Initial Workup for Leukopenia
The initial workup for a patient with leukopenia should include a complete blood count with differential, peripheral blood smear evaluation, and a thorough clinical assessment to determine the underlying cause. 1
Initial Laboratory Studies
- Complete blood count (CBC) with differential is essential to confirm leukopenia and determine which white blood cell lines are affected 1
- Peripheral blood smear evaluation to assess morphology of remaining white blood cells and identify potential dysplastic changes 1
- Review of previous blood counts to determine if leukopenia is acute or chronic 2
- Evaluation of other cell lines (red blood cells, platelets) to determine if there is isolated leukopenia or pancytopenia, which suggests bone marrow involvement 2
Clinical Assessment
- Detailed medication history to identify drug-induced leukopenia (common medications include carbamazepine and other anticonvulsants) 3
- History of recent infections, as viral infections can cause transient leukopenia 4
- Assessment for signs of infection, as infection can both cause and result from leukopenia 5
- History of exposure to toxins, radiation, or chemotherapy 1
- Family history of hematologic disorders to identify potential hereditary causes 6
- Physical examination with focus on lymphadenopathy, hepatosplenomegaly, and signs of infection 1
Further Diagnostic Workup Based on Initial Findings
For Suspected Bone Marrow Disorders
- Bone marrow aspirate and biopsy for morphologic evaluation if acute leukemia or bone marrow failure is suspected 6
- Flow cytometry immunophenotyping to distinguish between different types of leukemia if suspected 6
- Cytogenetic analysis (karyotype) and molecular genetic testing for suspected leukemia 6
For Other Etiologies
- Autoimmune markers if autoimmune disease is suspected 1
- Vitamin B12 and folate levels to rule out megaloblastic anemia 1
- Spleen imaging if hypersplenism is suspected 1
- Comprehensive metabolic panel to evaluate for tumor lysis syndrome if malignancy is suspected 6
Common Etiologies of Leukopenia
- Decreased production due to bone marrow failure (aplastic anemia, leukemia) 5
- Medication-induced leukopenia 3
- Viral infections (HIV, hepatitis, influenza) 4
- Autoimmune disorders (lupus, rheumatoid arthritis) 4
- Hypersplenism causing increased sequestration 5
- Nutritional deficiencies (B12, folate) 4
Special Considerations
- If neutropenia is severe (absolute neutrophil count < 500/mm³), there is a high risk of infection requiring immediate attention 3
- For patients with fever and neutropenia, prompt initiation of broad-spectrum antibiotics is essential to reduce mortality 2
- Avoid invasive procedures in patients with severe neutropenia due to risk of infection 7
Management Approach
- Identify and treat the underlying cause 5
- For drug-induced leukopenia, consider discontinuation of the offending agent 3
- For infection-related leukopenia, treat the underlying infection 4
- For severe neutropenia with fever, immediate hospitalization and broad-spectrum antibiotics are required 2
- For suspected acute leukemia, urgent hematology consultation and specific diagnostic workup are needed 6