Warm auto questions

[Jives]

Couple of questions concerning warm auto work-ups:

1. how do you tell the difference between a warm auto that won't absorb out of your plasma specimen and a warm auto + HTLA?

2. when you have a patient who has been recently tx'd and can therefore NOT do an auto absorption, does anyone use a phenotypically matched cell to absorb instead of the traditional differential absorptions with 3 different cells?

thanks for the help, jane:)

[Malcolm Needs ☆]

Couple of questions concerning warm auto work-ups:

1. how do you tell the difference between a warm auto that won't absorb out of your plasma specimen and a warm auto + HTLA?

2. when you have a patient who has been recently tx'd and can therefore NOT do an auto absorption, does anyone use a phenotypically matched cell to absorb instead of the traditional differential absorptions with 3 different cells?

thanks for the help, jane:)

These are pretty difficult questions (well, actually, the questions are easy - it's the answers that are difficult)!

In answer to your first question, it is very rare indeed that a warm auto, that reacts by IAT and by enzyme technique, will not be adsorbed out by auto-adsorption (if that is possible), and then you can usually show that the auto-antibody has been adsorbed out by reacting the adsorbed plasma against chloroquine-treated autologous red cells. If these then give negative results, but random red cells still give positive results, then there is a fair chance that you have an underlying HTLA antibody, the specificity of which, if you have the available red cells, you can then identify.

In answer to your second question, it very much depends if you have performed the patient's phenotype before the transfusion, otherwise you are, to a large extent, guessing what phenotyped cells to use (unless you are lucky enough to be able to use PCR to genotype your patient.

Given that you may know your patient's type, and particularly if you suspect an underlying antibody directed against a high-incidence (or reasonably high-incidence) antigen, or if we are thinking in terms of multiple antibodies directed against "common" antigens, then we would often use this kind of adsorption, rather than the traditional differential adsorption with the three cells (BUT, be aware that finding the correct cells can sometimes take an enormous amount of time, and might involve adsorption and elution techniques).

:):)

[Jives]

malcom, i read in another thread that HTLA's do not adsorb out of the plasma....is this true and where can i read up on it

thanks, jane

[Jives]

malcom, i read in another thread that HTLA's do not adsorb out of the plasma....is this true and where can i read up on it

thanks, jane

[Malcolm Needs ☆]

malcom, i read in another thread that HTLA's do not adsorb out of the plasma....is this true and where can i read up on it

thanks, jane

Yes, this is true about HTLA's. This is why I say that, following auto, or indeed alloadsorption, an auto-antibody will be adsorbed out, but will leave the underlying HTLA (which will, of course, be an alloantibody) in the plasma.

Where can you read it - that is an extremely good question! Off the top of my head (and I am off work at the moment), I honestly cannot remember! I will get back to you, unless anyone else knows.

:):)

[LaraT23]

I just wanted to add that with recently transfused patients, you could do a retic cell separation and get the transfused cells out, and phenotype the patient cells. The transfused cells are more dense and can be separated that way.

As far as reading, try the techniques section of the AABB manual. I have some of my own references of course, like Blood groups by Marion Reid, that lists HTLA's as their specific names ( i.e. Anti-He) and gives some techniques in the back.

If I think of something else I will let you know!!

[Mau Feitio]

Malcolm, do you think we can use the genotype as our reference to transfuse the patient? For instance if you had the chance of a quick PCR would you rely on that information and transfuse the patient without doing adsorptions? Or would you use the information given by PCR to select cells for your adsortions?

[Malcolm Needs ☆]

Malcolm, do you think we can use the genotype as our reference to transfuse the patient? For instance if you had the chance of a quick PCR would you rely on that information and transfuse the patient without doing adsorptions? Or would you use the information given by PCR to select cells for your adsortions?

That is an extremely good question, to which the answer really depends on the case.

If the patient is one of those rare cases where the auto-antibody is really stubborn and will not adsorb out however many times you perform the adsorption procedure, and whether you use enzyme-treated or non-enzyme-treated red cells, then you are almost forced to rely on the results of the PCR and give as near as possible antigen matched blood throughout the extended genotype (by that, I mean not just Rh and K, but D, C, c, E, e, M, K, k, Kp(a), Kp(, Fy(a), Fy(, GATA-1 mutation, JK(a) and Jk(, and, on occasions Do(a) and Do().

If, on the other hand, you are able to adsorb, but you suspect that the patient has made an antibody against a high, or reasonably high incidence antigen, then I would request PCR against certain of the genes encoding such high or reasonably high incidence antigens (I know it is not yet possible to do this for VEL, but they are working on this at Cambridge University - not a bad university, even if, this year, they proved that they cannot play cricket!) and then, again, if possible, I would choose to make adsorption cells as near the patient's own type as possible, but negative for the high, or reasonably high incidence antigen.

You have to remember though, that such a choice is really only open to the priviledged few who have access to a) such technology and the appropriate primers, and access to such rare red cells.

I am hugely privileged in that I have access to the genotyping performed for us by the International Blood Group Reference Laboratory in Filton (run by Geoff Daniels) and to the entire country's blood supply. I know for a fact that very few people throughout the world are as lucky as me (and I do appreciate this luck has been enormously helpful to me throughout my career).

I hope this, somewhat lengthy and clumsy post answers your questions, but if not, feel free to get back to me.

:):)

[Mau Feitio]

The truth is where I work technicians always complaint about the adsortion and eluition techniques. Spend hours and hours with this patients and don´t give straight answers about the outcome of this studies. We use gel in our routine and I believe that it was lost the habit of working in tube by the youngsters. They seem to have difficulties on choosing the right paths during those studies. wonder if you could give me some suggestions on literature to help me creating a SOP where the work out strategy could be established. The real doubt is do you use always the same strategy on this cases? Could you help me out. Tx

[Malcolm Needs ☆]

The truth is where I work technicians always complaint about the adsortion and eluition techniques. Spend hours and hours with this patients and don´t give straight answers about the outcome of this studies. We use gel in our routine and I believe that it was lost the habit of working in tube by the youngsters. They seem to have difficulties on choosing the right paths during those studies. wonder if you could give me some suggestions on literature to help me creating a SOP where the work out strategy could be established. The real doubt is do you use always the same strategy on this cases? Could you help me out. Tx

I'll do my best, but we are being audited this week (AGAIN!) and so it may not be until next week.

If I should forget, please feel free to badger me!!!!!!!!!!!!!!!!

:D:D:D:D

[Eagle Eye]

Good Luck Malcom..I am sure they will not find any problem.

[Malcolm Needs ☆]

Good Luck Malcom..I am sure they will not find any problem.

I'm not quite so sanguine - they dig very deep (but then, in the blood business, I guess we also bury quite a few of our mistakes deep - if you see what I mean)!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

:eek::eek:

[Liz]

Good Luck Malcolm!!

[Liz]

I too am interested in seeing the suggestions on literature to help me creating an SOP on adsortion and elution techniques.

I did read the PeG insert it does not seem to be for removal of warm autoantibodies. I would appreciate advice on how to procede, in the adsortion and eluition techniques.

Thank you

Liz :)

[adiescast]

I'll do my best, but we are being audited this week (AGAIN!) and so it may not be until next week.

If I should forget, please feel free to badger me!!!!!!!!!!!!!!!!

:D:D:D:D

I hope all goes well. You did hide those skeletons somewhere safe, right?

[Mau Feitio]

Anyone can help me out.... how to create a SOP TO study warm autoantibodies? What should I use? PEG? WARM?

[LisaM]

I'd like to ask, too, how is an adsorption performed to get rid of a warm auto? We don't do this procedure where I work, and whenever we get a person that looks like they have one, we have to stop the workup and send the sample to the Red Cross Reference Lab for completion. It's frustrating, because we can only go to a certain point and then we're stuck, not being able to rule out anything.

I think it would be great to be able to have the staffing as well as resources to work with warm autos where I am, but we don't. So I was just curious, how it's done, procedure, etc.

Thank!

[Liz]

Does anyone have a reference for the retic cell separation for in vitro testing?

Thanks

Liz

[SMW]

AABB Technical Manual.

[Liz]

AABB Technical Manual.

I did not find it, and so I asked. Do you have the page, is it under another name?

Thanks.

Liz

[Boazdexter]

HIIII

I M NEW IN THIS FORUM AND I JUST NEED A HELP IN IT

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______________________________________

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[Liz]

HIIII

I M NEW IN THIS FORUM AND I JUST NEED A HELP IN IT

I WISH THAT THIS SITE WILL RESPONSE ME WELL,,

______________________________________

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Yes, this forum, site, will surely be of help to you.

Do you have a specific question that we can help you with?

Liz

[Dr. Pepper]

I did not find it, and so I asked. Do you have the page, is it under another name?

Thanks.

Liz

Hi Liz - 16th edition, pp. 896-897. So long as your patient is reticing it works pretty well.

[Dr. Pepper]

I'd like to ask, too, how is an adsorption performed to get rid of a warm auto? We don't do this procedure where I work, and whenever we get a person that looks like they have one, we have to stop the workup and send the sample to the Red Cross Reference Lab for completion. It's frustrating, because we can only go to a certain point and then we're stuck, not being able to rule out anything.

I think it would be great to be able to have the staffing as well as resources to work with warm autos where I am, but we don't. So I was just curious, how it's done, procedure, etc.

Thank!

I'm a big fan of the PEG autoadsorption, tech manual, 16th edition, pp. 929-930. I buy the PEG from Immucor. It's the easiest, quickest, cheapest, most efficient technique I've tried.

[Liz]

Hi Liz - 16th edition, pp. 896-897. So long as your patient is reticing it works pretty well.

Thank you Dr Pepper, I appreciate it.

Liz