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HELP!!! stumped


LaraT23

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Okay,

I have a patient scheduled for a joint replacement who has severe RA and denies any previous tranfusions. Her screen was pos, strong 1+ in the gel on cell one. Her panel is negative on 2 different lots. I drew extra and sent it out. They are getting an auto-e, C, Le-a, and a cold. I did a quick cold panel and it was 4+ after 10 minutes in the fridge. I carried those tubes out to AHG and still got nothing, even the check cells worked.

My issue is, how can my screen cells be pos, and the panel cells show nothing?? I am wondering if my panels were shipped improperly or not stored correctly before they got to me.

I also had a patient with a E, who had a pos screen about 1+ maybe 2+ in the gel, and negative panel. The reference lab used a ficin panel to get the rxns to come out. My question here is again, there is no ficin in my screen cells but they worked!!!! ARRGGGHHH:confused:

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I did try two lots of panel cells and got nothing on both. I have also after playing with it and talking to the reference lab, done a cold panel. It is 4+ in the fridge and then comes apart. Shouldn't I be getting the cold in the gel?? I had a patient with an E and Lu-a come up the next day, and her rxns came down fine.

Also I am not sure why ficin would enhance a cold ab? They have said it is a cold auto ( funny no pos DAT and aggl. everything in the fridge incl. cord cells) that mimics e, but I never got it to do anything.:confused:

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Hey Lara,

Did your lot verification work when you received the questionable lot of panels? We use the same Ab sample to verify our screen cells that we do our panel cells and test them at the same time. Any major difference in reactivity between our screen or panel are communicated to our techs. Also, did you try a converted panel (3% to .8%)? We get significantly stronger reactions using our Panocell16 in Gel. Love your icon by the way. Hope this helps.

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RULE 1: Always use the freshest panel if more than 1 lot # available. Antigens deteriorate with storage.

RULE 2: Always incubate panels 30-60 minutes for strongest reactions.

We do our panels at IS, 15' RT, 30' 37C, and IAT with IgG.

If a cold antibody is suspected, avoid using LISS, PEG, N-Hance, because they all enhance cold antibodies and may interfere with identifying warm antibodies if the colds react at IAT. Do a strict prewarm IAT phase only for eliminating interference from colds.

If you have both a cold auto and Le(a), I bet the patient is an A1 or A1B. The cold auto is probably an anti-IH or anti-H, that reacts stronger with O cells, then with A or B cells.

Lewis antibodies are usually found in patients who are negative for both Le(a) and Le(B), and they are often found transient in obstetric patients.

In patient's with anti-E, you should also consider if they are c neg, as R1R1 patients with anti-E, are usually exposed to c as well, and the anti-c may be undetectable. In this case only, we give E=c= blood. There is a paragraph in the technical manual that discusses this instance - Rh chapter, Con-commitant antibodies.

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In response to Lara's question I have a question that is still unclear to me. From what is written it sounds like you are screening in gel and trying to identify specificity using a different method, (i.e. tube methodology). If this is a correct assumption on my part then the explanation to no reactivity in the panels is that you are using a less sensitive method. If you are using gel panels then the explanation is less obvious. In my institution, we run all panels in the same method that we detect reactivity. This is because we frequently encountered weakly positive screens in which we could not identify specificity when using tube panels. If you cannot run gel panels, I would suggest testing your panels in PEG which will often give you comparable results to gel.

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Thanks for all of the replies. The patient was found to have a cold auto that mimics anti-e. I never found that. I only found 4+ in a tube that was incubated in the refrigerator for 10 minutes. I did try to increase the amount of plasma and the incubation time, (GilT). IgM should have shown in the gel. Still stumped. Although, the cold does not show at all if we prewarm everything and saline replace the crossmatch. Last week I also had a E that showed 3+ in screen cells and 1+ on the panel. This is happening on both my newest lot and the one about to expire. I may ask for a ficin panel to evaluate.

Thanks again.:D

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  • 2 weeks later...

Theoretically cold antibodies are not picked up in Gel. Cold autos are suppose to be IgM and gel only detects IgG antibodies. Not all cold antibodies behave themselves and will show up in Gel. Most of the time it doesn't look like a true antibody. It will kind of cascade thru the gel. We have never found a way to "pre-warm" gel. When we pick up a cold in gel we have to go back to tube crossmatch on these patients.

Has anyone found a way to do a "pre-warm" crossmatch in gel?

Antrita

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Dear Lara: as we "old timers" say, the antibodies do not read the books!In your first patient, why did one screening cell react and the panel was nonreactive? It is true to check and see if the screening cells are fresher then the panel. You can try in your facility is increasing the incubation time of the panel. I am not sure getting a ficin panel is necessary, unless you have a lot of weak antibodies that are not clearcut for specificity that you have to send off, like this one.

However, back to the patient's history. She says she has never been transfused but has she been pregnant? What is her Rh phenotype? Is the anti-C autoantibody like the anti-e? I work in a reference lab, and we would perform a warm autoadsorption to show that the antibodies were auto or alloantibody. The anti-C could be alloantibody produced by pregnancy, but that is not very common.

On the patient with the anti-E, again what is the transfusion and pregnancy history? This is again a weak antibody that might be picked up with the panel if you extended the incubation time. Is it a naturally occurring antibody, which they can be some times, with no known red cell stimulus.

Just some rambling thoughts. Marilyn

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