Abstract: SA-PO0650
Serum Galactose-Deficient IgA1 in IgAN: Cross-Sectional Comparison of Two Enzyme-Linked Immunosorbent Assays (ELISAs) Against Clinical and Histologic Severity in an Indian Cohort
Session Information
- Glomerular Diseases: Clinical, Outcomes, and Therapeutics Research - Other
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
- Kalva, Venkat Praneeth Reddy, Asian Institute of Gastroenterology, Hyderabad, Telangana, India
- Tanwar, Sonam, Asian Institute of Gastroenterology, Hyderabad, Telangana, India
- Prathyusha, Bollam, Asian Institute of Gastroenterology, Hyderabad, Telangana, India
- Kumari, Pallavi, Asian Institute of Gastroenterology, Hyderabad, Telangana, India
- Kshatry, Sai Sindhu Singh, Asian Institute of Gastroenterology, Hyderabad, Telangana, India
- Veeranki, Vamshidhar, Asian Institute of Gastroenterology, Hyderabad, Telangana, India
- Reddy, Sujith, Asian Institute of Gastroenterology, Hyderabad, Telangana, India
- Keithi Reddy, Sai Ram Reddy, Asian Institute of Gastroenterology, Hyderabad, Telangana, India
Background
Galactose-deficient IgA1 (Gd-IgA1) is central to the pathogenesis of IgA nephropathy (IgAN), but its utility as a serum severity marker remains uncertain. Different ELISA platforms are used, yet their associations with clinical and histologic severity have not been well characterized in Indian IgAN cohorts.
Methods
We performed a single-center cross-sectional analysis of two independent IgAN cohorts evaluated with different serum Gd-IgA1 ELISA platforms: Reliant Lectin-based assay (Kit A) and a KM55 monoclonal antibody-based assay (Kit B). The primary analysis included patients with definite biopsy-proven primary IgAN. Serum was obtained at baseline before immunosuppressive therapy. Associations between Gd-IgA1 and baseline creatinine, pre-treatment urine protein-to-creatinine ratio (UPCR), and interstitial fibrosis/tubular atrophy (IFTA, %) were assessed by Spearman correlation, separately for each assay.
Results
The Kit A cohort comprised 29 patients with definite primary IgAN (median age 42 y; 17 M/12 F); paired creatinine, UPCR, and IFTA data were available in 29, 22, and 28 patients. The Kit B cohort comprised 73 patients (median age 41 y; 51 M/22 F); paired data were available in 45, 38, and 52 patients. Median Gd-IgA1 was 2650 U/mL (IQR 1405–4090) in Kit A and 2162 U/mL (IQR 1380–4350) in Kit B. In Kit A, Gd-IgA1 correlated positively with creatinine (rho=0.376, p=0.045) and UPCR (rho=0.513, p=0.015), but not with IFTA (rho=0.154, p=0.435). In Kit B, associations with creatinine (rho=0.128, p=0.401), UPCR (rho=−0.004, p=0.979), and IFTA (rho=0.139, p=0.325) were weak and non-significant.
Conclusion
In this Indian IgAN cohort, Gd-IgA1 measured by Reliant Lectin-based ELISA showed significant cross-sectional associations with baseline functional severity—most prominently proteinuria—whereas the KM55 antibody-based assay showed weak or absent associations. Neither assay correlated with chronic histologic injury (IFTA). Given the modest sample size, absence of paired head-to-head comparison, and cross-sectional design, findings are exploratory and assay-dependent. Larger longitudinal studies with paired measurement on both platforms are needed to determine whether assay-specific Gd-IgA1 adds prognostic value beyond established clinical and histologic parameters.
Acknowledgment
We sincerely acknowledge the Departments of Nephrology and Biochemistry, AIG Hospitals, Gachibowli, Hyderabad, for their academic, clinical, and laboratory support in conducting this study. We thank the faculty, clinical research team, laboratory personnel, and renal pathology team for their contributions to patient evaluation, serum Gd-IgA1 testing, data collection, and biopsy assessment.
Funding/Disclosures: This study received no external funding and had no sponsors