Please see the ABO discrepancies (reaction score 0 - 4+) below:

Gel reaction: Forward: Anti-A: 0  Anti-B: 0  Reverse: A1-cells: 0  B-cells 3+

Tube method: Forward: Anti-A: 0   Anti-B: 0    Reverse: A1-cells: w  B-cells: 3+s

Increased serum to cell ratio and incubated at RT: A1-cells got 1+

Since there is a big grade different between A1 and B cells, should we suspect it as an A subgroup? or use 4C or enzyme to enhance the A1-cell reaction?

Thank you very much.

 

 

You may not get much info from A subtyping, esp if the pt is actually a group O.  I think the only way to be sure of a group A status would be to try and absorb/elute anti-A from the pts rbcs.

How old is the patient? Is the patient immune compromised? We see this sort of back type

frequently in our oncology/elderly patients.

Also, what is wrong with the patient?  If they have certain types of leukaemia the A antigen can 'disappear'.  Has the patient had a marrow transplant?  Or a type of bowel cancer that can 'swamp' the A antigen with soluble A substance.

Or you could have a weak A subgroup (Ax or weaker) with a weak anti-A1

There are other possibilities but the 'normal' ones need to be checked out first

The patient is a middle-aged gentlemen. Neither a transplant nor an oncology patient. Sent to hospital because of pneumonia. Strange was the big grade different in the reverse group. Under what situation should I suspect it is an Ael subgroup?  Thanks.

I think at first step, test this patient's cells use anti-AB, if the reaction is stronger than with anti-A, then it is Ax type.

2nd, if the anti-AB reaction strength is the same with anti-A, then do adsorption and elution test, to see if there are A antigens on the cells.

3nd, test the cells use anti-H, to see if there is some kind of parabombay or more rarely bombay type.

As to the reverse group, I think we should add a tube of O cells as negtive control, to make sure the reaction when we add more serum or prolong the incubation time or incubation them at 4 degree C is actually anti-A.

This is my personally opinions

If the A antigen reaction only be seen in adsorption and elution test, I think it is Ael.

But with the use of monoclonal antibodies, I am not sure whether the reaction is so typical as book says. And some different A subgroup defined by serological method may have same genetic background, so I think the most important things is how to transfuse not the naming.

Patient's red cells has no reaction against Anti-A,B (actually most anti-A reacts with Ax cell nowadays). Group O cells was included in reverse group (increased serum to cell ratio,  and 4C incubation to avoid any cold auto-antibody interfere) during interpretation. Yes, you are right that monoclonal anti-A is not suitable in the absorption and elution study cuz IgM don't react with AHG.

Thank you very much for your help.

CK

you are welcome

On Saturday, April 09, 2016 at 10:59 AM, ckcheng said:

Patient's red cells has no reaction against Anti-A,B (actually most anti-A reacts with Ax cell nowadays). Group O cells was included in reverse group (increased serum to cell ratio,  and 4C incubation to avoid any cold auto-antibody interfere) during interpretation. Yes, you are right that monoclonal anti-A is not suitable in the absorption and elution study cuz IgM don't react with AHG.

Thank you very much for your help.

CK

I think you can still absorb and elute anti-A, whether monoclonal or not.  You are going to test for anti-A not an antiglobulin reaction.  We did this many times where I used to work

Isn't everyone overthinking this? Weak reverse groups are not uncommon and it's a lot of effort to go to for a naturally occuring and totally normal phenomenon. Is the patient aged, immunosuppressed or on chemo?