Antibodies with most risk for hemolytic transfusion rxn

[mollyredone]

I am currently revising many procedures in blood bank that have not been revised for over 10 years. In my high risk transfusion procedure there is a statement that if time does not permit for a complet antigen screening that units should be screened for the these antigens in the following order: Jka and Jkb, Rh system, K, and Fya and Fyb. I have been googling like crazy and haven't been able to come up with anything to corroborate this statment. Can anyone point me in the right direction...Malcolm???

Thanks, Molly

[David Saikin]

Under what cicumstances would you be screening units for all these ags? HgbS/Thalassemias?

[Malcolm Needs ☆]

I am currently revising many procedures in blood bank that have not been revised for over 10 years. In my high risk transfusion procedure there is a statement that if time does not permit for a complet antigen screening that units should be screened for the these antigens in the following order: Jka and Jkb, Rh system, K, and Fya and Fyb. I have been googling like crazy and haven't been able to come up with anything to corroborate this statment. Can anyone point me in the right direction...Malcolm???

Thanks, Molly

Hi Molly,

I don't suppose for one minute you will find anything! You will probably find various things about which antigens are most immunogenic, but as to which are most dangerous in any order, I have my doubts.

The reason I say this is that it is one thing to say an antibody is potentially dangerous; it is quite another to say that anti-X is more dangerous than anti-Y, when there is evidence that both have caused quite nasty transfusion reactions at one point or another.

The danger about putting such things into a peer reviewed document is that the document can then be held up in a Court of Law for scrutiny, and if they have written that anti-X is more dangerous than anti-Y, but in the case being "tried" anti-Y turns out to be more dangerous than anti-X in this particular patient, bang goes a lifetime's professional reputation - if not worse.

I would agree with your list to a certain extent, but I might put anti-Jkb a bit further down the list, as it is not usually that bad (and anti-Jka usually causes a delayed haemolytic transfusion reaction, rather than acute - so you can sometimes get away with transfusing Jk(a+) blood at the time, to save the life, and then doing en exchange with Jk(a-) blood afterwards). I stress "get away with", as it is not something you would do without a lot of heartache!

I hope that noncommittal answer is not too noncommittal for you!

[mollyredone]

Thanks Malcolm! I think I will just remove that statement from the procedure to prevent creating any new problems.

David, it was in a procedure for high risk transfusions and I'm actually not sure what it referred to!

Molly

[David Saikin]

David, it was in a procedure for high risk transfusions and I'm actually not sure what it referred to!

Molly

[mollyredone]

David, the procedure addresses uncrossmatched units, or giving out crossmatch compatible units without complete resolution of the antibody problem, or warm autoantibodies; anything the lab feels is not completely solved, but the doctor is requesting units anyway. As I said, this procedure was written 10 years ago by someone else and I have taken over the department and want to make sure everything still makes sense.

Molly

[Mabel Adams]

There was a Q&A in Lab Medicine a lot of years ago about choosing how to transfuse hemorrhaging patients with multiple antibodies. It talked a bit about the policies used for liver transplants also. Here is how I always train techs for urgent transfusions in patients with multiple antibodies: 1) Get the ABO right. 2) Even incompatible blood carries oxygen and can be used to save the patient's life until compatible blood can be given so don't let the patient exsanguinate because of antibodies. 3) If possible, honor the Jka antibody first due to its reputation for fixing complement. (We have 5 minute typing sera so this is reasonably possible) 4) Next, if there is time, honor the strongest reacting antibodies, but this is a sliding scale of time vs. the most compatible blood you can produce. 5) The doctor may ask you questions in a fit of panic and do whatever you tell him in the first sentence out of your mouth so be ready to tell him #2 above. Good communication is key. 6) Every tech should know some basic info--for instance, almost all Rh neg blood is cde/cde and the odds of a unit being incompatible with anti-K are about 10%. With those facts you will know what to choose for an emergency patient with anti-E ( Rh neg) and with anti-c (NOT Rh neg) and you will know that you are unlikely to give more than one K+ unit when issuing random uncrossmatched blood.

There was a very good presentation on clinical significance of antibodies at the 2012 AABB meeting. We got the sync to slide package so we had all techs view it and take a test as a competency exercise. I think you can purchase the sync to slide package even if you don't attend although I don't know if it is still available.

I once had a trauma patient that turned out to have anti-e. She wasn't a massive transfusion but she also couldn't wait for 8 hrs while we ID'd the antibody then ordered in e neg units. We had about 40 units that would have been ABO compatible with her so our odds of finding even 1 e neg unit in our stock were small. We communicated well with the surgeon and she took the best we had when she couldn't wait any longer. She got a couple of e+ units in surgery and later we gave her a couple that were e neg after they arrived. She had a pos DAT but no other evidence of the incompatibility. And make sure your golfing buddy won't run over you with the cart!

[mollyredone]

Great advice as usual Mabel! I will keep those tips in mind, but I think I'll heed Malcolm's advice and not put it in writing in a procedure.

[John C. Staley]

I'm with Mabel. I believe I heard it first from John Judd, get the ABO right, the rest can be delt with later.

[L106]

Excellent, Mabel! I'm going to print your post out and pass it around to my staff! Thanks!

Donna