3.20 CHESNEY Thalassemias Flashcards Preview

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Flashcards in 3.20 CHESNEY Thalassemias Deck (10):

Why do thalassemias exist?

Give carry advantage to survival in certain regions


Why is there anemia?

With lack of beta, there will be excess alpha which will ppt out and deform and destroy the RBC (hemolytic anemia)
-BM message to increase RBC production with quick turnover could lead to iron overload


What distorts bones in beta?

Increased production in BM can lead to hyperplasia which can lead to thinning of the bones and deformities of the bones
-Usually seen in major


What happens to the liver and spleen with Beta

-both are enlarged
-Spleen is overworked b/c of hemolytic anemia and trying to clear everything
-Liver is trying to help and enlarging, could see Fe overload


What are some consequences of Iron overload

-More likely to get infection
-Healing problems which could also lead to infection
-Ulcers on the ankles
-take out spleen, but very dangerous to do b/f the pt is 6y.o.
-Removal of spleen will make pt susceptible to encapsulated bacteria


Why iron overload?

-Transfusion Iron (no excretion mech)
-Increased absorption b/c of anemia and signaling to make more RBC
-Iron overload in liver can lead to hepatocellular carcinoma from the cirrosis damage



Membrane damage by alpha hemichromes and oxidant stress
Phosphatidylserine exposed to outside
--recognition site for cell removal during apoptosis
--increased thrombin production
-Increased plasma free Hgb
-Increased platelet activation (esp w/ stasis)
Thrombotic complication reduced with transfusion therapy


Why variable presentation?

-Outcome depends on what the pt can make, any beta at all is better than none
-and ability to upregulate other froms of Hgb


Peripheral Smear

Target Cells and basophilic stippling, hypochromatic
-means bm is cranking out new cells rapidly and the spleen is overworked b/c it would have otherwise clear these.
-With major will see nucleated RBC



Present with Tiredness, low MCV, normal RDW
-Normal or high iron
-HPLC and electrophoresis with beta to look for increased A2 and other conc of other Hgb's