Leukopenia

Type

Clinical features

Definitions

• Leukopenia
  • WBC < 4400 cells/microliter 
• Neutrophils 

• • Make up 40-70% of white blood cells (WBC)
  • Mature neutrophils also known as polymorphonuclear cells (PMNs)
• Absolute neutrophil count (ANC)
  • Number of neutrophils + bands
  • Excludes metamyelocytes and less mature forms
  • ANC= WBC (cells/microliter) times percent (bands + PMNs)
• Neutropenia (ANC < 1500 cells/microliter)
  • Mild
    • ANC 1000-1500 cells/microliter
  • Moderate
    • ANC 500-999 cells/microliter
  • Severe
    • ANC < 500 cells/microliter
  • Agranulocytosis
    • ANC < 200 cells/microliter
• Chronic neutropenia
  • • Neutropenia > 3 months
• Absolute lymphocyte count (ALC)
• • ALC= (WBC times percent lymphocytes)/100
• Lymphocytopenia
  • ALC < 1000 cells/microliter

Mechanisms of leukopenia

• Decreased bone marrow production or differentiation of precursor cells
• Increased destruction of cells
• Redistribution of ciculating cells to spleen or vascular endothelium