What is the appropriate management for a patient with leukocytosis and neutrophilia?

From the Guidelines

The appropriate management for a patient with leukocytosis and neutrophilia involves identifying and treating the underlying cause, with a focus on supportive care and targeted therapy based on the suspected source of the condition, as recommended by recent guidelines 1. The patient's laboratory results show a white blood cell count of 13.9 thousand/uL, which is above the normal range, and an absolute neutrophil count of 10,522 cells/uL, which is also elevated.

• Initial steps in management include a thorough history and physical examination to identify potential causes of the leukocytosis and neutrophilia.
• Laboratory tests such as blood cultures, inflammatory markers like C-reactive protein and procalcitonin, and a complete blood count with differential can help guide diagnosis and treatment.
• Common causes of neutrophilia include bacterial infections, inflammation, stress, medications (particularly corticosteroids), and hematologic disorders.
• For infectious causes, targeted antimicrobial therapy should be initiated based on the suspected source; for example, community-acquired pneumonia might require amoxicillin-clavulanate 875/125 mg twice daily for 5-7 days or ceftriaxone 1-2 g IV daily for more severe cases, as suggested by guidelines 1.
• In cases of inflammatory conditions like rheumatoid arthritis, disease-specific treatments are indicated.
• Hematologic malignancies require prompt hematology referral.
• Supportive care including hydration and antipyretics may be needed while addressing the underlying cause.
• Regular monitoring of white blood cell counts is essential to assess response to treatment, and adjustments to therapy can be made based on clinical guidelines 1.
• The physiological basis for neutrophilia involves increased production and release of neutrophils from bone marrow in response to cytokines and growth factors triggered by infection or inflammation.
• Recent studies suggest that a watch-and-wait approach may be appropriate for patients with mild-to-moderate leucocytosis, while careful lowering of white blood cell count with low doses of hydroxycarbamide may be necessary in cases of extreme leucocytosis in asymptomatic patients, as recommended by a panel of international experts 1.

From the Research

Leukocytosis and Neutrophilia Management

The patient's lab results show a white blood cell count of 13.9 thousand/uL, which is higher than the normal range of 3.8-10.8 thousand/uL, indicating leukocytosis. The absolute neutrophil count is 10,522 cells/uL, which is also elevated, indicating neutrophilia.

• The causes of leukocytosis can be benign, such as infections or inflammatory processes, or more serious, such as primary bone marrow disorders 2.
• Neutrophilia can be caused by various factors, including bacterial infections, stress, and certain medications 3.
• The patient's lab results also show an elevated absolute monocyte count of 973 cells/uL, which may indicate a chronic inflammatory condition or infection 3.

Diagnostic Approach

To determine the underlying cause of the patient's leukocytosis and neutrophilia, a thorough diagnostic approach is necessary.

• A repeat complete blood count with peripheral smear may provide helpful information, such as the types and maturity of white blood cells, uniformity of white blood cells, and toxic granulations 3.
• The leukocyte differential may show eosinophilia in parasitic or allergic conditions, or it may reveal lymphocytosis in childhood viral illnesses 3.
• Other diagnostic tests, such as blood cultures, imaging studies, and biopsies, may be necessary to determine the underlying cause of the patient's symptoms.

Treatment Approach

The treatment approach for the patient's leukocytosis and neutrophilia will depend on the underlying cause.

• If the cause is a bacterial infection, antibiotics may be necessary 4.
• If the cause is a viral infection, such as COVID-19, treatment may involve antiviral medications and supportive care 5, 6.
• If the cause is a primary bone marrow disorder, referral to a hematologist/oncologist may be necessary 3, 2.