[Durgical](https://durgical.com/en/) › [DurgiPedia](https://durgical.com/en/durgipedia/) › [General pathology](https://durgical.com/en/general-pathology/) › [Kidney](https://durgical.com/en/general-pathology/areas/kidney/) › Postinfectious glomerulonephritis # Postinfectious glomerulonephritis - Lesion After a throat or skin infection with certain streptococci, immune complexes inflame the glomeruli and cause the classic nephritic syndrome. Updated Nov 12, 2026 ## Key points - Latent period: about one to two weeks after pharyngitis, longer after skin infection (impetigo). - Low C3 that returns to normal within about two months; ASO or anti-DNase B show the recent infection. - LM: large hypercellular glomeruli with neutrophils (diffuse endocapillary proliferation). - IF: granular IgG and C3 (lumpy-bumpy, starry sky); EM: subepithelial humps. - Staphylococcal infection-associated GN: during infection, older adults, often diabetic, IgA-dominant deposits. ## What it is Postinfectious glomerulonephritis follows an infection, classically with nephritogenic group A streptococci, by one to several weeks, the time needed to make antibodies. Streptococcal antigens such as SpeB settle in the glomerulus and form complexes that activate complement. Children usually recover; adults do less well. A related form occurs during ongoing infections, notably staphylococcal ones in older or diabetic adults, and can be IgA-dominant. ## Structure - Kidneys are enlarged and pale, sometimes with petechiae on the surface. - Glomeruli are swollen and bloodless, packed with proliferating endothelial and mesangial cells and neutrophils. - Electron microscopy shows dome-shaped electron-dense humps on the epithelial side of the basement membrane. - Interstitial edema and red cell casts in tubules are common. ## Step by step - A nephritogenic streptococcus infects the throat or skin. - Bacterial antigens, such as the cationic protease SpeB, reach the glomeruli. - Antibodies made over the next one to two weeks bind them in place or as circulating complexes. - Complement is consumed (low C3) and neutrophils and monocytes are drawn in. - Inflamed capillaries close: GFR falls, red cells leak, salt is retained and blood pressure rises. - In most children the deposits clear and function returns; some adults keep proteinuria or progress. ## Clinical notes - Cola-coloured urine, periorbital edema and hypertension in a child after a sore throat or impetigo. - Persistent low complement beyond two months suggests another disease (MPGN, C3 glomerulopathy, lupus). - Infection-associated GN in endocarditis, abscesses or shunt infections clears only when the infection is treated. ## Memory aid The throat speaks first, the kidney answers two weeks later with humps and cola urine. ## Test yourself Think of the answer, then tap the question to see it. ## Why is there a delay between strep throat and glomerulonephritis? Antibodies must be produced before immune complexes can form in the glomeruli. ## What does electron microscopy show in poststreptococcal GN? Subepithelial humps: dome-shaped electron-dense deposits on the epithelial side of the basement membrane. ## What happens to C3 and how long does it last? C3 falls during the acute phase and usually returns to normal within about eight weeks. ## How does staphylococcal infection-associated GN differ? It occurs during the infection, often in older diabetic adults, and the deposits are frequently IgA-dominant. [Add to my cards (4)](https://durgical.app/estudiar/?add=/en/general-pathology/postinfectious-glomerulonephritis/) [More Pathology questions →](https://durgical.com/en/practice/?f=pathology) ## Elsewhere in DurgiPedia - [Type III hypersensitivity (immune complexes)](https://durgical.com/en/immunology/type-iii-hypersensitivity/) - [Molecular mimicry and post-infectious autoimmunity](https://durgical.com/en/immunology/molecular-mimicry-and-post-infectious-autoimmunity/) ## Connections ## Related 4 - [Immune mechanisms of glomerular injury](https://durgical.com/en/general-pathology/immune-mechanisms-of-glomerular-injury/) - [Glomerular diseases: comparison table](https://durgical.com/en/general-pathology/glomerular-diseases-comparison-table/) - [IgA nephropathy and IgA vasculitis](https://durgical.com/en/general-pathology/iga-nephropathy-and-iga-vasculitis/) - [Infective endocarditis](https://durgical.com/en/general-pathology/infective-endocarditis/) ## Related conditions 4 - [Post-streptococcal glomerulonephritis](https://durgical.com/en/conditions/post-streptococcal-glomerulonephritis/) - [Infective endocarditis](https://durgical.com/en/conditions/infective-endocarditis/) - [Scarlet fever](https://durgical.com/en/conditions/scarlet-fever/) - [Nephrotic syndrome](https://durgical.com/en/conditions/nephrotic-syndrome/) ## Microorganisms 2 - [Streptococcus pyogenes](https://durgical.com/en/microbiology/streptococcus-pyogenes/) - [Staphylococcus aureus](https://durgical.com/en/microbiology/staphylococcus-aureus/) [← All of general pathology](https://durgical.com/en/general-pathology/) Educational content on the mechanisms of disease; not a diagnostic or treatment guide and no substitute for a health professional's advice. No doses are given. Sources: [Poststreptococcal glomerulonephritis (GN): MedlinePlus Medical Encyclopedia](https://medlineplus.gov/ency/article/000503.htm) (MedlinePlus, US National Library of Medicine, 2025). ## **Spotted a mistake?** We are always improving for the community. Tell us what is wrong and our team will review it. Report a mistake Representative model, for educational purposes only. --- Source: https://durgical.com/en/general-pathology/postinfectious-glomerulonephritis/ License: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Cite as: DurgiPedia (durgical.com), https://durgical.com/en/general-pathology/postinfectious-glomerulonephritis/