ASN's Mission

To create a world without kidney diseases, the ASN Alliance for Kidney Health elevates care by educating and informing, driving breakthroughs and innovation, and advocating for policies that create transformative changes in kidney medicine throughout the world.

learn more

Contact ASN

1401 H St, NW, Ste 900, Washington, DC 20005

email@asn-online.org

202-640-4660

The Latest on X

Kidney Week

ASN / Education & Meetings / Kidney Week /

Please note that you are viewing an archived section from 2021 and some content may be unavailable. To unlock all content for 2021, please visit the archives.

Abstract: PO2269

Comparison of Two Immunoassay Technologies for Plasma Biomarker Measurement

Session Information

Category: CKD (Non-Dialysis)

  • 2101 CKD (Non-Dialysis): Epidemiology, Risk Factors, and Prevention

Authors

  • Schmidt, Insa Marie, Boston Medical Center, Boston, Massachusetts, United States
  • Colona, Mia, Boston Medical Center, Boston, Massachusetts, United States
  • Srivastava, Anand, Northwestern University Feinberg School of Medicine, Chicago, Illinois, United States
  • Sabbisetti, Venkata, Brigham and Women's Hospital, Boston, Massachusetts, United States
  • Bonventre, Joseph V., Brigham and Women's Hospital, Boston, Massachusetts, United States
  • Waikar, Sushrut S., Boston Medical Center, Boston, Massachusetts, United States
Background

Anti-double-stranded DNA (anti-dsDNA) antibodies in autoimmune diseases such as systemic lupus erythematosus (SLE) may interfere with immunoassay technologies that use oligonucleotide-based antibodies (Olink) or aptamers (SomaScan). In this study, we compare measurements of plasma kidney injury molecule-1 (KIM-1), a well-known marker of tubular injury, across two different immunoassay technologies in patients with and without SLE.

Methods

We measured plasma KIM-1 levels in 444 individuals enrolled into a prospective, observational cohort study of patients with chronic kidney disease using microbead-based sandwich ELISA and the proximity extension assay (PEA, Olink). The PEA uses oligonucleotide-labeled antibodies that bind to the target protein. We investigated differences in plasma KIM-1 measurements between the two assays in individuals with SLE (n=68) and individuals with other diseases than SLE (n=376) using Bland-Altman plots and Spearman correlation coefficients.

Results

Mean eGFR was 85.2±37 and 52.3±33 ml/min/1.73m2 and the median proteinuria (IQR) was 1.5 (0.7, 3.2) and 1.7 (0.4, 4.2) g/g creatinine in individuals with and without SLE, respectively. The correlation between paired plasma KIM-1 measurements from both assays was 0.7 (p<0.001) in individuals with SLE and 0.9 (p<0.001) in individuals with other diseases than SLE (Figure 1A). The Bland-Altman plots show the bias between the mean differences in plasma KIM-1 in individuals with and without SLE, indicating that the bias in measurements was significantly greater in those with than without SLE (-2.8 vs. -3 units, p=0.008, Figure 1B).

Conclusion

Anti-dsDNA antibodies in SLE may interfere with measurements by oligonucleotide-labeled antibodies.

Figure 1.

Funding

  • NIDDK Support