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Acc to Goljan, serum LDH levels are increased in extravascular hemolysis (RBC phagocytosis in macrophages of spleen n liver)..shouldn't the LDH levels increase in Intravascular hemolysis instead of extravascular?
 

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LDH levels shouldn't be elevated in Extra vascular hemolysis

Btw checked goljan RR 4ed pages 303,304 it says LDH is increased in both extra and intravascular hemolysis from hemolyzed RBCs

But I think you want to take a look at this thread

Code:
http://www.usmle-forums.com/usmle-step-1-bits-pieces/324-intravascular-versus-extravascular-hemolysis.html
:cool:
 

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Acc to Goljan, serum LDH levels are increased in extravascular hemolysis (RBC phagocytosis in macrophages of spleen n liver)..shouldn't the LDH levels increase in Intravascular hemolysis instead of extravascular?
LDH levels are elevated in both intra- and extra-vascular hemolysis, though they would be higher in intra- than they are in extra-.

Understanding LDH is an important clinical mechanism for step 1. Remember that it's function is regenerating NAD+ in the absence of O2. In the case of RBCs, it's because they lack mitochondria and have to rely only on glycolysis to generate ATP.

If you lyse RBCs in the vasculature, you release all of that LDH into circulation. If you do it extravascularly in the spleen, you'll still release LDH into circulation albeit in smaller amounts. You will never be asked to distinguish intra vs extra only by LDH; they will also give you haptoglobin, a direct coombs, or urine Hgb levels to help you distinguish them.

Remember that other things can also increase LDH: anything that increases anaerobic metabolism(ischemia), anything that preferentially uses glycolysis (some cancers), and anything that generates more NADH than you can handle (high EtOH ingestion).
 
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