIIb, and IV. Within each stage, 4 had diabetes, and 4 had history of CVD. Using the SOMAscan v.4, 4933 unique proteins were quantified in each paired sample in fluorescent units.
Results
Prior to unblinding, 1 sample was excluded for having a technical error. For the remaining 23 paired samples, the median intra-assay CV for all proteins was 7%; 95.6% of all 4,993 proteins had CV ≤10% and 99.8% had a CV ≤20%. The distribution of CV’s did not differ by CKD stage (Figure).
Conclusion
Measurement of 4,993 unique proteins with SOMAscan in plasma samples of patients with CKD was achieved with low levels of analytical variability. These data demonstrate that the SOMAscan assay is suitable for large-scale proteomic studies of individuals with CKD.
Funding
- NIDDK Support