Kidney nontumor
Primary glomerular diseases
IgA nephropathy (Berger disease)

Author: Nikhil Sangle, M.D. (see Authors page)

Revised: 21 September 2017, last major update July 2012

Copyright: (c) 2002-2017, PathologyOutlines.com, Inc.

PubMed Search: Berger's disease [title]

Cite this page: Sangle, N. IgA nephropathy (Berger disease). PathologyOutlines.com website. http://www.pathologyoutlines.com/topic/kidneyiga.html. Accessed December 17th, 2017.
Definition / general
Pathophysiology
  • Excess amounts of poorly galactosylated serum immunoglobulin IgA1 trigger the generation of glycan specific IgG and IgA autoantibodies, resulting in circulating IgA immune complexes (Kidney Int 2012;81:833)
  • IgA immune complexes are deposited in mesangium and activate alternative complement pathway and possibly the lectin pathway (J Biomed Biotechnol 2012;2012:476739)
  • Podocyte injury, due to epithelial to mesenchymal transition, plays an important role in glomerulosclerosis in IgA nephropathy (Cell Physiol Biochem 2012;29:743)
Clinical features
  • Most common form of primary glomerulonephritis worldwide; causes 10% of cases of end stage renal failure in many countries (eMedicine: IgA Nephropathy)
  • Common at ages 10 - 29 years, usually males who present with gross or microscopic hematuria after respiratory infection but no systemic disease (Pediatr Nephrol 2012;27:1293)
  • More common in southern Europe, Asia and Native Americans, less common in individuals of African lineage
  • Slowly progressive: 25 - 50% have renal failure at 20 years; recurs in 20 - 60% of allografts
  • Rarely causes death due to pulmonary hemorrhage (Arch Pathol Lab Med 1994;118:542)
  • Note: IgA deposits are also present in Henoch-Schönlein purpura; diseases may be related
  • Secondary disease associated with gluten enteropathy (celiac disease), liver disease and dermatitis herpetiformis (Arch Pathol Lab Med 1983;107:324)
  • Poor prognosis: prominent arteriolar hyalinization, older age, heavy proteinuria and hypertension
Treatment
Case reports
Microscopic (histologic) description
  • Diffuse proliferation of mesangial cells and matrix without significant involvement of capillary walls or lumina
  • Mesangial involvement is often uneven and resembles focal and segmental glomerulosclerosis
  • Normal or hypercellular glomeruli with diffuse necrotizing crescentic glomerulonephritis
Microscopic (histologic) images

Images hosted on PathOut server:

Mesangial expansion
and loop adhesion
on Jones silver stain

Mesangial expansion and global sclerosis on PAS stain

Mesangial expansion and loop adhesion on PAS stain

Mesangial IgA



Images hosted on other servers:

Various images including EM

Mild mesangial expansion

Granular mesangial staining for IgA

Immunofluorescence
  • IgA, often granular IgG and C3 in mesangium
  • IgA also in capillaries of dermis, lung, liver and intestine
  • IgA more intense or equally intense compared to IgG and IgM
  • Staining for C1q should raise the suspicion for lupus nephritis
Electron microscopy description
  • Electron dense deposits in mesangium of all glomeruli
Electron microscopy images

Images hosted on PathOut server:

Mesangial deposits

Differential diagnosis