Neutropenia Classification by Severity
Neutropenia is classified as mild (1000-1500 cells/mm³), moderate (500-1000 cells/mm³), and severe (<500 cells/mm³) based on absolute neutrophil count. 1
Detailed Classification
- Mild neutropenia: Absolute neutrophil count (ANC) between 1000-1500 cells/mm³ 1
- Moderate neutropenia: ANC between 500-1000 cells/mm³ 1
- Severe neutropenia: ANC less than 500 cells/mm³ 1, 2
Clinical Significance
Infection Risk
- Infection risk is directly proportional to the severity and duration of neutropenia 1
- Severe neutropenia (ANC <500 cells/mm³) presents the highest risk for bacterial infections 3, 2
- Patients with severe neutropenia typically have a history of oral ulcers, inflammation, and recurrent skin infections 2
Risk Assessment
- Patients with neutropenia should be assessed for risk of febrile neutropenia 4
- In cancer patients, neutropenia is graded according to the National Cancer Institute-Common Toxicity Criteria of Adverse Events (CTCAE v3):
- Grade 0: within normal limits
- Grade 1: lower normal limit to 10.0 g/dl
- Grade 2: 8.0 to <10.0 g/dl
- Grade 3: 6.5 to <8.0 g/dl
- Grade 4: <6.5 g/dl 5
Management Considerations
Prophylaxis
- Anti-bacterial or anti-fungal prophylaxis should be considered in cases where absolute neutrophil count is <0.5 × 10⁹/L, or in febrile neutropenia that is prolonged or chronic 5
- Colony-stimulating factors are recommended in patients with documented ≥Grade 3 neutropenia 5
Treatment
- Patients with febrile neutropenia should receive prompt antibiotic therapy 4
- G-CSF (granulocyte colony-stimulating factor) is indicated for patients with severe chronic neutropenia 3, 6
- The optimal dose of G-CSF is the lowest enabling to reach the goal (minimal effective dose) to avoid side effects like bone pain 5
Special Populations
Pediatric Transplant Recipients
- Neutropenia occurs in up to 25%-30% of pediatric solid organ transplant recipients within the first year after transplantation 6
- Management should address underlying causes including reducing medications, treating infections, and addressing nutrient deficiencies 6
Cancer Patients
- Neutropenia is common in cancer patients, especially during chemotherapy 5
- High-risk patients (sustained, profound neutropenia anticipated to last >1 week) require more aggressive management 5
By understanding these classifications and their clinical implications, clinicians can appropriately assess risk and implement timely interventions for patients with neutropenia.