Anemia Syndromes

    Approach to Anemia

    • Pathologic state due to insufficient erythrocytes.
    • Easiest way to classify:
      • 2ndary to loss
      • 2ndary to lack of production
      • 2ndary to destruction
    • Symptoms:
      • Tachycardia, exertional dyspnea, pallor of nails/conjunctiva, fatigue, reduced exercise tolerance.
    • Labs:
      • CBC
    • Pathology:
      • To make RBC, require: Epo (Made in Kidney), Iron, Cobalamin, Vitamin B12, marrow microenvironment.
    • Approach:
      • Look at MCV (micro/normo/macrocytic)
      • Peripheral blood smear (always look at smear).
      • Reticulocyte Count: (tells you if the marrow is working).
        • Typically a % of normal erythrocytes
        • Now done with flow cytometry.  
        • Patients with anemia have LOW total erythrocytes 
        • Often corrected as reticulocyte index as bone marrow stress causes increased Epo production --> doubles of half-life of circulating reticulocytes (multiply by 0.5).
          • Therefore, must correct to reticulocyte index = %retics * hematocrit (/45 *0.5)
          • (last part is the correction factor for the doubling of retics)
        • Absolute Retic Counts:
          (some labs do FLOW cytometry, which reports Absolute Number--> eaier to use, less available)
          • Retic Count Retic Index Interpretation
            23,000-90,000/uL <2% Normal (Inappropriate Response to Anemia)
            > 100,000/uL >3% Appropriate Anemia Response

            (Retic Index numbers: wikipedia, Retic count numbers: MKSAP 16)
          •  
      • AnemiaApproach copy.png
    • Mentzner index to distinguish thalassemia vs iron def anemia
      • MCV/RBC -->
        • <13 - talassemia (bone marrow still produces enough RBC)
        • >13 - Iron def anemia (bone marrow cannot produce as many, so there are few RBCs and microcytic)

    AnemiaApproach2nd.png

    Microcytic Anemia

    DDx TAILS

    • Thalassemia
    • Anemia of Chronic Disease
    • Iron Deficiency Anemia
    • Lead Poisoning
    • Sideroblastic Anemia

    Standard Workup:

    • Blood Film
    • Ferritin
    • Retics
    • B12  (Folate low yield)

    Can use RDW to help distinguish etiologies:

    • Iron Deficiency: increased RDW (anisocytosis)
    • Thalassemia minor: normal RDW (also expect high RBC count)

     

    Thalassemia

    • Risk factors:
      • Thalassemia major --> only in kids
      • B-thalassemia --> Mediterranian, Middle eastern.
    • Labs:
      • Microcytic anemia but Normal Ferritin.
      • Persistently low MCV (MCV not changing if you trend it).
      • Low RDW
      • Hemoglobin electrophoresis
        • If normal can still be alpha-thalassemia (B-thal will show up).  Need to do genetic testing.
      • Genetic testing = Definitive.

    Normocytic Anemia

    • Nutritional (Can be IDA, folate, B12, sick cell, methotrexate)
    • Renal Failure (Often CKD stage 4)  EPO deficiency.  If giving Epo, ensure has iron too.
    • Active Bleed

     

    Macrocytic Anemia

    • EtOH Use
    • Myelodysplastic Syndrome
    • Folate Deficiency
    • B12 Deficiency (also glossitis, weight loss, macroovalocytes, hypersegmented PMNs, hemolysis, posteriour columns neuro deficits).
    • etc...

    Multiple Myeloma

    • Pt may have history of fractures
    • sPEP and uPEP (Serum Protein ElectroPhoresis, and urine Protein Electrophoresis)
    • sPEP --> 80% sensitivity
      • adding uPEP --> raises sensitivity to 80-95% sensitivity
      • for uPEP they do spot urine for Bence Jones Proteins (even thought called uPEP)
    • 5% of patients with MM will have normal sPEP and uPEP

     

    Pancytopenia

    Causes

    • Primary BM Failure:  (MDS, Aplastic Anemia)
    • Malignancy:  (Leukemia)
    • Infiltrative Process (TB, Amyloidosis, Sarcoidosis)
    • Drugs (Chemotherapy)

    Aplastic Anemia

    • Destruction of hematopoietic cells in BM leading to pancytopenia and hypocellular bone marrow.
    • Etiology: (BROAD!)
      • Congenital
        • Fanconi's Anemia (genetic DNA repair problem, leads to leukemias and BM failure in Ashkenazi)
        • Shwachman-Diamond Syndrome (BM failure and pancreatic insufficiency)
      • Acquired
        • Idiopathic (T-cell mediated - 1/3 to 2/3 of cases)
        • Drugs (Chemotheraputic agents, and idiosyncratic rxns chloramphenicol, phenylbutazone)
        • Toxins (Benzene, organic solvents, DDT, insecticides)
        • Ionizing Radiation
        • Post-Viral Infection (parvovirus B19, EBV, HDV, HEV, HHV6, HIV)
        • Autoimmune (SLE) - rare
        • Paroxysmal nocturnal hemoglobinuria (PNH) - associated with aplastic anemia, but not cause.
    • Investigations:
      • No LAD, can be acute or insidious
      • Anemia, neutropenia, Thrombocytopenia +/- pancytopenia.
      • Blood film (decreased number of RBC)
      • Bone Marrow (Hypocellular, hypoplasia, fat replacement)
    • Treatment:
      • Remove Offending Agent
      • Supportive care (transfusions, antibiotics)
      • Immunosuppression (anti-thymocyte globulin - 50-60% respond, cyclosporine).
      • Allogenic BM transplant.

    Notes

    • Bone Marrow Suppression causes 10 g/L/week loss of Hb.  NOT MORE!  
    • High RDW associated with:
      • Iron deficiency anemia, hemolytic anemias, myelofibrosis, blood transfusion
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