Acceptance of Positive Antibody Sceen Units

[Lynn]

I am looking for an agreement letter (to use as a starter) to send to transfusion services stating that they agree to accept (minor) antibody positive RBC donor units. Does anyone have anything like that?

Does your institution accept these units?

I am a non-technical person that has been working in a donor center setting for 15 years and before that in a TS, so I could use any help I could get.

Thanks!

Edited June 10, 2009 by Lynn

[Antrita]

As a transfusion service we provide type compatible blood. I don't see a difference between giving O packed cells to an A patient compared to giving O packed cells with an anti-K to an O patient that is K positive. I am more concerned when I've typed units for K and give a known K positive unit to a patient that is probably K negative (our patient population is about 95% K negative).

There is nothing in our contract with our blood supplier about antibody positive packed cells. It doesn't happen very often and we have never had a problem.

AntRita

[Malcolm Needs ☆]

As a transfusion service we provide type compatible blood. I don't see a difference between giving O packed cells to an A patient compared to giving O packed cells with an anti-K to an O patient that is K positive. I am more concerned when I've typed units for K and give a known K positive unit to a patient that is probably K negative (our patient population is about 95% K negative).

There is nothing in our contract with our blood supplier about antibody positive packed cells. It doesn't happen very often and we have never had a problem.

AntRita

Hi AntRita,

I tend to agree with a lot of what you say, but I still think that you have to take into account the stature of the recipient, in particular, if the recipient is a neonate, baby or young child. One only has to look at pages 445 to 448 of Mollison's Blood Transfusion in Clinical Medicine, 11th edition, Harvey G. Klein and David J. Anstee, Blackwell Publishing 2005, to see that this has to be taken into account.

In addition, in previous editions of this tome (but I'm blowed if I can find it right now - never can when you want to) there was the infamous case of a K- recipient, given blood from a K+ donor, and then from a K- donor, who had anti-K in their plasma, and the recipient underwent a pretty nasty transfusion reaction.

[SMW]

Be careful about applying old literature to today's situations. Those reports were from the 1960's when minor crossmatches, rather than donor antibody screens, were performed. The initial report (Transfusion, Volume 3) was from 1963 and just refers to "blood" but in 1963 was very, very likely Whole Blood. A second report in 1967 (Transfusion, Volume 7) did describe the implicated products transfused as Whole Blood units. Similar to transfusing group O Whole Blood to a non-group O patient, a much higher volume of plasma (and therefore antibody) was passively transfused than would likely be seen in today's world of primarily additive solution Red Blood Cells which contain minimum amounts of plasma.

[Marilyn Plett]

We titered the amount of antibody in antibody-positive RBCs in Adsol. The results were comparable to the antibody titers in group O Adsol RBCs. The results were presented at AABB (5 years ago?). Several of our trauma hospitals are happy to use the antibody-positive units. We have have no formal letter. Our transfusion service has used these units for several years with no problems in its adult patient population.

Thank you, SMW, for reminding everyone about the pitfalls of older literature. People raised in a packed cell environment have forgotten that the standard transfusion used to be whole blood. The shift to packed cells occurred somewhere in the early to mid '70's.

[Malcolm Needs ☆]

WHat SMW and Marilyn PLett write is absolutely true for those countries with a "first-world" transfusion service and I would not dispute a single letter of their replies. I do think, however, that we would do well to remember that this is the world wide web, and that not everyone that reads these threads and posts has that advantage.

There are very many countries that do still use whole blood.

[Jaimie Nicholson]

Here in New Zealand, we would discard a unit if the antibody is strong enough. I don't work in that section of the blood service, so don't quote me, but from what I can find out, if the donor's sample is still reactive when diluted 1:50, then that's considered strong enough to discard. I guess the dilution is supposed to replicate the effect of packing the cells and taking the plasma off. So short answer to the OP is: sometimes

[gonneb25]

We use antibody positive units, but have restricted their use to non-pregnant, non-heme/onc, non-dialysis patients. We have given units with anti-K to some patients who then have a positive antibody screen 3 days later showing anti-K. The staff are not happy when that happens!

[L106]

Barb G -

That's our main concern and reason for not accepting Antibody-Positive donor units. If the antibody shows up the next time we do an antibody screen / panel on the patient, most staff would assume that the patient is making a new antibody. Then, that causes more work, expense, and time delay every time we crossmatch blood for that patient in the future (since we would have to procure Antigen-Negative donor units for the patient.) Not worth the trouble.

Donna

[keisterkid]

At our blood center all antibody positive units are washed before they are shipped to our clients. We don't charge for that and only ship to clients that have agreed to accept them or are looking for antigen negative units. We don't feel that we can discard such a valuable product given to us in good faith. Besides, you would be surprised how many Rh negative donors have an anti-D; we would need to import Rh negs if we didn't wash the units.

[L106]

That is an excellent way to handle it!! (I would not have a problem accepting a unit of washed red cells that had originally been antibody-positive.)

[adiescast]

We are a large transfusion service in the US. We accept antibody positive units. They may not be used for neonatal or intrauterine transfusions. In adsol units with the new technology available, the red cells are almost dry before the adsol is added. The amount of antibody present is extremely small. I do not recall any formal agreement with our blood center about this. I know others of their clients do not accept these units.

It is extremely rare, although possible, to encounter a positive antibody screen after infusion of one of these units. The other thing that can happen is a positive direct antiglobulin test. On the very rare occasions this has happened here, we did not charge the patient for the workup and we identified the antibody as passively acquired.

Many times, we have found the antibody information useful to select an antigen negative donor for a patient who also has the same antibody. It can make screening more efficient.

For places that are still using whole blood or even red cells containing much plasma, I would recommend either refusing the antibody positive unit or using it only for patients that type negative for the corresponding antigen (which may be more expense than is possible to bear).

[geekay]

Hi there,

"Blood Banking is an art of playing safe". If that statement is true why take the risk of transfusing an "antibody positive" unit and have sleepless nights ? Play it safe..and have a beautiful sleep.

best wishes !

engeekay2003

[TimOz]

The situation is Australia is that antibody screening is done using a pooled 2 cell screen in a single gel column. This is done intentionally to provide a desensitised antibody screen This should never be used for a patient test as this will miss many weak antibodies and has variable sensitivity. The idea is that this type of screen allows the detection of units with clinically relevant antibodies with a titre of more than about 10 or so and these are discarded. Perhaps more importantly, high titre antibody plasma does not get into the plasma or fractionated products.

Note that this is in a system that almost always converts to packed cells. Whole blood is very very rarely used. While the residual plasma in packed cells is low, a high titre antibody will cause patient harm. Why infuse an antibody that could harm a patients own cells?

I am sure that this approach is characterised and published but I don't have the reference.

If washing or Adsol systems are not used it would be very wise to have an understanding of the antibody levels in the unit. An anti-D titre of 2 in a unit of packed cells is likely to cause little harm but a high titre Rh antibody certainly could.

I have to agree with Engeekay. Immunohaematology is a numbers game but I NEVER play roulette.

[ANORRIS]

What is everyones policy on transfusing FFP with known antibodies?

[khalidm3]

Hi there,

"Blood Banking is an art of playing safe". If that statement is true why take the risk of transfusing an "antibody positive" unit and have sleepless nights ? Play it safe..and have a beautiful sleep.

best wishes !

engeekay2003

.... Ditto..... We do not use any blood product having ABS even Additive-S red cells

[adiescast]

What is everyones policy on transfusing FFP with known antibodies?

While we are willing to transfuse red cell products containing non-ABO antibodies because of the low plasma volumes, we do not use plasma containing products (whole blood, plasma, platelets, or cryoprecipitate) containing non-ABO antibodies for transfusion.

[Mabel Adams]

Years ago we used to get occasional packed cell units tagged as containing antibodies--I only remember seeing anti-D which we made sure we gave to an Rh neg adult. I think this was before adsol units which I think contain even less plasma than CPD-A1 units did. If you record that they recieved passive antibody you should be able to desist with the full workup once it is no longer detectable--unless your computer disapproves, of course.

Our current supplier (ARC) apparently asked a few years back if we would take units with antibodies. I think we said yes but have never received any.

I guess if I were sending out the letter, I would define what products might include antibodies (I wouldn't want FFP with antibodies, for instance, but RBCs would be okay) and maybe provide some information on the risk and what patients should not get them--like babies and children. It would also be good to know that someone had done the calculations/research on the sort of units involved to assure that even at titers of, say, 10,000 they would not cause harm in people of, say, over 90 lbs.

Malcom, do you have a way to wash the units so they have an outdate over 24 hrs? That would be the problem here. Otherwise that sounds like a great idea. Does anyone know if the amount of plasma in pheresis adsol red cells is the same as in regular collection adsol red cells?

[Malcolm Needs ☆]

Malcom, do you have a way to wash the units so they have an outdate over 24 hrs? That would be the problem here. Otherwise that sounds like a great idea. Does anyone know if the amount of plasma in pheresis adsol red cells is the same as in regular collection adsol red cells?

The honest answer is Mabel, that I don't know. I think we use 24 hours too, but I will make it my business to find out and report back.