Abstract: SA-PO0809
Development and Validation of a Lectin-Based Assay for the Detection of IgG Fc Glycosylation as a Biomarker in Lupus Nephritis
Session Information
- Glomerular Diseases: Management, Evolving Strategies, and Practice-Changing Advances
October 24, 2026 | Location: Exhibit Hall A, Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Glomerular Diseases
- 1402 Glomerular Diseases: Clinical, Outcomes, and Therapeutics
Authors
- Upadhyay, Rohit, Tulane University School of Medicine, New Orleans, Louisiana, United States
- Gao, Juan, Tulane University School of Medicine, New Orleans, Louisiana, United States
- Orellana, Alexia, Tulane University School of Medicine, New Orleans, Louisiana, United States
- Wenderfer, Scott E., Baylor College of Medicine, Houston, Texas, United States
- Tsokos, George C., Beth Israel Deaconess Medical Center, Boston, Massachusetts, United States
- Bhargava, Rhea, Tulane University School of Medicine, New Orleans, Louisiana, United States
Background
Lupus Nephritis (LN) is a severe complication of systemic lupus erythematosus (SLE), and recent studies show aberrant IgG glycosylation drives podocyte injury and is a robust LN marker. Mass spectrometry (LC-MS/MS) is the primary detection method but is unsuitable clinically due to complexity and cost. We aimed to develop an assay to detect glycosylation patterns using multiple lectins.
Methods
We developed and optimized a lectin-based ELISA to detect major IgG glycans: fucose, galactose, and alpha 2,6-linked sialic acid. Lectins were selected based on glycan structures detected in a SLE cohort and differentially expressed in SLE with or without nephritis. Ninety-sixwell plates were coated with protein L. Blocking solutions were chosen from 5% BSA, deglycosylated BSA (deBSA), or Carbo-free solution. IgG standards were optimized from 0–20 μg/mL. Fucose was detected by Aleuria Aurantia Lectin (AAL), galactose by Erythrina Cristagalli Lectin (ECL), and sialic acid by Sambucus Nigra Lectin (SNA). A SLE cohort tested the assay’s ability to differentiate LN from non-renal SLE.
Results
Selected lectins generated reproducible standard curves with strong linearity. ELISA with IgG from a healthy donor and an LN patient revealed glycan differences consistent with mass spectrometry and within the dynamic range. AAL (fucose) binding did not differ among SLE subgroups; ECL (galactose) binding showed significant differences in active LN versus active non-renal SLE and quiescent disease. SNA (sialic acid) distinguished active LN from quiescent SLE but did not discriminate renal vs non-renal SLE.
Conclusion
The lectin-ELISA detects IgG glycosylation more cost-effectively and clinically practically than mass spectrometry. Validation data support ECL binding assays to aid LN diagnosis and monitoring.
Funding
- Other NIH Support