USMLE Step 1 Question 298

Question:

A 28-year-old man presents with recent onset decreased urinary output, and a general malaise for the past week. Physical exam is remarkable for blood pressure of 190/94, edema, and mild flank pain. Urinalysis shows red blood cell casts. A renal biopsy is performed, with nearly all glomeruli appearing as shown.

What is the most likely pathological process, and what is the likely prognosis?

Correct Answer: A.  Goodpasture’s Disease; disease is self-limited

Rapidly progressive (crescentic) glomerulonephritis rapidly progresses to renal failure; the number of crescents roughly corresponds with prognosis. The disease may follow a flu-like syndrome, but is distinct from poststreptococcal glomerulonephritis.

Poststreptococcal glomerulonephritis classically presents with “Coca-Cola” colored urine and occurs 2 weeks after an upper respiratory infection such as strep throat. Biopsy shows a uniform “filling” of glomerular capillaries with white blood cells. Most cases fully recover.

Goodpasture’s Disease often presents similarly to rapidly progressive glomerulonephritis, but requires pulmonary involvement. This condition will also rapidly progress to renal failure if left untreated.