Significance of glomerular deposition of C3c and C3d in IgA nephropathy

Am J Nephrol. Mar-Apr 2000;20(2):122-8. doi: 10.1159/000013568.


Background: Complement activation plays an important role in the pathogenesis of IgA nephropathy. The clinico-pathological significance of the glomerular deposition of complement breakdown products, C3c and C3d in IgA nephropathy remains to be clarified.

Methods: We examined the relationship between glomerular staining patterns of C3c and C3d and clinico-pathological findings with 163 patients with IgA nephropathy. Renal biopsy specimens were stained with C3c and C3d by immunofluorescence, and patients were divided into the following two groups: the intensity of C3c deposition stronger than C3d deposition, or equal to it (group A); the intensity of C3d deposition stronger than C3c deposition (group B).

Results: In group A, the incidence of severe hematuria (over 20 urinary red blood cells in high-power field microscope (x400)) or of higher urinary fibrinogen degenerated products (over 0.1 microg/ml) was significantly higher than that in group B. In addition, group A showed a significant decrease in the glomerular filtration rate. Group A also showed a significantly higher incidence of glomerular endocapillary proliferation than in group B.

Conclusion: These findings suggest that the glomerular deposition of C3c is associated with the inflammatory active phase of glomeruli in IgA nephropathy.

Publication types

  • Comparative Study
  • Multicenter Study

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Biomarkers
  • Biopsy
  • Cell Division
  • Child
  • Child, Preschool
  • Complement Activation / physiology*
  • Complement C3c / metabolism*
  • Complement C3d / metabolism*
  • Female
  • Fluorescent Antibody Technique
  • Glomerular Filtration Rate
  • Glomerular Mesangium / metabolism*
  • Glomerular Mesangium / ultrastructure
  • Glomerulonephritis, IGA / complications
  • Glomerulonephritis, IGA / metabolism*
  • Glomerulonephritis, IGA / pathology
  • Hematuria / etiology
  • Hematuria / pathology
  • Hematuria / urine
  • Humans
  • Immunoglobulins / metabolism
  • Male
  • Middle Aged
  • Severity of Illness Index
  • Urinalysis


  • Biomarkers
  • Immunoglobulins
  • Complement C3c
  • Complement C3d