The majority of primary glomerulonephritides is mediated by the deposition of circulating or in situ formed immune complexes, which may be confirmed by immunofluorescence finding of glomerular granular immune deposits. Their composition and electron microscopically defined localization identify various forms of immune complex glomerulonephritides with different courses and prognoses. Acute postinfectious glomerulonephritis is endocapillary proliferative glomerulonephritis characterized by subepithelial hump-like