Does anyone have a specific policy for A or AB patient's reacting with A cells in their backtype and reacting with IS crossmatch?  We use gel, and will get negative XM in the gel, but some still feel that these patient's need O cells.  I'm looking for a specific guideline that could be followed by all!  Thanks!

Does anyone have a specific policy for A or AB patient's reacting with A cells in their backtype and reacting with IS crossmatch?  We use gel, and will get negative XM in the gel, but some still feel that these patient's need O cells.  I'm looking for a specific guideline that could be followed by all!  Thanks!

 

If you are in the US, please remember that the "gel" test cannot be used to detect ABO incompatibility, so you should not be using that result alone to determine compatibility.

 

When you're referring to reacting with A cells in their backtype, I'm assuming you mean A1 cells?  Since approximately 1 of 5 A units (20%) will be A1-negative, I would encourage the use of these units rather than group O units.  Save the group O units for O patients!

I would advise giving cross-match compatible units of group A, whether they be A₁ or A₂ (or any other subgroup of A), unless the anti-A₁ is of the very rare type that reacts strictly at 37^oC, as this is the only kind of anti-A₁ that may be clinically significant).  Very, very few examples of anti-A₁ react at strictly 37^oC, and so the vast majority of antibodies of this specificity are clinically insignificant.

Malcolm - I am presuming you mean - crossmatch at 37°C by IAT when you say cross-match compatible.  Well, I know you are - but just felt I had to make the point for our American friends who still do IS crossmatches

Yes indeed Anna.

To clarify, the Anti-IgG Gel card may not be used to detect ABO incompatibility by the indirect antiglobulin test.  However, the Buffered Gel card may be used to detect ABO incompatibility by the direct immediate-spin test.

I suppose the question is 'Would a clinically significant anti-A1 be best detected by IAT or 'immediate spin''?

Thanks for your answers!  We do an IS in addition to the IgG gel card.  XM will be compatible in gel, incompatible at IS.  Screen is negative, so, what do you do with the incompatible portion of the XM?

Edited October 8, 20159 yr by BBfuntimes

What do you do if the IS XM is incompatible because of an 'insignificant cold antibody'?

What do you do if the IS XM is incompatible because of an 'insignificant cold antibody'?

We do a prewarm, no IS phase.  Which I know is a controversial procedure in itself.

BBfuntimes,

 

Is you IS crossmatch done in standard tube or in Buffered Gel?

Does it matter Dansket? The human body (core temperature), will never get down to room temperature, unless the patient is dead!

I agree with Malcolm.  You are really making a lot of extra work for yourselves.  The immediate spin - in gel or tube  or anything is definitely NOT the best way to deteect an ABO incompatibility.  If you have a combination of very weak antibodies in the patient and a weak antigen expression in the donor, you will have  a nice negative IS result and possibly a not very happy patient.  The best way to detect ABO incompatibility is to make sure that you've done the ABO group on your patient correctly - and, if the donor centre don't guarantee their results, the same for your blood bags.  Anything else that only comes up in your IS (and not in IAT) is clinically significant and you don't need to be looking for it.

I agree with Malcolm.  You are really making a lot of extra work for yourselves.  The immediate spin - in gel or tube  or anything is definitely NOT the best way to deteect an ABO incompatibility.  If you have a combination of very weak antibodies in the patient and a weak antigen expression in the donor, you will have  a nice negative IS result and possibly a not very happy patient.  The best way to detect ABO incompatibility is to make sure that you've done the ABO group on your patient correctly - and, if the donor centre don't guarantee their results, the same for your blood bags.  Anything else that only comes up in your IS (and not in IAT) is clinically significant and you don't need to be looking for it.

Anna, I think that last phrase should read "is clinically INSIGNIFICANT and you don't need to be looking for it"!!!!!!!!!!

Woops.  Well spotted!

BBfuntimes,

 

Is you IS crossmatch done in standard tube or in Buffered Gel?

standard tube