Malcolm Needs

Once a specificity has been definitely identified, there is no requirement to "re-identify" it every time you receive a sample. You may want to test to see if it is still detectable, but that can be done using a single red cell sample. However, as screening red cell phenotypes tend to be complementary, I still contend that a panel should be performed (albeit, it may be an abbreviated panel), to ensure no de novo specificity has developed.

Welcome Rachel Phinney.

Well Muhammad, my immediate question is, does it matter whether the antibody is IgG or IgM, but the reaction is most certainly due to incomplete adsorption? That having been said, you could treat the plasma with 0.01 M dithiothreitol (DTT), which would disrupt the di-sulphide bonds that hold an IgM molecule together, via the J-chain, which will prevent the molecule forming agglutinates with the red cells, but it really doesn't matter whether the antibody is IgG or IgM (or, indeed, a mixture of the two), if the reaction is by enzyme-only. Indeed, within NHSBT, we do not bother to test adsorbed plasma with enzyme-treated red cells after adsorption.

Welcome Muhammad. Let's see if we can fill that "bowl"!

Welcome Lisa63heme.

How on Earth can one body claim to "own" a procedure, if that procedure is 1) almost universal throughout the world, and 2) if the proper procedure is there to enhance patient safety? It seems absolutely preposterous to me (if I were them, I would be very flattered that people wanted to follow my example/direction, UNLESS of course, they are unsure of what they have written vis-a-vis patient safety and are frightened of being sued if something goes wrong.

In answer to your last sentence Teristella - GOOD LORD YES! Turning to your first sentence, the problem with performing an extended cross-match is that, if, for example, the patient has either sprouted a weak anti-Fya, or worse, has made an anti-Fya in the past (unrecognised), but has not been re-stimulated for a long time. Either the units could both be Fy(a+b+), or one could be Fy(a+b+) and the other Fy(a-b+), and the cross-match may not detect it. This is because the red cells in the antibody identification panel are in a preservative that maximises the expression of the red cell antigens, but NOT the oxygen carrying capacity of the red cells, whereas the red cells in the units are in a preservative that maximises the oxygen carrying capacity of the red cells, but does not maximise the antigen expression of the red cells (and the Duffy antigens are known for deteriorating upon storage (as are the Knops antigens, but they don't matter). So, by cross-matching without performing a panel, you may be missing an anti-Fya, and if the screening cell that is Fy(a+b-) may have come from an individual who has the FYA/FY genotype, if these red cells have come from a donor of the Black ethnicities, but the human immune system is MUCH more sensitive than our tests, so you have a DHTR on your hands. This, however, is purely a personal point-of-view.

I must admit that makes me nervous Teristella.

Welcome Eva Mafera.

I take it that you have discussed this with the likes of Geoff Daniels, Joyce Poole, Nicole Thornton etc, plus the equivalent blood group serology greats of the USA, the Netherlands, etc, almost all of whom swear by manual tube testing, as do I. Yes, without a doubt, if you are not competent in this technique through lack of proper training and constant practice, then it has many pitfalls, but to condemn a technique outright as being almost prehistoric is a bit rich, with all due respect.

Welcome miraje.

Thank you Nikki, and indeed, THANK YOU to all of you who have written such kind words about an old fool with a hobby called blood group serology!

I think you would be sorely disappointed.

Welcome waever.

Welcome Pjd.