Autoimmune Hemolytic Anemia


Autoimmune Hemolytic Anemia, Autoimmune Hemolysis, Immune Hemolytic Anemia, AIHA, Warm Hemolysis, Cold Hemolysis, Cold Agglutinin Disease, Warm Agglutinin Disease, Warm Autoimmune Hemolytic Anemia, Cold Autoimmune Hemolytic Anemia

  • Type
  • Warm Antibody (IgG mediated, more common)
  1. Mechanism
    1. IgG binds RBCs typically at Rh complex at 37 C (Body Temperature)
    2. Reticuloendothelial Macrophages ingest IgG-bound membrane
    3. Form microspherocytes which are trapped by Spleen (may result in Splenomegaly)
  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. Drug Induced Immune-Mediated Hemolysis
  • 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 at PolysaccharideAntigens
    3. C3 bound RBCs are lysed on rewarming and 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
  • Type
  • Paroxysmal (Cold Hemolysis mediated by IgG)
  • Labs
  1. Direct Coombs Test positive
  • Management
  1. General
    1. Consult with Hematology
    2. Blood Product transfusions
      1. Use caution if pRBC transfusion needed
      2. Identify least cross-reacting pRBC match
  2. Cold Hemolysis
    1. Avoid cold exposure
    2. Supportive management
  3. Warm Hemolysis
    1. Corticosteroids (e.g. Prednisone 1-1.5 mg/kg/day)
    2. Splenectomy
    3. Immunosuppressants
    4. Danazol
    5. Intravenous Immunoglobulin
    6. Plasma exchange