Abstract: TH-PO0451
Evaluating Gd-IgA1 for Early Detection and Monitoring of IgAN
Session Information
- Glomerular Diseases: Clinical, Outcomes, and Therapeutics Research - IgAN
October 22, 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
- Kohmescher, Lisa, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, United States
- Rose, James E., Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, United States
- Kathman, Thelma, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, United States
- Benoit, Stefanie W., Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, United States
Group or Team Name
- Nephrology Clinical Lab
Background
IgA nephropathy (IgAN) is characterized by formation of galactose-deficient IgA1 (Gd-IgA1) containing immune complexes that accumulate within glomeruli, leading to inflammation and progressive kidney injury. Elevated serum Gd-IgA1 levels are associated with disease onset, progression, and post-transplant recurrence. However, there is currently no clinically available assay with high sensitivity and specificity for Gd-IgA1 detection. Therefore, the Cincinnati Children’s Hospital Medical Center Nephrology Clinical Laboratory sought to validate a novel high-sensitivity indirect sandwich enzyme-linked immunosorbent assay (ELISA) combining IgA capture with lectin-based detection of galactose-deficient O-glycans on IgA1.
Methods
Serum Gd-IgA1 concentrations were measured in 35 patients with biopsy-confirmed IgAN and 131 healthy controls. Testing was performed using a high-sensitivity indirect sandwich ELISA with anti-human IgA capture and biotin-labeled lectin detection of aberrantly glycosylated IgA1, followed by avidin-peroxidase colorimetric detection with tetra-methyl-benzidine measured at 450 nm. Receiver operating characteristic (ROC) analysis was performed using EP Evaluator to assess diagnostic performance. The optimal diagnostic cutoff, sensitivity, specificity, diagnostic efficiency, and area under the curve (AUC) were calculated.
Results
The IgAN cohort demonstrated higher serum Gd-IgA1 concentrations than healthy controls, with mean concentrations of 120.43 µg/mL (SD 44.88; 95% CI 75.2–247.8) versus 54.12 µg/mL (SD 24.71; 95% CI 3.3–128.7), respectively. Median concentrations were 104.40 µg/mL in IgAN patients and 46.4 µg/mL in healthy controls. ROC analysis identified an optimal diagnostic cutoff value of 83.2 µg/mL. The ROC curve demonstrated excellent diagnostic performance with an AUC of 0.950, sensitivity of 82.9%, specificity of 91.6%, and diagnostic efficiency of 89.8%.
Conclusion
This novel high-sensitivity indirect sandwich ELISA demonstrated excellent diagnostic performance for serum Gd-IgA1 detection and effectively distinguished patients with IgAN from healthy controls. These findings support the potential clinical utility of this assay for diagnosis and disease monitoring in IgAN. Further studies in larger and more diverse populations are warranted to support clinical implementation and evaluate associations with disease activity and long-term outcomes.