What is the treatment for neutrophils (white blood cells) leukocytosis (elevated white blood cell count)?

Management of Neutrophilic Leukocytosis

The treatment of neutrophilic leukocytosis should focus on identifying and addressing the underlying cause rather than treating the elevated white blood cell count itself, as leukocytosis is typically a symptom rather than a primary disease. 1

Evaluation of Neutrophilic Leukocytosis

• Neutrophilic leukocytosis is most commonly caused by infections, inflammatory processes, physical or emotional stress, and certain medications 1, 2
• Complete blood count with differential and peripheral smear examination is essential to determine the types and maturity of white blood cells present 2
• An elevated total band count (>1500/mm³) has the highest likelihood ratio (14.5) for detecting bacterial infection, while an increase in the percentage of neutrophils (>90%) and band neutrophils (>16%) have likelihood ratios of 7.5 and 4.7, respectively 3

Common Causes of Neutrophilic Leukocytosis

• Infections: Particularly bacterial infections are the most common cause 1
• Medications: Corticosteroids, lithium, and beta-agonists are frequently associated with leukocytosis 1, 4
• Stress responses: Physical stress (seizures, anesthesia, overexertion) and emotional stress can elevate white blood cell counts 1
• Inflammatory conditions: Chronic inflammatory disorders can cause persistent leukocytosis 2
• Other factors: Smoking, obesity, and asplenia can contribute to elevated neutrophil counts 2

Management Approach

For Infection-Related Leukocytosis

• If fever is present with neutropenia (ANC < 0.5 × 10⁹/L), immediate empiric antibiotic therapy is required 3
• For patients with fever and neutropenia:
  • Low-risk patients who become afebrile with ANC ≥ 0.5 × 10⁹/L at 48 hours can be switched to oral antibiotics 3
  • High-risk patients who become afebrile with ANC ≥ 0.5 × 10⁹/L at 48 hours may have aminoglycosides discontinued if on dual therapy 3
  • If a specific pathogen is identified, continue appropriate targeted therapy 3

For Medication-Induced Leukocytosis

• Consider discontinuation or dose adjustment of medications known to cause leukocytosis (corticosteroids, lithium, beta-agonists) when clinically appropriate 1
• Corticosteroid-induced neutrophil leukocytosis occurs through decreased adhesion of marginated neutrophils and induction of granulocyte-colony stimulating factor 4

For Malignancy-Related Leukocytosis

• Primary bone marrow disorders should be suspected in patients with extremely elevated white blood cell counts or concurrent abnormalities in red blood cell or platelet counts 1
• Warning signs suggesting hematologic malignancy include:
  • Weight loss, fever, fatigue
  • Bleeding or bruising
  • Hepatosplenomegaly or lymphadenopathy
  • Immunosuppression 1
• White blood cell counts above 100,000/mm³ represent a medical emergency due to risk of brain infarction and hemorrhage and require immediate hematology consultation 1

Special Considerations

• In patients with hematologic malignancies receiving chemotherapy, neutrophil counts should be monitored closely 3
• For patients with acute promyelocytic leukemia (APL) with hyperleukocytosis (WBC >10 × 10⁹/L), cytoreductive therapy should be started without delay 3
• In patients with chronic neutrophilic leukemia, neutrophil function may be impaired despite elevated counts, requiring special attention to infection risk 5

Duration of Treatment

• If treating infection-related leukocytosis:
  • If neutrophil count is ≥0.5 × 10⁹/L, the patient is asymptomatic, has been afebrile for 48 hours, and blood cultures are negative, antibacterials can be discontinued 3
  • If neutrophil count is <0.5 × 10⁹/L but the patient has been afebrile for 5-7 days without complications, antibacterials can generally be discontinued 3
  • In high-risk cases (acute leukemia, post-high-dose chemotherapy), antibacterials are often continued for up to 10 days or until neutrophil count is ≥0.5 × 10⁹/L 3