Goodpasture antibody disease vs ANCA-associated vasculitis antibodies
How to tell Goodpasture antibody disease and ANCA-associated vasculitis antibodies apart when a board question makes them look alike.
Goodpasture is anti-GBM linear IgG; ANCA vasculitis is PR3/MPO pauci-immune small-vessel disease.
Side by side
Goodpasture disease uses anti-GBM antibodies against type IV collagen causing pulmonary hemorrhage and rapidly progressive glomerulonephritis with linear IgG staining.
ANCA-associated vasculitides use PR3/c-ANCA or MPO/p-ANCA patterns causing pauci-immune small-vessel vasculitis with pulmonary renal disease or ENT/lung involvement.
Goodpasture disease uses anti-GBM antibodies against type IV collagen causing pulmonary hemorrhage and rapidly progressive glomerulonephritis with linear IgG staining.
ANCA-associated vasculitides use PR3/c-ANCA or MPO/p-ANCA patterns causing pauci-immune small-vessel vasculitis with pulmonary renal disease or ENT/lung involvement.
The repair move
Before naming the answer, force the stem through the separator: Goodpasture is anti-GBM linear IgG; ANCA vasculitis is PR3/MPO pauci-immune small-vessel disease.
Try a free question
CoreA 25-year-old man has 2 weeks of progressive cough, hemoptysis, and rapidly rising creatinine (1.0 to 4.5 mg/dL). Urinalysis shows RBC casts. Chest CT shows bilateral diffuse alveolar opacities. Kidney biopsy shows crescentic glomerulonephritis with LINEAR IgG deposition along the glomerular basement membrane on immunofluorescence. Which antibody is most likely positive?
Show answer and explanation
Answer: A. Anti-GBM antibody (type IV collagen alpha-3). Goodpasture syndrome is anti-GBM antibody disease targeting the non-collagenous (NC1) domain of the alpha-3 chain of type IV collagen, present in glomerular AND alveolar basement membranes. Features: pulmonary hemorrhage + rapidly progressive glomerulonephritis. Kidney biopsy shows linear IgG deposition (vs pauci-immune in ANCA vasculitis). Treat with plasmapheresis plus corticosteroids plus cyclophosphamide.
Why the other choices are tempting
- B. c-ANCA/PR3 is associated with GPA with sinusitis, lung cavities, and pauci-immune (NOT linear) GN.
- C. p-ANCA/MPO is associated with microscopic polyangiitis and EGPA with pauci-immune GN, not linear IgG.
- D. Anti-dsDNA is associated with SLE with immune complex GN, not linear IgG.
- E. Anti-CCP is for rheumatoid arthritis.
Flashcards
Tap a card to flip it.
What clue supports Goodpasture antibody disease?
Choose Goodpasture antibody disease when the stem gives this pattern: Goodpasture disease uses anti-GBM antibodies against type IV collagen causing pulmonary hemorrhage and rapidly progressive glomerulonephritis with linear IgG staining.
What clue supports ANCA-associated vasculitis antibodies?
Choose ANCA-associated vasculitis antibodies when the stem gives this contrasting pattern: ANCA-associated vasculitides use PR3/c-ANCA or MPO/p-ANCA patterns causing pauci-immune small-vessel vasculitis with pulmonary renal disease or ENT/lung involvement.
Quick answers
What is the fastest way to tell Goodpasture antibody disease from ANCA-associated vasculitis antibodies?
Goodpasture is anti-GBM linear IgG; ANCA vasculitis is PR3/MPO pauci-immune small-vessel disease.
What is the key clue for Goodpasture antibody disease?
Goodpasture disease uses anti-GBM antibodies against type IV collagen causing pulmonary hemorrhage and rapidly progressive glomerulonephritis with linear IgG staining.
What is the key clue for ANCA-associated vasculitis antibodies?
ANCA-associated vasculitides use PR3/c-ANCA or MPO/p-ANCA patterns causing pauci-immune small-vessel vasculitis with pulmonary renal disease or ENT/lung involvement.