From the Guidelines
Management of leukocytosis and neutrophilia should focus on identifying and treating the underlying cause rather than the elevated white blood cell count itself. The first step is a thorough clinical evaluation including a complete history, physical examination, and appropriate laboratory tests to determine the etiology, which commonly includes infection, inflammation, stress, medication effects, or hematologic malignancy. For infectious causes, targeted antimicrobial therapy based on culture results is essential, as seen in the study by 1, which highlights the importance of considering the likelihood of bacterial infection in older adults with elevated white blood cell counts. Some key points to consider in the management include:
- Identifying the underlying cause of leukocytosis and neutrophilia
- Targeted antimicrobial therapy for infectious causes
- Anti-inflammatory medications for inflammatory conditions
- Discontinuing offending agents in medication-induced cases
- Addressing underlying stressors in stress-related neutrophilia
- Prompt referral to a hematologist for suspected hematologic malignancies, such as chronic myeloid leukemia, which may involve treatment with tyrosine kinase inhibitors like imatinib, as noted in general medical knowledge. Symptomatic management may include hydration, antipyretics for fever, and pain control, with the goal of improving quality of life and reducing morbidity and mortality, as emphasized by the study 1 on the management of febrile neutropenia. Regular monitoring of complete blood counts is important to track response to treatment, and the prognosis varies widely depending on the underlying cause, with infectious and medication-induced cases typically resolving with appropriate intervention, while malignant causes may require long-term specialized care, as discussed in 1.
From the Research
Elevated White Count and Neutrophils
- An elevated white blood cell count, also known as leukocytosis, can have many potential etiologies, including malignant and nonmalignant causes 2.
- Neutrophilia, or an elevated neutrophil count, is often a sign of infection, particularly bacterial, and can also be caused by stressors such as surgery, exercise, trauma, and emotional stress 2, 3.
- The peripheral white blood cell count can double within hours after certain stimuli due to the large bone marrow storage and intravascularly marginated pools of neutrophils 2.
Diagnosis and Management
- A repeat complete blood count with peripheral smear may provide helpful information, such as types and maturity of white blood cells, uniformity of white blood cells, and toxic granulations 2.
- The leukocyte differential may show eosinophilia in parasitic or allergic conditions, or it may reveal lymphocytosis in childhood viral illnesses 2.
- Neutrophils and total leukocytes remain the two most suitable parameters for the diagnosis of infections in the emergency department (ED) 4.
- Eosinopenia, or a low eosinophil count, can be a valuable tool for the diagnosis of bacterial infections, particularly urinary and biliary tract infections 4.
Prognosis and Outcome
- An increased neutrophil/lymphocyte ratio has been associated with poor prognosis and outcome in patients with pulmonary arterial hypertension (PAH) 5.
- Persistent leukocytosis despite antibiotic treatment for ventilator-associated pneumonia (VAP) can have many etiologies, including normal inflammatory response, inadequate VAP antimicrobial therapy, and the presence of additional infectious diagnoses 6.
- Daily white blood cell count was higher for patients with VAP and an additional infectious source compared to those with VAP alone, suggesting that providers should have increased suspicion for additional sources of infection when ICU patients with a VAP continue to have elevated WBC despite appropriate antibiotic therapy 6.