Doing Rule Outs

[jhaig]

I'm in the process of updating my panel procedure (we use Ortho 0.8% panel A and B, with Immucor Panocell 10 as a backup) and I want to do rule outs on homozygous cells. I wan to use the following rules: rule out on 2 homozygous cells (preferred), 3 heterozygous cells, or a combination of 3 cells of the above.

I need to tap into your collective wisdom and knowledge. Where are the holes in this thinking and what do I need to fix or re-think?

[Malcolm Needs ☆]

I'm in the process of updating my panel procedure (we use Ortho 0.8% panel A and B, with Immucor Panocell 10 as a backup) and I want to do rule outs on homozygous cells. I wan to use the following rules: rule out on 2 homozygous cells (preferred), 3 heterozygous cells, or a combination of 3 cells of the above.

I need to tap into your collective wisdom and knowledge. Where are the holes in this thinking and what do I need to fix or re-think?

I think that your preferred method is best, but beware of the ethnic origin of the donors of the cells.

For example, two Fy(a-b+) red cells could both come from Black donors, and so actually be FYB/FY, meaning that the cells have a single dose of the Fyb antigen.

I still, however, think this is the best method.

:redface::)

[jlemmons]

There is a program that helps with rule outs called Antibody Check. It only rules out by homozygous cells and has a component in the program that allows for help in finding select cells. This might be something you would want to look into. I believe you can just go to www.antibodycheck.com and you will find them and they have examples on their web site.

I would never rule out anti-M, anti-N, anti-Jka, anti-Jkb, anti-Fya or anti- Fyb with just heterozygous cells. I have actually also seen an anti-K that showed dosage like these previous ones that I have mentioned so I tend to be careful with just heterozygous. Given a choice, I like to have 2 or 3 homozygous to completely rule out an antibody but many times that is a pipe dream and not available. We are blood bankers and must use our knowledge and skill to make these decisions as to how to rule out but there must also be the rules in place that you are trying to make. Our facility actually uses 1 homozygous or 2 heterozygous with the exception of the above antibodies. Those must have homozygous only. Hope this helps.

[adiescast]

I've never been a fan of the 3 heterozygous cell rule out. It may be that your antibody is reacting variably and will react with some heterozygous cells, but it is just a possible that your antibody doesn't like heterozygous cells and will only react with homozygous cells. Having said that, how dangerous is that antibody? Who knows? As Malcolm is fond of pointing out, we haven't killed a bunch of patients with our current methods. In the old days, if we could not figure out what the antibody was, we would go ahead with the transfusion and hope that it made the antibody show itself. Then we could identify it. On the other side, I allow rule out with one homozygous cells, although I prefer more. Is that any "safer" than using 3 heterozygous cells for rule out? Maybe, maybe not...it depends on the antibody.

[Malcolm Needs ☆]

I've never been a fan of the 3 heterozygous cell rule out. It may be that your antibody is reacting variably and will react with some heterozygous cells, but it is just a possible that your antibody doesn't like heterozygous cells and will only react with homozygous cells. Having said that, how dangerous is that antibody? Who knows? As Malcolm is fond of pointing out, we haven't killed a bunch of patients with our current methods. In the old days, if we could not figure out what the antibody was, we would go ahead with the transfusion and hope that it made the antibody show itself. Then we could identify it. On the other side, I allow rule out with one homozygous cells, although I prefer more. Is that any "safer" than using 3 heterozygous cells for rule out? Maybe, maybe not...it depends on the antibody.

I agree (I must do, because you were quoting me!), but I would add the caveat that I would always use Jk(a+b-) and Jk(a-b+) cells, because very weak antibodies within the Kidd Blood Group System (in particular, anti-Jka) have been known to cause very serious delayed haemolytic transfusion reactions, due to an anamnestic response.

:):)

[Bill]

There is a second company with the "Antibody Check" software--see www.rowny.com. I do not know the name and do not recommend either, just know there are 2 available.

[LaraT23]

Well I have a lovely little procedure that was handed down by a pathologist who is since retired. She was very good in blood bank, and I think it just sums everything up. See attached

antibody rule outs.doc

[LisaM]

Ok, so here's my question: when doing rule-outs, where I work, we have a pile of gel and tube panel cell sets that we use for this purpose, most of which are past their outdates. They still "work", as in, the reactions will still show up, but that's always not made a lot of sense to me--what's the purpose of having an outdate on reagents if they're to be used beyond the expiration? I know you can't always rule out everything on the first shot, with an in-date panel, so what does everyone else here do? I always thought that using outdated reagents was a no-no with CAP, AABB and other regulatory agencies, in any section of the lab? Thoughts?

[LaraT23]

This was discussed recently under the Quality forum, but with CAP the transfusin service can deem a reagent or antisera as "rare". This includes cells from expired panels, and has to be defined in a policy. The QC of those must also be defined, as your blood bank sees necessary. The package inserts for those cells aren't very helpful in the QC area.

But you are right, in other departments, nothing is used after its expiration date. :tongue:

[LisaM]

^^^Hmmm, I have a copy of the current CAP regulations in my closet--I'll have to browse through them as well as our policy book. I know we have a lot of work to do in updating policies/procedures, and having done complete overhauls of Hematology, Chemistry and Lab Safety in the past as well as having done CAP inspections myself, I tend to nitpick and try to go at things from every possible angle that an inspector could nail us on.

[Deny Morlino]

On a side note: Welcome back Lisa M.!

[LisaM]

^^Thanks, Deny! I'm just catching up on my online reading, since I'm post-op and don't want to pop my stitches--lol! (Forum posting is about as non-strenuous as it gets!)

[Malcolm Needs ☆]

Great to have you back Lisa.

:D:D:D:D

[Abdulhameed Al-Attas]

Nice to have you back Lisa.

[Melanie]

It is custom to use outdated cells for antibody identification and ruleout. Cells have shown to be useful more than two months past the manufacturers expiration date for most antigen systems. We use cells up to this time for all antigens except Lewis. Cells must be visually inspected prior to use and must not be hemolyzed or discolored.

[tbostock]

We don't use expired reagents here.

[LisaM]

We don't use expired reagents here.

What do you use, then, or what process is used if you need to rule out antibodies? What about multiple antibodies? Do you have a few different lot numbers of in-date reagents?

[tbostock]

We keep 3 panels in house; this enables us to rule out almost everything we need to. Really difficult patients (multiple antibodies) we send to the reference lab (just a few per year). Worst case scenario, for example if we can't rule out K, we screen the units for that too just in case.

It's very difficult in my state (NY) to do things that are custom everywhere else. The regs are very stringent, the inspectors are pretty tough, so I try not to "push the envelope".

[LisaM]

^^Oh, thanks! Was just curious in comparison to what we do at our facility. I sometimes wonder how we have passed inspections with some of the things I've found, after the fact. . .. not just in Blood Bank, but in all areas of the lab. Makes me wonder if I'm being too picky, or if something got overlooked (or in some cases, "hidden").

[generalist]

hi, im new here and hope someone can help me , recently we had a person with acold m (done by arc) they suggested m neg units, next time pt came back we id the m but was unable to rule out E as we didnt have enough panels. So heres the prob, we have no bb sup. but one tech said we now have to always give this pt E neg units and put it in the pts. history, i have never heard of this and when i talked to the redcross they also said no it is unable to be ruled out as that time.This came to light as the pt came back and we had a total neg screen and panel so we gave the pt mneg units but not E neg and was told that was wrong that once you couldnt rule it out you must always give neg units to the anitibody. we have no sop that says this and i couldnt find a reference in AABB standard. wondering what everyones take on this was.

[Malcolm Needs ☆]

hi, im new here and hope someone can help me , recently we had a person with acold m (done by arc) they suggested m neg units, next time pt came back we id the m but was unable to rule out E as we didnt have enough panels. So heres the prob, we have no bb sup. but one tech said we now have to always give this pt E neg units and put it in the pts. history, i have never heard of this and when i talked to the redcross they also said no it is unable to be ruled out as that time.This came to light as the pt came back and we had a total neg screen and panel so we gave the pt mneg units but not E neg and was told that was wrong that once you couldnt rule it out you must always give neg units to the anitibody. we have no sop that says this and i couldnt find a reference in AABB standard. wondering what everyones take on this was.

If the anti-M was a "cold" reacting antibody, I would not have recommended giving M- blood in the first place. I would have recommended cross-match compatible. I most certainly would not give M- typed blood now that the anti-M can no longer be detected.

On the other hand, however, anti-E is much more clinically significant, and I would recommend cross-matching E- blood from now on.

Sorry; that's not really a lot of help to you, is it?!!

:redface::redface:

[LaraT23]

I would suggest that the patient be phenotyped for E. If the person has the E antigen and the DAT is negative, then E is likely not one of the possible antibodies. As for M, I don't type units for M as a cold. There are very few instances of M being clinically signficant ( i.e. active at body temperature). My M pos patients just get type specific and full crossmatched.

Hope this helps.

[generalist]

hi again, ii know E is clinically significant, but as the pt was never id big E only unable to rule out , so do you now always give neg units even though it has now been ruled out? this was a for instance as i guess we are going to mark all pts with give neg units for life for an unable to rule out. even if we rule it out at a later date and it was never id as an antibody.

[Malcolm Needs ☆]

hi again, ii know E is clinically significant, but as the pt was never id big E only unable to rule out , so do you now always give neg units even though it has now been ruled out? this was a for instance as i guess we are going to mark all pts with give neg units for life for an unable to rule out. even if we rule it out at a later date and it was never id as an antibody.

In that case, no, but if you couldn't ruke it out, why didn't you send it to ARC again in the first place?

:confused::confused:

[LaraT23]

No we do not result an antibody in a permanant history just because it cannot be ruled out. Only firmly identified antibodies will be put there. Any that "cannot be ruled out" are dealt with for that visit only. The next time the patient comes in is a new look at those.