Which finding suggests a need for further evaluation for glomerular disease?

Which finding suggests a need for further evaluation for glomerular disease?

• A. Blood pressure of 135/85
• B. Proteinuria with red blood cell casts in the urine
• C. Bright red urine
• D. Urine culture showing 100,000 bacteria per mL

Answer: (B)

RBCs embedded in casts in the urine point to injury at the glomerulus. Red blood cell casts form when red blood cells leak through damaged glomerular filtration barriers and then get trapped in a protein matrix within the tubules. When this red blood cell–containing cast appears, along with protein in the urine, it strongly suggests glomerular disease such as nephritic syndrome or glomerulonephritis and prompts further evaluation (renal function, complement levels, blood pressure assessment, and nephrology referral as needed). A single elevated blood pressure value can occur for various reasons and isn’t specific to glomerular disease. Bright red urine can result from non-glomerular sources like lower urinary tract bleeding or contamination, and a positive urine culture indicates a urinary tract infection rather than glomerular injury.

RBCs embedded in casts in the urine point to injury at the glomerulus. Red blood cell casts form when red blood cells leak through damaged glomerular filtration barriers and then get trapped in a protein matrix within the tubules. When this red blood cell–containing cast appears, along with protein in the urine, it strongly suggests glomerular disease such as nephritic syndrome or glomerulonephritis and prompts further evaluation (renal function, complement levels, blood pressure assessment, and nephrology referral as needed).

A single elevated blood pressure value can occur for various reasons and isn’t specific to glomerular disease. Bright red urine can result from non-glomerular sources like lower urinary tract bleeding or contamination, and a positive urine culture indicates a urinary tract infection rather than glomerular injury.