gagpinks Posted February 6, 2017 Share Posted February 6, 2017 Hi Patient has Known Anti-K. Since than patient been transfused with K neg unit. Current sample shows Anti-K with positive DAT. Sample sent reference lab for eluate. Anti-K detected from eluate.If patient given K neg blood why would Anti-K still be detected from eluate? Link to comment Share on other sites More sharing options...
Malcolm Needs ☆ Posted February 6, 2017 Share Posted February 6, 2017 How long since the patient was last transfused with K Positive blood (or was pregnant)? Link to comment Share on other sites More sharing options...
gagpinks Posted February 6, 2017 Author Share Posted February 6, 2017 (edited) Last time patient was transfused was 6 month ago. Reference lab suggested this could be due to Matuhasu-ogata phenomenon. Would please explain this phenomenon. Edited February 6, 2017 by gagpinks Link to comment Share on other sites More sharing options...
Malcolm Needs ☆ Posted February 6, 2017 Share Posted February 6, 2017 13 minutes ago, gagpinks said: Last time patient was transfused was 6 month ago. Reference lab suggested this could be due to Matuhasu-ogata phenomenon. Ah, the old "Matuhasu-Ogata phenomenon", commonly used when an antibody specificity cannot be explained in an eluate (for details, I would draw your attention to page 342 of Klein HG and Anstee DJ. Mollison's Blood Transfusion in Clinical Medicine. 12th edition, 2014. Wiley-Blackwell). Sadly, I find this explanation somewhat unconvincing in almost every occasion it is given. I prefer the explanation that Joyce Poole (a superb red blood cell serologist of international standing) gave me when I consulted her on a very similar case some time ago. We had been following a patient from a hospital on the south-east coast of England, with a positive DAT for well over a year, who also had an anti-K in his plasma. The hospital in question had (and has) an excellent reputation for both blood transfusion and blood group serology. They swore that the patient had been given K Negative red cells (and other blood components) for over two years, and yet, the eluate always contained an anti-K! I consulted Joyce on this and she said that she suspected that what we were detecting was an auto-antibody with a specificity that closely mimicked an anti-K (rather in the same way that such antibodies usually mimic antibody specificities within the Rh Blood Group System, such as anti-e). While I had only ever seen this one case myself, Joyce, working at the IBGRL, said that she had seen a few, albeit that she still considered it a rare case. Personally speaking, and not having seen the serology of your own case, I am still inclined to think that Joyce's explanation for your case is much more likely than the "Matuhasu-Ogata phenomenon" explanation. AMcCord, AuntiS and Yanxia 3 Link to comment Share on other sites More sharing options...
gagpinks Posted February 6, 2017 Author Share Posted February 6, 2017 1 hour ago, Malcolm Needs said: How long since the patient was last transfused with K Positive blood (or was pregnant)? What else could it be ? Link to comment Share on other sites More sharing options...
Malcolm Needs ☆ Posted February 6, 2017 Share Posted February 6, 2017 22 minutes ago, gagpinks said: What else could it be ? Well, I've written about the Matuhasu-Ogata phenomenon (and just because I wrote that I don't believe that this is the correct explanation, does not mean that it is not the correct explanation - I am not above admitting that, like most other people, I can make a right twit of myself!) and the possibility of it being an auto-anti-K-like specificity. I can't think (immediately, anyway) of any other explanation, although other members may so do. Otherwise, your guess is as good as mine!!!!!!!!!! Link to comment Share on other sites More sharing options...
AMcCord Posted February 7, 2017 Share Posted February 7, 2017 Some years ago I had a crossmatch order on an elderly gentleman with a hip fracture. At that time we did an auto control with every antibody screen (crazy, I know) and his was positive, though his antibody screen was negative. I did an eluate - perfect, strong, beautiful anti-K. I asked about his transfusion history. Both he and his family members were excellent historians and were adamant that he had not received blood recently, had never received blood or blood products and in fact, had never even been hospitalized before in his entire life. He was a very healthy 90+ year old man who was on no prescription meds and who did not take any supplements or over the counter meds except a rare aspirin. I sent it to the reference lab, because I was thinking maybe I messed up somewhere. They eluted anti-K but insisted he had to have been transfused or there was some medication causing the problem. I was not convinced by their (weak) explanation and I still think that it was auto-anti-K-like specificity. Only example of this I've seen in I won't say how many years of blood banking. MaryPDX, gagpinks, albaugh and 2 others 5 Link to comment Share on other sites More sharing options...
R1R2 Posted February 7, 2017 Share Posted February 7, 2017 I have seen this so many times. We used the Gamma Elukit. On a related note - while doing an annual competency assessment on an experienced tech, it was noted that she prepared the Elukit last wash with saline!!!! Once corrected and all staff re-educated I noticed that the numbers of unexplained anti Ks in eluate decreased. AMcCord, Malcolm Needs and gagpinks 3 Link to comment Share on other sites More sharing options...
Malcolm Needs ☆ Posted February 7, 2017 Share Posted February 7, 2017 1 hour ago, R1R2 said: On a related note - while doing an annual competency assessment on an experienced tech, it was noted that she prepared the Elukit last wash with saline!!!! Once corrected and all staff re-educated I noticed that the numbers of unexplained anti Ks in eluate decreased. Interesting! Link to comment Share on other sites More sharing options...
AMcCord Posted February 8, 2017 Share Posted February 8, 2017 22 hours ago, R1R2 said: I have seen this so many times. We used the Gamma Elukit. On a related note - while doing an annual competency assessment on an experienced tech, it was noted that she prepared the Elukit last wash with saline!!!! Once corrected and all staff re-educated I noticed that the numbers of unexplained anti Ks in eluate decreased. Actually ... I was using Elukit at that time. However, I SWEAR that I was doing the last wash with the wash solution. That is an interesting observation, however. Malcolm Needs 1 Link to comment Share on other sites More sharing options...
Malcolm Needs ☆ Posted February 8, 2017 Share Posted February 8, 2017 13 minutes ago, AMcCord said: Actually ... I was using Elukit at that time. However, I SWEAR that I was doing the last wash with the wash solution. That is an interesting observation, however. Me too. Never used saline with that kit. Link to comment Share on other sites More sharing options...
Sandy L Posted February 8, 2017 Share Posted February 8, 2017 Thanks to Malcolm for your explanation auto-antibody with a specificity that closely mimicked an anti-K. Over the years I have seen a few patients that continued to elute anti-K for up to a year after the last transfusion. Link to comment Share on other sites More sharing options...
Malcolm Needs ☆ Posted February 9, 2017 Share Posted February 9, 2017 8 hours ago, Sandy L said: Thanks to Malcolm for your explanation auto-antibody with a specificity that closely mimicked an anti-K. Well, thank you, but in all honesty, the explanation really originated from the great Joyce Poole! gagpinks 1 Link to comment Share on other sites More sharing options...
macarton Posted February 9, 2017 Share Posted February 9, 2017 (edited) was the antigen type rechecked on the unit? we've had some antisera that if you didn't let it incubate the full time limit, (example if 5-10 in procedure, and didn't go full 10 min) got negative to wk reactions. Edited February 9, 2017 by macarton Link to comment Share on other sites More sharing options...
gagpinks Posted February 10, 2017 Author Share Posted February 10, 2017 In UK, antigen type is done by our national bloos service, there are 101% right because it's been checked twice. Link to comment Share on other sites More sharing options...
galvania Posted February 14, 2017 Share Posted February 14, 2017 One of the units could have had a weak K antigen (depression due to other antigens present in the KEL system) which was missed (through no fault of anybody) and called K- Link to comment Share on other sites More sharing options...
Malcolm Needs ☆ Posted February 14, 2017 Share Posted February 14, 2017 55 minutes ago, galvania said: One of the units could have had a weak K antigen (depression due to other antigens present in the KEL system) which was missed (through no fault of anybody) and called K- It could, but now it is known which clones of anti-K do and do not react with the two known weak K variants, the anti-K used by NHSBT is designed to detect these weak antigens, and so, unless it was a novel mutation (which would be REALLY unlucky for the patient), such units should not be marked as K Negative. gagpinks 1 Link to comment Share on other sites More sharing options...
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