Scientific Reports (Aug 2020)

Glomerular galactose-deficient IgA1 expression analysis in pediatric patients with glomerular diseases

  • Shinya Ishiko,
  • Tomoko Horinouchi,
  • Rika Fujimaru,
  • Yuko Shima,
  • Hiroshi Kaito,
  • Ryojiro Tanaka,
  • Shingo Ishimori,
  • Atsushi Kondo,
  • Sadayuki Nagai,
  • Yuya Aoto,
  • Nana Sakakibara,
  • China Nagano,
  • Tomohiko Yamamura,
  • Momoka Yoshimura,
  • Koichi Nakanishi,
  • Junya Fujimura,
  • Naohiro Kamiyoshi,
  • Hiroaki Nagase,
  • Norishige Yoshikawa,
  • Kazumoto Iijima,
  • Kandai Nozu

DOI
https://doi.org/10.1038/s41598-020-71101-y
Journal volume & issue
Vol. 10, no. 1
pp. 1 – 6

Abstract

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Abstract Galactose-deficient IgA1 (Gd-IgA1) is important in the pathogenesis of IgA nephropathy (IgAN). A Gd-IgA1-specific monoclonal antibody (KM55) has revealed glomerular Gd-IgA1 deposition solely in patients with IgAN and IgA vasculitis with nephritis (IgAV-N). However, this specificity is controversial and has not been demonstrated in pediatric patients. Here, we conducted double-immunofluorescence staining of IgA and Gd-IgA1 in 60 pediatric patients with various glomerular diseases. We divided patients into four groups: (1) patients with IgAN and IgAV-N (n = 23); (2) patients with immunocomplex-mediated glomerulonephritis accompanied by IgA deposition, including lupus nephritis, membranoproliferative glomerulonephritis, and membranous nephropathy (n = 14); (3) patients with other glomerular diseases involving IgA deposition, including idiopathic nephrotic syndrome (INS), oligomeganephronia, Alport syndrome, dense deposit disease, and crescentic glomerulonephritis (n = 11); and (4) patients with IgA-negative diseases including INS, membranoproliferative glomerulonephritis, membranous nephropathy, oligomeganephronia, Alport syndrome, C3 glomerulonephritis, poststreptococcal acute glomerulonephritis, and hemolytic uremic syndrome (n = 12). KM55 staining revealed Gd-IgA1-positive findings in 23/23 patients in Group 1 and 13/14 patients in Group 2, but not in patients in Groups 3 or 4. Therefore, KM55 may detect incidental IgA deposition in pediatric patients. Gd-IgA1 may be involved in the pathogenesis of these immune-related diseases; alternatively, KM55 may recognize IgA-related immunocomplexes in a non-specific manner.