Rosh Internal Medicine Boost Practice Exam

Which urinary finding is most indicative of glomerulonephritis?

1. Proteinuria

2. Hematuria with red blood cell casts

3. Creatinine clearance

4. Urinary tract infection

The correct answer is: Hematuria with red blood cell casts

Hematuria with red blood cell casts is a key urinary finding that is particularly indicative of glomerulonephritis. In glomerulonephritis, inflammation of the glomeruli leads to the leakage of red blood cells from the glomerular capillaries into the urine. The presence of red blood cell casts is a specific indicator of glomerular damage, as these casts form in the renal tubules and are made up of red blood cells that have been molded by the tubular structures. This finding suggests that there is an intrinsic renal process affecting the glomeruli, distinguishing it from other potential causes of hematuria. While proteinuria is also a common finding in glomerulonephritis, it is not as specific as the combination of hematuria with red blood cell casts. Creatinine clearance is a measure of kidney function and does not offer direct insight into the nature of the urinary findings characteristic of glomerular disorders. A urinary tract infection, though it can cause hematuria and other abnormalities in urine, is not associated with red blood cell casts and points to an entirely different etiology. Therefore, hematuria with red blood cell casts stands out as the most specific and indicative finding in the context of