Hematology and Oncology Book

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Autoimmune Hemolytic AnemiaAka: Autoimmune Hemolysis, AIHA, Warm Hemolysis, Cold Hemolysis, Cold Agglutinin Disease, Warm Agglutinin Disease

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  1. Type: Warm Antibody (IgG mediated)
    1. Mechanism
      1. IgG binds RBCs at 37 C (body temperature)
      2. Macrophages ingest IgG-bound membrane
      3. Form microspherocytes which are trapped by spleen
    2. Causes
      1. Idiopathic Hemolytic Anemia (most common)
      2. Non-Hodgkin's Lymphoma
      3. Chronic Lymphocytic Leukemia (CLL)
      4. Systemic Lupus Erythematosus (SLE)
      5. Human Immunodeficiency Virus (HIV)
      6. Medications
        1. See Drug-Induced Hemolytic Anemia
  2. Type: Cold Antibody (IgM and complement mediated)
    1. Mechanism
      1. IgM transiently binds RBCs at 32 C (cold)
      2. Activates complement and C3 binds RBC membrane
      3. C3 bound RBCs are cleared by the liver
    2. Causes
      1. Human Immunodeficiency Virus (HIV)
      2. Mycoplasma pneumonia or other infection
      3. Infectious Mononucleosis
      4. Lymphoma
      5. Idiopathic
  3. Type: Paroxysmal (Cold Hemolysis mediated by IgG)
    1. See Paroxysmal Cold Hemoglobinuria
    2. Causes
      1. Tertiary Syphilis
      2. Acute Viral Infection (Mumps, Measles)
  4. Labs
    1. Direct Coombs Test positive
  5. Management
    1. General
      1. Consult with Hematology
      2. Transfusing Blood Products
        1. Use caution if pRBC transfusion needed
        2. Identify least cross-reacting pRBC match
    2. Cold Hemolysis
      1. Avoid cold exposure
    3. Warm Hemolysis
      1. Corticosteroids (Prednisone 1-1.5 mg/kg/day)
      2. Splenectomy
      3. Immunosuppressants
      4. Danazol
      5. Intravenous Immunoglobulin
      6. Plasma exchange
  6. References
    1. Schreiber in Goldman (2000) Cecil Medicine, p. 876-82
    2. Dhaliwal (2004) Am Fam Physician 69:2599
    3. Petz (2001) Curr Opin Hematol 8(6):411

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