Membranous glomerulonephritis pathophysiology
|
Membranous glomerulonephritis Microchapters |
|
Differentiating Membranous glomerulonephritis from other Diseases |
|---|
|
Diagnosis |
|
Treatment |
|
Case Studies |
|
Membranous glomerulonephritis pathophysiology On the Web |
|
American Roentgen Ray Society Images of Membranous glomerulonephritis pathophysiology |
|
Directions to Hospitals Treating Membranous glomerulonephritis |
|
Risk calculators and risk factors for Membranous glomerulonephritis pathophysiology |
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]
Overview
Pathophysiology
MGN is caused by circulating immune complex. Current research indicates that the majority of the immune complexes are formed via binding of antibodies to antigens in situ to the glomerular basement membrane. The said antigens may be endogenous to (from) the basement membrane, or "planted" from systemic circulation.
The immune complex serves as an activator that triggers a response from the C5b - C9 complements, which form a membrane attack complex (MAC) on the glomerular epithelial cells. This, in turn, stimulates release of proteases and oxidants by the mesangial and epithelial cells, damaging the capillary walls and causing them to become "leaky". In addition, the epithelial cells also seem to secrete an unknown mediator that reduces nephrin synthesis and distribution.
Morphology
The defining point of MGN is the presence of subepithelial immunoglobulin-containing deposits along the glomerular basement membrane (GBM). By light microscopy, the basement membrane is observed to be diffusively thickened. Using Jones' stain, the GBM appears to have a "spiked" or "holey" appearance. On electron microscopy, subepithelial deposits that nestle against the glomerular basement membrane seems to be the cause of the thickening. Also, the podocytes lose their foot processes.
As the disease progresses, the deposits will eventually be cleared, leaving cavities in the basement membrane. These cavities will later be filled with basement membrane-like material, and if the disease continues even further, the glomeruli will become sclerosed and finally hyalinized.
Immunoflourescence microscopy will reveal typical granular deposition of immunoglobulins and complement along the basement membrane.
Pathological Findings
-
Membranous Glomerulonephritis: Electron micrography. An excellent example to show thickened basement membrane and immune complexes. -
Membranous Glomerulonephritis: Micro trichrome high mag excellent to show thickened capillary basement membranes -
Membranous Glomerulonephritis: Micro PAS high mag excellent example of this lesion -
Membranous Glomerulonephritis: Micro PAS med mag
