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IHO Week 2 > Anemia II > Flashcards

Anemia II Flashcards

1
Q

Things you MUST know about hemoglobinopathies:

A

(large group that sickle cell falls under)

  • Qualitative hemoglobin abnormality
  • Sickle cell - most imp.
  • Sickle cells –> hemolysis, faso-occlusion
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2
Q

Hemoglobinopathies:

A
  • Structurally abnormal hemoglobin
  • Often one amino acid away from normal!
  • Best lab test: hemoglobin electrophoresis
  • Most imp. one: sickle cell anemia
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3
Q

How does hemoglobin electrophoresis work?

A
  • Pos. charged proteins move toward cathode
  • Neg. charged proteins move toward anode
  • Mixture starts in center
  • Used to detect sickle-cell anemia and sickle-cell trait
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4
Q

What does Sickle-cell anemia, sickle-cell trait and normal show in hemoglobin electrophoresis?

A

Normal - HbA (more toward anode +)
Sickle-cell anemia - HbS (more toward cathode -)
Sickle-cell trait - HbS and HbA (both!)

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5
Q

What is the genetics of sickle-cell anemia?

A

The patient has a point mutation in beta chain (HbS) —>
Abnormal beta chains (substitution of valine for glutamate —> Nasty!
-Hemoglobin aggregates and polymerizes on deoxygenation
-Red cell becomes sickle shaped - clog up vessels and are fragile

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6
Q

What happens in capillaries of patients with sickle cell anemia?

A
  • They will get ‘infarcted’ areas of their body where blood builds up/clogs
  • Sickle cells get stuck in capillaries
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7
Q

What are the clinical findings in sickle cell anemia?

A
  • Blacks (8% are heterozygous)
  • Severity of disease is variable
  • Chronic hemolysis
  • Vaso-occlusive disease
  • Inc. infections!
  • –> sometimes due to autosplenectomy
  • –> need spleen to take care of encapsulated organisms (these are very difficult to get rid of without a spleen)
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8
Q

What is autosplenectomy?

A

It occurs in sickle cell anemia.

  • The RBCs cause little infarctions in the spleen which cause patches of fibrosis (bit of worthless fibrous tissue)
  • Usually by your teenage years with the disease you don’t have a spleen anymore
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9
Q

What other physical symptoms are seen on hands and feet of people with sickle cell anemia?

A

Ulcers! Commonly show up on hands and feet with sickle cell disease

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10
Q

What five things are seen in a “post-splenectomy blood picture”?

A
  1. Nucleated red blood cells (if hemolysis and production of RBC is ramped up - spleen usually takes care of these but here it doesn’t because the spleen is damaged
  2. Targets (red cells that look just like targets)
  3. Howell-Jolly bodies (little remnants of nucleus that usually don’t get excluded normally)
  4. Pappenheimer bodies (aggregates of iron in the cell - removed by spleen)
  5. Inc. platelet count
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11
Q

How do you treat sickle cell anemia?

A
  1. Have patient avoid climbing mountains, stay hydrated, not fly in airplanes, etc. to avoid deoxygenating their blood
  2. Prevent triggers (everybody has their own particular set of triggers): infection, fever, dehydration, hypoxemia
  3. Vaccinate against encapsulated bugs
    - –S. pneumoniae
    - –H. influenzae
  4. Blood transfusions - not always necessary
  5. Bone marrow transplantation - usually done in children
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12
Q

What do you need to know about thalassemia?

A
  • Quantitative defect in hemoglobin
  • Can’t make enough alpha or beta chains
  • Variable disease severity
  • Hypochromic, microcytic anemia with increased RBC and target cells
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13
Q

When does the gamma to beta hemoglobin switch happen?

A

Around a few months to a year of age

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14
Q

What is Hgb F?

A

Hemoglobin in fetus alpha2gamma2

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15
Q

What is Hgb A?

A

Dominant hemoglobin in adult alpha2beta2

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16
Q

Why is it better to have beta-thalassemia?

A

No other chain substitutes for alpha chains!

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17
Q

What genes are related to thalassemia?

A
  1. Normal globin genes
    - –4 alpha genes (nothing you can substitute for alpha chains)
    - –2 beta genes
  2. Globin genes in thalassemia
    - –alpha-thal: deletion of alpha-chain gene(s)
    - –beta-thal: deletion of beta-chain gene(s)
  3. Globin chains in thalassemia
    - –alpha-thal: Dec. amount alpha chains
    - –beta-thal: Dec. amount beta chains
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18
Q

What happens when the beta gene is defective?

A

Problem in beta-thalassemia: defective transcription, translation and processing of mRNA of beta-chain gene

  • Severity of defect:
  • –beta gene: normal gene
  • –beta+ gene: produces some beta chains
  • –beta0 gene: produces no beta chains
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19
Q

Genes in alpha-thalassemia:

A 
Problem: alpha-chain genes are absent
-Gene combinations in alpha-thalassemia: 
a/aa silent
--/aa or -a/-a alpha-thal trait
--/-a HbH disease
--/-- Hydrops fetalis
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20
Q

What causes anemia in thalassemia?

A
  1. Alpha thalassemia
    - Not enough alpha chains
    - Excess unpaired beta, gamma or delta chains
    - –Newborns have gamma4 tetrameters that stick together and then macrophages will try to eat the cells
    - –Adults: beta4 tetramers (HbH)
  2. Beta thalassemia
    - Not enough beta chains
    - Excess unpaired alpha chains
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21
Q

What is the morphology of thalassemia?

A
  • Hypochromic, microcytic anemia (In iron deficiency, each new wave of red cells gets smaller, but in thalassemia this doesn’t happen. Iron stores are going down in other conditions but in thalassemia it will remain the same size)
  • Depending on severity:
  • –minimal anisocytosis (odd size) and poikilocytosis(odd shape), or
  • –marked anisocytosis and poikilocytosis
  • Target cells
  • Basophilic stippling (little punctate blue dots through the cell)
  • Some nucleated red cells in severe cases
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22
Q

What are the clinical findings in alpha-thalassemia?

A
  • Asians, black
  • Carrier state and that trait: asymptomatic
  • HbH disease: moderate to severe disease (hemoglobin H disease)
  • Hydrops fetalis: fatal in utero (not compatible with life)
23
Q

What can happen with medullary expansion in thalassemia?

A
  • Patient may start making bone marrow where you normally don’t - make marrow in the skull (funny looking striations coming up from the skull = lines of marrow)
  • Can see this and chipmunk face in anemia that’s extremely severe!! (bones of face become enlarged (maxilla and parts of jaw)
24
Q

What are the clinical findings in beta-thalasssemia?

A
  • Mediterraneans, blacks, asians
  • Thal. minor: usually asymptomatic
  • Thal. major: variable severity, usually presents in infancy
25
Q

What things MUST you know about Glucose-6-Phosphate Dehydrogenase Deficiency?

A
  • Dec. G6PD –> Inc. peroxides –> cell lysis
  • Oxidant exposure
  • Bite cells (removal of Heinz bodies)
  • Self-limiting
  • Need G6PD in order to keep NADP in reduced state and glutathione in a state that can detoxify free radicals and oxidants
  • Oxidants can damage hemoglobin and cause heinz bodies
26
Q

Why do G6PD-Deficient red cells die?

A
  • They can’t reduce nasties
  • Nasties attack hemoglobin bonds
  • Heme breaks away from globin
  • Globin denatures, sticks to red cell membrane (“Heinz body”)
  • Spleen bite out Heinz bodies
27
Q

Where is the highest incidence of G6PD?

A

Areas where malaria is epidemic - because the disease heterozygote is protective in areas of the world with malaria!

28
Q

What are clinical findings with C6PD deficiency?

A
  • Some patients are asymptomatic
  • Others have episodic hemolysis
  • Triggers: broad beans (fauvism), drugs (antibiotics, aspirin)
  • Spontaneous resolution
  • Can have jaundiced sclera due to hemolysis (high bilirubin)
29
Q

What is the morphology of G6PD deficiency?

A
  • Without exposure, there’s no anemia
  • After exposure, you get acute hemolysis (get an episode)
  • –Bite cells, fragments (macrophage bitten heinz bodies)
  • –Heinz bodies (blue dots in cytoplasm)
30
Q

What MUST you know about microangiopathic hemolytic anemia (MAHA)?

A
  • Physical trauma to red cells
  • Schistocytes (fragmented RBCs)
  • Find out why!!
31
Q

What are the causes of MAHA (microangiopathic hemolytic anemia)?

A
  • Artificial heart valve

- Anything causing DIC, TTP or HUS

32
Q

What is seem morphologically in MAHA?

A
  • Fibrin thrombi in microvasculature (blood clot of lung capillaries)
  • Red cells stuck in fibrin strand
33
Q

How can fragmented cells (schiztocytes) form?

A

-Going through small vessel, bursting open (could be implied on fibrin strand in microcirculation) and then reselling into something with points on it (larger half become helmet cell and smaller half becomes microspherocyte

34
Q

What must you know about anemia of blood loss?

A
  • Normal size and shape RBCs
  • Cause: traumatic, acute blood loss
  • At first, hemoglobin is normal!!
  • After 2-3 days, you see reticulocytes (body trying to replish itself quickly - they are a little larger than RBCs and have bluish tinge to their cytoplasm)
  • Chronic blood loss is different (it causes iron deficiency anemia)
35
Q

What are reticulocytes?

A

-A little large than normal, mature red blood cells, bluish purple tinge - should be 1% or less in normal person

36
Q

What things MUST you know about anemia of chronic disease?

A

AOCD - normal size and shape RBCS

  • Infections, Inflammation, malignancy
  • Iron metabolism disturbed
  • Normochromic normocytic anemia
  • Anemia usually mild
37
Q

What is frustrating about anemia of chronic disease?

A

When you look on the slide, the red cells look totally normal!!

38
Q

What different conditions can cause AOCD?

A
  • Malignant conditions: Carcinoma, Lymphoma, Leukemia, Multiple Myeloma
  • Inflammatory conditions: Rheumatoid arthritis, Systemic lupus erythematus, severe trauma
  • Infectious conditions: Pulmonary infections, Subacute bacterial endocarditis, Pelvic inflammatory disease, Osteomyelitis, Chronic UTI, Meningitis
39
Q

What is the pathogenesis of anemia of chronic disease?

A
  • Disturbed iron metabolism
  • –Absorption is okay. . . but release is screwed up
  • –Can’t get iron into hemoglobin
  • –Hepcidin over-produced
  • Shortened RBC survival
  • Impaired marrow response to anemia
40
Q

What do the labs look like in ACD vs IDA?

A 
ACD (anemia of chronic disease)
-Dec. serum iron
-Dec TIBC (=transferrin)
-Inc. ferritin
-Inc. marrow storage iron (shouldn't look at this though)
IDA (iron deficiency anemia)
-Dec. serum iron 
-Inc. TIBC (=transferrin)
-Dec. ferritin
-Dec. marrow storage iron
41
Q

What things must you know about anemia of renal disease?

A
  • End-stage renal failure
  • Cause: lack of erythropoietin
  • May see echinocytes (spiky red blood cells!!)
42
Q

What are the clinical features of anemia of renal disease?

A
  • End-stage renal failure

- Anemia severity roughly correlates with degree of renal failure

43
Q

How to manage anemia of renal disease?

A
  • If mild, need to treat

- If severe, you need to replace erythropoietin

44
Q

What things MUST you know about anemia of liver disease?

A
  • Anemia is frequent in liver disease
  • Multiple causes
  • “uncomplicated” cases are rare
  • May see acanthocytes (spur cells), targets
45
Q

What are causes of anemia of liver disease?

A
  • Uncomplicated anemia of liver disease:
  • –Dec. RBC survivial and impaired marrow response
  • Other factors can complicate the picture
  • –Folate deficiency
  • –Iron deficiency from frequent hemorrhages
46
Q

What is the morphology of anemia of liver disease?

A
  • Uncomplicated cases
  • –mild anemia
  • –usually normocytic; sometimes macrocytic
  • –Poikilocytosis (targets, acanthocytes- spur cells!)
  • Complicated cases:
  • –Megaloblastosis (from folate deficiency)
  • –Microcytosis (from iron deficiency)
47
Q

What are the clinical findings of anemia of liver disease?

A
  • 3/4 of patients with liver disease are anemic!
  • Most cases are “complicated”
  • Alcohol abusers may get hemolytic episodes (which resolve with withdrawal of alcohol)
48
Q

What things MUST you know about Aplastic Anemia?

A
  • Pancytopenia (reduced red cells, white cells and platelets)
  • Empty marrow
  • Most are idiopathic
49
Q

What are the causes of aplastic anemia?

A
  • Idiopathic
  • Drugs
  • Viruses
  • Pregnancy
  • Fanconi anemia
50
Q

What are the clinical findings in aplastic anemia?

A
  • Pallor, dizziness, fatigue (anemia)
  • Recurrent infection (leukopenia)
  • Bleeding, bruising (thrombocytopenia)
51
Q

What is the morphology of aplastic anemia?

A

Blood: empty

Bone marrow: empty

52
Q

What do you see on a blood smear of aplastic anemia?

A
  • Large spaces between red cells
  • RBCs look normal because there is much hemoglobin
  • All three cell lines are decreased
53
Q

What does the bone marrow look like in aplastic anemia?

A
  • Bone marrow fills with fat

- Don’t see many red or white cell precursor cells

54
Q

How do you treat aplastic anemia?

A
  • Avoid further exposure
  • Give blood products
  • Drugs: G-CSF, prednisone, ATG
  • Bone marrow transplant as last resort
  • 3-year survival: 70%

IHO Week 2 (12 decks)

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