Antigen Negative or Crossmatch Compatible?

[Mary**]

Do you give antigen negative blood or crossmatch compatible blood for patients with anti-M, N, Lea?

[Malcolm Needs ☆]

I voted for cross-match compatible for this, as this is what we do as a general rule.

HOWEVER, if the anti-M reacts by LISS tube IAT at strictly 37oC (pre-warmed and warm-washed) we would cross-match M- blood. This is quite unusual.

I have heard of 2 cases during my career (starting in 1973) that contained an anti-N that reacted extremely strongly by LISS tube IAT at strict 37oC (again, pre-warmed and warm-washed) that required N- cross-matched blood. One case was one of my own and the other was in Scotland.

I have read of anti-Lea causing a haemolytic transfusion reaction, but have never come across one myself (and I gather that such reactions are "self-limiting", in that the Lea substance transfused with the Le(a+) red cells "mops up" the patient's anti-Lea, and the rest of the unit can be transfused quite safely - I wouldn't like to try that myself!!!!!!!!!!!!!!!!!!!!).

:eek::eek:

[Mary**]

So you voted for crossmatch compatible for Anti-M and N, but would not do it for anti-Lea? Correct?

[Malcolm Needs ☆]

So you voted for crossmatch compatible for Anti-M and N, but would not do it for anti-Lea? Correct?

Sorry to confuse you (my fault entirely).

No, I would do cross-match compatible for all three.

What I meant was that I would not like to try to give the rest of an Le(a+) unit to a patient who had reacted severely to the first part of the transfusion. Seems like it's asking for trouble.

Again though (which is why I would give compatible blood) an anti-Lea that reacts like that is disappearingly rare.

:)

[crummer]

Agreeing with Malcom, generally give M- units if the patients sample shows anti-M @37C, xm compatible the rest -however if Transfusion reaction was suspected with the others -I would request a sample and investigate/ crossmatch before issuing antigen typed blood to hospital. We are in the unusual situation as covering as a hospital blood bank and a reference lab, I worry greatly as to the identification of such antibodies by labs with limited reagents (as in what really is the antibody!)

[Malcolm Needs ☆]

Agreeing with Malcom, generally give M- units if the patients sample shows anti-M @37C, xm compatible the rest -however if Transfusion reaction was suspected with the others -I would request a sample and investigate/ crossmatch before issuing antigen typed blood to hospital. We are in the unusual situation as covering as a hospital blood bank and a reference lab, I worry greatly as to the identification of such antibodies by labs with limited reagents (as in what really is the antibody!)

Yes, the lack of reagents in certain hospitals worries me too, but there are so many financial constraints these days that I can understand why they would not want to buy a reagent they might only use once or twice (or, in some instances, not at all) before its expiry. That having been said, paying for our Reference Services is not cheap either.

[CYGI]

Antigen negative units unless the antibody is reacting at 37

[Malcolm Needs ☆]

Antigen negative units unless the antibody is reacting at 37

I'm not certain that you mean what you have posted do you CYGI? The way it reads, you would give cross-match compatible if the antibody reacts at 37oC, but would give antigen negative if it did not react at 37oC.

Have I read it incorrectly??????????

:confused::confused:

[janet]

I posted this in the "rule out" post too but for those who just give IAT compatible units (not phenotyped) do you bother rulling out these "clinically insignificant" antibodies?

Our rule is 2 M, one for Lewis and one P but one of my technologists is asking me why .... we just give IAT compatible units for those antibodies so why bother ruling them out when in the end the crossmatch will tell all.

I agree with here but am looking for other's thoughts for or against :0)

[CYGI]

HI Malcolm,

The question was a two part question depending how you viewed the question, therefore I answered it in two parts without explaination, sorry for the confusion.

Patients that have Anti-M that are not reacting at 37 degrees are crossmatched compatible , if the M antigen is reacting at 37 degrees, we use M negative units and proceed with AHG crossmatch. Was I able to clear this up??? I hope so. Thanks for looking at that.

[Malcolm Needs ☆]

HI Malcolm,

The question was a two part question depending how you viewed the question, therefore I answered it in two parts without explaination, sorry for the confusion.

Patients that have Anti-M that are not reacting at 37 degrees are crossmatched compatible , if the M antigen is reacting at 37 degrees, we use M negative units and proceed with AHG crossmatch. Was I able to clear this up??? I hope so. Thanks for looking at that.

Hi CYGI,

Yes, that clears it up perfectly thanks very much (and I agree entirely with what you say).

The confusion was probably all on my part.

:)

[Mary**]

What about anti-Le b?

[Malcolm Needs ☆]

What about anti-Le b?

I am tempted to be facetious and say "What about anti-Leb!", but,actually, that is exactly how I feel about anti-Leb.

Anti-Leb has, on very, very rare occasions, caused red cell destruction, but, like anti-Lea, the reaction is self-limiting, and , after initial destruction, most of the red cells transfused are still in circulation many hours after they are transfused (probably because the antigens themselves are soluble and "come off" the red cells pretty quickly, and then block the antibody in vivo).

There has only ever been one report of anti-Leb causing HDN, and even then it was sub-clinical HDN (so the case was fairly dubious).

I would quite happily ignore the antibody completely and given cross-match compatible blood.

:)

[jcdayaz]

We no longer antigen type units for M,N, P1,Cw, Lea, Leb (probably some others I am forgetting). We give AHG crossmatch compatible units.

[jcdayaz]

I posted this in the "rule out" post too but for those who just give IAT compatible units (not phenotyped) do you bother rulling out these "clinically insignificant" antibodies?

Our rule is 2 M, one for Lewis and one P but one of my technologists is asking me why .... we just give IAT compatible units for those antibodies so why bother ruling them out when in the end the crossmatch will tell all.

I agree with here but am looking for other's thoughts for or against :0)

Huh. Interesting point by your technologist. We do electronic crossmatching on every patient lacking an antibody. We only do AHG crossmatching when there is an "issue".

We rule out everything. There are certain antibodies that we will ONLY rule out on homozygous cells....they are M, N,S,Jka,Fya. I have seen countless presentations of Anti-M that only react with homozygous screening cells---and then sometimes even not all homozygous cells. Is Anti-M clinically significant? Most times not. But for us identifying the "issue" we are having is a MUST.

Anytime we have a patient presenting with an antibody we automatically AHG crossmatch 2 units. Regardless of what the antibody is.

[tbostock]

We do crossmatch compatible units for Le and M/N antibodies. We are also seeing many more anti-M with the gel, mostly only the homozygous cells reacting.

[DPruden]

My question is, in the age of solid phase and gel testing in which you have no IS reaction, do you treat all anti-Lea and anti-M as clinically significant and provide antigen negative blood?

[tbostock]

We use gel here, and if we see evidence of M or Lea in gel, we "honor it" by providing crossmatch compatible units. We don't antigen type the units...ever since the price of antisera skyrocketed, we don't even carry these antisera anymore.

Many years ago, we antigen typed for M in one case because it was a young female sickle cell patient with 3 other antibodies, so we REALLY didn't want to take a chance with her.

[Eagle Eye]

we give crossmatch compatible by Gel unless antibody is clinically significant. We have a couple sickle patient who has clinically significant anti-M and we honor anti-M and give M-, crossmatch compatiblebest compatible.

[marquij@caribe.net]

Agree with Malcom:

Crossmatch compatible if anti-M not reacting at 37C.

Confirmed antigen negative if anti-M reactive at 37C.

[LIMPER55]

crossmatch compatible is the way we go