Significance of Elevated Urine WBCs (>182) and RBCs (177) in Microscopic Analysis
Elevated urine WBCs (>182) and RBCs (177) strongly suggest a urinary tract infection with possible underlying urologic or renal pathology requiring further evaluation. 1
Diagnostic Implications
Urinary Tract Infection
- WBC count >182/μL significantly exceeds the established cutoff of 13 WBCs/μL for detecting urinary tract infections, indicating active inflammation in the urinary tract 1
- The combination of elevated WBCs and RBCs has a sensitivity of 99.8% and negative predictive value of 100% for urinary tract infection when using the algorithm of ≥85 bacteria/μL and ≥13 WBCs/μL 1
- Pyuria (elevated WBCs) in conjunction with bacteriuria is the most common presentation of urinary tract infection 2
Potential for Urologic Pathology
- Concurrent hematuria (elevated RBCs) and leukocyturia (elevated WBCs) may indicate:
- Urinary tract infection with mucosal inflammation and bleeding
- Urolithiasis (kidney stones) with secondary infection
- Underlying urologic malignancy with superimposed infection
- Glomerular disease with secondary infection 3
Clinical Approach
Immediate Assessment
- Confirm findings with repeat urinalysis if clinically indicated 3
- Obtain urine culture to identify causative organism and determine antibiotic sensitivities 4, 3
- Complete additional laboratory workup including:
- Complete blood count
- Serum creatinine and BUN
- Urinalysis with microscopic examination 3
Risk Stratification
- Higher risk factors requiring more aggressive evaluation:
- Age >60 years
- Male gender
- Smoking history
- Gross hematuria (if present)
- History of pelvic radiation
- Occupational exposure to chemicals 3
Imaging and Further Evaluation
Imaging Recommendations
- If infection is confirmed and responds to treatment, repeat urinalysis after treatment to ensure resolution 3
- If hematuria persists after treatment of infection, further imaging is indicated:
- CT Urography (92% sensitivity, 93% specificity) is preferred for detecting stones, malignancy, and structural abnormalities
- MR Urography if contrast allergy or renal insufficiency exists
- Renal ultrasound as an alternative, especially in younger patients 3
Specialist Referral
- Urologic referral is indicated for:
- Persistent hematuria after treatment of infection
- Age >60 years with unexplained hematuria
- Recurrent UTIs 3
- Nephrology referral if glomerular disease is suspected (especially if proteinuria is also present) 3
Common Pitfalls to Avoid
- Relying solely on dipstick results without microscopic confirmation - microscopic examination is essential for accurate diagnosis 3
- Assuming anticoagulant therapy is the cause of hematuria without further evaluation 3
- Failing to repeat urinalysis after treating a presumed cause can lead to overlooked significant renal disease 3
- Inadequate evaluation of concurrent hematuria and leukocyturia, which may represent more serious underlying pathology 3
- Collecting urine samples improperly (from extension tubing or collection bag in catheterized patients) can lead to false results 3
Follow-up Recommendations
- If infection is confirmed and treated:
- Repeat urinalysis 1-2 weeks after completing antibiotics to confirm resolution
- If hematuria or leukocyturia persists, more comprehensive evaluation is needed 3
- For patients with resolved infection but risk factors for malignancy:
- Consider surveillance with repeat urinalysis at 6,12,24, and 36 months 3
- For patients with persistent abnormalities despite treatment:
- Consider cystoscopy and upper tract imaging 3
The presence of both significant leukocyturia and hematuria requires thorough evaluation as it may represent serious underlying pathology beyond simple urinary tract infection.