In a patient with end‑stage renal disease (chronic kidney disease stage V) who has neutrophilic leukocytosis on a complete blood count but no fever, should antibiotics be initiated?

Do Not Start Empiric Antibiotics for Isolated Neutrophilic Leukocytosis Without Fever in CKD Stage V

In a patient with end-stage renal disease (CKD stage V) who has neutrophilic leukocytosis without fever or other signs of infection, empiric antibiotics should not be initiated. Leukocytosis alone, in the absence of fever or clinical instability, does not warrant antimicrobial therapy and may represent chronic inflammation or other non-infectious causes common in advanced CKD 1, 2.

Key Clinical Assessment Required

Before considering antibiotics, you must evaluate for specific indicators of infection:

• Fever ≥38.0°C sustained over 1 hour or single temperature ≥38.3°C – the threshold that defines febrile neutropenia requiring empiric therapy 3
• Hemodynamic instability (hypotension, tachycardia, altered perfusion) 3
• New respiratory symptoms with infiltrates on chest imaging 3, 4
• Localizing signs of infection such as catheter-site cellulitis, skin/soft-tissue changes, or new abdominal pain 3, 5
• Neurologic changes suggesting possible CNS infection 3

The absence of fever is critical – afebrile patients with leukocytosis should be evaluated for non-infectious causes rather than treated empirically 3, 6.

Why Leukocytosis Occurs in CKD Stage V Without Infection

CKD patients, particularly those with end-stage disease, frequently have elevated white blood cell counts due to:

• Chronic inflammation from uremic toxin accumulation (p-cresyl sulfate, indoxyl sulfate) and reduced clearance of proinflammatory cytokines 2, 6
• Persistent inflammation-immunosuppression and catabolism syndrome (PICS), characterized by ongoing leukocytosis without active infection 1
• Elevated procalcitonin levels that occur in CKD independent of infection (reference value should be adjusted to >0.075 ng/mL in CKD patients to avoid unnecessary antibiotic use) 2

One study found that 94.7% of CKD patients had PCT levels above the standard cutoff without infection, emphasizing the need for adjusted thresholds 2.

Risks of Inappropriate Antibiotic Use in CKD Stage V

Starting antibiotics without clear indication carries substantial risks in this population:

• Antibiotic nephrotoxicity that accelerates progression to dialysis dependence 7, 6
• Clostridioides difficile infection – occurred in 21% of patients with unexplained leukocytosis who received prolonged empiric antibiotics 1
• Colonization with multidrug-resistant organisms (MRSA, VRE, ESBL-producing gram-negatives, carbapenemase-producing organisms) 3, 1, 8
• Drug accumulation and toxicity – approximately 30% of antibiotics used in CKD patients lack appropriate dose adjustment 7

When to Initiate Antibiotics in CKD Stage V

Start empiric broad-spectrum antibiotics immediately only if:

1. Fever develops (≥38.0°C sustained or ≥38.3°C single measurement) with neutropenia (ANC <500 cells/µL) 3, 5
2. Hemodynamic instability appears (sepsis criteria met) 3
3. Documented infection is identified by culture or imaging 3
4. High clinical suspicion exists with localizing symptoms (pneumonia, catheter infection, urinary symptoms with pyuria) 3, 9

For asymptomatic bacteriuria in CKD patients: Do not screen for or treat, as it does not improve outcomes and increases antibiotic resistance 9.

Appropriate Next Steps for This Patient

• Repeat CBC to confirm persistent leukocytosis and assess trend 3
• Obtain blood cultures only if fever or clinical instability develops 3
• Assess for non-infectious causes: recent dialysis access procedures, medication effects (corticosteroids), underlying malignancy, or tissue damage 1
• Monitor closely for development of fever or clinical deterioration 3, 6
• Consider inflammatory markers (CRP, ESR) to distinguish infection from chronic inflammation, recognizing that these are often chronically elevated in CKD 1, 2

Common Pitfall to Avoid

Do not equate leukocytosis with infection in CKD patients. The constellation of immunological and metabolic disturbances in advanced CKD creates a pro-inflammatory state that mimics infection 6. Empiric antibiotics based solely on laboratory values without clinical signs leads to a cascade of complications: prolonged hospitalization, C. difficile infection, and emergence of resistant organisms 1, 8.