Quality Control of Anti-A and Anti-B reagent antisera

[Dansket]

Manufacturer's Instructions for Use state "To confirm the reactivity and specificity of the microtubes containing Anti-A and Anti-B, it is recommended that each lot of cards be tested each day of use with antigen positive and antigen negative red blood cells."

Do you interpret this statement that Anti-A should be tested against group O red blood cells as well as group A red cells and group B red cells to demonstrate reactivity and specificity, i.e., Anti-A agglutinates only group A red blood cells and does not agglutinate group O or group B red blood cells?

[Malcolm Needs ☆]

Yes, in a word.

[Dansket]

Malcolm,

In your laboratory, do you control your anti-A antiserum with A, B and O red blood cells on a daily basis?

[Malcolm Needs ☆]

Yes, we do.

[Dansket]

Malcolm,

Appreciate your conversation.

Thanks,

Dan

[Auntie-D]

We do too, as do the two other laboratories I have worked in...

[aafrin]

We do so too (1st thing in every morning shift)

[Mabel Adams]

I would be interested to see if US labs are doing the same as the UK. Most that I have worked in run a commercial QC kit and they don't usually have you test more than one neg ABO sample (if they even include one).

[mollyredone]

We don't test for negatives on our daily QC for anti-A,anti-B,anti-AB, and A1,B, and A2 cells, as per our manufacturer's package insert. We just had a CAP inspection where we were cited for not doing a negative, but challenged with the package insert and it was accepted.

[Dansket]

We don't test for negatives on our daily QC for anti-A,anti-B,anti-AB, and A1,B, and A2 cells, as per our manufacturer's package insert. We just had a CAP inspection where we were cited for not doing a negative, but challenged with the package insert and it was accepted.

From the CAP Transfusion Medicine Checklist (07.11.2011):

TRM.31400 Antisera/Reagent Red Cell QC

Records document acceptable reactivity and specificity of typing sera and reagent cells on each day of use, including a check against known positive and negative cells or antisera, or manufacturer's directions for daily quality control are followed.

I assume you used the underlined portion of this CAP requirement to challenge your inspection. I am curious which reagent manufacturer does not require testing for specificity (pos and neg controls) each day of use for anti-A, anti-B or anti-D?

Thanks

[Dr. Pepper]

I assume you used the underlined portion of this CAP requirement to challenge your inspection. I am curious which reagent manufacturer does not require testing for specificity (pos and neg controls) each day of use for anti-A, anti-B or anti-D?

For Immucor's anti-A and -B, they say that (1) the front and back types must match up, and to (2) test the antisera with positive cells. No negatives. Same for their backtype cells, just test against weakly reacting antisera, no negatives. Yet for their anti-D they want both positive and negative controls. Interesting.

Edited November 30, 2012 by Dr. Pepper

[David Saikin]

In the US the FDA only requires anti-D reagent to be tested with a positive and negative cell (when used for tube testing). Other certifying agencies (like CAP) have a more stringent standard. ABORh testing using gel mandates qc with positive and negative moieties for both antisera and reagent cells.

[mollyredone]

We use Immucor, and only do ABO in tube. It does say to follow instrument requirements for automated microplate testing.

[tbostock]

We only test Anti A reagent with a positive control (A cells) and a negative control (B cells). Using O cells as well would be performing 2 negative controls, correct?

[Malcolm Needs ☆]

Not if the anti-A has an elemwnt of anti-H present as well.

[Mabel Adams]

In the US, doesn't every lot of reagent have to pass the Bureau of Biologics testing so that we know it started out as adequately specific (i.e. ABO typing sera do not contain anti-H)? Our QC then, is to make sure that nothing has changed since the lot was approved, right? Usually this would be a loss of potency but could also be contamination.

[bb4me]

We only test Anti A reagent with a positive control (A cells) and a negative control (B cells). Using O cells as well would be performing 2 negative controls, correct?

CAP has cited us for not doing daily negative controls on anti-A and anti-B, but (curiously) not with anti-A,B - same antisera manufacturer, same package insert. We have decided to institute daily testing of all 3 reagent antisera, since reconfiguring the computer QC worksheet is so labor-intensive, we don't want to do this again soon!

CAP has confirmed that using an in-house 3% preparation of group O cells would be acceptable. Does anyone else use patient cells to test their commercial reagent antisera, and if so, would you be willing to share your recipe? I would be grateful for guidance on additives and outdate/frequency of preparation.

[Dr. Pepper]

You could just use your antibody screening cells like we do. If you want to make your own, you can use cells from a donor segment or two (already typed & tested for nasty diseases, but so are your reagent cells) or from a patient. We get a vial of modified alseavor's with each panel lot. Put the appropriate amount of washed packed O cells (I will leave it to you to practice your lab math!) in there, label it and give it a month outdate and you're good to go.

[mollyredone]

bb4me,

I also got cited by CAP for not running negative controls on anti-A and anti-B, but I challenged it with the package inserts which state that only a positive control has to be run, and the challenge was successful. The checklist states that both must be run unless "manufacturer instructions state otherwise", and my reagents from Immucor state that only a positive control needs to be run.

Hope that helps, Molly

[BBCLS]

I would be interested to see if US labs are doing the same as the UK. Most that I have worked in run a commercial QC kit and they don't usually have you test more than one neg ABO sample (if they even include one).

In addition to QC kits we freeze AB plasma for negative control. The AB plasma is known negative for screen.