AsubB or B(A)?

[yanhan]

I've a donor.

anti-A= 1+ ,anti-B= 4+，anti-A1=neg , anti-H=3+

A1 cells=2+,A2 cells=1+，B cell= neg , screen cell= neg, auto ,controll = neg

AsubB or B(A)?

many thanks

[Yanxia]

I will report it as AsbuB just has this serologic reaction pattern, because I think B（A） is a genetic type, we need to do NDA typing to say if it is an B(A).

I will call this AxB.

[Yanxia]

And have not the DNA ,if we have family member 's blood type, we will deduce if the B and A glycosyltransferases gene are on the same chromosome.

[Malcolm Needs ☆]

I agree with shily.

It could also just actually be something as simple as the phenotype being AxB, but the geotype being A2/B, with the A transferase, which is competing with the B transferase, in terms of getting their own terminal immunodominant sugar residues onto the backbone chains, losing out in the competition, but I think shily is correct.

[yanhan]

thanks shily and malcolm.

if we have family member 's blood type, we will deduce if the B and A glycosyltransferases gene are on the same chromosome.

Can you detail it . thanks

[Malcolm Needs ☆]

Well, if one parent is group O, and the other is AB, and their child is also AB, then the A and B genes must be in the cis position.

[Mabel Adams]

In another thread you said that cis AB people usually have a weak anti-B. This case has a weak anti-A it appears. Can it work either way? Or is this why it is more likely to be an AsubB than a cisAB?

[Yanxia]

In another thread you said that cis AB people usually have a weak anti-B. This case has a weak anti-A it appears. Can it work either way? Or is this why it is more likely to be an AsubB than a cisAB?

Mabel, I think the CisAB and the B(A) is genetic type rather than serologic type. Cis AB is the A transferase has one or more point change, it can produce A and B transferase ,although B is weak .

And B(A) is just the other side, the B transferase has some base change, it can produce B and weak A transferase.

And most of CisAB has anti-B, but some not.

The two is same because they all has one alle express O .

I don't know if I say it clearly.

[Malcolm Needs ☆]

In another thread you said that cis AB people usually have a weak anti-B. This case has a weak anti-A it appears. Can it work either way? Or is this why it is more likely to be an AsubB than a cisAB?

To be honest, and so not to claim kudos, when it is not deserved, it was actually my very good friend and colleague John Eggington who said that; all I did was agree with him. That having been said, whenever I have seen examples of cis AB, it has been the B antigen that has been weaker than the A antigen, but there has also been anti-B in the plasma that is weak, not the anti-A. So, yes, this is one reason why I am thinking in terms of A subgroup B, rather than cisAB.

[John Eggington]

I would also lean toward A(sub)B (assuming the donor is otherwise healthy) with this one. Although, weak reaction with both A1 and A2 cells seems a little odd. I would have expecetd a stronger reaction with A1 cells, when A2 cells are reactive.

[Mabel Adams]

Thanks, Yanxia. I think I understand although it seems like they should use similar nomenclature like A( and B(A) rather than calling one cis AB. Or maybe I should just go read about them instead of making you all explain them to me.

[Malcolm Needs ☆]

Thanks, Yanxia. I think I understand although it seems like they should use similar nomenclature like A( and B(A) rather than calling one cis AB. Or maybe I should just go read about them instead of making you all explain them to me.

No Mabel. A( and B(A) are not quite the same as cisAB, and so the nomenclature cannot be "standardised".

A( and B(A) are conditions (if that is the correct word, and I don't think it is!) where an apparent group A individual can, eventually, adsorb out anti-B, but the B antigen on their red cells is incredibly weak (and vice verse for B(A)), but the cisAB phenotype, although giving somewhat weaker reactions with anti-A and/or anti-B (usually anti- than would be expected, the reactions are most certainly not as weak as those given by A( and B(A) individuals.

[GinaL]

How I would interpret these results is dependent upon what reagents were used! Different reagents are in use all over the world. We cannot expect that all reagents of a given specificity will react in the same way! In the US, we have one manufacturer's monoclonal anti-A, Ortho's BioClone anti-A which contains MHO4, that reacts with B(A) RBCs. While Most B(A) react weakly with this anti-A, some react quite well (e.g. 2+). The plasma is expected to contain anti-A (reacting with both A1 and A2 RBCs) whereas plasma from AsubB may occasionally contain weak anti-A1. Testing other monoclonal anti-A reagents (i.e. not containing the MHO4 clone) would be used to differentiate a B(A) from AsubB. The weak reactivity of the plasma with the A1 and A2 RBCs could just be this donor's anti-A, reacting weaker than expected. I would test this donor's RBCs with other monoclonal anti-A and the plasma with other A1 and A2 RBCs.

[Rh-fan]

What puzzels me is the strong reaction with the anti H (3+), with a normal B antigen I would expect that the H antigen would be weaker. In cisAB a stronger reaction with anti H can be seen.

It can be a strong anti H reagent, how strong is the reagent with A1 and A2 control cells?

Peter

[yanhan]

We used the anti-A、anti-B、anti-A1、 anti-H、A1 、A2、B and screen cell of immucor company.

Anti-A is gamma clone.

I had used another manufacturer's anti-A and A1 、A2 cell. The result is same.

Anti-H reagent with A1 、A2 control cells result (A1=neg , A2 =2+)

I agree with Ginal.

Plasma from A(sub)B may occasionally contain weak anti-A1,so it can react with A1 cell.

why serum from the donor agglutinate both A1 and A2 cell. I am confused

My English is not good. Am I understood?

[Rh-fan]

A normal B antigen has the same amount of H antigen as an A2 control. In this case the H antigen is stronger, sugesting a weakening of the B antigen.

Peter