Malcolm Needs

Although it is now 7-years-old, and so some of the newer antibodies described are not quoted, you couldn't get a much better paper , in my opinion, than: Daniels G, Poole J, de Silva M, Callaghan S, Smith N. The clinical significance of blood group antibodies. Trans Med 2002; 12: 287-295.

The simple answer is "yes". You must treat these patients in exactly the same way that you would treat other patients, with the proviso that they are possibly more likely to make alloantibodies, as they have been exposed to many that are foreign (although, that having been said, I doubt if their immune system is up to much for the first couple of days).

Ah right. Now I understand where you are coming from. Sorry about the misunderstanding.

It's a pleasure.

I must agree with L106 that this system must "hold you to ransom" on occasions. It may be okay if you have a plasma containing one or two antibodies, but when you have an plasma containing three or four (or more) alloantibodies (even if they are of a "common" specificity), it must give you a headache as to how to find the necessary red cells. How do you cope with, for example, a sickle cell patient with an anti-U, an anti-Fy3 or an anti-Jsb? How would you find three examples of U-, K+k- or Fy:-3, K+k- cells, or, come to that three examples of Js(a+b-), Jk(a-b+) red cells (or would you alloadsorb in such circumstances)? :confused:

Yes, it can be a bit obscure. Basically, what it means is that, if we cross-match using the raw plasma and we detect no reactions, or we cross-match using auto-adsorbed plasma, and we detect no reactions, then the blood is issued as "compatible with". If we cross-match using the raw plasma, in which we have detected a clinically insignificant antibody, such as anti-Kna, we cannot provide Kn(a-) blood, as so we will cross-match and choose the least incompatible, and issue it as "suitable for". If we cross-match using inhibited plasma, as in the case of anti-Ch or anti-Rg, we will also issue as "suitable for". If we cross-match using alloadsorbed plasma, and we detect no reactions, we issue the blood as "suitable for". The difference between the autoadsorbed plasma and the alloadsorbed plasma is that autoadsorption will leave behind an alloantibody directed against a high frequency antigen (such as an anti-Vel) - hence the "compatible with", whilst the alloadsorption will almost certainly take out an antibody directed against a high frequency antigen (again, such as anti-Vel) - hence the "suitable for". To put it another way, if we issue blood as "compatible with", we are pretty sure that there will be no adverse reactions, whereas if we issue blood as "suitable for" we are hoping that there will be no adverse reactions (but it is still, to a certain extent, an in vivo cross-match). I hope that helps to explain the difference. If not, get back to me. :)

We had a lady in today with an anti-D level of 829 IU/mL. We assume this one to be immune, rather than prophylactic!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

Tonight (its 21.30 over here) I found the article on the computer by going into: Google Put in "Transfusion AABB" Go to "Transfusion - Journal Information" Once in, over on the right hand side is a bit marked "view sample issue" Go to 2003 - Volume 43 and expand it. Go to Issue 11 (November 2003). Go to the editorial and you can download a PDF of the article. AND, I KNOW YOU WON'T BELIEVE THIS, BUT IT WAS FREE!!!!!!!!!!!! :D:D

Hi Brenda, If there is, then I'm afraid I don't know it. You could try going onto the Transfusion website, but I suspect you would have to pay for any downloads. Occasionally, very occasionally, you can Google and get a paper up. Sorry I can't be more help. The only other thing I can suggest is that you send me an email on malcolm.needs@nbs.nhs.uk with your work address, and then I can photocopy my copy and send it to you. Sorry, not a lot of help I know. :redface::redface: Good news! I've just Googles Transfusion AABB and managed to get the article up that way, so you can get via their site! :):):)

No problem (after all, he wrote it, not me)!!!!!!!!!!! :D

Brain power? Bang goes any chance that I could do it then!!!!!!!!!! :o:o

There ws an editorial, written by Lawrie Petz, a few years ago in Transfusion that may be of interest to people. It is: Petz LD. "Least incompatible" units for transfusion in autoimmune hemolytic anemia: should we eliminate this meaningless term? A commentary for clinicians and transfusion medicine professionals. Transfusion 2003; 43: 1503-1507. The final paragraph should be of particular interest. :)

Our National SOP actually states that we should cross-match with the raw plasma and the adsorbed plasma, if there is sufficient raw plasma available. On average, we deal with about 4 or 5 DAT positive samples a day, most with a panagglutinin giving a 4+ or 5+ reaction across the board. I've never quite seen the point of cross-matching against the raw plasma in such circumstances, knowing before I start that the units will be 4+ or 5+ incompatible. It's a waste of time (1+ or 2+ panagglutinins maybe, but not when they are that strong). You would be amazed just how many times I have insufficient raw plasma left to perform these useless cross-matches! The 50 odd hospitals that we deal with as their Reference Laboratory (from very large London Teaching Hospitals to small Private Hospitals) are a varying lot too. SOme are quite happy to perform an immediate spin cross-match if we detect no atypical alloantibodies following differential adsorption, some will do this if the auto-antibody is 1+ to 2+, but will want us to cross-match if the auto-antibody is strong, or if we identify atypical alloantibodies following differential alloadsorption, whilst others (some quite reasonably sized District General Hospitals) want us to cross-match for them even when the autoantibody results in 2 cells kissing each other in the IAT. This last cohort really annoy us! :mad::mad:

p.s Malcolm.... too much info!!!....my analysers have a strictly professional relationship with the LIMS.

Yes; firstly I would agree with you that, in this particular case, there is insufficient evidence (well, none actually) for the presence of an auto-antibody. Secondly, I agree with you about the antibody characteristics making a difference. Thirdly, I would agree with you that these discussions are wonderful, especially if one can keep a mind open to other people's opinions, which, it would seem, nearly every poster can do. P.S. Thanks for the comment.

Hi Trey, and welcome. If you are as lucky as I have been, you will learn enormously from this site (and in a very short period). There are some wonderfully knowledgable people who post, who are more than willing to share their knowledge. It is great.

In principle, I do agree with you Brenda, but when we detect an underlying atypical alloantibody post-adsorption (say an anti-Fyb for arguement's sake), we do like to cross-match, just to make sure that we are not giving Fy(b+) blood (albeit, the cross-match could easily miss an Fy(a+b+) unit if the anti-Fyb is very weak).

Whilst I hate to admit this, particularly on a worldwide site, I have to agree with you about the knowledge of an antibody screen prior to prophylaxis. This is why, unless we have been told by a hospital that prophylaxis has been given, and we detect an anti-D with a level of 0.5 IU/mL or below, we state that an unspecified anti-D is present. If, however, the level is above 0.5 IU/mL, we are confident that it is an immune anti-D, as extensive tests have shown that, even with a prophylaxis dose of 1, 500 IU (and a BSW {British Standard Woman!]) the level never exceeds 0.5 IU/mL. Of course, if the lady is very petite, or they give the world's supply of anti-D immunoglobulin to a single lady (or, a married lady, come to that, ha!, ha!), then we may be caught out by stating the anti-D to be immune, but then, if we are not told of these circumstances by the hospital, what can we do?

I would agree that, in this case, there are clear cut specificities, and that more cells could be used to rule in and rule out. I would dispute, however, that performing differential alloadsorptions in a case where there are some negative reactions is dangerous. Yes, there is some dilution effect, but a few years ago a colleague of mine deliberately spiked a panagglutinin with a very weak anti-D, and then adsorbed the plasma 8 times with some rr red cells. At the end of this process, the panagglutinin had disappeared, but the anti-D could be readily detected, albeit the reactions were very slightly weaker. The trick is to ensure that the cells used for adsorption are really, really packed, by centrifuging on high for about 10 minutes, and then removing the supernatant and the top layer of cells, and then centrifuging again for another couple of minutes and taking off any residual supernatant and the top layer of cells. After this, the only fluid left to dilute the antibody is, for want of a better way of putting it, "interstitial fluid". I am always more worried when there are NO negative reactions, because then you may be taking out an antibody directed against a high incidence antigen that may be lurking under the auto-antibody. Actually, differential adsorption can be extremely useful when you know that there is no auto-antibody present, but there is a complex mixture of "common" alloantibodies and when there is an alloantibody present directed against a high incidence antigen of known specificity. This can be adsorbed out, leaving any other alloantibodies present in at least one of the plasma samples that have been adsorbed. I have used this method on several occasions with specificities such as anti-U and anti-HrB.

And wedding anniversaries; don't forget they have a very close and intimate relationship with a computer!

You know, I really don't think you're taking this seriously!!!!!!!!! :rolleyes::rolleyes:

Brilliant! :D

Oh how I wish I worked with you or someone similar. In our place the people that work in Quality seem all to have had two "ectomies". The first is a "pragmatismectomy" and the second is a "humourectomy"!

Being a Reference Laboratory, we also perform differential alloadsorptions on such patients (or auto-adsorptions if the patient has not been transfused within the previous 3 months [rare] and if there is sufficient autologous red cells [almost never]). As you may have seen from my posts on threads asking similar (but not identical) questions, I have no problem issuing blood that reacts in vitro with the auto-antibody in the patient's raw palsma, unless the haemolysis is fulimating. When issuing this blood we do not need a doctor's signature, but we would not issue it either as compatible, or as incompatible, but would issue it as "suitable for". In addition, we print a phrase on the bottom of the cross-match form that goes out to the hospitals as follows: "Please note that when suitable blood, rather than compatible blood is provided, observation of the patient during transfusion is of paramount importance." I am almost happy with this, except that the phrase itself seems to imply that observation of the patient during transfusion is not of paramount importance for any other transfusion, which is, of course, complete nonsense! :)

I am entirely sympathetic with your views Lekota40. a) I am glad that I don't have to work for this supervisor. I hope that she never has to deal with me if I need a transfusion (she may think my anti-B is some kind of strange auto-antibody)