Gel vs Tubes - warm auto

[Losmeister]

"my insistence on understanding "

thats just good science If ya ask me...

um, which you didn't...

[Liz]

I apologize asking again but how does this happen?

"PeG enhances adsorption on untreated autologous cell; one usually pre-treats autologous cells to remove the Abs sensitizing the auto cells to allow for adsorption. If the untreated cells are well sensitized (Ags well saturated with Abs), how can they adsorb the autos even with PeG... are there any free sites?"

Thank you

Please forgive my insistence on understanding the mechanism.

:blowkiss:

Liz

No one knows??

Thats not possible.........

Liz :cool:

[Malcolm Needs ☆]

No one knows??

Thats not possible.........

Liz :cool:

I'm not convinced of that Liz. I think there are an awful lot of things we do because it is "traditional" to so do, but we rally don't know why we are doing it (particularly in Blood Transfusion)!

:(:(

[Liz]

Thank you Malcolm, I read all the articles and I thought that it was only me who was missing something.

When and if I stumble over the mechanism I shall post it.

Liz

:flirty:

[Malcolm Needs ☆]

No problem. I notice that I still can't spell (rally, instead of really)!

[jcdayaz]

I don't understand this. Immucor states that PeG enhances reactions. How does it "absorb out any auto" ? Pardon my ignorance.

Thank you,

Liz

I believe David was referring to performing a PeG autoabsorption. That is different than a regular antibody screen/crossmatch. We are currently investigating this procedure to replace our current W.A.R.M absorption procedure.

You are correct in your statement that PeG generally enhances reactions more than LISS in a regular screen/antibody panel situation--but not more so than gel. Gel is the most sensitive technique I've seen.

[jcdayaz]

I believe David was referring to performing a PeG autoabsorption. That is different than a regular antibody screen/crossmatch. We are currently investigating this procedure to replace our current W.A.R.M absorption procedure.

You are correct in your statement that PeG generally enhances reactions more than LISS in a regular screen/antibody panel situation--but not more so than gel. Gel is the most sensitive technique I've seen.

OOPPSS! I guess I should have scrolled down a bit more in this post before making my reply.

[jcdayaz]

No problem. I notice that I still can't spell (rally, instead of really)!

You crack me up Malcolm.

Did you get my private message about the HrB or hrB antibody patient we thought we recently had? Thank goodness it turned out not to be, but I would still love to have the information.

[Malcolm Needs ☆]

You crack me up Malcolm.

Did you get my private message about the HrB or hrB antibody patient we thought we recently had? Thank goodness it turned out not to be, but I would still love to have the information.

I don't think I did (or, at least, I can't find it). WOuld you be very kind and send it again please?

[OPUS104]

I havent been on for some time now, so this may have been stated and I have missed.... We always make sure the original Gel reactions ARE a pan. We run all available high frequency negative cells we have, along with a standard panel. Check trans history, eluate, once satisfied it is a warm-auto we go straight to tube. Usually LISS or unenhanced.

[Malcolm Needs ☆]

I havent been on for some time now, so this may have been stated and I have missed.... We always make sure the original Gel reactions ARE a pan. We run all available high frequency negative cells we have, along with a standard panel. Check trans history, eluate, once satisfied it is a warm-auto we go straight to tube. Usually LISS or unenhanced.

Hmm, not sure I'd use high frequency negative cells like that myself, unless both the DAT and auto were negative?

:confused::confused:

[Yanxia]

Me, too.

[Liz]

I havent been on for some time now, so this may have been stated and I have missed.... We always make sure the original Gel reactions ARE a pan. We run all available high frequency negative cells we have, along with a standard panel. Check trans history, eluate, once satisfied it is a warm-auto we go straight to tube. Usually LISS or unenhanced.

Can you elaborate on why you would do that?

Thanks

Liz

[Liz]

Hmm, not sure I'd use high frequency negative cells like that myself, unless both the DAT and auto were negative?

:confused::confused:

Malcolm, the DAT and AC can be falsely negative, due to many reasons, so how would it make you feel comfortable, or would it?

Thanks

Liz

[Malcolm Needs ☆]

Malcolm, the DAT and AC can be falsely negative, due to many reasons, so how would it make you feel comfortable, or would it?

Thanks

Liz

If both were negative, for whatever reason, then I would run rare negatives (although I may well check the patient's red cells with antibodies against rare antigens first, to see if the patient can make the antibody in the first place - sometimes, the red negative red cells are even rarer than the rare antibodies), but if either was positive, I would not (unless, of course, the patient had recently been transfused).

Mind you, to a certain extent, it depends on what is the definition of rare. As a Reference Laboratory Manager, my definition of rare (say Vel-, Lan-, Co(a-), null phenotypes, etc) may not be the same as someone who does not have access to these cells.

:):)

[Liz]

Thank you, Malcolm.

I am jealous you have all the great stuff to work with:lonely:... but ofcourse I am happy for you!

Liz

[OPUS104]

Hey Liz, I often cant get online frequently and just saw your question. My situation is like what Malcolm is talking about.... we are a small ref. lab so our stock of rare cells is not near as impressive as his. We have been questioned a couple of times by our super about making sure the reactions are a pan even though the DAT and Auto are +. For us its a matter of CYA so we dont get second guessed later.

[Liz]

Hey Liz, I often cant get online frequently and just saw your question. My situation is like what Malcolm is talking about.... we are a small ref. lab so our stock of rare cells is not near as impressive as his. We have been questioned a couple of times by our super about making sure the reactions are a pan even though the DAT and Auto are +. For us its a matter of CYA so we dont get second guessed later.

Hello OPUS104, what is pan = is it a pan agglutinating antibody?

And what is CYA?

Thanks

Liz

[Deny Morlino]

I will let OPUS104 answer for the "pan" part of the question. Usually CYA stands for Cover Your Backside (substitute another name for Backside here beginning with an "a").

[Liz]

Haha and I thought CYA was an antigen that I had not heard of!!

In a way, it is !!!

Liz :wow:

[jcdayaz]

What do you call such a blood unit?

Thanks

Liz

We call any unit of blood that reacts at AHG by the same testing methodology at a lower strength than the patient's DAT "Least Incompatible" in the Autoantibody cases. A different physician's order is required for us to issue/transfuse "Least Incompatible" blood.

These patients have typically(hopefully) been referred to one of our Heme-Oncs who know a bit about transfusion medicine. Our two most prominent Heme-Oncs(Hematology-Oncology specialists) know when we call them there is a valid reason. They are well versed in our procedures.

They also know it is best NOT to transfuse a patient with an autoantibody. We almost always recommend steroid treatment first--patient condition certainly plays a factor--but the chance of enhancing that auto is in most circumstances not worth the risk. Obviously, trauma-ish circumstances don't apply here.