Anti A,B usefulness

[Jodi Barsha]

I am currently wanting to delete Anti-A,B testing on patient types. I am interested in knowing how many of you just use Anti-A and B? I would like to be able to take this info to my medical director . Thanks in advance.

[Lcsmrz]

We use Anti-A,B to retype group O units only.

Not sure how that got started, since at our volume, I think it's less complex and probably just as expensive overall to retype all units with Anti-A and Anti-B.

[Cliff]

We use Anti-A,B to retype group O units only.

Not sure how that got started, since at our volume, I think it's less complex and probably just as expensive overall to retype all units with Anti-A and Anti-B.

Doesn't anti-A,B have a higher likelihood of detecting subgroups of A? We also retype our donor units and have found a few A subgroups over the years. Our volume is relatively high, about 40,000 RBC's a year.

[Eagle Eye]

We stop using anti-A,B in 2003. We retype our donor using anti-A and anti-B.

[janet]

We stopped using A,B routinly over 10 years ago....still used for cord and infant types though since you don't have a reverse to aid you. Occassionaly we will troubleshoot mixed fields or weak forwards + one time our supplier sent us a group A we grouped as an O until they told us it was a subgroup and the A,B helped us then.

[donellda]

The only thing we use Anti-A,B for is retyping group O units.

[Lcsmrz]

The "new" monoclonal Anti-A is pretty good at detecting weak subgroups.

Also, our blood supplier uses enzyme-treated donor cells to do the unit's blood grouping. Subgroups come up real nice on their system ...

[Mabel Adams]

Is human source anti-A,B still readily available? Or did all the manufacturers make a monoclonal of it? I was under the impression that the stuff bottled as monoclonal anti-A & B was just a mixture of monoclonal anti-A and monoclonal Anti-B and it was marketed for retyping O units. If it is a mixture now, is its strength somehow altered so it behaves like human source anti-A,B with weak subgroups? We haven't used it in many years so I have no package insert to read. I know that monoclonal anti-A reacts much more strongly with most subgroups so that the old serological definitions don't really apply to monoclonal anti-A testing. Heaven help the definitions when they finish DNA profiling of them.

[adiescast]

I saw an interesting talk at an AABB meeting a couple of years ago by a guy who used only one antisera to retype any blood type unit. I have not tried it myself and wondered if anyone else has...

Basically he advocated testing with the antisera you expect to be negative. So for type A, you would test only with anti-B; for type B, test with Anti-A; Type O test with A,B. I can't remember what he said about type AB units.

Rh negative units, of course still require anti-D testing.

Anybody ever heard of this?

[Kwenz]

We also use A,B only for bag typings.

[rcurrie]

We use anti-A,B for retyping O units.

BC

[Mabel Adams]

I have thought about only retyping units to detect false positives but haven't done it. By this logic no testing would be required on AB+ units because you would not give them to any patient but an AB+ and if the unit was falsely labeled it would do him no harm.

I got an email answer from Ortho regarding their anti-A,B. It is a combination of the same two clones in their anti-A and 2 of the 3 clones in their anti-B. There seems to be no evidence that it reacts more strongly with subgroups. They no longer offer human source anti-A,B.

I read the Gammaclone package insert. Their anti-A,B is a mixture of several clones including one that is supposed to react with both A and B antigens (like human source anti-A,. They seem to imply that it reacts more strongly with Ax but don't say anything about its reactions with other subgroups. I have asked for more expert input and will share it if I get some.

[Karen Olsen]

We also only use Anti A,B for retyping of donor units.

[bbbirder]

We don't anti-A,B reagent except to retype group O units.

A few weeks ago we had a patient who appeared to be an A3. We will sometimes use anti-A,B for ABO discrepancies. The reactions for this patient were a little stronger with anti-A,B than with anti-A.

(We use Immucor reagents, monoclonal anti-A & anti-B and monoclonal blend anti-A,

This is just one patient, so who knows how others will react? There is a good chapter on ABO & Rh discrepancies by Mary Kowalski in the AABB book, "Serologic Problem Solving". Her statement is that "to categorize cells into traditional subgroups, human polyclonal reagents must be used."

We don't have any of those reagents. We sometimes will take plasma off donor units as a source of anti-A,B to use to help resolve an ABO typing problem. This is a rare event for us.

Linda Frederick

[bbbirder]

I have been reminded by another BBTalk Forum member that using donor plasma in this way may constitute 'reagent' manufacturing... or some other FDA prohibited event.

We only use it as 'educational/informational'...not as an 'official reagent'.

(This reminds me, does anyone still use mixed urine for neutralization of Sids? talk about unlicensed reagents!)

Linda Frederick

[rcurrie]

Ah! The old days! I can still remember going around to the nursing stations looking for urine. I usually had no trouble getting any, as I took care of the nurses on my shift by running this test and that one for them, usually pregnancy tests, although one particular nurse always needed a CBC. I did break her of that "need" one night by running the low control through the analyzer and faxing that to her. I gave her 5 minutes to absord the results, then called to say "April fool." However, she had already called her supervisor to replace her, clocked out, and presented to the ER with an urgent need for transfusion. She never asked for a freebie again.

BC

[Gloria]

Human source ABO reagents have not been available in the US market for several years. Currently, there are reagents that are just a mixture of anti-A and anti-B, some that contain anti-A,B in addition to anti-A and anti-B and some that are actually anti-A,B. Check the direction insert of the reagent to find out which one you are using.

[Geriann]

We use A,B to retype Group O units and for Cord Blood Workups.

We have not done completely away with it but do not use it for routine testing with the exception of Cord Blood specimens.

Geri

[Mabel Adams]

For those of you that use anti-A,B on babies/cords, what change in patient care ensues if you find a weak subgroup? Are you comfortable transfusing, say, A units to the baby? Have you found any subgroups only in the anti-A,B test?

It could answer an otherwise mysterious case of ABO HDN, I would think. It would register a more accurate type for the baby's records should you ever deal with it as an older patient and it still had the same name etc. (we do cords under the mother's account and don't have an NICU.) Is there any other value doing this test has added to cord/infant testing that I haven't thought of?

[ckcheng]

Since most of us are using monoclonal anti-sera, anti-A is potent enough to react with weak subgroup like Ax, anti-A,B no longer required for forward grouping in patient sample. It is useful for retype group O donor.

CK Cheng, MSc, SBB(ASCP), CQA(ASQ)

Hong Kong

Oct 29, 2008

[DFields]

Having been a blood banker for MANY years I like anti-A,B for both "confirming" the front type (old school) but I assure you it does still (albeit rarely) pick up subgroups much more strongly than the anti-A..

Last week we had a patient type as an O front and reverse with gel (A1 cells were 1+) whereas with tube reagents the anti-A forward was weakly pos, the anti-A,B was 2+.........the reverse showed and anti-A1

[Mabel Adams]

As with Rh, we may be safer NOT finding weak antigens on our recipients' cells.

[Likewine99]

We use anti A,B for donor retypes only.

We d/c'd it for patients about 10 years ago and just d/c'd it for cord bloods 2 months ago when we went live with HCLL.

[jayinsat]

same here. we only use A,B to retype O units we receive in inventory from our supplier.

[jayinsat]

same here. we only use A,B to retype O units we receive in inventory from our supplier.