Antibody formation after blood transfusion?

[nikka8506]

Patient had sample collected and crossmatched 4 units of pack cells on day 1.

No transfusion on day 2.

Patient started transfusion of first unit of packed cells only on day 3

Patient was transfused 2nd unit of packed cell on day 4.

My question are:

Can patient still be transfused with the remaining 2 units of packed cells after day 4 ?

Or do we need to get a new sample from the patient and re-do the antibody screen and

re-crossmatch the 2 remaining units packed cells assigned for her.

[John C. Staley]

Our SOP is to release the remaining 2 units and re-crossmatch on a new sample. Logically it doesn't make a lot of sense if your patient has not been transfused or pregnant during the previous 3 months but sometimes it's easier to stick to the easy rule than identify all the exceptions.

:abduction

[bbbirder]

If you know that the patient hasn't been transfused or pregnant within the previous 3 months (and you can document this), you can extend the specimen. The clock starts ticking with the first transfusion. Just make sure your SOP allows this.

Depending on the circumstances, I agree with John. Sometimes it is easier to start over with a new specimen.

Linda Frederick

[Yanxia]

Logically it doesn't make a lot of sense if your patient has not been transfused or pregnant during the previous 3 months ...

:abduction

Would someone tell me why it is 3 months , please?

[John C. Staley]

The general concensus is that anytime within 3 months after a transfusion or pregnancy an antibody can be produced. If, after 3 months, there is no antibody the patient is highly unlikely to produce an antibody do to that transfusion or pregnancy. Every transfusion or pregnancy is a new opportunity and resets the 3 month clock.

[Yanxia]

Thank you,John.

Sorry for my poor English, so if my understanding is not right, please forgive me and point it out.

If the person had been transfused before , the allo-antibodies may disappear during the time, the cross-match will be compatible. After transfused the former 2 unite of RBC may evoke the memory reaction, so I think it is better to re-crossmatch the remaining 2 unite of RBC.

[John C. Staley]

That is a possible concern, especially with anti-Jka and anti-Jkb. They have a nasty habit of dropping below detectable levels and then popping up as a delayed transfusion rxn. This is one of those issues that asks the question: where is your paranoia level?

Obviously you would be more comfortable recrossmatching. But, would this not be the same for a patient that was crossmatched for 4 units, received 1 on day 1, a 2nd on day 2 and then they wanted to transfuse a 3rd on day 3. Would you then re-crossmatch the 3rd unit? It certainly falls within guidelines to simply issue that 3rd unit on day 3. The only difference between this scenerio and the original one posed by nikka8506 is the 1 day lag between the original crossmatch and the 1st transfusion.

I think the general concern with the 3 month period is not old antibodies that have dropped below detectable levels as much as it is with newly developing antibodies that have not yet reached detectable levels.

As I indicated above, we would have simply requested a new sample and retested the patient in the original scenerio but not for fear of an undetectable antibody but because it is just easier than identifying all the times we would not need to.

One other thing about this scenerio, we have always counted the day the sample was collected as day "0" not day "1". It's like birthdays. You were not born 1 year old. That 1st birthday did not come until you completed that 1st year.

[OPUS104]

John, I'm a firm believer in K.I.S.S. and always having chicken feathers falling off of me. Having PRN people and generalist that work in BB twice a month on graveyard is a recipe for disaster if the 3 day rule has "exceptions". (Of course WARMS dont count)

[Mabel Adams]

And computer systems sometimes have a hard time dealing with exceptions. Likewise, if you use the Hollister banding system that has "band cards", it might have been discarded unless you take pains to avert that. The whole thing becomes an outlier if you don't have a regular policy for extended times. It is very hard to keep all of the pieces in the right place for such exceptions.

[mamafrank81]

The way the question is posed, the red cell units SHOULD be crossmatched on a new specimen. There is no parameter stated by which the patient's transfusion history previous to the initial crossmatch at your facility can be considered against this occurrence. If the patient has been transfused in the three months previous to sample collection, that sample is only good for 72 hours regardless. If the patient's transfusion history is UNKNOWN, the sample is still only good for 72 hours. Only if the patient has not been transfused in the previous 3 months can a specimen's outdate be extended. At no time should it be a matter of convenience, but only a predetermined facility practice as in larger hospital that have large outpatient surgery services and make preadmit testing samples good for 14 days under these circumstances.