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I can't refresh your memory, but I do know of a case of anti-Vel in the UK that caused a fatal transfusion reaction. The DAT was positive by anti-complement only, and the anti-Vel itself could only be detected in a clotted sample, not in an EDTA sample.

Strange. The Direct Antiglobulin Test has been around since 1946, and this is the first time that I have heard that IgG antibodies will NEVER cause agglutination to the naked eye. IgG ABO antibodies cause agglutination visible to the naked eye all the time, as do many examples of IgG anti-M and other specificities. Sorry, but I rather think you could be wrong here.

A magnification aid is optional for N-Hance. It could be an agglutination viewer, rather than a microscope.

Just curious, but why even have a card catalog at all? That was the first thing I got rid of when we computerized my last blood bank. It took about a year, if I remember correctly, to move all the old info from the paper records into the computer. One thing we did was research each patient that we had not seen in over a year to see if they were deceased or assumed they were if over 100 years old and not seen for a certain period of time. It made no sense to fill space in the computer with patients who were obviously no longer with us.

Can I just point out here that no one serological test, or even combination of tests will detect all weak / variant Ds . And that includes women who test D+ but actually have a partial D and may make anti-D antibodies. It is SO important to know your reagents, and know what your anti-D reagents will and will not detect

I was also thinking about 'why not drop the unit retesting' after all of the donor centers went to computerized donor labeling/retesting and I hadn't seen a labeling error in years (you did use to see a very few go by) and then realized that with so many places going to computerized "compatible unit release" - the retesting done by the receiving facility is the only chance they get to check that the RBCs in the unit do indeed match the label on the bag. Without, at least, an Immediate Spin crossmatch check of the unit vs. the pt - there would be NO other physical check done if unit retesting was dropped. So there we go, the inspection agencies will want the unit recheck for forever! If the UK's figures were studied and accepted by the FDA/CMS/AABB, etc. - we might eventually see a change, but it probably won't be soon. (my 2 cents )

I have cited this reference over and over and over again. Sachs UJH, Röder L, Santoso S, Bein G. Does a negative direct antiglobulin test exclude warm autoimmune haemolytic anaemia? A prospective study of 504 cases. British Journal of Haematology 2006; 132: 651-661, and it refers to transfusion reactions too.

Thanks Malcolm - I'll let him know.

I would certainly think in terms of a full crossmatch, BUT using a clotted sample, just in case. That experience in the UK, although not my own, shook me up a bit!

So Malcolm, do you see any need to do a full crossmatch if say, the patient was transfused in the past two weeks (antibody mopped up, so negative antibody screen but hgb dropping and only complement pos DAT )? I know this is far fetched with EDTA spec but this new tech is really smart...and I'm having trouble keeping up.

We had one of those decades ago before monoclonals. Typed a unit as B+. Transfused to a B patient. Next time we saw the donor we were trying out monoclonals. anti-A rx was 2+. AsubB. We checked the transfusion on the B patient. H&H stayed up, no evidence of rbc destruction upon chart review. My techs were freaking out.

Sorry, you must be fed up with me. I know I am like a dog with a bone, but, although IgG is a monomer antibody, it does have a valency of two, which is why, occasionally, it can cause agglutination visible to the naked eye. Notably, some examples of IgG anti-D cause agglutination at 37oC with D--/D-- red cells, with no potentiator.

Our blood bank (~900 beds) went live with HCLL and Epic in August 2019. There have been a lot of bumps along the way. We previously had Cerner and wish we could go back. We were told that HCLL was the best BB system to use with Epic, but we think Cerner was probably better. Every day we have to correct something that is just an HCLL-ism. The system has caused extra work for our techs and management alike. With all that said, I think it would work really well for a much smaller blood bank that doesn't do traumas as much.

Also, the vendor of the device should be responsible for training your Nursing staff. (at least that was the deal for the ones I was looking at). In the ER they will probably be using uncrossmatched I am assuming.

One thing I discovered in my many years as a Transfusion Service Supervisor is that inertia is the most powerful force in the Universe! Trying to initiate change, especially in blood banking can be extremely difficult, often impossible. Pick your battles carefully and make sure they are worth fighting. Good luck.

Do keep us updated. I am sure we are all looking forward to news of a healthy baby

Apologies for not answering earlier. No, I did not mean 12 cells in the screening cell panel. I meant putting up 12 different antibody screens (12 different patients) each using a three-cell screening panel. Putting up = testing

No we don't use the microscope.

You have NEVER seen a baby who is Weak D Positive. There is no such thing as anti-Weak D! May I suggest that you read Stratton F. A new Rh allelomorph. Nature 1946; 158: 25-26, followed closely by Race RR, Sanger R, Lawler SD. The Rh antigen Du. Ann Eugen (Camb) 1948; 14: 171-184, which will explain why there is no such thing as anti-Weak D. I appreciate that CAP seem to be incapable of using correct terminology, but that does not mean that we should all descend to their levels of incompetence. Sorry for the "vent", but this wrong terminology has gone on now for 72 years; six years more (embarrassingly) than I have been alive! I'm sorry if this sounds like a personal RANT against you. YorkshireExile; it is certainly not meant as such. It is just a general rant against people who use poor nomenclature because they don't learn even the basic history of their own specialist subject - and that includes the people who SUPPOSEDLY make sure the rest of us "follow the rules"!

I'd say that you have to consider the capabilities of your staff. I do ask my techs to use the microscope for DATs. They are all generalists and their time in blood bank is limited. Some of them shake too hard, in spite of my best efforts to fix that problem. They use a mirror, but some don't use a mirror well. So, in order to not miss weak positive reactions they use the scope with a tube roller. We also have a definition for microscopic agglutination (right out of the Technical Manual) that says it is a clump of 4-5 cells (though I do tell them that they should be cautious with this - if tests look suspicious, check them out, don't blindly ignore what you see). When I train, I stress the difference between a clump of cells that are friendly/kissing and a clump of cells that 'love each other' (agglutination). They do very well - false positives are rare. I don't see a lot of unnecessary work being done.

I will quote (one of my favourite quotes) from Issitt Peter D and Anstee David J. Applied Blood Group Serology. 4th edition, 1998, Montgomery Scientific Publications, pages 63-64 (only because I cannot get to my copies of earlier editions at the moment - as while looking for them, a large number of my text books almost knocked me sideways, as they fell off the top of my wardrobe, and my wife nearly "brained" me too for making our bedroom look a mess!). "Reading Methods for In Vitro Tests. Now that most routine tests are carried through to an antiglobulin reading the question of how to read them does not often arise. They are usually read macroscopically in order that the cells and serum are left in the tube for progression of the test. A few cells may, of course, be removed and examined microscopically at any stage if this type of reading is required. However, one of us (PDI) has believed for years that routine use of the microscope in the blood bank creates far more problems than it solves. Almost any cell suspension, including those in which washed cells have never been exposed to antibody, if examined carefully enough under the microscope will be found to contain a few small clumps of red cells. Thus, while reading aids such as mirrors or hand lenses are acceptable, routine use of the microscope is not condoned. This reasoning also applies to the reading of antiglobulin tests. Again if agglutination cannot be seen with the naked eye, a hand lens, a convex mirror, or the type of microscope in which the contents of the tube are viewed while still inside the tube by placing the tube itself on the microscope slide, IT IS NOT THERE. Were it not for special tests, such as those in which mixed-field reactions may have occurred or when a small percentage of fetal cells might be present in a maternal sample, the microscope should be banned from the blood bank. Enzyme tests for agglutination or following conversion to antiglobulin reading, should NEVER be read microscopically." Several things should be noted about this quote. Firstly, there is NO distinction here between the indirect and direct antiglobulin test. Peter Issitt (see PDI, although I happen to know that Dave Anstee agrees with him) talks about reading antiglobulin tests. Secondly, this quote was originally written well before 1998. Since that time, there have been huge steps made in improving the sensitivity of tests within blood transfusion and blood group serology (often at the expense of specificity, and certainly at the expense of making diagnosis from the results of these tests straightforward - see the introduction of the term "delayed serological transfusion reaction", when there is laboratory evidence of a transfusion reaction, but no clinical evidence of a "delayed haemolytic transfusion reaction" (Petz LD and Garratty G. Immune Hemolytic Anemias, 2nd edition, Churchill-Livingstone, 2004). Thirdly, both Peter Issitt (1986) and Dave Anstee (1997) have been awarded the AABB Emily Cooley Memorial Award and Lectureship (amongst numerous other international awards - Dave was the President of the British Blood Transfusion Society, the Kenneth Goldsmith Award in 1985 and the James Blundell Award in 2003; these two are far from idiots! Lastly though, looking down a microscope is no panacea to detecting a transfusion reaction. I would draw your attention to Sachs UJH, Röder L, Santoso S, Bein G. Does a negative direct antiglobulin test exclude warm autoimmune haemolytic anaemia? A prospective study of 504 cases. British Journal of Haematology 2006; 132: 651-661. This paper talks about the production of de novo antibodies and anamnestic antibody production post-transfusion, as well as WAIHA. It comprehensively debunks the fallacy that a mixed-field reaction can, in all cases, be detected by the use of a microscope. So, perhaps the question should be, if the DAT is negative to the naked eye, should we perform an elution in each case? I REALLY, REALLY hope that nobody (seriously) answers YES to that suggestion (believe me, it was made with my tongue very firmly in my cheek)! Sorry about the rant!

Yes we test for weak D in cord bloods or even capillary sticks if that is what is drawn and we have seen weak D's. Also keep in mind (sorry if you already know this) if the DAT is positive the positive weak D isn't valid

Sorry, that was a very old post, those tools are no longer available.