Renal Pathology II Flashcards
What are the characteristics of rapidly progressive glomerulonephritis (RPGN)?
It is a clinical syndrome characterized by a rapid and progressive loss of renal function, often with severe oliguria, and laboratory findings typical of the nephritic syndrome. Crescents are a classical finding of RPGN.
What are crescents?
Crescents are formed by proliferation of the parietal epithelial cells, shaped into a crescent-like structure, as they fill the Bowman’s space. The proliferation of parietal cells is in response to severe injury of the glomerular basement membrane resulting in necrosis and breaks with leakage of blood and fibrin to the urinary space.
What is the problem with crescent formation?
Crescents obliterate the urinary space and compress the tuft, with shutting-off of blood circulation and filtration; rapid renal failure ensues.
What are the types of RPGN and what are they caused by?
Type I - anti-glomerular basement membrane antibody mediated glomerulonephritis
Type II - severe immune-complex glomerulonephritis
Type III - pauci- immune/ANCA associated glomerular injury
What is the pathogenesis of RPGN Type I?
Anti-glomerular basement membrane antibodies form often from exposure to things like paints, dyes, drugs, smoking, etc.
What is the typical patient of RPGN Type I?
Young men - although the cases are RARE
What are the clinical presentations of RPGN Type I?
- gross hematuria
- drop in urinary output (acute renal failure)
- hemoptysis (lung is affected)
What are the lab findings for RPGN Type I?
- Linear Stain for IgG
- Crescents
- Anti-glomerular basement membrane antibodies in serum
Why is there gross hematuria in RPGN Type I?
The glomerular basement membrane is RAPIDLY destroyed, leading to widespread necrosis - holes - that causes the “sieve” effect
What is Goodpasture Syndrome?
Antibodies in RPGN Type I will have cross reaction with with pulmonary alveolar basement membrane, causing pulmonary hemorrhage associated with renal failure - DEADLY
What is the treatment of RPGN Type I?
Plasmapheresis to remove the Ab
What is the pathogenesis of RPGN Type II?
Severe immune complex formation leads to necrosis and breaks in glomerular basement membrane
What is the typical patient of RPGN Type II?
Children and young adults (10-40 yo)
What are the clinical presentations of RPGN Type II?
- gross hematuria
- drop in urinary output (acute renal failure)
What are the lab findings of RPGN Type II?
- crescents
- immune complexes (IgG+C3; IgA+C3)
- electron dense deposits by electron microscopy
What are the two main etiologies of RPGN Type II?
- IgG-C3 in postinfectious glomerulonephritis and lupus
- IgA-C3 complexes in IgA nephropathy
What is the pathogenesis of RPGN Type III?
Antineutrophil cytoplasmic autoantibodies (ANCA), react with neutrophil cytoplasmic antigen but do NOT form immune complex.
What is the typical patient of RPGN Type III?
Older female