dcubed Posted February 19, 2014 Share Posted February 19, 2014 We have a Mom: A neg with a positive antibody screen presumed to be positve due to antenatal RhIG. A set of D neg screening cells yielded a positive reaction with one cell that prompted a full antibody ID. Anti K was ID'ed. Here is the rub. Mom's antibody screen at time of antenatal RhIG administration was negative and the baby does not appear to be the source of antibody stimulation as she types as K neg. Could this be a "naturally occuring" antibody? Link to comment Share on other sites More sharing options...
Yanxia Posted February 19, 2014 Share Posted February 19, 2014 Or RhIg source. rebeccarjthomas 1 Link to comment Share on other sites More sharing options...
dcubed Posted February 20, 2014 Author Share Posted February 20, 2014 Shily, that thought did cross my mind! Link to comment Share on other sites More sharing options...
rravkin@aol.com Posted February 20, 2014 Share Posted February 20, 2014 (edited) Is it possible that it is too early in the baby's development to depend on an accurate rbc antigen type, at least for Kell? But then that still doesn't define of the source of sensitization. Edited February 20, 2014 by rravkin@aol.com Link to comment Share on other sites More sharing options...
Malcolm Needs ☆ Posted February 20, 2014 Share Posted February 20, 2014 Ronald, the only time that I have seen a baby that is K+ typing as K- at birth (unless serial IUTs have been given of course), is a case where the mother had such a high titre anti-K that all of the baby's K antigen sites were blocked by the maternal anti-K, so I don't think that is the answer. It could be that the baby is Ser193, which is a K antigen mutation that means the K antigen does not react with certain monoclonal anti-K reagents, and so is giving a false negative result. This mutation is incredibly rare, and so I doubt if that is the answer. It could be that the mother has been carrying a bacteria that expresses a sort of "K antigen" on it's surface (Escherichia coli, Enterococcus faecalis, Morganella morganii and mycobacterium sp have eebm implicated) and the mum has made anti-K as a result, but this is another incredibly rare scenario, and so I doubt that is the answer. "Naturally occurring" is very, very rare, so I doubt if that is the answer. I'm with shily on this one. I think that it is a contaminant of the RhIG. carolyn swickard, Eagle Eye, Yanxia and 2 others 5 Link to comment Share on other sites More sharing options...
rravkin@aol.com Posted February 20, 2014 Share Posted February 20, 2014 (edited) Ronald, the only time that I have seen a baby that is K+ typing as K- at birth (unless serial IUTs have been given of course), is a case where the mother had such a high titre anti-K that all of the baby's K antigen sites were blocked by the maternal anti-K, so I don't think that is the answer.It could be that the baby is Ser193, which is a K antigen mutation that means the K antigen does not react with certain monoclonal anti-K reagents, and so is giving a false negative result. This mutation is incredibly rare, and so I doubt if that is the answer.It could be that the mother has been carrying a bacteria that expresses a sort of "K antigen" on it's surface (Escherichia coli, Enterococcus faecalis, Morganella morganii and mycobacterium sp have eebm implicated) and the mum has made anti-K as a result, but this is another incredibly rare scenario, and so I doubt that is the answer."Naturally occurring" is very, very rare, so I doubt if that is the answer.I'm with shily on this one. I think that it is a contaminant of the RhIG.Thank you Malcolm; but are you saying that the Kell antigen is readily expressed with the initial or later production of rbc's in the fetus and/or infant? Edited February 20, 2014 by rravkin@aol.com Link to comment Share on other sites More sharing options...
Malcolm Needs ☆ Posted February 20, 2014 Share Posted February 20, 2014 Yes, very early indeed. Experiements performed some years ago (Daniels GL, Hadley AG, Green CA. Fetal anaemia due to anti-K may result from immune destruction of early erythroid progenitors (Abstract). Transfusion Medicine 1999; 9 (suppl. 1): 16.) showed that the K antigen is expressed on much early erythroid progenitors (before they are haemoglobinised) than is Rh. This explains why there are much lower concentrations of amniotic fluid bilirubin and post-natal hyperbilirubinaemia, and reduction in reticulocytosis and erythroblastosis in cases of HDFN caused by anti-K, compared with cases of HDFN caused by anti-D. To put it another way, it is anaemia without the by-products of haemolysis. carolyn swickard and rravkin@aol.com 2 Link to comment Share on other sites More sharing options...
dcubed Posted February 20, 2014 Author Share Posted February 20, 2014 1. Baby was full term. 2. Mom was treated for E Coli UTI. 3. We have given this same lot of RhIG to other patients and have not noticed anything other than passive anti D when these patients come back to us. Yanxia 1 Link to comment Share on other sites More sharing options...
Malcolm Needs ☆ Posted February 20, 2014 Share Posted February 20, 2014 Then it might just be due to the E. coli infection. Just to square the circle, as it were, if you have any of that batch of RhIG left, it may be worthwhile testing it with a couple of rr, K+ red cells, just to check that there is no anti-K in it. The things is, all humans, being humans, are a bit awkward and don't all react as they should! It may be that the others have adsorbed the immunoglobulin at a slower rate into their peripheral circulation (see that the anti-K may not have been detected), whereas this lady adsorbed it quite quickly, and so you were able to detect the anti-K. Just a thought. dcubed and Yanxia 2 Link to comment Share on other sites More sharing options...
rravkin@aol.com Posted February 20, 2014 Share Posted February 20, 2014 Decubed, what is the reaction strength reported for the positive cells? Link to comment Share on other sites More sharing options...
AMcCord Posted February 20, 2014 Share Posted February 20, 2014 Since we are on the subject of anti-K........I have a patient who has anti-K, anti-Fya, anti-S, probable anti-Jka. His anti-K is always detected at IS (PeG). We ID'd the anti-K 2 years ago. He has received only K negative (Fya, S and Jka negative) cells since that time. This week we also picked up a single strongly reactive cell with solid phase that doesn't fit the above antibodies or anti-C (which is the only other top ten parade antibody he could yet make and hasn't) - directed against a low incidence antigen I would suppose - the reference lab ran a bunch of cells and didn't see it. My reference lab is telling me that his anti-K is probably naturally occurring. His laundry list of problems is chronic renal failure, CAD, COPD, chronic anemia, etc etc. It's real obvious he is a responder. So, I'm thinking that perhaps we could explain his anti-K with a past urinary tract infection/sepsis, since E coli is the most likely suspect there. He's been in and out of the hospital with those kinds of problems. If the anti-K is due to the E coli (or other bug), would it be likely to persist with a strong IgM antibody - explaining why we always see it at IS? Or is this just a case where his anti-K is from immune stimulus and showing a little individuality? Link to comment Share on other sites More sharing options...
Malcolm Needs ☆ Posted February 20, 2014 Share Posted February 20, 2014 From my point-of-view AMcCord, and this will probably of no use to you whatsoever, the answer about the anti-K is PASS! AMcCord 1 Link to comment Share on other sites More sharing options...
galvania Posted February 21, 2014 Share Posted February 21, 2014 I would want to know how it behaves in gel before passing an opinion. I don't have enough experience with PEG. Link to comment Share on other sites More sharing options...
EDibble Posted February 24, 2014 Share Posted February 24, 2014 My reference lab is telling me that his anti-K is probably naturally occurring I don't know. If Malcolm says that naturally occurring anti-K is very rare, I would go with his opinion. tbostock and AMcCord 2 Link to comment Share on other sites More sharing options...
dcubed Posted February 25, 2014 Author Share Posted February 25, 2014 Decubed, what is the reaction strength reported for the positive cells?R1wR1 cell=wk posR1R1 cell =1+R2R2 cell=1+ strongRor cell=1+strongrr Kk cell=1+strongR1R1 Kk=2+ Rhig was given Dec 11, 2013. Tested on Feb 19, 2014 Link to comment Share on other sites More sharing options...
Sandy L Posted February 27, 2014 Share Posted February 27, 2014 dcubed, Just another thought regarding "rr Kk cell=1+strong". Was this multiple examples of rr Kk cells or just one? Pregnant women are notorious for forming HLA antibodies. Frequently we see an occaional extra D .neg panel cell turning up positive. The extra pos reaction could be "Bg" reactivity and could be the patient's own antibody or in the RhIg Malcolm Needs 1 Link to comment Share on other sites More sharing options...
janet Posted March 1, 2014 Share Posted March 1, 2014 dcubed, Just another thought regarding "rr Kk cell=1+strong". Was this multiple examples of rr Kk cells or just one? Pregnant women are notorious for forming HLA antibodies. Frequently we see an occaional extra D .neg panel cell turning up positive. The extra pos reaction could be "Bg" reactivity and could be the patient's own antibody or in the RhIgWe have had two reactions similar to this!?!?! Our gel reactions were not 2+ mind-you......weak 1+ and testing on other K+ cells show weak reactions also but not with all K+ cells (2 out of 3). When the patient typed as K- (I know, odds are they would) we felt safest to call it an Anti-K but were a bit puzzled when one of the baby's was K- (will have test the other baby Monday!). Baby's DAT was negative so doesn't fit that it was false negative due to antigen sites being coated. I have seen once and found support in "Applied Blood Group Serology" by Issett that Anti-K has been found naturally occurring but now I am thinking more about the HLA antibodies as we have seen this so many times with gel testing in certain screen/panel cells We give WinRho brand RhIg .... I have detected and Anti-C a couple days after giving it but would be surprised this Anti-K would still be detected a month plus later (as with you our ladies had their RhIg at 28 weeks and are presenting now at delivery. Link to comment Share on other sites More sharing options...
galvania Posted March 5, 2014 Share Posted March 5, 2014 Hello Dcubed. Now I am confused. Are ALL of those cells that you reported above K+? Or are you assuming that the reactions with the other cells are due to the anti-D from the RhIg? And did you assume anti-K just on the basis of this one cell? Link to comment Share on other sites More sharing options...
Joanne P. Scannell Posted March 5, 2014 Share Posted March 5, 2014 To add another angle to this view ... Has the patient EVER been transfused? I'm thinking this because not only is that the first question I ask, but also because I have a tech in my BB who received 2 units RBC when she was a teenager. When she was a student in college during her BB rotation, she tested her own plasma and found Anti-K. Two children later ... no issues. Now, 20+ years later, her Anti-K 'comes and goes. It's possible it could show up now and then if her system becomes stimulated ... like maybe by an infection ... hmmm. We forget that antigens are merely chemical combos ... sometimes those combos appear in nature ... Malcolm Needs and Sandy L 2 Link to comment Share on other sites More sharing options...
dcubed Posted March 5, 2014 Author Share Posted March 5, 2014 dcubed, Just another thought regarding "rr Kk cell=1+strong". Was this multiple examples of rr Kk cells or just one? Pregnant women are notorious for forming HLA antibodies. Frequently we see an occaional extra D .neg panel cell turning up positive. The extra pos reaction could be "Bg" reactivity and could be the patient's own antibody or in the RhIgYou hit the nail on the head! The K positive cells were also positive for Bg. Went back and found D neg Bg neg K pos cells and they did not react. Mystery solved. Malcolm Needs 1 Link to comment Share on other sites More sharing options...
janet Posted March 6, 2014 Share Posted March 6, 2014 I had my student work on our two patients some more - both women we thought had Anti-K along with their Passive D's have had K negative babies - they have not been transfused and pre-RhIg injection screens were negative! I too looked at all the cells that were reacting and they are Bg positive.3 more K+Bg- cells are negative.BUT a couple K-Bg+ cells are not reacting!?!?! Malcolm Needs and Yanxia 2 Link to comment Share on other sites More sharing options...
Shelby56 Posted March 8, 2014 Share Posted March 8, 2014 We also had this problem with February's standing order of 0.8% screening cells - SCI reacting 1+ and two cells on Panel A that also happened to be pos for K (Kk) same 1+ reaction. Luckily the Panel B we had available had one cell that was KK and those same patients tested negative with that homozygous cell. I did report to Ortho J&J because was weird the SCI was Bgb neg while the panel cells were both Bgb positive. Really don't want that donor in future lol Link to comment Share on other sites More sharing options...
galvania Posted March 10, 2014 Share Posted March 10, 2014 Bga and Bgb are horrible. There is so much cell to cell variation and so much difference between one anti-Bga and another that the normal 'rule-out' rules just don't apply. Sandy L and Malcolm Needs 2 Link to comment Share on other sites More sharing options...
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