Anatomic Pathology: Renal Pathology

• The classic presentation of acute postinfectious glomerulonephritis (APIGN) includes acute nephritis (i.e., acute renal failure, hematuria, hypertension, fluid overload) and hypocomplementemia approximately 2 weeks after an upper respiratory tract infection.

• The most common etiology of APIGN in children is streptococcal pharyngitis resulting from group A β-hemolytic streptococcal infection. Most children have a complete recovery.

• On light microscopy, APIGN typically manifests a diffuse proliferative glomerulonephritis with numerous infiltrating neutrophils.

• The deposits of APIGN stain dominantly or codominantly for C3 on immunofluorescence, with weaker and more variable staining for IgG.

• The most characteristic finding in APIGN on ultrastructural evaluation is subepithelial “hump-shaped” electron-dense deposits. Compared with the subepithelial deposits seen in membranous nephropathy, the subepithelial deposits in APIGN are larger, are less numerous, have a “hump-shaped” appearance, and are not associated with intervening glomerular basement membrane (GBM) spikes.

Nasr SH, Markowitz GS, Stokes MB, et al: Acute postinfectious glomerulonephritis in the modern era: experience with 86 adults and review of the literature. Medicine (Baltimore) 2008;87(1):21-32.

* = Required 
* Note Title
* Note