Elution problem

[FEL]

PLEASE EXPLAIN WHAT DO WE DO IF A PATIENT HAS A SUSPECTED TRANSFUSION REACTION, THE DAT IS POSITIVE , ELUTION IS NEGATIVE AND THIS PATIENT HAS RECEIVED NON-GROUP SPECIFIC PRODUCTS.

[L106]

Do you have a pretransfusion patient specimen available? If so, it would be helpful to do a DAT on that sample. If it is positive, the patient probably has a positive DAT due to some drug or disease. If the DAT is Negative, it fits the pattern of your suspected transfusion reaction.

Assuming that the pretransfusion DAT was negative, I would suggest that you test the eluate from the post-transfusion specimen against the A and B Reverse Cells. If either of those cells is positivewhen tested against the eluate, the positive DAT is almost certainly due to the recent transfusion of non-group-specific platelets.

If the eluate does not react with either the A or B Reverse Cells, it is possibly an antibody in the eluate directed against a low frequency antigen. To prove this, you might want to crossmatch the eluate against the recently transfused donor units. If your facility does not have access to a variety of red cells with low frequency antigens, you will probably need the help of a reference laboratory.

Edited September 14, 2009 by L106

[galvania]

Lots of questions -

Why do you think the patient has had a transfusion reaction?

What blood products has he received? What blood groups?

What pre-transfusion tests were carried out, and what were their results?

What is wrong with the patient?

[FEL]

Thanks for leading me in the right direction.

[David Saikin]

did you run your eluate against A1 and B cells?

[GilTphoto]

I assume you use the Gamma Elu-Kit. That is not the best elution method to detect anti-A or Anti-B.

We always do the Gamma Elu-kIt with a 30 minute incubation. If that method is negative and the patient has received blood not type specific, then we do the Lui Freeze/Thaw elution with A1 and B cells.

As far as if the patient had a reaction, you will have to use other indicators such as rise in bilirubin, LDH, haptoglobin, drop in H&H (if not blleeding).

What were the symptoms? vitals?

Elutions all positive or all negative are usually drug induced. What about the pre-transfusion DAT? was that positive?

Other possiblities include low incidence antibodies not on your panel.

[javvcr]

Probe, DAT on the sample of the red blood cell transfused, some times, blood donors appears with DAT positive.

Try also, if you want, washing the red cells, before elution, with, cold LISS solution, in case you DAT is positivo for low avidity antibodies!

Did u tested DAT in monospecific reactives (anti IgG and anti C3?), if you have a DAT positive with polispecific reagent, so you most look for the monospecificity

[TimOz]

AABB has some excellent publications that should help you:

Transfusion Reactions, 3rd edition

http://www.aabb.org/eServices/Marketplace/ProductDetail/tabid/55/Default.aspx?ProductId=678

Guidelines for the Laboratory Evaluation of Transfusion Reactions

http://www.aabb.org/eServices/Marketplace/ProductDetail/tabid/55/Default.aspx?ProductId=492

[BB enthusiast]

Hello guys,

Have u ever encountered a patient with auto antibody seen only in his elution? his phenotype is e positive, no antibody in his serum but anti-e was eluted. please shed light. I'll appreciate all the lectures and information related to this. thanks.

[Fluffy agglutinates]

If you sit & have a think about this for a while you will see that this is how an autoantibody begins to show itself!

If you were to make an autoantibody where would it attach itself to first?

Your own red cells = pos DAT! (IgG coated)

You peform an elution & you reveal the autoantibody.

If you hadn't made a lot of autoantibody yet it will be completely 'mopped' up by your own cells = negative antibody screen & panel.

In my personal experience most autoantibodies do not show a specificity & the elution shows panagglutination. However I have seen exactly what you are describing a number of times - it is not that unusual.

It would be interesting to follow your patient over the next few months to see if the autoantibody increases to the point where it starts to appear in the panel & eventually reacts with all cells. Alternatively it may stay as it is & not get any worse.

Hope that helps a bit!

(If you wish to read up on the subject try the AABB technical manual)

[Mau Feitio]

Do you believe it´s necessary to do an eluition when your DAT is 12 and you have panagluttination? What can we miss if we only do adsorptions?

[Malcolm Needs ☆]

Do you believe it´s necessary to do an eluition when your DAT is 12 and you have panagluttination? What can we miss if we only do adsorptions?

In very, very rare cases, we have noticed that a particular patient with panagglutinins has required an increase in the frequency and amount of transfusions, and yet we cannot identify any de novo antibody specificity in the adsorbed plasma.

In such cases, we have performed an elution and then performed differential alloadsorption studies on the eluate and have, on one occasion, detected an alloantibody that we could not detect in the alloadsorbed plasma. When we gave antigen negative blood to this patient, the frequency of the transfusions went back to their normal.

Under normal circumstances, however, I think that you are correct, and that making and testing an elution is a complete waste of time.

:):)