II. Epidemiology

  1. More common in females by 8:1 ratio

III. Causes: Acute Autoimmune Neutropenia

  1. Primary Autoimmune Neutropenia
    1. Peak Prevalence in children age <10 years
    2. Most common in girls
    3. Typically self limited
  2. Secondary Causes
    1. Drug-Induced Autoimmune Conditions
    2. Viral Infections

IV. Types: Chronic Autoimmune Neutropenia

  1. Primary Autoimmune Neutropenia
    1. Neutropenia >3 months
    2. Associated with minor infections
    3. ANC increases during times of infection or emotional stress
  2. Secondary Causes
    1. Autoimmune disorders
      1. Rheumatoid Arthritis (RA)
      2. Systemic Lupus Erythematosus
      3. Sjogren Synrome
      4. Felty Syndrome
    2. Hematologic Malignancy
      1. Chronic Lymphocytic Leukemia
      2. Hodgkin Lymphoma
      3. Non-Hodgkin Lymphoma
      4. Hairy Cell Leukemia
      5. Waldenstrom Macroglobulinemia
      6. T-Cell Large Granular LymphocyteLeukemia
        1. Associated with Felty Syndrome (advanced RA, Neutropenia, Splenomegaly)
    3. Solid cancers (e.g. thymoma)
    4. Immunodeficiency (e.g. Common Variable Immunodeficiency, autoimmune lymphoproliferative syndrome)

V. Labs

  1. Antineutrophil Antibody positive
    1. Low Test Sensitivity and Test Specificity
    2. Consider at least 2 separate tests
    3. Does not predict course
  2. Bone Marrow Biopsy indications
    1. Clinical suspicion high, but negative Antineutrophil Antibody

VI. Management

  1. See Neutropenia
  2. Treat underlying causes
  3. Consider Granulocyte Colony Stimulating Factor (G-CSF, esp. with severe recurrent infections)
    1. Filgrastim (Neupogen)
    2. Pegfilgrastim (Neulasta)
    3. Sargramostim

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