Management of Neutrophilic Leukocytosis

Evaluation and Diagnosis

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 1

If fever is present with neutropenia (ANC < 0.5 × 10⁹/L), immediate empiric antibiotic therapy is required, as recommended by the European Society for Medical Oncology 2, 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, according to the European Society for Medical Oncology 4
For patients with fever and neutropenia, high-risk patients who become afebrile with ANC ≥ 0.5 × 10⁹/L at 48 hours may have aminoglycosides discontinued if on dual therapy, as suggested by the European Society for Medical Oncology 4
If a specific pathogen is identified, continue appropriate targeted therapy, as recommended by the European Society for Medical Oncology 4

In patients with hematologic malignancies receiving chemotherapy, neutrophil counts should be monitored closely, as advised by the American Society of Hematology 5, 6
For patients with acute promyelocytic leukemia (APL) with hyperleukocytosis (WBC >10 × 10⁹/L), cytoreductive therapy should be started without delay, according to the American Society of Hematology 6, 7

If treating infection-related leukocytosis, antibacterials can be discontinued when the neutrophil count is ≥0.5 × 10⁹/L, the patient is asymptomatic, has been afebrile for 48 hours, and blood cultures are negative, as recommended by the European Society for Medical Oncology 4, 8
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, as suggested by the European Society for Medical Oncology 4, 8