Quinn
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What is the difference btw pyruvate kinase deficiency and glucose 6-phosphate deficiency? They both cause hemolytic anemia. Basically, if you had a px with hemolytic anemia. How would you differ btw the two.
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| peekay
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G6PD PATIENT MIGHT HAVE EXPOSURE TO A REDUCING AGENT/DRUG.AND I THINK ON SMEAR REVIEW U WILL SEE HEINZ BODIES.
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| Quinn
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right!!!! 
But, why exactly no heinz bodies in PK def.?
Good peekay, but there is more...what about inheritance....
Both are found in RBCs....so, what happens to the RBC if they are missing?
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| peekay
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i don't remember exactly but i think in PK it is glycolytic def. and in G6PD it also involve dna synth.( incomplete syn. leads to RNA remnants(heinz bodies)
PK is autsomal recessive and G6Pd is sex linked ( i need to check this again.
premature death of cells due to lack of these enzymes.
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| mjl1717
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They both cause hemolysis but PK is much less common
key words for G6PD
1) Bite cells 2) intrinsic anemia with mostly intravascular hemolysis**
3) to a lesser extent extravascular hemolysis
4)reduces glutahione
5)neutralize peroxide
6)peroxide derived from oxidant injury (infection or drugs)
7)miniscule amouts of NADPH/NADPH oxidase for neutrophils 
8)decrease MPO
9)some culprits-Bactrim,primaquine,acetanilid,fava bean
10) protect against falciparum
peekay as i remember and as you mentioned PK deficiency is between
phosphophenol pyruvate and pyruvate and water is given off.(Glycolysis)
Hope this gives some insight and some repitition
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| Sakaki-
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The Heinz bodies are oxidized, denatured hemoglobin; these insoluble precipitates are what stains with the supravital stain. The glucose-6-phosphate dehydrogenase is needed to maintain adequate levels of reduced glutathione, which is needed to protect the cells from oxidative stress. These RBCs with Heinz bodies are recognized as abnormal by the mononuclear phagocyte system, and the macrophages take "bites" out of them, leading to the "bite" cells. As mjl1717 stated, the hemolysis is mainly intravascular.
In pyruvate kinase deficiency, on the other hand, the only problem is a decreased ATP (ADP and AMP concentration), so there is "nothing" to stain. This lack of ATP results in failure of the membrane pumps (most notably the Na+-K+ ATPase), and the membrane starts to become distorted and rigid. These are destroyed mainly in the spleen and liver (extravascular hemolysis).
As for distinguishing between them, PK deficiency is a chronic hemolytic anemia (unlike G6PD, in which the individual usually suffers from acute hemolytic events precipitated by oxidative stresses or drugs). Nonetheless, the individual with PK deficiency may suffer from more pronounced hemolysis during periods of infection or other stresses.
The person with PK deficiency also may have less clinical symptoms of anemia for a given (low) hemoglobin level since there are elevated levels of 2,3-DPG.
Definitive diagnosis of both enzymopathies involves a screening test (that involves fluorescence) and then spectrophotometric techniques for confirmation.
Mjl1717, I haven't heard that G6PD deficiency has effects on WBCs. Do you have a reference for this?
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| peekay
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Sakaki-
THANKS FOR GOOD EXPLANATION.
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| mjl1717
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Sakaki my explanation was kind of abbreviated.
Here the sentence from Goljans Pathology Review page 160
"Pts are prone to infection owing to the small amount of NADPH available to
neutophils and monocytes that require NADPH as a cofactor for NADPH oxidase in the oxygen-dependent myeloperoxidase system of killing bacteria (for this reason,infection is the most common precipitating factor of hemolysis) Hope this helps
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| Sakaki-
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Yeah, it does. Thanks for the info.
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