SbbPerson

Ortho MTS gel instructions say to wash if there is interference from clots, which may happen with cord blood, but it doesn't say to always wash cord cells before running a gel DAT.

No need to wash. We run Cord Bloods on our Ortho Vision.
Could it be contaminated saline, perhaps?
I would repeat using freshly prepared bottle of saline.

I am so lazy that I just checked our IgG card today . I noticed it said that cord blood need to be washed before testing. I am at home now, I will attach the package insert tomorrow.

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I guess this may be caused by the Wharton's Jelly which can cause rouleaux formation of the cord cells. For the gel technique, it is good to test the adult cells without washing, but for the cord cells, maybe the Wharton's Jelly block  antigens on the cells' surface. I noticed that patients suffer from Multiple myeloma will not show false positive reaction in gel, but saddly I have not confirmed if there are false negative reactons.

I know this post is about 15 years old, but I recently came across a similar issue. I have always done DATs in tubes.  But currently switched to gel.  I am use to washing the cells when I do a DAT. I find it kind of odd that the package insert for the IgG cards doesn't include washing in it's procedure.  Do anyone know exactly why?   The insert said just to straight add 10uL of packed cells to 1.0 mL of your MTS diluent to get your 0.8% cell suspension.  
 
I got a weak positive reaction on a baby cord blood. I decided to wash the cells and the reaction came out stronger. Then I repeated this 2 more times and got similar results (see picture).  All controls were negative.

 
Has anyone experienced this ? And can I get your thoughts on this matter? Thank you so much, please have a nice day. 
 
 
 
 

Cliff has any thing changed recently.  For the past few days I've had to sign in every day?  Not sure how I managed but I do remember my password.

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My guess is the very hard part is getting the provider  (I very much dislike that term) to document the informed consent with a patient's signature.  How accessible is the form when the physician is actually with the patient?  If someone isn't there to hand the form to them they won't go looking for it.  On a side note, whose responsibility is it to make sure the form is signed and in the chart?  I certainly hope it's not the transfusion service's.  

WE provide Adsol units, predominantly and our NICU is over 70 beds.  Prisma Health Greenville Memorial Hospital

One additional approach would be to increase the sensitivity of the antibody screen by your preferred method (e.g., PEG, ± using enzyme treated red cells). Obviously increases the possibility of detecting pan-reactivity/false positive tests.  

I agree with Malcolm. I would dig as deep as possible to find that antibody history. If none can be found, I would do AHG crossmatches. If it was a frequent antibody, the titers should rise to detectable levels soon.

Extended cross-match, UNLESS, the history of which other hospitals the patient has been treated is known.

Of course, in the UK we have a national database of patient's antibodies, which makes life an awful lot easier, even if the data is just a "snap shop".

I have never encountered a patient that says they have antibodies unless they have a card. 

I just answered this question.

My Score PASS  

Well, the first thing to say is that red cells CANNOT be either homozygous or heterozygous (or, come to that, hemizygous).  These terms apply ONLY to genes, and red cells do not contain a nucleus.  The antigens can only be described as, at best, "homozygous", "heterozygous" or "hemizygous" expression, or, alternatively, "double" or "single dose" expression.

Then, it HAS to be accepted that, unless the maternal antibody is an autoantibody, it must be an alloantibody (or, possibly, an isoantibody), which means that to mimic the state of the foetal red cells, the red cells used to titrate the antibody MUST have a "single dose" expression.  However, that in itself presupposes that the foetal red cell antigens are all expressed at the same time, which we know is untrue (just look at the A, B and H antigens as an obvious example, but also the Kell antigens that are expressed much earlier than are the Rh antigens) or are ONLY expressed on foetal red cells, as opposed to other tissues (such as on the placental cells, which have, in some cases, been proved to adsorb the maternal antibodies).

Then, there is the fact that not all antibodies can be detected by all techniques.  This is why Reference Laboratories SHOULD have more than one technology available (and their workers should be provably competent in these techniques.  However, even then, not all techniques can predict the severity or otherwise of HDFN.  For example, antibodies within the Indian Blood Group System always show that they can cause severe HDFN by certain techniques, such as MMA, but they don't!  There is also the fact that the immunoglobulins may be IgM, IgA, IgG1, IgG2, IgG3 and IgG4 (to mention just a few), and I have yet to come across, or read about, an IgG4 immunoglobulin causing HDFN.

So, my answer is that there is a HUGE amount of knowledge known about the various antibody specificities, their titres, the expression of their cognate antigen, etc, etc, that there CANNOT be a single answer to your excellent question, but that the best thing that can be done is to read around the subject - and read around the subject from every source available - not just from a single country.

OKAY THEN, RIP ME APART!!!!!!!!!!!

I just answered this question.

My Score PASS  

DBritt,
We have experienced this at our facility enough so that we have a protcol of washing the sceening cells in saline and reconstituting in saline as well, and repeating the screen. The repeat is usually negative. I have some reservations about this procedure because there would be a difference in buffering range between MTS and saline. And I am not sure I accept the idea that a patient is reacting specifically with the MTS diluent either. I think that the correct way to describe this anomally is to say that a reaction is taking place in the presence of MTS but not in the presence of Saline. We have had no trnsfusion problems, however. So the MTS, with respect to certain patients, does cause what appears to be clinically insignificant reactivity.

Yes, we've seen this a few times with patients whose plasma has reacted to red cells kept in DiaMed Preservacell, but not in DiaMed Diluent 2. Apparently, it is an antibody directed against one of the antibiotics in the former, that coats the red cells.
DiaMed told me this, or, rather, Imelda Bromilow of DiaMed told me this, and I have huge respect for Imedla, and so I am quite content that this is the true reason.
:D:D:D:D

The UK has (I was one of the co-authors).

Guideline for blood grouping and red cell antibody testing in pregnancy.  White, J, Qureshi, H, Massey, E, Needs, M, Byrne, G, Daniels, G, Allard S, British Committee for Standards in Haematology.  Transfusion Medicine, 2016, 26, 246–263.  doi: 10.1111/tme.12299.

This PowerPoint Lecture gives some idea about how we approach things in the UK.  It may well be different in other countries.
In Depth Lecture on Alloimmune Haemolytic Disease of the Foetus and Newborn HDFN.pptx

I've been thinking about this question and I don't remember if our SOP specified what type of cell to use (I've slept a couple of times since last performing a titer).  What I do remember was that we wanted to use the same type with every repeat during the pregnancy.  In other words if the initial titer was done using an R1R1 cell for anti-D then every subsequent titer was performed with an R1R1 cell.  At the time, the change in titer was considered the most important finding.  Also, again I'm trying to awaken long dormant memories, we used a tube/saline or tube/albumin technique ( can't remember which) because that was how the original studies were done for anti-D and how the values utilized by the OB docs were derived.  I know this is ancient history for many of you but thought I would throw it out there.  
I seem to remember that titers were going out of vogue  about the time I retired and there were much more accurate methods of determining the effect on the fetus from maternal antibodies coming into use.

 

You did everything that was required in this situation. The patient was a trauma and needed emergency transfusion. The risk of death outweighed the risk of a hemolytic transfusion reaction in that scenario, according to the treating physician. I once had a trauma surgeon tell me "I can treat a transfusion reaction but I can't treat death!" That put things in perspective for me. That is why thy sign the consent.
Next step would be to report this to your risk management department so that follow-up can be made, including monitoring the patient for the s/s of DTR. 

There are hospitals now that has switched their verbiage from "least incompatible" to "most compatible". Which is true! This blood is the BEST blood possible considering the patient's situation. There is nothing you can do about the patient's auto, but you can make sure to provide the "best" compatible unit to the patient.  Of course you do this by making sure there are no underlying clinically significant alloantibodies in the patient's plasma.
 
Some places just straight out say "incompatible" on the transfusion report/tag.  The physician is then notified and made aware of this.  Some places make the doctor sign a form acknowledging the "incompatible" units and the risks involved, but where I work, a verbal "ok" would suffice.   We are all on the same team, working towards the same goal, the welfare of the patient.  We are not trying to "pin the blame" on anyone for possible hemolytic transfusion reactions.  We all want the same thing. 
 
Here is a really good podcast on the subject from the Blood Bank guy. It is really interesting and goes deeper into the subject and "what to do when everything is incompatible".  Good day. 
https://www.bbguy.org/2020/06/17/085/