Positive DCT Blood Donors

[hollowayl]

Does anyone know of any references/papers regarding the consequences of giving a patient (unintentionally of course) DCT +ve blood. There seems to be very little written about it. We do not routinely do a DCT on Donor blood and of course it should get picked up in the crossmatch, but if group specific uncrossmatched blood were given in an emergency its a possibility such blood could be given to a patient. What are the likely consequences?

[bbbirder]

DCT, does that stand for "Direct Coombs Test"?

Since most/many places have gone to Immediate Spin XMs or Electronic XMs, it probably happens fairly often that a unit from a donor with a positive DC is given and nobody ever knows.

Linda Frederick

[hollowayl]

Yes Direct Coombs Test DCT but what I was interested in is what is anything actually happens to the patient when they receive such blood? maybe nothing?

[Mabel Adams]

Apparently nothing that has jumped out and bit us anyway. Those cells could have shortened red cell survival, but they were apparently still circulating in a donor healthy enough to donate, so maybe they will survive normally. Probably depends on the recipient's immune system as well.

[hollowayl]

Thanks Mabel thats kind of what I thought but couldn't find anything concrete written about it

[bbbirder]

We don't have any written policy about what to do if we find a unit with a positive DAT. Normally we would not find these when doing immediate spin XMs (or if we ever get out of the dark ages and start doing electronic XM).

But what if we find one? Lately we have had bunches of patients with antibodies, so more AHG XMs. After a unit was incompatible with a couple of patients, we got suspicious, and sure enough it had a positive DAT. Should we just use it for somebody else, who only needs IS XM? In this case, our supplier said send it back. We returned it, but since it was an O neg, I was sad to see it go.

Linda Frederick

[Mabel Adams]

I think I would feel better sending it back. I don't mind if I don't know about it, but once I know something might have shortened survival in the recipient I would feel funny giving it. Maybe this falls under the FDA's "potency" requirement.

Back in the days of all AHG xms we used to find such units a few times a year. Of course they would never have been compatible with anyone so it was easy then to decide to send them back.

[galvania]

There is a short section on this in Issett (Applied Blood Group Serology by Peter Issitt and David Anstee)pp1018-1019 in the 4th edition, entitled 'significance of a positive DAT on a donor unit. I quote just 1 sentence: '..it has never been suggested that red cells from those units in which the DAT is only weakly positive will enjoy anything but normal survival in the recipient.' For strong positive DATs, he says 'In the absence of reports to the contrary, it can be assumed that the DAT-positive red cells do indeed survive as well in the recipient as in the donor'.

Having said that, if I had a donor wit a strong positive DAT, I think I would want to try and find out why!

Anna

[sramakrshn]

I also faced such problem that during AHG crossmatch the donor unit was incompatibe,subsquintly Donor Unit RBCs was

tested for DAT, and found "POSITIVE". Hence donor unit was

discarded.

[David Saikin]

We would return them to the supplier . . . in the "old" days of ahgxm it was not uncommon to find units like this. In fact, the 1st thing we did with an incompatible unit was do a DAT.

[Auntie-D]

Hmmm just had a transfusion reaction. - inc temp, rigors. Only thing wrong was a dct pos unit...

[Malcolm Needs ☆]

Hmmm just had a transfusion reaction. - inc temp, rigors. Only thing wrong was a dct pos unit...

But was it a haemolytic transfusion reaction? You can get a temperature rise and rigors with HLA antibodies, and, don't forget, although all units in the UK are leukodepleted, not all are tested for leukodepletion. It is known that the odd one can slip through that is above the required leukodepleted threshold.

[Eagle Eye]

we see this time to time..particularly antigen negative units for a patient with multiple antibodies. We always send the unit back to supplier.

[Auntie-D]

But was it a haemolytic transfusion reaction?.

Yeah rise in bilirubin and Hb dropping in the absence of bleeding. Just what you want on a night shift night night all - recovery time...

[Eagle Eye]

I am sure AHG Crossmatch with post and pre was incompatible. Are you using same technology for AHG XM & DCT? Was is same strength?

if XM was stronger then DCT (if same methodology was used) then make sure to rule out antibody to Low frequency antigen.