**Question:** Good-Pasture syndrome is characterized by -

A. Renal failure
B. Hemolytic anemia
C. Pulmonary hemorrhage
D. Both renal and pulmonary involvement

**Core Concept:** Good-Pasture syndrome is a rare autoimmune disease characterized by the production of autoantibodies against glomerular basement membrane, leading to both renal and pulmonary complications.

**Why the Correct Answer is Right:** In Good-Pasture syndrome, autoantibodies are directed against the α3 chain of type IV collagen in the glomerular basement membrane, leading to an immune complex-mediated injury. This results in both renal (glomerulonephritis) and pulmonary (alveolar hemorrhage) involvement.

**Why Each Wrong Option is Incorrect:**

A. Renal failure is a part of the clinical presentation, but the correct answer includes pulmonary involvement as well.
B. Hemolytic anemia is not a primary feature of Good-Pasture syndrome, although it may occur due to renal anemia and hypoxia.
C. Pulmonary hemorrhage is also a critical feature of the disease, but the correct answer includes renal involvement.
D. Renal and pulmonary involvement is consistent with the correct answer as it encompasses both primary manifestations of the disease.

**Clinical Pearl / High-Yield Fact:** Good-Pasture syndrome is typically associated with tobacco smoking and is often seen in patients with lung cancer. This association is known as the "Good-Pasture syndrome in lung cancer" or "alveolar hemorrhage in lung cancer."

**Correct Answer:** D. Renal and pulmonary involvement