Review Question - QID 100458

The disease the above patient presents with is Goodpasture's syndrome (anti-glomerular basement membrane disease), a type II hypersensitivity reaction (antibodies are generated that bind to an aspect of collagen IV molecules located in the basement membrane of glomeruli and alveoli). Myasthenia gravis is also a type II hypersensitivity reaction.

In general, type II hypersensitivity reactions are characterized by antibodies that bind to cell surface antigens and lead to tissue damage. Antibody deposition at these sites in Goodpasture's syndrome eventually leads to the destruction of these tissues. This explains the hemoptysis and uremia. In myasthenia gravis, another type II hypersensitivity reaction, antibodies are produced that bind to acetylcholine receptors (AChR) present at the neuromuscular junction (NMJ). This binding will lead to the inability of ACh to bind to AChR, internalization of AChRs, and ultimately the destruction of AChRs with resulting muscle weakness results.

Illustration A is an image of immunofluorescence of the kidney in Goodpasture syndrome. Note the linear deposition of antibodies along the basement membrane.

Incorrect Answers:
Answer 2: SLE is a type III hypersensitivity reaction.
Answer 3: A PPD test is a type IV hypersensitivity reaction.
Answer 4: Seasonal allergies are a type I hypersensitivity reaction.
Answer 5: Poison ivy rash is a type IV hypersensitivity reaction.