Aplastic anemia

    • Marrow failure resulting in severe pancytopenia
    • Two mechanisms for are postulated:
      • Stem cell defect
      • Immune-mediated destruction
    • Etiology
      • Viral hepatitis
      • Chloramphenicol (idiosyncratic)
      • Parvovirus B19 with sickle cell anemia (MCQ)
      • Benzene (dose related), lindane, DDT
    • Signs and symptoms
      • Weakness, fatigue
      • Mucosal bleeding
      • Pallor
    • Diagnosis
      • Normochromic, normocytic pancytopenia
      • Low reticulocyte count(MCQ)
    • Treatment
      • Bone marrow transplant is treatment of choice
      • prior blood transfusions can impair success due to sensitization to minor HLA antigens. (MCQ)
      • Immunosuppression (steroids, cyclophosphamide) (MCQ)
    • Clinical Pearls :
        • Patients with erythema infectiosum (causative agent: parvovirus B19) should avoid contact with patients with sickle cell anemia due to the risk of aplastic anemia. (MCQ)
        • No abnormal cells seen on peripheral smear
        • Causes of aplastic anemia. (MCQ)
          • Congenital (rare)
          • "Idiopathic" (probably autoimmune)
          • Systemic lupus erythematosus
          • Chemotherapy, radiotherapy
          • Toxins: benzene, toluene, insecticides
          • Drugs: chloramphenicol, phenylbutazone, gold salts, sulfonamides, phenytoin, carbamazepine, quinacrine, tolbutamide
          • Posthepatitis
          • Pregnancy
          • Paroxysmal nocturnal hemoglobinuria
      • Causes of pancytopenia. (MCQ)
        • Bone marrow disorders
          •   Aplastic anemia
          •   Myelodysplasia
          •   Acute leukemia
          •   Myelofibrosis
          •   Infiltrative disease: lymphoma, myeloma, carcinoma, hairy cell leukemia
          •   Megaloblastic anemia
        • Nonmarrow disorders
          •   Hypersplenism
          •   Systemic lupus erythematosus
          •   Infection: tuberculosis, AIDS, leishmaniasis, brucellosis
      • Severe aplastic anemia is defined by a (MCQ)
        • neutrophil count of less than 500/mcL
        • platelets less than 20,000/mcL
        • reticulocytes less than 1%,
        • bone marrow cellularity less than 20%
      • Treatment of choice for young adults (under age 50) who have HLA-matched siblings is allogeneic bone marrow transplantation. (MCQ)
      • Children or young adults may also benefit from allogeneic transplantation using an unrelated donor. (MCQ)
      • For adults over age 50 years or those without HLA-matched donors, the treatment of choice for severe aplastic anemia is immunosuppression with antithymocyte globulin (ATG) plus cyclosporine (or tacrolimus) (MCQ)
      • High-dose immunosuppression with cyclophosphamide, has produced remissions in refractory cases and should be considered for patients without suitable bone marrow donors. (MCQ)
      • Androgens (oxymetholone) have been widely used in the past, with a low response rate.

      Johns Hopkins Medicine: Aplastic Anemia
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      Aplastic Anemia Awareness
      Aplastic Anemia Awareness week is March 1-7. Share this video with everyone you know & spread awareness of this bone marrow disease! In this video you will be introduced to the basics of aplastic anemia as well as a few of the warriors who continue to fight it! Everyone diagnosed with AA wants others to know WHAT it is they’re fighting. Knowledge is power & this disease is no exception to the rule! Knowledge can SAVE LIVES! YOU can save someone elses life or even your own life with the information that you glean from watching this informative video. One important fact that all of us want to relay to the world is this: ****YOU are the CURE for this disease!**** With YOUR blood donations, with YOUR willingness to be on the bone marrow registry, we who fight this illness are given HOPE! (Please remember that during the holiday season the need for donations of blood increases. Please, if you have time, go donate blood & continue to save lives! Thank-you.)