What is the recommended treatment for a patient with leukocytosis and neutrophilia?

Management of Leukocytosis and Neutrophilia

The recommended treatment for a patient with leukocytosis (WBC 11.4) and neutrophilia depends on the underlying cause, with hydroxyurea being the first-line therapy for symptomatic cases or those at high risk for thrombotic complications. 1

Evaluation of Leukocytosis and Neutrophilia

Common Causes

• Infection: Most common cause, particularly bacterial infections
• Physiologic stress: Surgery, trauma, exercise, emotional stress
• Medications: Corticosteroids, epinephrine, lithium
• Hematologic malignancies: Leukemia, myeloproliferative disorders
• Inflammatory conditions: Rheumatoid arthritis, inflammatory bowel disease
• Other: Smoking, obesity, asplenia 2

Initial Assessment

• Determine if patient has symptoms (fever, weight loss, bruising, fatigue)
• Review medication list for potential causes
• Assess for signs of infection or inflammation
• Evaluate peripheral smear for cell morphology and maturity

Treatment Approach

For Asymptomatic Leukocytosis

• If mild elevation (as in this case with WBC 11.4) without symptoms:
  • Monitor complete blood count
  • Identify and treat underlying cause if present
  • No specific treatment needed for the leukocytosis itself

For Symptomatic or High-Risk Leukocytosis

1. First-line therapy: Hydroxyurea

   • Recommended by NCCN for patients with symptomatic leukocytosis 1
   • Initial dosing to normalize blood counts
   • Target WBC within normal range

2. For hyperleukocytosis (WBC >100 × 10^9/L):

   • Requires immediate medical treatment
   • Hydroxyurea at dosages up to 50-60 mg/kg per day until WBC <10-20 × 10^9/L 3
   • Leukapheresis may be considered in acute, severe cases with leukostasis 1
   • Prevention of tumor lysis syndrome (hydration, allopurinol or rasburicase) 3

3. For neutropenia associated with treatment:

   • Growth factors (G-CSF) can be used in combination with treatment for resistant neutropenia 3
   • If neutrophil count <1000/mm³, consider holding cytotoxic medications until recovery 3

Special Considerations

In Hematologic Malignancies

• For chronic myeloid leukemia (CML):
  • Tyrosine kinase inhibitors (imatinib, dasatinib) 1
  • Monitor BCR-ABL transcript levels every 3 months 3

In Febrile Neutropenia

• CSFs should be considered in patients with fever and neutropenia who are at high risk for infection-associated complications 3
• High-risk features include prolonged (≥10 days) and profound (≤0.1 × 10^9/L) neutropenia, age >65 years, uncontrolled primary disease, pneumonia, hypotension, multiorgan dysfunction, or invasive fungal infection 3

In Post-Surgical Patients

• Leukocytosis and neutrophilia are common after surgical procedures and may be part of normal response to surgery 4
• In post-surgical patients with persistent unexplained leukocytosis, consider persistent inflammation-immunosuppression and catabolism syndrome (PICS) 5

Monitoring

• Complete blood count weekly during initial treatment phase
• Target values: WBC within normal range
• Bone marrow assessment if disease progression is suspected 1

Complications to Watch For

• Thrombotic events are common complications requiring immediate anticoagulation and continued cytoreduction 1
• Disease transformation to myelofibrosis or acute leukemia in cases of myeloproliferative disorders 1

Remember that mild leukocytosis (as in this case with WBC 11.4) without symptoms often requires no specific treatment beyond addressing any underlying cause.