Abnormal IgA glycosylation in Henoch-Schönlein purpura restricted to patients with clinical nephritis

Nephrol Dial Transplant. 1998 Apr;13(4):930-4. doi: 10.1093/ndt/13.4.930.

Abstract

Background: Glomerular deposition of IgA1 is a common feature of Henoch-Schönlein purpura, and is indistinguishable from that seen in IgA nephropathy. Serum IgA1 is abnormally O-glycosylated in IgA nephropathy, and this may contribute to mesangial IgA1 deposition and the development of glomerular injury. This altered O-glycosylation of IgA1 can be detected by its increased binding to the lectin Vicia villosa.

Methods: To investigate whether IgA1 is abnormally glycosylated in Henoch-Schönlein purpura, the binding of Vicia villosa lectin to serum IgA1 was studied in the following subject groups: IgA nephropathy; adults and children with Henoch-Schönlein purpura and nephritis; children with clinically diagnosed Henoch-Schönlein purpura but no renal involvement; adults and children with non-IgA associated glomerulonephritis; and matched controls.

Results: The abnormality of lectin binding seen in IgA nephropathy was also found in both adults and children with Henoch-Schönlein purpura with nephritis. However, the lectin binding of serum IgA1 from children with Henoch-Schönlein purpura lacking renal involvement did not differ from controls, and similarly, no abnormality of lectin binding was seen in patients with non-IgA associated glomerulonephritis.

Conclusions: These data indicate that the abnormality of IgA1 O-glycosylation seen in IgA nephropathy is also found in Henoch-Schönlein purpura, but only in those subjects with renal involvement, while IgA1 O-glycosylation is normal in patients with other forms of renal disease. These findings lend strong support to a role for altered IgA1 O-glycosylation in the pathogenesis of IgA-associated glomerular disease.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Amino Acid Sequence
  • Child
  • Child, Preschool
  • Female
  • Glomerulonephritis, IGA / metabolism*
  • Glycosylation
  • Humans
  • Immunoglobulin A / metabolism*
  • Lectins / metabolism
  • Male
  • Middle Aged
  • Molecular Sequence Data
  • Plant Lectins*
  • Purpura, Schoenlein-Henoch / metabolism*

Substances

  • Immunoglobulin A
  • Lectins
  • Plant Lectins
  • Vicia lectins