Abstract: PO1845
Glomerular Galactose-Deficient IgA1 Expression Analysis in Pediatric Patients with Glomerular Diseases
Session Information
- Glomerular Diseases: Clinical, Outcomes, and Trials - 1
October 22, 2020 | Location: On-Demand
Abstract Time: 10:00 AM - 12:00 PM
Category: Glomerular Diseases
- 1203 Glomerular Diseases: Clinical, Outcomes, and Trials
Authors
- Ishiko, Shinya, Kobe University Graduate School of Medicine, Kobe, Japan
- Nozu, Kandai, Kobe University Graduate School of Medicine, Kobe, Japan
- Fujimaru, Rika, Osaka City General Hospital, Osaka, Japan
- Shima, Yuko, Wakayama Medical University, Wakayama, Wakayama, Japan
- Kaito, Hiroshi, Hyogo Prefectural Kobe Children's Hospital, Kobe, Japan
- Tanaka, Ryojiro, Hyogo Prefectural Kobe Children's Hospital, Kobe, Japan
- Ishimori, Shingo, Takatsuki General Hospital, Takatsuki, Japan
- Aoto, Yuya, Kobe University Graduate School of Medicine, Kobe, Japan
- Sakakibara, Nana, Kobe University Graduate School of Medicine, Kobe, Japan
- Nagano, China, Kobe University Graduate School of Medicine, Kobe, Japan
- Horinouchi, Tomoko, Kobe University Graduate School of Medicine, Kobe, Japan
- Yamamura, Tomohiko, Kobe University Graduate School of Medicine, Kobe, Japan
- Ninchoji, Takeshi, Kobe University Graduate School of Medicine, Kobe, Japan
- Nakanishi, Koichi, University of Ryukyus, Nishihara, Japan
- Yoshikawa, Norishige, Takatsuki General Hospital, Takatsuki, Japan
- Iijima, Kazumoto, Kobe University Graduate School of Medicine, Kobe, Japan
Background
Galactose-deficient IgA1 (Gd-IgA1) has been identified as a key molecule in the pathogenesis of IgA nephropathy (IgAN). Using a Gd-IgA1-specific monoclonal antibody (KM55), glomerular Gd-IgA1 deposition has been detected in patients with IgAN and IgA vasculitis with nephritis (IgAV-N), but not other glomerular diseases. However, this specificity is controversial and there are currently no studies in pediatric cases.
Methods
We conducted a retrospective, multicenter study to examine double-immunofluorescence staining of IgA and Gd-IgA1 (KM55) in 60 pediatric patients with various glomerular diseases.
Results
Glomerular Gd-IgA1 deposition was detected in all cases of IgAN (n=17/17) and IgAV-N (n=6/6), and in patients with immunocomplex-mediated glomerulonephritis, including lupus nephritis (n=9/9), membranoproliferative glomerulonephritis (n=3/4), and membranous nephropathy (n=1/1). However, Gd-IgA1 was negative in patients with non-immune related glomerular diseases with IgA deposition, including idiopathic nephrotic syndrome (n=6/6), oligomeganephronia (n=2/2), Alport syndrome (n=1/1), dense deposit disease (n=1/1), and crescentic glomerulonephritis (n=1/1). Both IgA and Gd-IgA1 were negative in patients with idiopathic nephrotic syndrome (n=5/5), membranoproliferative glomerulonephritis, membranous nephropathy, oligomeganephronia, Alport syndrome, C3 glomerulonephritis, poststreptococcal acute glomerulonephritis, and hemolytic uremic syndrome (n=1/1 each).
Conclusion
Gd-IgA1-positivity in patients with IgAN and IgAV-N was consistent with previous reports. However, Gd-IgA1 was also positive in patients with IgA-positive immunocomplex-mediated glomerulonephritis. KM55 may have the potential to distinguish incidental IgA deposition in pediatric cases. We speculate that Gd-IgA1 may be involved in the pathogenesis of these immune-related diseases, or KM55 may recognize IgA-related immunocomplex nonspecifically.