A 22 year old presents to his physician with hemoptysis and hematuria with basement membrane antibodies. Most likely diagnosis is –
**Core Concept**
Goodpasture syndrome is a rare autoimmune disease characterized by the presence of anti-glomerular basement membrane (anti-GBM) antibodies, leading to glomerulonephritis and pulmonary hemorrhage.
**Why the Correct Answer is Right**
The presence of basement membrane antibodies in a patient with hemoptysis and hematuria is indicative of Goodpasture syndrome. The anti-GBM antibodies target the type IV collagen in the glomerular and alveolar basement membranes, leading to their destruction and subsequent inflammation. This results in the characteristic symptoms of glomerulonephritis (hematuria) and pulmonary hemorrhage (hemoptysis). The disease is often associated with a poor prognosis if left untreated.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because it does not specify the presence of anti-GBM antibodies, which are a hallmark of Goodpasture syndrome.
**Option B:** This option is incorrect because it is a less specific term that could refer to various autoimmune diseases, rather than a specific diagnosis like Goodpasture syndrome.
**Option C:** This option is incorrect because it does not accurately describe the underlying pathophysiology of Goodpasture syndrome.
**Clinical Pearl / High-Yield Fact**
Goodpasture syndrome is a classic example of a type II hypersensitivity reaction, where the immune system produces antibodies against the host's own tissues.
**Correct Answer: C. Goodpasture syndrome. Goodpasture syndrome**