What are the implications and treatment options for hematuria (presence of blood in urine) and leukocyturia (presence of leukocytes in urine)?

Evaluation and Management of Blood and Leukocytes in Urine

Hematuria and leukocyturia require thorough evaluation as they may indicate serious underlying conditions including urinary tract infection, glomerular disease, or urinary tract malignancy, with gross hematuria carrying >10% risk of underlying cancer even when resolved. 1

Initial Assessment

Hematuria Evaluation

• Hematuria is defined as ≥3 red blood cells per high-power field (HPF) on properly collected urinalysis 1
• Types:
  • Microscopic hematuria: Only visible under microscope
  • Gross hematuria: Visibly bloody urine (higher cancer risk >10%)

Leukocyturia Evaluation

• Defined as presence of white blood cells in urine
• Most common cause: Urinary tract infection (UTI) in conjunction with bacteriuria 2
• Significant threshold: >5 cells/HPF 3

Diagnostic Approach

Laboratory Testing

1. Confirm hematuria with microscopic urinalysis showing ≥3 RBCs/HPF before further evaluation 4
2. Urinalysis with microscopic examination to evaluate both hematuria and leukocyturia 1
3. Urine culture - especially important for leukocyturia, as patients with UTI are 7.5 times more likely to have leukocyturia 3
4. Additional laboratory tests:
   • Serum creatinine and BUN
   • Complete blood count
   • 24-hour urine collection for protein quantification 1

Imaging and Specialized Testing

• For hematuria:

  • CT Urography: Primary imaging modality (92% sensitivity, 93% specificity)
  • MR Urography: For patients with contrast allergy or renal insufficiency
  • Renal Ultrasound: Alternative or for young patients 1

• Cystoscopy: Mandatory for all patients with gross hematuria regardless of resolution (sensitivity 87-100% for bladder cancer) 1

Management Based on Risk Stratification

For Hematuria

1. Risk stratification based on:

   • Age (>60 years increases risk)
   • Sex (male gender increases risk)
   • Smoking history
   • Exposure to industrial chemicals
   • Family history of urologic malignancy
   • History of pelvic radiation 1

2. Management by risk level:

   • Low-risk microscopic hematuria: Renal ultrasound
   • Intermediate-risk: Cystoscopy and renal ultrasound
   • High-risk or gross hematuria: Cystoscopy and CT urography 1

For Leukocyturia

1. With bacteriuria: Treat as UTI

   • A leukocyte count <5 cells/HPF predicts absence of UTI in 96% of women 3

2. Without significant bacteriuria: Further diagnostic evaluation required 2

   • Consider non-infectious causes: interstitial nephritis, stone disease, or malignancy

Important Clinical Considerations

Anticoagulation Status

• Anticoagulation may exacerbate bleeding but rarely causes it without underlying pathology
• Patients on antiplatelet agents or anticoagulants require the same evaluation as those not on these medications 1

Follow-up Recommendations

• Repeat urinalysis at 6,12,24, and 36 months
• Immediate re-evaluation if:
  • Recurrent gross hematuria
  • Abnormal urinary cytology
  • New irritative voiding symptoms 1

Common Pitfalls to Avoid

1. Assuming resolution means benign etiology - Gross hematuria carries >10% risk of malignancy even if resolved 1

2. Attributing hematuria to anticoagulation - Anticoagulation rarely causes hematuria without underlying pathology 1

3. Neglecting to evaluate leukocyturia without bacteriuria - May miss non-infectious causes 2

4. Using urinary cytology or urine-based molecular markers for initial bladder cancer detection - Not recommended 4

5. Failing to confirm dipstick results with microscopic analysis before initiating further evaluation 4

6. Incomplete evaluation in high-risk patients - Both cystoscopy and appropriate imaging are necessary 1