Anemia Kristine Krafts

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					Anemia
Kristine Krafts, M.D. | November 9, 2009
    Anemia Outline



• Background facts about blood
• Anemia: general information
• Anemia: specific types
    Anemia Outline



• Background facts about blood
Normal blood cells
      Complete Blood Count (CBC)



RBC           hemoglobin     hematocrit
               Complete Blood Count (CBC)


               MCV                             MCHC




microcytic   normocytic   macrocytic   hypochromic normochromic
Additional Red Blood Cell Properties


Size variation                 Shape




 anisocytosis                 poikilocytosis
Normal red blood cells
    Anemia Outline



• Background facts about blood
• Anemia: general information
             Definition



      An (without) -emia (blood):
      a reduction below normal
in hemoglobin or red blood cell number.
Symptoms of Anemia


• None! (if slow or mild)
• Fatigue
• Breathlessness
• Dizziness
• Pale skin, mucous membranes
• Jaundice (if hemolytic)
• Tachycardia
Three Ways to Become Anemic


   • Lose blood
   • Destroy too much blood
      • Extracorpuscular stuff
      • Intracorpuscular stuff

   • Make too little blood
      • Not enough building blocks
      • Not enough erythroblasts
      • Not enough room
    Anemia Outline



• Background facts about blood
• Anemia: general information
• Anemia: specific types
Three Ways to Become Anemic


   • Lose blood
      Anemia of Blood Loss

         Things you must know

• Cause: acute blood loss due to trauma.
• Immediately after blood loss,
  hemoglobin is normal!
• After fluid replacement, low
  hemoglobin, but cells look normal.
• After 2-3 days, see reticulocytes.
• Chronic blood loss is different (it causes
  iron deficiency anemia).
Reticulocytes
Three Ways to Become Anemic


   • Lose blood
   • Destroy too much blood
      Hemolytic anemias


• Intracorpuscular vs. extracorpuscular
• Chronic vs. acute
• Signs of destruction: ↑ bilirubin, ↑ LDH,
  ↓ haptoglobin
• Signs of production: ↑ reticulocytes,
  nucleated red cells in blood
Three Ways to Become Anemic


   • Lose blood
   • Destroy too much blood
      • Extracorpuscular stuff
Microangiopathic Hemolytic Anemia

         Things you must know


     • Lots of causes, many dangerous
     • Red cells get ripped up, forming
       schistocytes
     • Need to find out why!
Red cell snagged on fibrin strand
MAHA: schistocytes
Microangiopathic Hemolytic Anemia

               Causes

       • Dumpers
         • Obstetric complications
         • Adenocarcinoma
         • Acute promyelocytic leukemia
       • Rippers
         • Bacterial sepsis
         • Trauma
         • Vasculitis
Autoimmune Hemolytic Anemia

      Things you must know

     • Warm AIHA
        • IgG
        • Spleen
        • Spherocytes
     • Cold AIHA
        • IgM, complement
        • Intravascular hemolysis
        • Agglutination
Warm AIHA
Warm AIHA
Warm AIHA
Cold AIHA
Cold AIHA
patient red cells   +   AHG   =    agglutination


        Direct antiglobulin test (DAT)
Three Ways to Become Anemic


   • Lose blood
   • Destroy too much blood
      • Extracorpuscular stuff
      • Intracorpuscular stuff
      Sickle Cell Anemia

      Things you must know

• Hemoglobinopathy (qualitative defect
  in hemoglobin)
• Single amino acid substitution in beta
  chain of hemoglobin
• Can be heterozygous or homozygous
• Sickle cells are nasty:
   • Fragile (burst easily)
   • Get stuck in vessels
Hemoglobin
     Point mutation in  chain gene


           abnormal  chains
  (substitution of valine for glutamate)




                 Hgb S
                 Nasty!
Aggregates and polymerizes on deoxygenation
      Red cell becomes sickle shaped
         Sickles clog up vessels…
           …plus, they are fragile
Sickle cell anemia
Sickle cell anemia: foot lesion
Sickle cell anemia: spleen
           Sickle Cell Anemia

               Clinical features

• Blacks (8% are heterozygous)
• Chronic hemolysis
• Vaso-occlusive disease (bones, lungs, limbs)
•  susceptibility to infection (autosplenectomy)
• Treatment: prevent triggers, vaccinate, transfuse
               Sickle Cell Anemia

                   Boards Question

Which of the following describes a major effect of
sickle cell anemia?

A. Absence of biphosphoglycerate binding of hemoglobin
B. Substitution of 2 proximal histidines
C. Decreased solubility of the deoxy form of hemoglobin
D. A P50 value for hemoglobin similar to that of myoglobin
E. Decreased number of subunits in hemoglobin
          Thalassemia

       Things you must know


• Quantitative defect in hemoglobin
• Can’t make enough α or β chains
• Variable disease severity
• Hypochromic, microcytic anemia with
  increased RBC and target cells
       α
                                β
           γ




                       δ
               birth
Hgb F = α2γ2    Hgb A2 = α2δ2       Hgb A = α2β2


       Hemoglobin chain development
Thalassemia
Thalassemia: Medullary expansion
Hereditary Spherocytosis

   Things you must know


  • Defect in spectrin
  • Tons of spherocytes
  • Splenectomy curative
z
Hereditary spherocytosis
Jaundice
Splenomegaly in hereditary spherocytosis
Glucose-6-Phosphate Dehydrogenase Deficiency

               Things you must know

         • ↓ G6PD → ↑ peroxides → cell lysis
         • Oxidant exposure
         • Bite cells
         • Self-limiting
Glucose-6-Phosphate Dehydrogenase Deficiency

                  Clinical features

         • G6PD gene is on X chromosome
         • Highest incidence in malaria regions
         • After oxidant exposure, get acute
           hemolysis
         • Self-limiting
Glucose-6-Phosphate Dehydrogenase Deficiency

             Why do the red cells die?

         • They can’t reduce nasties
         • Nasties attack hemoglobin bonds
         • Heme breaks away from globin
         • Globin denatures and sticks to RBC
           membrane, forming Heinz body
         • Macrophages bite out Heinz bodies,
           leaving cell fragile and deformed
Glucose-6-phosphate dehydrogenase deficiency
Three Ways to Become Anemic


   • Lose blood
   • Destroy too much blood
   • Make too little blood
Three Ways to Become Anemic


   • Lose blood
   • Destroy too much blood
   • Make too little blood
      • Not enough building blocks
Iron Deficiency Anemia

   Things you must know

• Many causes; most important is
  bleeding from GI tract
• Hypochromic, microcytic anemia
• Must find out why patient is
  anemic! Then treat.
Hemoglobin
Iron-deficiency anemia
Atrophic glossitis in iron-deficiency anemia
Koilonychia in iron-deficiency anemia
Iron Deficiency Anemia

         Causes


 • Decreased iron intake
 • Chronic blood loss
 • Increased iron requirement
 Anemia of Chronic Disease

       Things you must know


• Infections, inflammation, malignancy
• Disturbance in iron metabolism
• Normochromic, normocytic anemia
• Anemia usually mild
 Megaloblastic Anemia

     Things you must know


• Defective DNA synthesis leads to
  nuclear/cytoplasmic asynchrony
• B12/folate deficiency
• Macrocytic anemia with
  hypersegmented neutrophils
Megaloblastic Anemia

 retarded DNA synthesis
unimpaired RNA synthesis




     BIG cells!
   immature nucleus
   mature cytoplasm
           Megaloblastic Anemia

               How is B12 involved?


• B12 (and folate) are required for DNA synthesis.
   • Slowed DNA synthesis means big, immature nucleus
   • Cytoplasm (with RNA in it) matures just fine
• B12 is also required for conversion of homocysteine
  to methionine
   • ↑ homocysteine = atherosclerosis!
   • ↓ methionine = subacute combined degeneration
Megaloblastic anemia
Megaloblastic anemia
Atrophic glossitis in megaloblastic anemia
Three Ways to Become Anemic


   • Lose blood
   • Destroy too much blood
   • Make too little blood
      • Not enough building blocks
      • Not enough erythroblasts
 Aplastic Anemia

 Things you must know


• Pancytopenia
• Empty bone marrow
• Most are idiopathic
Aplastic anemia
Aplastic Anemia

      Causes

• Idiopathic
• Drugs
• Viruses
• Pregnancy
• Fanconi anemia
               Aplastic Anemia

                 Boards Question

In anemia resulting from drug-induced bone marrow
suppression, the peripheral blood smear shows erythrocytes
to be:

A. hypochromic, microcytic
B. hypochromic, normocytic
C. normochromic, normocytic
D. normochromic, microcytic
E. hyperchromic, macrocytic
Three Ways to Become Anemic


   • Lose blood
   • Destroy too much blood
   • Make too little blood
      • Not enough building blocks
      • Not enough erythroblasts
      • Not enough room
Bone marrow full of fibrosis

				
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