Cold antibody reactive with A cells

[Rh-fan]

This is a question I received from a other lab, and I do have a clear solution. Can anyone help?

We met a case about ABO blood group typing few days ago, the patient is 81 years old, female, with colon cancer, this time she was being in hospital because of fractures. The results of the tests we have done as follows:

Direct antiglobulin test: 3+ (IgG 3+; C3 negative)

Antibody screening: negative

ABO blood group typing:

1. Test in tube: red cell and serum typing were both A;

2. Test in column (DG Gel ABO-CDE card from GRIFOLS):

Red cell antigen typing showed: anti-A 4+, anti-B negative; serum typing showed: Ac +, Bc 4+.

Saliva test: we detected A substance.

Cross matching test in column:

(DG Gel Coombs card from GRIFOLS, incubated 15min at 37℃,then centrifugate)

1. We selected 13 donors’ red cell with blood group A randomly to cross match with the patient’s serum, there were 4 negative and 11 positive including 10 (3+) and 1 (+).

2. The patient’s serum cross matched with 11 donors’ red cell with blood group O, the results were all negative.

All testing we have done were shown above, we are puzzled what is the specificity of the antibody? Why does it only agglutinate part of A cells? Do you have any suggestion for us to do some other tests? It will be very appreciated. Thank you very much in advance.

The patient cells are reactive with anti A1, so she is A1 positive, and also the 4 neg crossmatches are A1 positive.

I think it is some kind of antibody to an combination antigen, in this case a combination with A (or A1). Is there something like an anti ALeb?

Thanks,

Peter

Edited February 20, 2012 by Rh-fan
typing error

[Malcolm Needs ☆]

I think it is some kind of antibody to an combination antigen, in this case a combination with A (or A1). Is there something like an anti ALeb?

Thanks,

Peter

Sorry Peter, I've only had time for a VERY quick look at this case (I'll try to look at it properly tonight), but there most certainly is an ALeb antigen. It is the fifth antigen within the Lewis Blood Group System recognised by the ISBT (007:005).

[Rh-fan]

I know the antigen but I have never have read of a antibody that is reactive with that antigen. By the definition of Geoff Daniels of a bloodgroup antigen, the antibody must exist.

PS do you know the ISBT number from your head of from a table? I know soem of them (mostly Rh) but of this antigen I did not know the number.

[Malcolm Needs ☆]

I know the antigen but I have never have read of a antibody that is reactive with that antigen. By the definition of Geoff Daniels of a bloodgroup antigen, the antibody must exist.

PS do you know the ISBT number from your head of from a table? I know soem of them (mostly Rh) but of this antigen I did not know the number.

I've only come across one once or twice in my life.

No, I'm not that clever. I just happened to be at work and was able to look up the number on the internet. I wish I was that clever!!!!!!!!!!!!!!!!!!!!!!!

[jill]

Were they able to obtain Lea and Leb typings? Was an eluate performed?

[Malcolm Needs ☆]

Having thought about it (and having reread Race RR and Sanger R, Blood Groups in Man, 6th edition 1975, Blackwell Scientific Publications, pages 337 and 338, in particular the bit about the chimeric twins), the lady's Lewis type is extremely important, BUT, and it is a big BUT, the problem I have is with the DAT.

I cannot see how a person could make a Lewis auto-antibody that would adsorb onto their own red cells before their Lewis substance inhibited this auto-antibody, but left sufficient antibody in the plasma to sensitise the red cells from other people. That is, unless the DAT is a red herring (and she has made a weak auto-antibody of a completely different specificity), and she has made anti-ALeb as a seperate alloantibody. Even then, I think that she would have to be a non-secretor?

[David Saikin]

I would be interested in the elution studies . . . and I find the dx of colon ca interesting . . . who knows what abs those bugs can generate? She could be seeding bacteria into her circulatory system . . . elution study please.

[Yanxia]

This is a question I received from a other lab, and I do have a clear solution. Can anyone help?

We met a case about ABO blood group typing few days ago, the patient is 81 years old, female, with colon cancer, this time she was being in hospital because of fractures. The results of the tests we have done as follows:

Direct antiglobulin test: 3+ (IgG 3+; C3 negative)

Antibody screening: negative

ABO blood group typing:

1. Test in tube: red cell and serum typing were both A;

2. Test in column (DG Gel ABO-CDE card from GRIFOLS):

Red cell antigen typing showed: anti-A 4+, anti-B negative; serum typing showed: Ac +, Bc 4+.

Saliva test: we detected A substance.

Cross matching test in column:

(DG Gel Coombs card from GRIFOLS, incubated 15min at 37℃,then centrifugate)

1. We selected 13 donors’ red cell with blood group A randomly to cross match with the patient’s serum, there were 4 negative and 11 positive including 10 (3+) and 1 (+).

2. The patient’s serum cross matched with 11 donors’ red cell with blood group O, the results were all negative.

All testing we have done were shown above, we are puzzled what is the specificity of the antibody? Why does it only agglutinate part of A cells? Do you have any suggestion for us to do some other tests? It will be very appreciated. Thank you very much in advance.

The patient cells are reactive with anti A1, so she is A1 positive, and also the 4 neg crossmatches are A1 positive.

I think it is some kind of antibody to an combination antigen, in this case a combination with A (or A1). Is there something like an anti ALeb?

Thanks,

Peter

Thanks Peter for this interesting case.

I have a questin, is all of the pos crossmatch A donor cells A1 neg? I don't know the frequency of A1 in your country, in China the A1 is more than 4 in 13 or 15.

[Yanxia]

Sorry, I know my post before is not proper, but I can't delete it, sorry.

[Yanxia]

Peter, have you do the eluation?