Goodpasture's syndrome involves autoantibodies directed against the alpha-3 chain of type IV collagen in the glomerular basement membrane. Immunofluorescence of renal biopsy shows a linear pattern of IgG deposition. This is an example of which type of hypersensitivity?
- A Type I hypersensitivity
- B Type III hypersensitivity
- C Type II hypersensitivity ✓
- D Type IV hypersensitivity
Correct answer: C. Type II hypersensitivity
Explanation
Goodpasture's syndrome is a prototype of Type II (cytotoxic) hypersensitivity, where IgG autoantibodies bind directly to fixed antigens on the glomerular basement membrane. The antibodies activate complement and engage Fc receptors on neutrophils and NK cells, leading to complement-mediated lysis and antibody-dependent cellular cytotoxicity. The linear IgG staining pattern on immunofluorescence distinguishes it from immune complex (granular) deposition seen in Type III hypersensitivity nephritis.
Reference: Ananthanarayan & Paniker's Textbook of Microbiology, 11th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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