carolynn Posted July 20, 2012 Share Posted July 20, 2012 Hello (1st post ) We had a chemo patient come in a few months ago for a type and screen (no blood transfused) and she typed O pos, with a 3+ Rh (tube, Gamma). She came in again recently for a crossmatch, and now her D is typing 1+ to microscopic. If taken to coombs, it types 2+ to 3+. I incubated it in the refrigerator for a few minutes (perhaps the prior tech used cold sample/reagents?) and it does type stronger, 2+ to 3+. We ended up giving her O neg units. My question is, is that necessary? If the antigen is there, she shouldn't make antibody, should she? If she were a mosaic, would the tube pick it up at all? Also, does anyone know if chemo can affect Rh expression?Thanks a bunch! Link to comment Share on other sites More sharing options...
Malcolm Needs ☆ Posted July 20, 2012 Share Posted July 20, 2012 Hello (1st post ) We had a chemo patient come in a few months ago for a type and screen (no blood transfused) and she typed O pos, with a 3+ Rh (tube, Gamma). She came in again recently for a crossmatch, and now her D is typing 1+ to microscopic. If taken to coombs, it types 2+ to 3+. I incubated it in the refrigerator for a few minutes (perhaps the prior tech used cold sample/reagents?) and it does type stronger, 2+ to 3+. We ended up giving her O neg units. My question is, is that necessary? If the antigen is there, she shouldn't make antibody, should she? If she were a mosaic, would the tube pick it up at all? Also, does anyone know if chemo can affect Rh expression?Thanks a bunch!Well, first things first carolynn, welcome to this fabulous site!Could you tell us the underlying pathology of this patient; this may make a difference to the answer.Have you looked at the reagent insert for your anti-D? I presume it is a monoclonal anti-D. Some (most?) should not be taken to IAT, unless they specifically say that they can be so taken, otherwise they may not react specifically, which may explain the stronger reactions by IAT.The other thing is, does the insert say that the reagent is suitable for incubation in the cold? Many monoclonal anti-D reagents actually react a bit like an anti-I in the cold, which may explain the stronger reactions in the cold.AS long as the historic group is D Positive, and you are still finding that she is D Positive, albeit weakly, there is no reason why she should not receive D Positive blood. As far as I know (and I don't know everything!), there has only ever been one case in the literature where a proven D Positive (proper D Positive - not a genetically Weak or Partial D) with cancer has ever produced an "alloanti-D".Again, as far as I know, chemo doesn't affect the expression of the D antigen, but the underlying pathology can (which is why I asked what is the underlying pathology in this case). Link to comment Share on other sites More sharing options...
carolynn Posted July 20, 2012 Author Share Posted July 20, 2012 Thank you, Malcolm. The people on this sight are sooo smart, and I have learned so much from them! The patient has some kind of lung cancer, no bone marrow or stem cell transplants. The reagent was a polyclonal (both IgM and IgG)...we use it for weak D testing on our cord bloods. The reason I refrigerated it was a quickie experiment to see if I could reproduce the previous results, thinking that the prior testing may have been done with cold reagents or cold specimen. I don't know if the insert says it is suitable for cold (probably not), but I will definitely check! Link to comment Share on other sites More sharing options...
Mabel Adams Posted July 21, 2012 Share Posted July 21, 2012 I don't think Gamma makes a polyclonal anti-D, sure it isn't a monoclonal blend such as Gammaclone? I have seen one cancer patient drastically change the strength of her D antigen over time. Seems like it was a lymphoma or leukemia though. Since some partial D's type 4+ with typing sera at IS, maybe the one weakened antigen patient was a partial D of this sort all along and would have made anti-D regardless of the weakening of her antigen? Link to comment Share on other sites More sharing options...
Rh-fan Posted July 23, 2012 Share Posted July 23, 2012 If the chemo was for a heamtalogical-malignancy, I think that the weak reaction is caused by the absence of the RhD antigen from a part of the cells. These kind of malignancies can be the reseon that one of the Rh genes is not read and no protein is made, red cells from these stamcells can be lacking the RhD antigen (sometimes also a C or E, depending on the Rh phenotype). This can give a weak reaction or a mixed-field reaction. When the malignacy is cured the mixed-field/weak reaction can also disapear. Also when other stemcells are used for the production of red cells they will also have normal expression of RhD (and the other)PS Mabel in Europe we can by a polyclonal anti D (for IS and IAT) from Immucor/Gamma.Peter Link to comment Share on other sites More sharing options...
Mabel Adams Posted July 27, 2012 Share Posted July 27, 2012 By "polyclonal" we all mean human source, right? With antibody made by many clones of B cells? Not that the antisera contains more than one monoclonal antibody (which could be literally translated as poly-clonal)? Just making sure we don't have terminology differences too. Link to comment Share on other sites More sharing options...
Rh-fan Posted July 27, 2012 Share Posted July 27, 2012 polyclonal is human and has brood spectrum of antibodies, the sera with more then one monoclonal I always call them "monoclonal blend" reagents. And you are right, that are no polyclonal reagents! Link to comment Share on other sites More sharing options...
galvania Posted July 27, 2012 Share Posted July 27, 2012 Rh fan - what do you mean - there are no polyclonal reagents? In europe at least you can still get polyclonal .- and yes, I mean 'human' reagents Link to comment Share on other sites More sharing options...
Malcolm Needs ☆ Posted July 27, 2012 Share Posted July 27, 2012 No Anna - I could be wrong, but what I think Peter means is that there are no "polyclonal" monoclonal antibodies (i.e. there may be blends of monoclonal antibodies, but these tend to be two, three possibly monoclonal antibodies blended together, rather than seven, nine, fifteen, etc monoclonals blended together).Is that correct Peter? Link to comment Share on other sites More sharing options...
Mabel Adams Posted July 28, 2012 Share Posted July 28, 2012 That's how I took it too Malcolm. Link to comment Share on other sites More sharing options...
Rh-fan Posted July 28, 2012 Share Posted July 28, 2012 No Anna - I could be wrong, but what I think Peter means is that there are no "polyclonal" monoclonal antibodies (i.e. there may be blends of monoclonal antibodies, but these tend to be two, three possibly monoclonal antibodies blended together, rather than seven, nine, fifteen, etc monoclonals blended together).Is that correct Peter?That is What I mean. Link to comment Share on other sites More sharing options...
carolynn Posted August 1, 2012 Author Share Posted August 1, 2012 The anti D reagent was Ortho Bioclone (Murine Monoclonal Polyclonal Blend). One of the limitations of the procedure was if the cells were DAT positive, a weaker reaction could occur due to reduced available antigen sites or steric hindrance. We didn't do DAT testing, too bad. Link to comment Share on other sites More sharing options...
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