Outdated Red Cell panel - QC

[Walter]

Do you keep and use outdated red cell panels?

If so, for what purpose?

If used for antibody identification [in addition to in-date red cell panels], do you perform quality control on the outdated panel cells?

If you perform QC on outdated panels when used, what QC do you perform?

Walter

[Bill]

We use individual cells of outdated panels to aid in antibody ID's. We run a positive and negative for the particular cell we are using that time.

[David Saikin]

Ditto

[Rh-fan]

We do not use outdated red cell for the exclusion of clinical relevant antibodies, sometimes we use them as an extra positive cell (mostly in LFA cases).

The problem is that you use these cells when you have more than 1 antibody present (otherwise you don’t need them). When a patient has 2 or more antibodies than they will make also a new antibody (if that is possible), and for those patients you are going to work less sensitive (these cells are not outdate for no reason).

You can better screen with outdated cells than exclude a third antibody with an outdated cell. In a patient with no antibodies that change that there is an antibody is very low. And nobody will do that.

When you do use outdated cells a positive negative control is not enough. The antigen you want there to be is not gone in one day, it will be present but the expression can be lesser than you need. The only good control is an antigen strength determination (titration), where you compare the outdated cell with an not outdated cell. If the expression is the same you have prove the expression of the antigen is enough.

I know that working in a reference lab is easier, we have more than 100 cell from which we can pick. But also for a hospital situation I think that the risk you take is too high for these group of patients.

Peter

[Liz]

From what I read from you Peter, and Malcolm and others I think I would be so happy, just thrilled, to work in a reference lab!!!!

[adiescast]

We use outdated red cells for rule outs when we don't have an in date cell to use. We only check the antigen of interest at the time of use with liquid cells (not solid phase, obviously!).

[Malcolm Needs ☆]

From what I read from you Peter, and Malcolm and others I think I would be so happy, just thrilled, to work in a reference lab!!!!

We really are so lucky (and we sometimes forget this). Not only do I have access to a huge number of rare cells (either "wet" or cryopreserved) and rare sera, but, in London in particular, there is such a large mix of ethnicities that we see an awful lot of rare antibodies in patients. As an example, our lady who made anti-DOLG (anti-Do8) is pregnant again, as so we are able to "play" with her samples on a regular basis!

[pluto]

I am sure the London Olympics will throw up a few unusual cases as well for you to have fun with

[Malcolm Needs ☆]

Now, that could be fun!!!!!!!!!!!!!!!!!!

[David Saikin]

From what I read from you Peter, and Malcolm and others I think I would be so happy, just thrilled, to work in a reference lab!!!!

Ditto that Liz . . .

[Deny Morlino]

Also agree David and Liz. When talking to the reference lab I am often reminded that practically every patient presents to them as having a positive antibody screen!!

[jill]

We keep the last 3 months of 3% expired reagent red blood cells and the last 1 month og 0.3% reagent red blood cells to use mostly for ruling out and rarely for ruling in. We QC the expired reagent cell with the antisera that

corresponds to the antigen we are using the cell for by testing the antisera with the reagent cell, a positive control and a negative control/

[macarton]

We keep our old panels for ruling out also. We also have students that we will give or make up a multiple antiobody samples, so they can go through them & rule out.

[Malcolm Needs ☆]

We keep our old panels for ruling out also. We also have students that we will give or make up a multiple antiobody samples, so they can go through them & rule out.

Good point Mary.

[Dr. Pepper]

We keep the last 3 months of 3% expired reagent red blood cells and the last 1 month og 0.3% reagent red blood cells to use mostly for ruling out and rarely for ruling in. We QC the expired reagent cell with the antisera that

corresponds to the antigen we are using the cell for by testing the antisera with the reagent cell, a positive control and a negative control/

What is your criteria for acceptable reactivity for the outdated cell? Equal to an indated cell, or within 1+?

[webersl]

For American readers:

CAP has/had a special committee regarding QCing outdated panels. A recent phone call to the "Senior Technical Specialist, CAP Accreditation Program" revealed that their expectation is that you run both positive and negative controls on the specific cell that you are using, AND the controls should be analogous to the antibody(s) which you are ruling out. For example: On my original indated panel(s) I was not able to rule out anti-E. I select cell #5 from on expired panel in order to rule anti-E out. I must test cell #5 with a known anti-E to prove that the E antigen is still there, and I must test cell #5 with serum known to NOT contain anti-E as a negative control.

Before phone call, we ran a positive control if we were using the cell to rule OUT, or a negative control if we were using the cell to rule IN. CAP did not relent when I explained the logic of this. Outdated cells must have both positive and negative control run.

For ALL readers:

We did a study to determine the longevity of Ortho’s (MTS) 0.8% panel cells for gel (column agglutination). We tested panel cells that were 90 days past their expiration date. (We only tested those that passed visual inspection). We tested for the presence of Rh, Kell, Duffy, Kidd, and MNSs using a variety of antisera and compared the reaction strengths on those outdated cells to reaction strengths on similar (but not exact) in-dated cells. n=20 for each antigen. We also did this for 3% Immucor panels (diluted to 0.8% in MTS diluent for gel). We found that Immucor cells lost certain antigens, but Ortho cells retained antigens at acceptable levels [in my judgement, for our context, a small(ish) hospital transfusion service]. Though, I do respect Peter's thoughts and logic on the subject, we are too small to afford his level of scrutiny.

Oh, and my attempt to share the results of this study with CAP was met with scorn. I guess it is reasonable to assume that I should get it published first, then ask CAP to look at it...

[macarton]

We use a postive and negative control cell when ever running outdated panels

[Malcolm Needs ☆]

We run positive and negative controls, if we can. But some of our stuff is so rare that we cannot always do this!

[Rh-fan]

On my original indated panel(s) I was not able to rule out anti-E. I select cell #5 from on expired panel in order to rule anti-E out. I must test cell #5 with a known anti-E to prove that the E antigen is still there, and I must test cell #5 with serum known to NOT contain anti-E as a negative control.

Before phone call, we ran a positive control if we were using the cell to rule OUT, or a negative control if we were using the cell to rule IN. CAP did not relent when I explained the logic of this. Outdated cells must have both positive and negative control run.

The only problem is that the anti E reagent you use will mostly be strong reactive (3+/4+), so you only rule out strong antibodies, weak antibodies you can miss.

I like you study and hope you can publish it, maybe we can then the panel firms will stretch the expiration date, that would be nice.

From the things I hear from the USA, the rules are very thight (specialy the FDA). So I am surprised that the CAP (I do not know what it stands for) is accepting the use of a product that is past the expiration date.

I know that a reference lab has more possibilities and must be more secure, but for every hospital counts that patient care is patient care, if the hospital is very smal or very big, that should be the same.

Peter

[macarton]

We have a box back in our walkin, not in BB that we keep our expired antisera and panels in. It has a big label that says for student use.

[Malcolm Needs ☆]

Vis-a-viz something similar, but NOT exactly pertinent to this thread, we kept out-dated sera for trainees on the floor of our cold room, and reagents in date on shelves in the same cold room. We got dinged for having the sera in the same cold room, "in case the out-dated reagents got mixed up with the in-date reagents".

I asked the inspector if he/she had ever heard of Newton, and the Laws of Gravity, and how the out-dated reagents could fall upwards. Amazing, in an attempt to save face, the inspector decided that he/she was right, and that Newton was wrong.

[webersl]

he/she was right, and that Newton was wrong.

Don't we just LOVE our inspectors.

[Dr. Pepper]

Peter, the CAP is the College of American Pathologists, an organization which, among other things, runs a peer inspection program (your lab goes out to inspect another lab, another lab comes in to inspect you). Many, many labs participate in the program. They have a set of standards for each lab area. CAP allows you to use "rare" reagents (reagents not readily available) past their dating period, providing they react as expected with appropriate controls. These could be reagent antisera or red cells. You have to define what is considered "rare" for your lab.

[webersl]

"The only problem is that the anti E reagent you use will mostly be strong reactive (3+/4+), so you only rule out strong antibodies, weak antibodies you can miss." Perhaps we will switch to previously identified patient samples (frozen), known to have weaker reaction strengths.

"I know that a reference lab has more possibilities and must be more secure, but for every hospital counts that patient care is patient care, if the hospital is very smal or very big, that should be the same." Point taken.