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What? All this time I have been using the wrong stuff! Ha! SPELL CHECK IS NOT YOUR FRIEND! 🤣🤣🤣🤣

Um, sorry Jason, but I think you mean Dithiothreitol (DTT), rather than Dichlorodiphenyltrichloroethane (DDT)!!!!!!!

It is incredibly rare for anti-N to be an alloantibody, unless the individual is M+N-, and also S-s-U-. This is because the amino acids that characterise the N antigen on the Glycophorin A molecule (leucine, serine, threonine, threonine, glutamic acid) are identical to the amino acids that characterise the 'N' antigen on the Glycophorin B molecule. Is the lady of Black ethnicity by any chance? If not, to be N Negative AND 'N' Negative would be almost unique. This suggests to me that the anti-N reported to be in the maternal circulation by the other hospital may well have been an auto-antibody, and would almost certainly be sub-clinical in its significance. In such a case, I would not bother with performing genotyping of the baby's N type. However, as far as Rh, K, etc, I would certainly suggest that antigen negative blood is given to the baby, and I certainly WOULD perform foetal genotyping (see my answer to Cliff above).

The reason I said this (and I admit that I am being more than a little "Reference Laboratory Pedantic here) is because a very good friend of mine (Edmond Lee, who used to work at the NHSBT-North London Centre at Colindale, with such luminaries as Prof Dame Marcela Contreras, Dr Mahes de Silva and Martin Redman, amongst others, who described a case where the bay of a woman with an extremely strong anti-K,, where the baby's foetal K antigens were blocked by the maternal anti-K, and so tested as negative (Lee E, Redman M, Owen I. Blocking of fetal K antigens on RBC by maternal anti-K. Transfus Med 2009; 19(3):139-40. doi: 10.1111/j.1365-3148.2009.00917.x. Later, he reported the same sort of thing with a maternal anti-Fy(a) (Lee E, Cantwell C, Muyibi KO, Modasia R, Rowley M, New H. Blocking phenomenon occurs with murine monoclonal antibodies (anti-Fya) in a neonate with a positive direct antiglobulin test due to maternal anti-Fy(a). Blood Transfus 2015; 13: 672-674. doi: 10.2450/2015.0232-14. Obviously, in both these cases, the maternal antibody was easily detectable, so not the same as the case being described by BullDawgPath, and, in both cases, the baby's DAT was positive, BUT, in both cases, antigen negative blood was required by the baby.

All great questions, but I would also ask, what is the baby's Hb/Hct requiring a transfusion, and why not test the baby's DNA for the gene encoding the antigen cognate to the maternal antibody?

Couple of questions for clarification. What is the specificity of the known Alloantibody? "Baby is born and our testing shows negative antibody screen." Was this AB screen done on mom or baby? If on the baby, was a current ab screen performed on mom and if so what was the results? Was a DAT performed on the baby? If so, what was the result? If not, why not? Thanks

In that case, I would consider a genotype, as getting hold of M+ N-, S-s-U- fresh units is not going to be easy. That having been said, as you say yourself, anti-N is rarely clinically significant and, if it is not detectable in either the maternal circulation, or in the baby's circulation, I wouldn't worry too much about giving M+, N-, S-s-U- blood. BEAR IN MIND THOUGH, THIS WILL BE A CLINICAL DECISION, AND I AM NOT, AND NEVER HAVE BEEN, MEDICALLY QUALIFIED.

We do not have Meditech anymore, but when we did, we would create a worksheet in BBK worksheets. At first it seemed complicated but it worked out well in the end. Specially because we did not have to save paper QC for inspectors. I would just download a file to my desktop daily.

When we have a suspected transfusion reaction a process of investigation is initiated: clerical checks, DAT on pre/post-tx specimens, urine for blood, ABORh on post specimen., visual exam of pre/post specs for hemolysis/icterus. If all of these are negative, the pathologist will provide an interpretation based on the reaction defined by the Nursing staff. If the investigation indicates a possible hemolytic transfusion reaction an entirely different process is initiated . . . HOWEVER, just because a reaction does not appear hemolytic it cannot be assumed that a reaction has not occurred as there are many types of reactions to blood products the majority of which are not hemolytic. It would behoove you (and your Medical Director) to research the literature to discover these and then develop the processes of investigation according to the BB standards in your area of the world.

Nursing puts post-tx blood bags in biowaste. It only comes back to lab if there is a possible reaction. We do not remove excess blood from a bag being discarded.