Sterile pyuria refers to white blood cells in urine with a negative culture. It is most classically associated with which condition?

Sterile pyuria refers to white blood cells in urine with a negative culture. It is most classically associated with which condition?

• A. Acute bacterial cystitis
• B. Interstitial cystitis
• C. Pyelonephritis
• D. Nephrolithiasis

Answer: (B)

Sterile pyuria means white blood cells are seen in the urine, but no bacteria grow on standard culture. This points to an inflammatory process of the urinary tract without an active bacterial infection. Interstitial cystitis, a chronic inflammatory condition of the bladder, typically shows this pattern: you have leukocytes in the urine from bladder inflammation, yet cultures remain negative because there isn’t an invading bacterium. In contrast, acute bacterial cystitis and pyelonephritis usually produce a positive urine culture due to infection, and nephrolithiasis can irritate the urinary tract and cause white cells, but the classic, exam-favored association with sterile pyuria is interstitial cystitis.

Sterile pyuria means white blood cells are seen in the urine, but no bacteria grow on standard culture. This points to an inflammatory process of the urinary tract without an active bacterial infection. Interstitial cystitis, a chronic inflammatory condition of the bladder, typically shows this pattern: you have leukocytes in the urine from bladder inflammation, yet cultures remain negative because there isn’t an invading bacterium. In contrast, acute bacterial cystitis and pyelonephritis usually produce a positive urine culture due to infection, and nephrolithiasis can irritate the urinary tract and cause white cells, but the classic, exam-favored association with sterile pyuria is interstitial cystitis.