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Abstract: PO1927

Comparison of Aptamer-Based and Antibody-Based Assays for Protein Quantification in CKD

Session Information

Category: Pathology and Lab Medicine

  • 1600 Pathology and Lab Medicine

Authors

  • Lopez-Silva, Carolina, Johns Hopkins University, Baltimore, Maryland, United States
  • Surapaneni, Aditya L., Johns Hopkins University, Baltimore, Maryland, United States
  • Coresh, Josef, Johns Hopkins University, Baltimore, Maryland, United States
  • Reiser, Jochen, Rush University, Chicago, Illinois, United States
  • Appel, Lawrence J., Johns Hopkins University, Baltimore, Maryland, United States
  • Parikh, Chirag R., Johns Hopkins University, Baltimore, Maryland, United States
  • Obeid, Wassim, Johns Hopkins University, Baltimore, Maryland, United States
  • Grams, Morgan, Johns Hopkins University, Baltimore, Maryland, United States
  • Chen, Teresa K., Johns Hopkins University, Baltimore, Maryland, United States
Background

Novel aptamer-based technologies can identify over 7000 analytes per sample, offering a high-throughput alternative to traditional immunoassays in biomarker discovery. However, the specificity for distinct proteins has not been thoroughly studied in the context of chronic kidney disease (CKD).

Methods

We aimed to validate the use of SOMAscan, an aptamer-based technology, for the quantification of 8 immune activation biomarkers and cystatin C in 498 participants from the African American Study of Kidney Disease and Hypertension (AASK) using immunoassays as the gold standard.

Results

Six biomarkers (IL-8, TNFRSF1B, cystatin C, TNFRSF1A, IL-6 and suPAR) had moderate-to-high correlations (Pearson r=0.22 to 0.94, Spearman rs=0.30 to 0.98,) between SOMAscan and immunoassay measurements and three (IFN-γ, IL-10 and TNF-α) were uncorrelated (r=-0.03 to 0.10, rs=-0.03 to 0.06). Of those with moderate-to-high correlations, TNFRSF1B, cystatin C, TNFRSF1A, and suPAR were negatively correlated with iothalamate-measured GFR and associated with higher risk of ESKD. All 6 biomarkers with moderate-to-high correlations were associated with increased risk of mortality. On average, immunoassay measurements were more strongly associated with adverse outcomes than their SOMAscan counterparts (Figure).

Conclusion

SOMAscan is an efficient and relatively reliable technique for the quantification of biomarkers in the setting of CKD and for the detection of potential associations with clinical outcomes. Targeted immunoassays of candidate proteins may provide additional prognostic information.

Funding

  • NIDDK Support