Malcolm Needs

My immediate thought is, why are they sending out samples like this? The DAT involves washing, and always has done, unless it is being performed in column agglutination technology, in which case it usually involves centrifugation, followed by resuspension in the chosen medium, to the chosen concentration of red cells. If they want to ask you to perform a realistic test, and that, I would have thought, is the whole point of the test, then send out a whole blood sample, with the (presumably) IgG antibody sensitising the red cells and in the plasma; otherwise, what are they testing other than the AHG? :confused::(:confused:

Hmmm, not sure about that; I probably have many years more experience. I was weaned on the stuff!!

A true tour de force!

We still use this method occasionally in my Reference Laboratory for both antibody identification and cross-matching, if we suspect that the antibody is LISS dependent. Do not forget that this was not only the method of choice for many years before LISS and gel technology were invented, but was virtually the only method available - and we didn't kill hordes of patients. It is, it is true, not as sensitive as LISS and/or gel, but it is sufficiently sensitive to detect clinically significant antibodies (by that, I don't mean all antibodies that have the potential to be clinically significant in the future, such as a weak reacting anti-C, but those that are clinically significant in the patient at the time). You may boost the odd antibody, but that will not kill the patient, and will make it a darn sight easier to detect the next time! You will find this technique in virtually any old text book (pre-LISS and gel) that gives techniques. :):)

Right, I've checked some old notes, and I was more or less right, if the patient has had colloids or crystalloids prior to transfusion. Apparently, it depends upon the molecular weight of the colloid or crystalloid as to whether they stay in the patient's circulation (and for how long), whether they go out into the interstitial fluid, or how quickly they are excreted. The molecular weight influences the "suckability" (an anaesthetists word, not mine) of the fluid, as to whether fluid comes into, or goes out of the circulation. As a result, you should wait a little longer to let the whole thing settle down, so that you get an accurate Hb and Hct. Though I say it myself and shouldn't, not bad for someone who was awash with ethanol the other night!!!!!!!!!! :D:D:D

I'm not absolutely sure of my facts here, as I am just back from a wedding, and perhaps, cerebrally, not quite at my best (the champagne flowed), so I'll check properly tomorrow, but I think that this is not so much to do with the red cells being sequestered by the spleen, than the fluid being returned to the peripheral blood circulation from the interstitial fluid, and the deeper blood circulation, because, if a person requires a transfusion (or, at least, if a person requires a transfusion for massive blood loss), the peripheral blood circulation, largely, shuts down. As I say though, I am writing this through something of a haze, and will check my facts tomorrow. :tongue::tongue::redface::tongue::tongue:

Thanks Marilyn. I think GBS was right! We call it a FBC (full blood count). :)

Sorry, but being English, I'm not familiar with the term H&H. Please could you explain? Thanks! :redface::redface:

Actually Eoin, I don't entirely agree with this comment either, but for a different reason. There have been occasions when I, and others, have replied to threads/posts from donors or patients (lay people, if you will) who have asked questions because they are worried about something - like the lady who was rpegnany and worried about her anti-Cw, and the other lady who had a father who was HBC+, and who was worried as to whether she may also be HBC+ through birth, but wanted very much to donate blood. I think that, not only are these reasonble questions, but that it is our duty (and pleasure) to answer such questions and, I hope, reassure such people. :redface::confused::redface:

Yes, I think I might have told them to "expletive off" too!!!!!!!!!!!!

Sometimes, the NHSBT gets complaints if we take too long sorting out the specificity of an antibody and then providing cross-matched blood from a sample from a hospital who send it in because they cannot sort out the specificity of the antibody themselves and cannot cross-match the blood even when the antibody specificity is sorted and when provided with antigen negative blood - but we can live with that. Yesterday, however, I heard of a real goody! One of my colleagues (at another Laboratory) received a sample from a hospital requesting 4 units of cross-matched blood as soon as possible (always useful, as what does ASAP actually mean). There was no telephone call from the hospital. Anyway, they dutifully got on with identifying the antibody, cross-matching the blood and sending over to them. They then got an official complaint because they had done the work too quickly and sent over the blood before it was required!!!!!!!!!!!!!! Some people you just cannot please. :angered::angered:

I've used NEUTR-AB, and whilst there is no doubt it is "good stuff", I have my doubts that it only neutralises IgM. I think it also neutralises a certain amount of IgG. :confused::confused::confused:

Don't you just love 'em - and she will be teaching others! :eek:

I'm sorry to make light of a very serious situation, but (there is always a but) shouldn't it have been the knitting mills that held on by a thread???????? SORRY! :eek::eek:

It's almost the same in the UK John, except it's 12 weeks here.

Very good point! :):)

Boy, this is a difficult one! If the screen is positive the first time around as 1+, or maybe even 2+, but is negative again using the same cell at least twice more by the same technique, then I would be happy that the original findings was an error, but otherwise no. I certainly wouldn't be happy if the screen were positive, but two panels were negative, unless the positive screening cell was included. It may be that the screening cell is positive for an antigen not represented on any of the panel cells, and that the antibody is genuine. Do you perform your tube technique by pre-warming the reactants prior to mixing? If not, it could be worthwhile pre-warming one set and performing the same panels at room temperature (but, again, I would always include the positive screening cell). It could also be worthwhile trying a NISS tube technique, in parallel with the LISS tube technique, with, of course, an appropriately longer incubation time, just in case the antibody is "LISS only". These are only initial musings, whilst I'm waiting for my young son to get ready for bed. I'll think about it more tomorrow! :eek::eek:

There are such a huge number of ways of having a transfusion reaction, that I'm not sure that you could have a Transfusion Reaction Proficiency Test without a narrower title (see attachments). No, sorry, the file is 13.7MB in zipped form, and I can only attach a file 4.7MB large in zipped form. If you send me an email address to malcolm.needs@blueyonder.co.uk, I'll send it to you. :confused::confused:

I agree with you John, but in the UK it is the Law. This Law was passed with the thought (and now the realisation) that vCJD could be passed on by a blood transfusion. There is good reason why an individual who has themselves been transfused cannot be accepted as a blood donor (see slide 20 of the PowerPoint lecture "Donors and the Donation Process" in the References section). Sadly, this Law was passed by politicians who, although advised by the great and the good of Transfusion Microbiology, still made o right horlicks of the whole thing. So, under the Law in the UK, not only can we not use a person's blood for donation for other people if they themselves have been transfused, but, strictly speaking, without a medical deviation, we cannot use it for an autologous transfusion! Normally, of course, this would not matter, BUT this extends to ALL patients, and so, if we have a (non-existent) patient with, for example, an anti-k+Vel, requiring blood from another (non-existent) donor who is also k-, Vel-, they would not be able, under the Law as it stands, to give blood for an autologous transfusion! Clever eh???????!!!!!!!!!!!!!!!!!!!! We have to reject donors who have made an atypical alloantibody through stimulation by pregnancy, just in case they have had a transfusion without knowing it. Can you imagine the fuss if someone was to go down with vCJD having had blood from such a donor, even if there was no evidence that the transfusion caused the vCJD? So, basically, although I agree with you, we have no choice. :eek::eek:

Keisterkid I am really sorry; I have reread my post and it does indeed sound hostile, which was unintentional. What I meant was that I would not go to the expense of washing them in the first place (unless the antibody titre was really high, or the unit was destined for a recipient of small stature). You are absolutely correct in saying that the gift should not be wasted, but as far as I am aware, apart from when plasma-rich components have been given to recipients of small stature, there are no credible cases of such a component causing a clinically-significant transfusion reaction, save one case of an anti-K in a donor that reacted with another K+ transfused unit. Therefore, why go to the expense of washing the red cells when, as John says, there is so little chance nowadays, with the packing of red cells and the resuspension in something like SAG-M, of a reaction. As I said in an earlier post, I used to use these units myself, so I am not advocating throwing them away, but I am also not advocating washing them. Once again, sincere apologies for the unintended tone of my earlier post, which was, I admit on re-reading, well over the top. :redface::redface::redface::redface::redface:

I've checked with someone who has worked in our Testing Department for many years, and we do discard any unit found to have an atypical alloantibody, even if it is probable that the stimulation came about by pregnancy.

I'm sorry keisterkid, you may not pass on the cost, but there is a cost. There is the cost of the maintenance of the cell washer, there is the cost of the liquid consumables, such as the saline, there is the cost of the electricity to run the cell washer, there is the cost of the sterile bag into which the washed blood goes, there is the cost of the sterile docking tubing, there is the cost of the sterilising of all of these, there is the cost in terms of time of the person undertaking the washing, there is the cost of the labeling of the new bag, etc, etc. The fact that there is no difference in pricing is not down to the fact that there is no cost, but the fact that your clients do not complain is down to the fact that you do not pass on the cost; but ask your finance people if there is a cost. In no way am I saying that it is not a usable product (see my immediate previous post), but don't pretend that washing these units does not have a cost. :mad::mad::mad::mad::mad:

I agree entirely with everything you have posted Eoin, particularly about that fact that it is a very interesting case and well worth sharing. The one thing that I could possibly, not so much disagree with you, but just maybe remind you that many Laboratories do not have access to a monospecific anti-IgA reagent, either in a bottle, or in CAT, and I have my doubts as to whether skyanto would have such access (although, of course, I don't know for certain), which would probably mean that the coating is IgG, C3d or both (hence the anti-A eluted) - but I still agree with you about IgA-mediated AIHA, and about a positive DAT not always giving a significant AIHA. :):):)

Yes, actually, I'm looking at this with a UK-centric mind, and I do agree with both you and Ellen Zeigler, and, indeed, have used such units myself in the past. The problem in the UK is that anybody who has themselves been transfused is then banned from donating blood because of the risk from variant Creutzfeldt-Jacob disease, and, of course, any donor with an antibody (unless it is through pregnancy) will have been transfused. All units of blood in the UK are also leukodepleted and plasma reduced, but most are also tested for high-titre ABO antibodies, so, if it were not for the risk of vCJD, I'd probably be in totalfavour of using these units, but I still wouldn't go to the expense of washing them. :redface::redface:

I wouldn't want them, and I certainly wouldn't go to the expense of washing them.