Rapidly Progressive Glomerulonephritis Flashcards
What is Rapidly Progressive Glomerulonephritis (RPGN)?
A syndrome of rapid renal function loss over days to weeks, characterized by crescentic glomerulonephritis on biopsy seen on either light microscope or immunofluorescence.
What is the hallmark pathology of RPGN on biopsy?
Crescent moon shapes of fibrin on light microscopy (LM).
What are the three types of RPGN?
Type I (Anti-GBM):
Goodpasture syndrome.
Type II (Immune Complex):
Lupus nephritis, post-streptococcal GN.
Type III (Pauci-immune):
Granulomatosis with polyangiitis, microscopic polyangiitis, Churg-Strauss syndrome.
Type I RPGN
Etiology: Autoantibodies against glomerular basement membrane (GBM).
Clinical Features: Hemoptysis (pulmonary hemorrhage) and glomerulonephritis.
Diagnosis: Linear IF with anti-GBM antibodies.
Treatment: High-dose corticosteroids, cyclophosphamide, and plasmapheresis.
Type II RPGN
Etiology: Immune complex deposition from systemic diseases (e.g., lupus nephritis, post-streptococcal GN).
Clinical Features: Signs of underlying systemic disease.
Diagnosis: Granular IF pattern with immune complex deposits.
Treatment: High-dose corticosteroids and disease-specific therapy.
Type III RPGN
Etiology: Associated with ANCA-associated vasculitides (e.g., granulomatosis with polyangiitis).
Clinical Features: Systemic vasculitis symptoms (e.g., hemoptysis, sinusitis, purpura).
Diagnosis: No IF staining; ANCA positive.
c-ANCA: Granulomatosis with polyangiitis.
p-ANCA: Microscopic polyangiitis or Churg-Strauss syndrome.
Treatment: Corticosteroids, cyclophosphamide, and rituximab.
Clinical Presentation of RPGN
Rapidly declining renal function.
Oliguria or anuria.
Systemic symptoms (e.g., hemoptysis in Goodpasture, purpura in ANCA vasculitis).
Labs:
Elevated serum creatinine and BUN.
Dysmorphic red blood cells or red blood cell casts in urine.
Proteinuria.
What diagnostic patterns are seen in RPGN on immunofluorescence (IF)?
Type I (Anti-GBM): Linear pattern.
Type II (Immune Complex): Granular pattern.
Type III (Pauci-immune): No immunofluorescence (pauci-immune).
What is Goodpasture syndrome and its key features?
Autoimmune disease with anti-GBM antibodies causing hemoptysis (pulmonary hemorrhage) and glomerulonephritis.
How is Goodpasture syndrome diagnosed?
Linear immunofluorescence pattern with anti-GBM antibodies.
What is the treatment for Goodpasture syndrome?
High-dose corticosteroids, cyclophosphamide, and plasmapheresis.
What causes Type II RPGN?
Immune complex deposition from systemic diseases like lupus nephritis or post-streptococcal GN.
What is seen on IF in Type II RPGN?
Granular pattern due to immune complex deposits.
What is the treatment for Type II RPGN?
High-dose corticosteroids and therapy specific to the underlying disease.
What diseases are associated with Type III RPGN?
ANCA-associated vasculitides:
Granulomatosis with polyangiitis
Microscopic polyangiitis
Churg-Strauss syndrome
What diagnostic findings are seen in Type III RPGN?
No immunofluorescence (pauci-immune)
and
ANCA positivity
(c-ANCA for granulomatosis with polyangiitis or p-ANCA for microscopic polyangiitis).
How is Type III RPGN treated?
Corticosteroids, cyclophosphamide, and rituximab.
What is the general treatment for RPGN?
High-dose corticosteroids, cyclophosphamide, and plasmapheresis (if anti-GBM antibodies are present).
