Malcolm Needs

Absolutely correct John, and I should have mentioned it.

As long as the unit is being given as a "top-up" transfusion, and the neonate was not given an IUT, and is not very small for age or very premature, then, yes, you can use blood up to its normal expiry, with no particular problems with, for example, potassium ion concentration in the suspending medium. It is also important that one complete unit is reserved for one neonate. There are two reasons for this. Firstly, and most commonly quoted, is the desire to minimize the exposure of the neonate to "foreign" antigens (although I've often wondered about this, as the neonates immune system is so immature that he/she is unlikely to be immunized, but may become "used" to the foreign antigens, and would not necessarily make antibodies to these antigens when challenged in later life). The second (more gruesome) reason is that, if the donation is infected by a bacterium, if it is transfused to one neonate, rather than several, only one neonate will die, rather than several. There are good arguments that all cellular blood components transfused to a neonate should be irradiated, on the grounds that, just by chance, there may be a shared HLA haplotype, and also by chance, some viable T cell lymphocytes present, that may result in transfusion associated graft versus host disease. This is particularly true with premature neonates, when their own immune system is compromised by age. One has to remember that not every single unit of cellular components will have been tested to ensure that the leucodepletion has "worked", and that one may slip through that has a near normal leucocyte count (and, of course, they will, almost by definition, be "fresh" blood components). All that having been said, the literature to support this theory is pretty scant! As for CMV negativity, unless you have tested the mum to ensure that she is CMV negative, and has not, therefore, passed on the CMV virus to her baby, and taking into account that, unless the CMV testing is performed by nucleic acid testing, there is approximately a 2% false negativity for serological testing for CMV, and looking at the data coming out of Scandinavia (admittedly by Pall, who make the filters) then leucodepletion is as good as, if not better than, CMV testing. PLEASE NOTE THAT, AS ALWAYS, THIS IS A PERSONAL POINT OF VIEW. :):)

I am in total agreement with you eric1980, and do not agree with all the points made by AMCWHC. It is not just a question of those patients with an antibody. ALL patients (except most of those who are group AB) have antibodies, and very dangerous ones, called anti-A, anti-B and anti-A,B. If you read my post in the thread on witnessing blood withdrawals AMCWHC, you will see a horror story that (nearly) took place at an (unnamed, but world famous) London Teaching Hospital. Now, I am not saying that transferring all of the patient records would have prevented this, but it would have minimized the chances. Yes, it is expensive (and a pain in the ****) but, as eric1980 says, it is probably less than the price of being sued. :eek:

In a way though, the anti-C3d is irrelevant. If there is an IgM element to the antibody, as well as an IgG (as can often happen with an antibody produced de novo during a pregnancy) you may still get agglutination prior to 37oC incubation.

No, not necessarily. We use cassettes that contain anti-IgG and anti-C3d (although cassettes containing anti-IgG only are available). But we often find that when an IgM antibody is present, particularly if it reacts better in the cold (well, cool) as most of them do, the sensitisation occurs before we put the cassettes in to incubate at 37oC, and you then get agglutination when you centrifuge. This is why did so much comparative work and change control. With experience, you can usually tell (although I'm sure we don't detect every time there is an IgM present).

True, but I did say "if at all possible".

galvania, that's just showing off!!!!!!!!!!!!!!!!!!!!!!!!!! What does it mean, for those of us who can only just speak English and have trouble with that if there are more than a couple of syllables?????????!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

Yes, thinking more about it, I also agree with galvania.

clmergen, I wouldn't mind betting it was a mixture of an IgG and IgM, and that you were detecting the IgM in the gel (same specificity, but a mixture of immunoglobulins).

Very true. I tend to forget that over this side of the puddle!

True, there may be David, but surely they would not intervene physically, unless they had performed other studies such as MCA Doppler/ultrasound? I know our doctors would only use the titre as a guide, rather than the be all and end all.

I'm with you alanh1954. It may be a little "over the top", but I would rather be safe than sorry. Both anti-A and anti-Fya tend to cause haemolytic disease of the newborn, rather than haemolytic disease of the fetus, and both can be delayed. I would rather be prepared if blood were to be needed in an emergency (e.g. a flat baby coming back into the hospital after being taken home). Mind you, I would have performed Duffy typing on the dad prior to delivery, just to see if the baby was likely to inherit the FYA gene, as the mum may have made the anti-Fya as a result of the transfusion. Then, if the baby had a positive DAT, I would suspect maternal anti-A, but would also be a bit wary of the mother having made an atypical alloantibody against a low incidence antigen carried by the dad (in other words, if at all possible, I would adsorb the eluate with another group A cell, and then test it against the dad's red cells, if at all possible). That all having been said, I work in a Reference Laboratory, where we do everything to the nth degree. If I were working in a busy hospital, I could well think very differently!

Not necessarily, but it is as good as any! It could be an AbantuB, or an AintB, but does it really matter? The point is, it is A1 Negative, and so it can be safely given to an A2B recipient (as can A1B blood, unless there is an anti-A1 reacting strictly at 37oC in the recipient's plasma). There is an awful lot of fuss made about A subgroups (in my opinion) and most of the differences are purely esoteric (except in extremely rare cases of real anti-A1 reacting strictly at 37oC).

Another really good place to look is: A Manual for Blood Conservation, edited by Dafydd Thomas, John Thompson and Biddy Ridler, 1st edition, published in 2005, tfm Publishing Ltd. (ISBN 1 903378 24 9). This is a really excellently written book that even I understood!

No, you are perfectly okay doing your titrations in DiaMed columns BoroCliff. We have been doing this for at least two years (probably longer) in the NHSBT, following a national study and change control. The correlation between our tube and DiaMed titration end points was almost perfect. Obviously, there was the odd antibody that was a couple of dilutions more or less in either method (sometimes the tubes gave, for example, a titre of 64 and the DiaMed 256, sometimes the tubes gave, for example, a titre of 256 and the DiaMed 64 - 2 dilutions difference, so the actual titre was probably 128; this was using master dilutions), but we already know that certain antibodies react differently by certain techniques (tile antiglobulin, tube antiglobulin, capillary tube antiglobulin, liquid-phase microplates, solid-phase microplates, column agglutination technology - you name it). We actually use Diluent2 as our suspension medium, but there is no reason why you should not use the cells in the diluent in which they are supplied (we looked at that too). We just feel, subjectively, that we get crisper results with Diluent2. :)

Another reason for performing titrations that is becoming more common is for major side ABO incompatible renal transplants (i.e. A2 donor, O recipient).

In the UK, the Guidelines state that before 12 weeks gestation, anti-D immunoglobulin is only given for surgical terminations. Between 12 weeks and 20 weeks, we are to give 250IU anti-D immunoglobulin for a potentially immunizing occurrance. After 20 weeks gestation, we have to perform an estimation of the foeto-maternal haemorrhage, but give 500IU anti-D immunoglobulin as a minimum.

Tee hee! :D:D:D:D:D:D:D

Now, let's see. 3 x21 is 63,,,,,,,,, so happy retirement too Rashmi:D:D:D:D:D:D:D:D

Well, put it this way Rashmi, that's what I have been talking about! Maybe I've got the wrong end of the stick. Youare quite correct about "top-up" blood being safe for the full 35 days. :confused: Is that what others have been talking about??????????????

Tests have been performed that show that the potassium leakage in fresh units (up to about a week) is minimal, and so there is no need to wash. After that time the leakage starts to accelerate, and the potassium level eventually rises to a concentration that could be dangerous. It is, therefore, not a great idea to give neonates older blood, but, if needs must (if you will excuse the pun on my name), then washing the red cells is one way to reduce the potassium concentration to an acceptable level. Of course, at the same time, you will be washing away other electrolytes and clotting factors. This must be taken into account, and the neonate may require FFP or the red cells may be resuspended in group AB FFP.

A belated, but heartfelt HAPPY BIRTHDAY to you Rashmi. I didn't think you still admitted to them!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! :rolleyes::rolleyes::rolleyes:

Hi shily, It is not that the patient has a high level of potassium, so much as the unit having a high level of potassium through membrane leakage, which accelerates with the age of the unit after storage (i.e. it is a storage lession). This high level of potassium can be toxic to the heart, and this is why you need to wash the units prior to transfusion, particularly if the neonate is premature or of small stature for age.

This is not entirely true NedB (although I do note your use of the word "usually"). There are quite a few occasions when the grading of the reaction is important. Off the top of my head, there are subgroups of ABO, weak and partial D's, k typing, when the KE02 gene is in trans with a KE03, Fyx, titration end points, to name but a few. You are, of course, absolutely correct in saying that the inspectors will want you to QC both techniques, but there is slightly more to it than that. There does have to be some correlation between the two, otherwise some of the results will be meaningless.

As I said in an earlier post, and as far as I know, within the UK there is no requirement for a Blood Bank staff member to be present when a sample is drawn, but I wonder if we could learn something here. I know of an incident at a large London Teaching Hospital (that, for obvious reason, will remain nameless) where a sample of blood was drawn on the ward on a Mrs X. This sample was group A, D Positive. For some reason (maybe fate) the Blood Bank telephoned the referring hospital's Blood Bank to ask about the lady. They had made her group O, D Negative. Obviously, a mistake had been made somewhere. Another sample was requested, but, upon receipt, it too grouped as A, D Positive. Then a third sample arrived, and this time it was grouped as O, D Negative! The Blood Bank Manager went up to the ward and decided to watch as yet another sample was drawn. This typed as O, D Negative. It turned out that the phlebotomist had asked one of the patients if she was Mrs X. Unfortunately, this particular patient was a little confused, and answered in the affirmative. No other checks were performed. When the second sample was requested, the same phlebotomist went straight to the same confused patient and bled her again, with no checking at all this time, as the phlebotomist "already knew that she was Mrs X". The third (correct) sample had been taken by the doctor. The telephone call had save a group O, D Negative lady being transfused with group A, D Positive blood! What happened to the phlebotomist? Was she sacked for not following the strict protocol? No, she was "re-trained" and, as far as I know, is still out there somewhere. :eek::eek::eek: