Washed cells for patient with Anti-Pl1b?

[janet]

Do you wash red cells for transfusion in these patients?

References?

[Malcolm Needs ☆]

I cannot think why.

[janet]

I was told it was to prevent post transfusion purpura but I can't find any supporting papers, articles or journals!?

[David Saikin]

I think the only reason for washed cells is anti-IgA.

[bbbirder]

The NHSBT (Malcom?) for using red cells from donors negative for the offending PLT antigen to reduce the risk of post-transfusion purpura (see below).  It would seem to me that if red cells from such donors are not readily available, washed red cells is a legitimate alternative.

We have had 3 patients with PTP at our 'small' hospital over the years (a high number I think, plus we have more cases of NIAT than I would expect), and each has come back with a recommendation from a 'big city' hematologist to get washed RBCs.  Each of these patients was found to have a PLT antibody and all were 60+ years-of-age women who reported later that there had been a problem with one or more of her infants years ago.

 

As I understand it, the risk of PTP is greater when the PLT antibody declines and then rebounds, but I don't know of any studies that say when this could be a problem.

 

http://hospital.blood.co.uk/library/pdf/INF272_1_3.pdf

 

5.2 Transfusion advice

Patients including pregnant women and mothers with HPA antibodies are at risk of post transfusion purpura (PTP) and should be transfused with HPA compatible red cells and platelets if these are readily available and will not result in the delay of an urgent transfusion.

5.2.1 Antibody card and information sheet

The NHSBT H&I Reference laboratory will issue an HPA antibody card for patients with HPA antibodies in case they require further transfusions in the future. An information leaflet will be provided for women with pregnancies affected by NAIT.

5.2.2 For the mother

Red cell concentrates obtained from donors negative for the relevant HPA antigen should be made available at delivery if the risk of transfusion is high. This should be discussed with the Obstetrician.

 

Linda Frederick

[Yanxia]

I don't know if red cells express the HPA?

[Yanxia]

Or those antigens can adsorb on recd cells surface, but what about Bg antigens, can we wash it out?

[Malcolm Needs ☆]

Yes Linda, we do use red cells that are negative for the offending antigen.

Just washing the red cells will not remove Bg(a) Yanxia, but you can remove it with chloroquine diphospahte (but not for transfusion purposes - just so that the red cells can be used in a panel).

[Yanxia]

Thank you , Malcolm. I don't know why to use offending antigen neg red cells , because HPA not expressed on red cells.

[Malcolm Needs ☆]

True, but there may still be some viable platelets around that could cause problems.

[Mabel Adams]

I assume the point of washed cells would be to remove residual platelets, right?