How is morphology of post infectious glomerulonephritis?

➢By light microscopy, the most characteristic change in postinfectious GN is increased cellularity of the glomerular tufts that affects nearly all glomeruli—hence the term diffuse GN. ➢The increased cellularity is caused both by proliferation and swelling of endothelial and mesangial cells and by infiltrating neutrophils and monocytes. ➢Sometimes there is necrosis of the capillary walls. ➢In a few cases, “crescents” may be observed within the urinary space, formed in response to the severe injury ➢Electron microscopy shows deposited immune complexes arrayed as subendothelial, intramembranous, or, most often, subepithelial “humps” nestled against the GBM. ➢Mesangial deposits also are occasionally present. ➢Immunofluorescence studies reveal scattered granular deposits of IgG and complement within the capillary walls and some mesangial areas, corresponding to the deposits visualized by electron microscopy. ➢These deposits usually are cleared over a period of about 2 months