Malcolm,

I would just send this for molecular testing and in the meantime call the ABO undetermined and give group O+ or O- depending on the patient's red cell type.

I can quite see from where you are coming nancysorensen, with regard to giving group O blood (as the true reason for the weak B antigen has yet to be determined, but I don't actually agree with you, for the following reasons.

There is no doubt whatsoever that this lady is expressing the A antigen on her red cells, but still doubt about the origin of the B antigen. I would, therefore, give group A, negative for high-titre anti-B, rather than group O, which would have to be negative for both high-titre anti-A and anti-B (or, as has now been proposed - see the Storry/Olsson review I have quoted in other threads - the antibody directed against the AB cross-reacting antigen). This is harder to find (the ABO antibodies present in group O plasma tend to have a higher titre than the anti-B present in the group A plasma.

I would not, however, write-off your suggestion.

:redface:

Malcolm,

Really great practice here; but can I ask how are these titers detemined and when during the process of component preparation would this testing be performed? I am assuming we are speaking of transfusing packed RBC units here.

Malcolm,

Really great practice here; but can I ask how are these titers detemined and when during the process of component preparation would this testing be performed? I am assuming we are speaking of transfusing packed RBC units here.

The original work backing up my theory with regard to the (usually) stronger ABO antibody titres in group O, than either a or B plasma goes back to, at least, the early 1970's, when the Blood Group Reference Laboratory (as it was then named when it was based in London, before it became the International Blood Group Reference Laboratory) used to produce most of the ABO grouping reagents used in the UK. These titrations were performed in precipitin tubes, with non-standardised saline; they were not very accurate or precise, but the trend was clearly shown.

Nowadays, the lack of high-titre ABO antibodies is determined by a simple addition of A or B red cells to a pre-determined dilution of the donor's plasma. This is done before the final lable is added to the front of the unit.

Yes, I am speaking of transfusing, not only packed, but SAGM suspended red cells to this lady, and so my points about high-titre ABO antibodies do lose a lot of relevence!!!!!!!!

:D:D:D:D

The original work backing up my theory with regard to the (usually) stronger ABO antibody titres in group O, than either a or B plasma goes back to, at least, the early 1970's, when the Blood Group Reference Laboratory (as it was then named when it was based in London, before it became the International Blood Group Reference Laboratory) used to produce most of the ABO grouping reagents used in the UK. These titrations were performed in precipitin tubes, with non-standardised saline; they were not very accurate or precise, but the trend was clearly shown.

Nowadays, the lack of high-titre ABO antibodies is determined by a simple addition of A or B red cells to a pre-determined dilution of the donor's plasma. This is done before the final lable is added to the front of the unit.

Yes, I am speaking of transfusing, not only packed, but SAGM suspended red cells to this lady, and so my points about high-titre ABO antibodies do lose a lot of relevence!!!!!!!!

:D:D:D:D

Malcolm,

Forgive my post. I thought that you were speaking of actually titering the units of PC's for their corresponding ABO antibodies. My bad! I am aware of the info you gave here; not the actual dates or sites of the testing you wild and crazy serologist. If you don't mind me saying since you have mentioned an apparent illness in a previous post; I hope that you are feeling much better.

I'm sorry but there is no allowence for ill Malcolms on this web site; please read your contract; Ha..ha..:)

Malcolm,

Forgive my post. I thought that you were speaking of actually titering the units of PC's for their corresponding ABO antibodies. My bad! I am aware of the info you gave here; not the actual dates or sites of the testing you wild and crazy serologist. If you don't mind me saying since you have mentioned an apparent illness in a previous post; I hope that you are feeling much better.

I'm sorry but there is no allowence for ill Malcolms on this web site; please read your contract; Ha..ha..:)

Yes, thank you rravkin, I am well on the mend, but have been through a bit of a rough patch just recently.

I was in hospital in January with a bout of diverticulitis (fortunately, no surgery involved) and have just been hit by norovirus (which I wouldn't wish on anyone); put it thisway, it has helped me with my diet!!!!!!!!!

:(:(:D:D:D

Yes, thank you rravkin, I am well on the mend, but have been through a bit of a rough patch just recently.

I was in hospital in January with a bout of diverticulitis (fortunately, no surgery involved) and have just been hit by norovirus (which I wouldn't wish on anyone); put it thisway, it has helped me with my diet!!!!!!!!!

:(:(:D:D:D

Well I have to say that I am a fan of the "see-food" diet with a side of self control.:):)

The "self-control" is the big problem!!!!!!!!!!!!!!!!!!!!!!!!

:redface::redface:

......

Edited April 5, 201015 yr by AMcCord
changed my mind

Well, we've had a new sample that has been sent down to the IBGRL.

As soon as we get an answer, I'll let everyone know what caused the weak B antigen.

:D:D:D:D

Somewhat disappointing results I'm afraid.

The lady's genotype turned out to be AO1, which begs the question, why were we able to adsorb and elute anti-B from her red cells? I have no answer.

:confuse::confuse:

Grasping at straws...but could she have a very weakly expressed acquired B antigen that allowed some of the anti-B to adsorb onto the cells?

Grasping at straws...but could she have a very weakly expressed acquired B antigen that allowed some of the anti-B to adsorb onto the cells?

That's a very good point that I hadn't considered Heather.

Thanks.

:D:D:D:D

At our institution, we must issue blood as "uncrossmatched" until a valid ABO/Rh has been recorded (i.e., all discrepancies resolved.) In a case such as this, I think that we would probably get the medical director's approval to issue group A, uncrossmatched (as opposed to group O), until the molecular results had come back. I'm curious - what would other labs do in the interim?

Thanks,

Julie

Malcolm you DID think about aquired B, you know - go back to your post where you attached all the tests you did and your musings on each stage...

At our institution, we must issue blood as "uncrossmatched" until a valid ABO/Rh has been recorded (i.e., all discrepancies resolved.) In a case such as this, I think that we would probably get the medical director's approval to issue group A, uncrossmatched (as opposed to group O), until the molecular results had come back. I'm curious - what would other labs do in the interim?

Thanks,

Julie

In the UK, Guidelines tell us to give group O, that is negative for high-titre ABO antibodies.

The bad news was that we were the Reference Laboratory that was supposed to "sort out" this case; have a care if you ever have to come to the UK and require a transfusion!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

:redface::eek::redface:

To Malcolm, I think it is interesting that no B transferase gene but have anti-B adsorbtion and elution from the cells. You haven't ask this question to the molecular expert who do this, I remember there is s case of japanese no Aor B transferase gene but express it, it is because gene exchange, maybe, I can't remember how to say it.

To Malcolm, I think it is interesting that no B transferase gene but have anti-B adsorbtion and elution from the cells. You haven't ask this question to the molecular expert who do this, I remember there is s case of japanese no Aor B transferase gene but express it, it is because gene exchange, maybe, I can't remember how to say it.

Hi shily,

No, I haven't had a chance to talk to him yet (I hope to this week), but you are quite correct about the Japanese case.

:D:D:D:D

Malcolm,

I’m sure you have considered this already but, it wasn’t Anti-A,B that you absorbed and eluted was it? I wasn’t sure what you used for antibody.

Jeanne

Malcolm,

I’m sure you have considered this already but, it wasn’t Anti-A,B that you absorbed and eluted was it? I wasn’t sure what you used for antibody.

Jeanne

Oh no! It was quite definately anti-B, and we used both A1 and O cells as a negative control for the Lui eluate (and, of course, the last wash).

:eek::eek:

Is it possible that the A transferase produced by this lady is also adding a small amount of the B determinant sugar hence the presence of B antigen demonstrated by absorption and elution studies.

Edited September 11, 201014 yr by Colin Barber
To correct typo

Is it possible that the A transferase produced by this lady is also adding a small amount of the B determinant sugar hence the presence of B antigen demonstrated by absorption and elution studies.

Very true.

Thanks for your comments.

As I say, according to the referring hospital, the lady is somewhat nervous by nature, and so, if we can prove the cause by other ways, we would rather not go down this road just yet, but if we have to do so eventually, I suppose we will.

:):):)

Is there any way you can get word to the lady that she has just starred in a world wide web case? Would that make her more willing to come back or freak her out totally - or does the whole enjoyable case violate pt privacy rules in some way???

From what the referring hospital tells me, she is, unfortunately, likely to be freaked out by the whole thing.

Somewhat disappointing results I'm afraid.

The lady's genotype turned out to be AO1, which begs the question, why were we able to adsorb and elute anti-B from her red cells? I have no answer.

:confuse::confuse:

By: (article in Spanish)

González Campos J, Jiménez Jiménez JM, Caso Sanz F, Pérez Garrido R, Rodríguez Fernández JM.

"We studied a discrepancy between red blood cells and serum test. The red cell test was identified as an A group, and the serum test as an AB group. Then we performed adsorption-elution and saliva test, in order to demonstrate A, B and H substances. We found that the blood group was AB, and the B antigen belonged to a weak group named Bel. We studied her parent blood groups. Her mother was AB and her father 0. We conclude that the blood group belonged to an cis-AB phenotype and the B antigen was a weak Bel variant."

Thanks Liz.