What does a urine analysis with elevated WCC (White Cell Count) and red cells but no growth indicate in a patient with increased urinary frequency?

Sterile Pyuria: Elevated WBC and RBC with No Growth in Urine Culture

The presence of elevated white blood cells (WBC 658) and red blood cells (RBC 36) in urine with no bacterial growth indicates sterile pyuria, which requires further investigation as it may represent non-infectious inflammation, partially treated infection, or an underlying urological condition. 1

Diagnostic Interpretation

• Sterile pyuria is defined as the presence of white blood cells in urine without bacterial growth on standard culture media 1
• The significant elevation of WBCs (658) strongly suggests inflammation in the urinary tract, while the presence of RBCs (36) indicates some degree of bleeding 1
• This combination without bacterial growth on culture can occur in several clinical scenarios:
  • Recent antibiotic use that suppressed bacterial growth but inflammation persists 2
  • Infection with organisms that don't grow on standard culture media (e.g., Chlamydia, Mycoplasma, Ureaplasma) 1
  • Non-infectious inflammatory conditions of the urinary tract 1
  • Early or resolving urinary tract infection 1

Clinical Significance in a 57-Year-Old Female with Increased Urinary Frequency

• Increased urinary frequency without abdominal pain, fever, or dysuria in this age group with sterile pyuria warrants consideration of:
  • Interstitial cystitis/bladder pain syndrome 2
  • Partially treated or resolving UTI 1
  • Urolithiasis (kidney stones) 3
  • Early bladder malignancy (especially with hematuria) 3
  • Genitourinary tuberculosis (rare but important consideration) 2

Recommended Next Steps

1. Repeat urinalysis and culture in 2-4 weeks to determine if findings persist 1

2. Consider expanded culture techniques if symptoms persist, including:

   • Extended culture incubation for fastidious organisms 2
   • Specific testing for atypical organisms (Chlamydia, Mycoplasma) if risk factors present 2

3. If findings persist or symptoms worsen, proceed with:

   • Renal function assessment with serum creatinine 3, 1
   • Upper urinary tract imaging (ultrasound or CT urography) to evaluate for structural abnormalities 3, 1
   • Cystoscopy if hematuria persists beyond 6 weeks, especially given the patient's age >40 years 3

Important Considerations

• The absence of dysuria, fever, and abdominal pain makes an active bacterial infection less likely, but doesn't completely exclude it 3
• Microscopic hematuria (RBC 36) requires follow-up regardless of the cause of the sterile pyuria 3
• In women over 50, persistent microscopic hematuria warrants complete urologic evaluation due to increased risk of underlying malignancy 3
• The threshold for significant pyuria is typically ≥10 WBC/mm³, and this patient's count of 658 is substantially elevated 3

Common Pitfalls to Avoid

• Don't assume sterile pyuria is always benign, especially with persistent symptoms and hematuria 3
• Don't overlook the possibility of partially treated infection if the patient has recently taken antibiotics for any reason 2
• Don't dismiss persistent urinary frequency without obvious infection, as it may indicate underlying pathology requiring intervention 2
• Don't delay evaluation of microscopic hematuria in a patient over 40 years of age 3