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Discrepancies in Antigen Typing


lehooke

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Just wondering if anyone has encountered discrepancies between antigen typing performed at the transfusion service and the reference lab. I recently sent a patient's sample over to the reference lab to rule out an antibody for us and they repeated the Rh phenotyping. They typed the patient as C negative and I typed the same patient as C positive, (only positive after 15 minute incubation). When I spoke to the reference tech about it, he replied that he had seen this before since we use different antisera than they do. He suggested that we result the C typing as indeterminate and transfuse with C negative blood , which I agreed, but I have not encountered that discrepancy in the past. Is it common?

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We have not encountered a phenotype mismatch from the reference lab. We however do encounted a phenotype discrepancy from our donor center somewhat often..ie...unit is supposed to be antigen negative and isn't.
Just wondering if anyone has encountered discrepancies between antigen typing performed at the transfusion service and the reference lab. I recently sent a patient's sample over to the reference lab to rule out an antibody for us and they repeated the Rh phenotyping. They typed the patient as C negative and I typed the same patient as C positive, (only positive after 15 minute incubation). When I spoke to the reference tech about it, he replied that he had seen this before since we use different antisera than they do. He suggested that we result the C typing as indeterminate and transfuse with C negative blood , which I agreed, but I have not encountered that discrepancy in the past. Is it common?

Unless in exceptional circumstances, neither of there should EVER happen.

:eek::eek::eek::eek::eek:

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Yeah...in our blood suppliers defense...they do not perform phenotyping at all...they are dependent on the phenotypes provided by hospitals which then they enter slowly to donor record for "hisotrically" antigen negative unit searches.

Oh My God! Then you blood supplier has no defence at all!!!!!!!!!!!!!!!!

Do you believe other people's blood groups without checking??????????????

:omg::omg::omg::omg::omg:

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Nope! :) We retype the blood. Phenotype if necessary. But if a ARC sends us a rare unit that they have phenotyped and it is IAT compatible then we don't redo all the phenotypes.....it happens pretty rarely that we have to get units from Red Cross....

Ah! They're a different kettle of fish. I believe a bloke called George Garratty works for them!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

I think I'd believe something that came from them (with his backing)!

:):):):):)

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Unless in exceptional circumstances, neither of there should EVER happen.

:eek::eek::eek::eek::eek:

This is true, but it does not mean that it does not happen. We have had times when we ordered antigen negative blood, say Jka negative and received blood that was Fya negative. We have had the labeling go both ways. Sometimes it was accurately labeled for what they tested (even though it wasn't what we ordered). I only recall one occasion where it was not accurately labeled.

We thought that having a computer based order system would relieve these problems (of not getting what we ordered) because we thought they might be verbal miscommunications, but at least one of these mishaps has occurred despite the computer ordering system. It seems to be very difficult to get a fool proof process. What is the saying? "Nothing is foolproof for the clever fool?"

:rolleyes:

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Guess what? When I returned to work this morning, I received the final written report from the reference lab and interestingly enough- under additional red cell typings, the C typing was reported as C+weak. I'm wondering if the reference tech went back and repeated the testing again after our telephone conversation. If he did, he never called me back to inform me of his corrected interpretation. Hmmm...

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I'm not saying it doesn't happen (I certainly wouldn't argue with you or anyone else).

What I will say, however, is that if the NHSBT sends out a "wrong" unit there is all hell to pay, involving root cause analysis, quality incidents, you name it, and heads could well roll. I am just amazed that blood suppliers elsewhere in the world don't have the same systems.

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Guess what? When I returned to work this morning, I received the final written report from the reference lab and interestingly enough- under additional red cell typings, the C typing was reported as C+weak. I'm wondering if the reference tech went back and repeated the testing again after our telephone conversation. If he did, he never called me back to inform me of his corrected interpretation. Hmmm...

Hmmm indeed!

Just as a matter of interest, what was the ethnic origin of this patient? Was he/she of Black ethnic origin, as individuals from this ethnic origin do sometimes show a very weak C antigen (THAT, BY THE WAY, IS NO EXCUSE - INDEED, IT IS EVEN MORE REASON TO LOOK CLOSELY AT THE TEST RESULTS).

:confused::confused::confused::confused::confused:

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Hmmm indeed!

Just as a matter of interest, what was the ethnic origin of this patient? Was he/she of Black ethnic origin, as individuals from this ethnic origin do sometimes show a very weak C antigen (THAT, BY THE WAY, IS NO EXCUSE - INDEED, IT IS EVEN MORE REASON TO LOOK CLOSELY AT THE TEST RESULTS).

:confused::confused::confused::confused::confused:

Malcolm,

She was of Hispanic descent and I agree with you completely! :)

~Lisa

Edited by lehooke
spelling error!
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Guess what? When I returned to work this morning, I received the final written report from the reference lab and interestingly enough- under additional red cell typings, the C typing was reported as C+weak. I'm wondering if the reference tech went back and repeated the testing again after our telephone conversation. If he did, he never called me back to inform me of his corrected interpretation. Hmmm...

It is unfortunate that the orginical C antigen typing was discrepant between your lab and your reference lab, but doesn't it deteriorate your confidence in the reference lab even more when their written report differs from their initial verbal report???!

I would call the manager of the reference lab and ask for an explanation of why the final writen report is different from the initial verbal report. (ie: If different reagents gave different results, that would be helpful to know. However, if there is some other reason that involves the reference tech, the manager should be aware of that.) Don't get me wrong......none of us is beyond making an error, but don't try to "sweep it under the carpet!"

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It is unfortunate that the orginical C antigen typing was discrepant between your lab and your reference lab, but doesn't it deteriorate your confidence in the reference lab even more when their written report differs from their initial verbal report???!

I would call the manager of the reference lab and ask for an explanation of why the final writen report is different from the initial verbal report. (ie: If different reagents gave different results, that would be helpful to know. However, if there is some other reason that involves the reference tech, the manager should be aware of that.) Don't get me wrong......none of us is beyond making an error, but don't try to "sweep it under the carpet!"

As the manager of a Reference Laboratory, I agree with you ENTIRELY.

The only thing I would say is that we always make sure tht the hospital receiving a telephoned report KNOW from the word go that such a report is an interim report and that the final report may differ from the telephoned report, on the grounds that not all the tests will have been finished. In such a situation, we always err on the side of safety (e.g. give X negative blood, assume the patient is X negative, assume the antibody to be allo, rather than auto, until proved otherwise, etc).

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Just spoke with the reference tech who performed the testing and I asked him about the result. He replied, "Oh yes, we went back and did more testing with an in-dated Biotest reagent and got a very weak positive result. Most likely the patient is R2 RZ." Apparently, it didn't warrant a follow-up phone call. :confuse:

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Just spoke with the reference tech who performed the testing and I asked him about the result. He replied, "Oh yes, we went back and did more testing with an in-dated Biotest reagent and got a very weak positive result. Most likely the patient is R2 RZ." Apparently, it didn't warrant a follow-up phone call. :confuse:

"in-dated"!!!!!!!!!!! That is disgusting.

For a start off there is no way that they should be using an out-dated reagent.

Secondly, most anti-C reagents (anti-Rh2) are, in fact, anti-Ce (anti-Rh7), and that includes monoclonal "anti-C" reagents (I've been caught out myself with this one) and that is why, if there is any chance whatsoever that the Rz haplotype may be involved, YOU LOOK EVEN MORE CLOSELY.

Indeed, I would go as far as to say that any decent reference laboratory should use an R2Rz as a positive control for their anti-C reagents (I know this is impossible for Hospital Blood Banks, but that is why samples are sent to Reference Laboratories - they have more access to rare reagents, if not, so it would seem, to more conscientious Technicians/Biomedical Scientists!!!!!!!!!!

My own staff (and some of them are members of this site) had better not make a similar error!

Sorry, that sounds like a threat. It's not meant to sound like a threat. It's meant to sound like a PROMISE.

:angered::angered::angered::angered::angered:

Edited by Malcolm Needs
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Yeah...in our blood suppliers defense...they do not perform phenotyping at all...they are dependent on the phenotypes provided by hospitals which then they enter slowly to donor record for "hisotrically" antigen negative unit searches.

WHOA!! Seriously?? NO NO NO!! You are being supplied by a donor facility that does not confirm "historic" types on each donation?? RUN RUN RUN away from them...if you have the option. If you don't, then you should be confirming antigen status upon the unit's arrival in your BB.

Sorry to be so forceful, but this practice is just plain wrong.

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Nope! :) We retype the blood. Phenotype if necessary. But if a ARC sends us a rare unit that they have phenotyped and it is IAT compatible then we don't redo all the phenotypes.....it happens pretty rarely that we have to get units from Red Cross....

To me your kee phrase here is "that they have phenotyped"...I thought you stated ARC was going on only historical information?!

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"in-dated"!!!!!!!!!!! That is disgusting.

For a start off there is no way that they should be using an out-dated reagent.

Secondly, most anti-C reagents (anti-Rh2) are, in fact, anti-Ce (anti-Rh7), and that includes monoclonal "anti-C" reagents (I've been caught out myself with this one) and that is why, if there is any chance whatsoever that the Rz haplotype may be involved, YOU LOOK EVEN MORE CLOSELY.

Indeed, I would go as far as to say that any decent reference laboratory should use an R2Rz as a positive control for their anti-C reagents (I know this is impossible for Hospital Blood Banks, but that is why samples are sent to Reference Laboratories - they have more access to rare reagents, if not, so it would seem, to more conscientious Technicians/Biomedical Scientists!!!!!!!!!!

My own staff (and some of them are members of this site) had better not make a similar error!

Sorry, that sounds like a threat. It's not meant to sound like a threat. It's meant to sound like a PROMISE.

:angered::angered::angered::angered::angered:

Malcolm....

We routinely use "out-dated" panel cells/screen cells in our antibody ID attempts. We most frequently have the need for "select cells" and we turn to our back inventory. As long as the cells are not hemolyzed we use them. Is this an incorrect practice?

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Malcolm....

We routinely use "out-dated" panel cells/screen cells in our antibody ID attempts. We most frequently have the need for "select cells" and we turn to our back inventory. As long as the cells are not hemolyzed we use them. Is this an incorrect practice?

No, we do exactly the same when we are trying to identify the specificity of an antibody, but the way I read it (and I am happy to be corrected if I've got it wrong) they were using out-dated grouping reagents to type an antigen (and a pretty common grouping reagent in anti-C at that). This is something that we would NEVER do, except in exceptional cases where the grouping reagent is fantastically rare (say an anti-Era).

:(:(:(:(:(

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WHOA!! Seriously?? NO NO NO!! You are being supplied by a donor facility that does not confirm "historic" types on each donation?? RUN RUN RUN away from them...if you have the option. If you don't, then you should be confirming antigen status upon the unit's arrival in your BB.

Sorry to be so forceful, but this practice is just plain wrong.

We do confirm antigen status from our blood supplier. The reference laboratory is the one we do not phenotype again if it is a rare unit....

Hope that helps to make it clear as mud....

:)

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To me your kee phrase here is "that they have phenotyped"...I thought you stated ARC was going on only historical information?!

Nope....we get out blood from our supplier. Our blood supplier has "historical" antigen histories of donors. Rare cases of difficult antibodies crossmatches we have to rely on the ARC for units. They phenotype.

Clear as mud I know. :D

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We do confirm antigen status from our blood supplier. The reference laboratory is the one we do not phenotype again if it is a rare unit....

Hope that helps to make it clear as mud....

:)

Just as a matter of interest, what is your definition of rare in such cases?

Working in a Reference Laboratory, I suspect my definition may be quite different to yours.

:confused::confused:

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