Group A subgroup

[lab217]

I am interested in knowing how everyone tests and reports A subgroups. We only use an anit-A1 lectin and if the patient is negative, we report the patient as A2. It seems to be a common practice with our surrounding hospitals. Would is be more appropriate to report the patient as just an A subgroup vs specifically A2? I realize that A2 is the most common and the others are less so.

[Malcolm Needs ☆]

As a Reference Laboratory, even we rarely report any A subgroup definitively, other than A1, A2 and A3. The reason for this is that the "definitions" of the A subgroups were really made back in the days when we were using human-derived polyclonal ABO reagents. These days, of course, we are all using highly specific, and extremely avid monoclonal ABO reagents (albeit that many of these are blends of different clones). This means that even an Ax can be detected quite strongly with certain monoclonal anti-A reagents. Therefore, the old "definitions" of A subgroups are now largely redundent.

My own vote is that they stay that way. With so many different mutations having been described for the genes producing the different A, B and H transferases, very many of which produce, as near as anything, identical ABO phenotypes, I just don't think it is worthwhile trying to categorise these different phenotypes (although the molecular genetisists would, I am certain, still think it worthwhile to categorise the different genotypes).

[Yanxia]

We will category it , but just as Malcolm described , the type is not so typical as drescribed by book.

We emphasize if it has anti-A or anti-A1, if it has and react at 30 degree C, we think it is clinical significance and we will avoid transfused A antigen to it.

[LCoronado]

Often the first clue that we have an A subgroup is the demonstration of anti-A in the reverse typing. We then use the Anti-A1 lectin to verify that the patient is a subgroup. Our interpretation of this reaction pattern is A2 (or A2B), with an exception message that explains "subgroup of A", but the patient's type is reported and charts as A or AB with Anti-A1 antibody. We were tired of calls from nurses (and occasionally doctors) asking what in the world was meant by A2 as they had never heard of such a thing. Since the Blood Bank techs see the actual reactions, investigation and conclusions, they can honor the Anti-A1 when necessary while the nurses remain blissfully unconfused. We have not felt the need to categorize subgroups of A any further.

[Dr. Pepper]

...I just don't think it is worthwhile trying to categorise these different phenotypes (although the molecular genetisists would, I am certain, still think it worthwhile to categorise the different genotypes).

[Dr. Pepper]

Sorry Dave, I missed your post the first time, and you put it in perspective as well. We do as you do.

[Barbarakym]

We do not differenciate in types of A. But we do mention if Anti A1 is present. We do the A1 lectin and A2 testing and document this, but in the results what is put in the computer is Type A, Antibody iD: Anti A1. Then of course follow our internal procedures on how to deal with that.

[Malcolm Needs ☆]

We do not differenciate in types of A. But we do mention if Anti A1 is present. We do the A1 lectin and A2 testing and document this, but in the results what is put in the computer is Type A, Antibody iD: Anti A1. Then of course follow our internal procedures on how to deal with that.

Which, hopefully, unless the anti-A1 is detected strictly at 37oC, is to give cross-match compatible group A blood?

[Barbarakym]

Which, hopefully, unless the anti-A1 is detected strictly at 37oC, is to give cross-match compatible group A blood?

Actually our policy is to give XM compatible blood if antibody shows anywhere, even IS (cold) while showing. Colds if not showing revert to IS XM, but all other non-specific and/or clinically significant antibodies remain at AHG forever.

So bottom line: Yes, AHG XM. Which means sometimes O blood instead of A.

[Nisar]

According to the AABB standers there is no need even to test A individual with lectin,as there is no clinical significance for using lectin.If discrepency arise then it should be used to resolve the problem otherwise not needed.It a wastage of money and time:cries:

[Barbarakym]

Niser what kind of discrepancy would you test for? We use it along with A2 cells when back type doesn't match front type on a patient.

[Nisar]

We do not differenciate in types of A. But we do mention if Anti A1 is present. We do the A1 lectin and A2 testing and document this, but in the results what is put in the computer is Type A, Antibody iD: Anti A1. Then of course follow our internal procedures on how to deal with that.

[LCoronado]

According to the AABB standers there is no need even to test A individual with lectin,as there is no clinical significance for using lectin.If discrepency arise then it should be used to resolve the problem otherwise not needed.It a wastage of money and time:cries:

Would you please point me to the particular AABB standard to which you refer? Thank you.

[Nisar]

r y0u using lectin f0r all A gr0up indivdual?

[Barbarakym]

r y0u using lectin f0r all A gr0up indivdual?

No. Only when there is Anti A showing in back type.

[RDA26]

According to the AABB standers there is no need even to test A individual with lectin,as there is no clinical significance for using lectin.If discrepency arise then it should be used to resolve the problem otherwise not needed.It a wastage of money and time:cries:

I agree with Nisar and Barbarakym - we don't report subgroups but if there is a discrepancy in the reverse group we do Antibody ID and report ABID as Anti A1 and issue cross match compatible blood.