Which finding on urinalysis best supports a diagnosis of a urinary tract infection?

Which finding on urinalysis best supports a diagnosis of a urinary tract infection?

• A. Pyuria
• B. Proteinuria
• C. Hematuria without leukocyte esterase
• D. Casts in urine

Answer: (A)

Pyuria, or white blood cells in the urine, best supports a urinary tract infection because infection in the urinary tract triggers an inflammatory response with neutrophils entering the urine. This presence of leukocytes directly reflects bacteria-driven inflammation of the urinary tract. While proteinuria, hematuria, or casts can occur for other reasons or with more renal involvement, they are not as specifically linked to a simple UTI. Thus, finding white blood cells in the urine most strongly points to an infection in the urinary tract.

Pyuria, or white blood cells in the urine, best supports a urinary tract infection because infection in the urinary tract triggers an inflammatory response with neutrophils entering the urine. This presence of leukocytes directly reflects bacteria-driven inflammation of the urinary tract. While proteinuria, hematuria, or casts can occur for other reasons or with more renal involvement, they are not as specifically linked to a simple UTI. Thus, finding white blood cells in the urine most strongly points to an infection in the urinary tract.