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Agreed. I would however like to add the caveat that some physicians do not understand the risks associated with antibody history and uncrossmatched blood, so getting a pathologist involved to ensure the situation is truly life/death.

Stop blaming the Canadian Smoke. We in Canada, do result as No Antibodies detected. If the patient had an antibody in the past, that is maybe below detectable limits, but was previously identified, those are also in report as historical and as such the patient would have a full crossmatch in gel as well as phenotypically matched for previously discovered antibodies.

In the UK, it is STANDARD practice in all laboratories that I know to use either the phrase "No Antibodies Detected", or, more frequently, "No Atypical Antibodies Detected", as the latter also includes such things as the iso-antibodies of the ABO and H Blood Group Systems. Indeed, some go further still and use "No Atypical Allo-antibodies Detected", as this covers such findings as an auto-anti-H, auto-anti-I and auto-HI, as well as the ABO and H iso-antibodies. These phrases do not mean that there are no atypical allo-antibodies detected. It would be an incredibly rare set of screening cells and antibody identification panel cells that would both express, for example, the HJK antigen, or any other genuine low prevalence antigen. In some cases, where an atypical allo-antibody IS detected, but it is known to be clinically-insignificant (such as anti-Kna), we may use the phrase "No Clinically-Significant Atypical Allo-antibodies were Detected" (or words to that effect). One thing is for certain, and that is that a UK Reference Laboratory (and most hospital laboratories) worth their salt would report out as "Negative", or "No Antibodies", although, even using the phrases I've quoted above, occasionally the phrase, "All Clinically-significant Allo-antibodies have been Ruled Out using etc.", or words to that effect. MIND YOU - you have to remember that I am RENOWNED for being a pedant - but I learned it from a few good sources; Peter Issitt, Carolyn Giles and Joyce Poole (to name but three).

Another thing to try to increase sensitivity (other than PEG or other enhancement) is to increase the serum/cell ratio in the screen/indirect antiglobulin test. If there is no reactivity with enhancement, enzyme treated rbc (agree with Malcolm's caveat that some antigens will be destroyed) and increased serum/cell, one can be more confident there is nothing detectable pre-transfusion. Some consolation at least ...

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".

Give this a try. https://www.nist.gov/pml/time-and-frequency-division/time-distribution/radio-station-wwv/telephone-time-day-service

The trouble was that, in those days the anti-D immunoglobulin was known as "anti-D for Mum's Bums" in the UK, as the shot was given in the gluteal muscle. But, there was an awful lot of fat in that muscle, so the anti-D had a habit of "staying there", rather than being adsorbed into the blood stream. This meant that, even when the dose of anti-D immunoglobulin was calculated from the Kleihauer-Bekte test, the actual dose reaching the circulation was far lower than the calculated dose, and women used to produce allo-anti-D as a result. Nowadays (at least in the UK) the shot is given in the lateral deltoid muscle, where there is a good deal less fat, and so the shot is adsorbed into the circulation much easier, and so there are fewer cases of maternal allo-anti-D. I realise that this is a very vague explanation, and that there are many other causes of anti-D immunoglobulin being less than effective (such as giving it to the father, or even to the ambulance staff (SHOULD be unbelievable, but is actually true), but it does show just how complicated such a simple thing as this can be.

Believe me when I say that you are lucky!

For an antibody screen “Neg” or “Negative” has been historically used. This may have been heavily influenced by DOS based computer systems that had very limited memory so “Neg” made sense. Reporting a SCREEN as negative seems logical to me, however a work-up requires more detail as Malcom’s described above.

I meant that they would NOT report it as "Negative", or "No Antibodies", but WOULD report occasionally as "All Clinically-significant Allo-antibodies have been Ruled Out using etc.", or words to that effect.

The USA is considerably larger, we do not have a national healthcare system (which I personally hope we never have), and there is not a central data base that is accessible to all. I'm afraid the cost / benefit analysis of establishing such would not favor attempting one. Just my opinion.

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.

Jason Bourne all over again!!

Thank you very much Malcolm - you're the best! If you would clarify in the second paragraph please - worth their salt "would" or "would not" report out... we're filled with Canadian smoke here and it may be causing me confusion

I've attached copies of our procedure and our worksheet. Our Heme/Onc docs also order them on our patients post-transplant, and we occasionally get them ordered on kids where they suspect some sort of immune deficiency disease. TO-310 Isohemagglutinin Workup - Test and Titer__uncontrolled_copy (2).pdf TO-310F01 Isohemagglutinin Test and Titer Worksheet__blank_copy_id_8428444.pdf

The Bone Marrow Transplant unit orders them post transplant, not anything to do with newborn/fetus

Im guessing since uk has a national database that this happens alot less. The usa should have something similar. Is there statistics on anamnestic response? How often have you delt with it?

I would be wary of relying on enzyme-treated red cells, as a negative reaction could be due to the cognate antigen being denatured by the particular enzyme used.

The trouble is that, if the antibody happened to be an anti-Jka or, worse, an anti-Vel, the resulting rise in titre, following an anamnestic response, could be fatal on rare occasions.

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.

Oh yeah.... that dates us. And I remember doing antibody screens post RhoGAM, prior to patient discharge, to 'see if the RhoGAM dose was adequate'. No anti-D detected = give more RhoGAM. Something the OB folks thought seemed like a grand idea before the fetal bleed screen was available. Fortunately fetal screens came out about then. We were able to convince the docs to stop with the ABS orders by running parallel tests with the fetal bleed screen for several months to demonstrate how meaningless the antibody screen idea was..

I always based my judgement on the fact that the original studies to determine significant titers were done using double dose cells. Plus, nowadays, with donor eggs, the baby can be homozygous for the antigen.

we use a calibrated stopwatch

I've never heard of that. While I can understand the rationale, I'm afraid that if there was enough of a fetal bleed to impact antigen testing mom there are bigger problems than just getting the antigen type right. Just my thoughts.

Most blood bankers I know have a pain tolerance only slightly less than their resistance to change!!

Agreed. The ONLY time we might perform anything like a post-partum screen is if the baby's DAT is positive, and the baby has clinical signs of HDFN, but the mother has not been shown to have an alloantibody in her circulation during the pregnancy. In such a case, we may well test the maternal plasma (or an ABO adsorbed and eluted sample of the plasma) against the paternal red cells (if available) to see if the antibody is directed against a low prevalence antigen expressed on the paternal red cells. Having said that, however, this would only be useful in a further pregnancy with the same male, as providing the present baby with a unit for top-up or exchange would be easy if the antibody is directed against a low prevalence antigen

In the UK, such a unit would be offered to the National Frozen Blood Bank, and would only be frozen AFTER a thorough aseptic wash, followed by addition of a chemical to prevent the formation of sharp ice crystals, and then more washing upon thawing. There would be no allo-anti-Kpb left!

We do not accept units from our regional supplier from donors with alloantibodies.

We accept patient (and unit) antigen typing done at our reference lab. I don't see why this would be different. You are there reference lab for anything that is beyond their limited ABID scope, right?

All, I am about to blow your mind.... Our plasma freezer is down and so is our backup. The freezer will not get colder than -18 C. I was preparing to move all the products into boxes with dry ice until I had a conversation with my 87 year old dad, a retired blood banker from University of Chicago. He said to me, do not take the plasma out of the freezer and put it in boxes, PUT THE DRY ICE IN THE FREEZER, IT IS THE BEST STORAGE BOX YOU HAVE!!!! MIND=BLOWN!!!! I did that. Our freezer is currently reading -25.1C and getting colder. Furthermore, the probes in the freezer continually monitor the temp in the freezer so you don't have to record temps every 4 hours, the chart is doing that for you!!! Isn't that cool? That perfectly illustrates the difference between wisdom and knowledge there. I wish we could hire my dad. I just had to share this here. PS. Freezer is now at -26.4C.

This is awesome! As many times as our freezer has gone done over the years, we never thought of putting dry ice in the freezer. Your dad is awesome!!!

Just be aware that dry ice turns into a gas. I presume your freezer is not fully airtight, but it could open rather violently depending on how tight it is sealed, and how long since the last time it was opened.

Best story/advice I've heard in a long time!!! Thanks for sharing it.

Agree! Save the life first. Our medical director would likely order at least one DAT the next day, possibly for additional days, to monitor. Anti-E is generally relative benign (though I have seen one patient who had an acute hemolytic reaction), We might also monitor plasma Hgb or haptoglobin, depending on the antibody involved.

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.

Nothing is ever simple, is it? Especially when you get other folks involved. I stopped a dose of RhoGAM from being given to the baby. I've had nurses squirt some out of the syringe because "it's an early miscarriage, they don't need the full dose". I asked how they were calculating that dose and how did they know how much they squirted out...no answer .