IgA nephropathy and IgA vasculitis with nephritis have a shared feature involving galactose-deficient IgA1-oriented pathogenesis

Kidney Int. 2018 Mar;93(3):700-705. doi: 10.1016/j.kint.2017.10.019. Epub 2018 Jan 10.


Galactose-deficient IgA1 has been proposed as an important effector molecule in IgA nephropathy (IgAN). We previously showed that the galactose-deficient IgA1-specific monoclonal antibody KM55 can detect circulating galactose-deficient IgA1 in patients with IgAN, enabling us to study the molecular roles of galactose-deficient IgA1. Herein, we further examined the pathophysiological significance of galactose-deficient IgA1 in glomerular deposits of patients with IgAN by immunohistochemistry using KM55. Immunostaining of galactose-deficient IgA1 with KM55 was performed in paraffin-embedded sections of renal biopsy specimens from 48 patients with IgAN and 49 patients with other renal diseases such as lupus nephritis, HCV-related nephropathy, IgA vasculitis with nephritis (IgA-VN), and membranous nephropathy. Glomerular galactose-deficient IgA1 was specifically detected in IgAN and IgA-VN but not in the other renal diseases. Galactose-deficient IgA1 was localized predominantly in the mesangial region as IgA deposition. However, galactose-deficient IgA1 was not detected in patients with lupus nephritis accompanied by glomerular IgA deposition. Thus, our study strongly suggests that IgAN and IgA-VN have a shared feature regarding galactose-deficient IgA1-oriented pathogenesis.

Keywords: IgA nephropathy; IgA vasculitis; renal biopsy.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antibodies, Monoclonal / immunology
  • Biopsy
  • Fluorescent Antibody Technique
  • Galactose / blood
  • Galactose / deficiency*
  • Glomerulonephritis, IGA / blood*
  • Glomerulonephritis, IGA / diagnosis
  • Glomerulonephritis, IGA / immunology
  • Humans
  • Immunoglobulin A / blood
  • Immunoglobulin A / immunology*
  • Kidney Glomerulus / chemistry*
  • Kidney Glomerulus / immunology
  • Kidney Glomerulus / pathology
  • Microscopy, Fluorescence
  • Vasculitis / blood
  • Vasculitis / diagnosis
  • Vasculitis / immunology*


  • Antibodies, Monoclonal
  • Immunoglobulin A
  • Galactose