Q. I’m currently doing my rotations at Children’s Memorial Hospital’s blood bank and I was reading the standard operating procedure for washing red cells. One of the conditions in which they need to be washed is paroxysmal nocturnal hemoglobinuria. Do you know why this is?
A. The reason for washing red cells for people with PNH is to get rid of any ABO incompatible plasma.
In a person without PNH, ABO incompatible plasma doesn’t cause any perceptible hemolysis. The antibodies in the donor unit probably just get diluted out enough that they don’t have much of an effect. Or perhaps they get sopped up by other ABO antigens on other cells (did you know that you have A and B antigens on cells besides red cells?! Weird.).
But patients with PNH are super susceptible to complement-induced red cell destruction. They lack the ability to anchor certain proteins (including proteins that protect the red cell against complement) to the red cell membrane. Patients with PNH have a hard time down-regulating even a small amount of complement activation – so theoretically, a transfusion of even a small amount of non-ABO compatible plasma could lead to hemolysis. There have been a few cases of hemolytic transfusion reactions in patients with PNH that have been attributed to this phenomenon…so in 1948, blood banks began washing red cells before giving them to patients with PNH.
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- yohannes molalign said thank you!!!
- Madiha said Very nice explanation.
- blueheather said Thank you very much for your well explanations. Yours is clearer than my professor’s.
- Dr Sagara said Grate summery…cleared problems….thanks P bites
- Vidhi motka said Love to be part of this
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- Brian said Ah, I suppose that does sense, especially in light of their respective reference ranges. Thanks for...
- Kristine said Great question! I’ve never seen an explanation of this – but I think it’s because...
- Anna said Thanks a lot.yoir explanations a very easy to comprehend and remember
- Brian said Thanks for the great explanation. A thought occurred to me, though. Perhaps I’m missing someth...