armymt2002 Posted April 6, 2006 Share Posted April 6, 2006 We have a 9 day baby who had a negative DAT cord blood. He had a high bilirubin and so the call went up for an exchange transfusion. Another DAT sample (pink tube) was drawn for a DAT and it was positive (weak to 1+). The 2nd DAT was drawn a day after the baby was born. We repeated the first DAT and it was negative. The baby's bili went down later that day so there was not a need for the exchange transfusion. The mother was Opos and the baby Bpos. The baby's H&H are dropping and the docs don't know why. They are also questioning why the DAT can be negative then positive and then negative. I and my technical supervisor tried to explain that is was an ABO incompability. We no longer do Lui Freeze. I tried to do a search on the web for any journal articles about this but got so many hits that I can't tell which are the releative ones and which are not. If anyone can point me to a article so I can give it to the docs that would be awesome. How many do Lui Freeze? I have never done one before here. Thanks.l Link to comment Share on other sites More sharing options...
javvcr Posted June 26, 2006 Share Posted June 26, 2006 If u want to be sure about the presence of an anti-B, performe a coombs or AHG reaction with B cells incubated at 37º, if the reaction is positive the baby has an anti-B. Lui Freeze, is an option, u can find in the web, many technics for elution of antibodys, all can help u, in diferent ways but someone will help.it´s traditional in ABO incompatibility having this kind of discrepancies, not only because the nature of the antigen also ´cos the antibody some are developed with diferent or alterated afinity or potency so sometimes appear and other disapear depending of the conditions in the lab. Link to comment Share on other sites More sharing options...
SandyR Posted June 27, 2006 Share Posted June 27, 2006 We still have the Lui freeze procedure in our manual but haven't done one in probably 2 years. Our pediatricians don't particularly care for proof when they know there is an ABO discrepancy so they just treat the baby and don't order any follow-up to positive DATs. We talked about eliminating this test but it's pretty easy to do so we decided to keep it around since physicians seem to change their practices when any new journal article comes out recommending something. I'm surprised the cord blood wasn't positive but medicine is not an exact science so we'll always have those peculiar results around. Unfortunately I can't think of any articles that I've seen that touch on this. Hopefully someone else has.Sandy Link to comment Share on other sites More sharing options...
donellda Posted June 27, 2006 Share Posted June 27, 2006 We did the LUI eluate at my old hospital. It is a very easy procedure. We don't do heat or LUI eluates at my current facility. We do a homologous antibody screen with A1 and B cells on the cord blood serum. It seems to work just as well as an eluate and is a lot quicker. Link to comment Share on other sites More sharing options...
Sandy Rechtine Poling Posted February 4, 2008 Share Posted February 4, 2008 I'm an "old" blood banker. The cord blood was probably "negative" because of prozone. The 1+ later some of the antibody site were avalable to react with the AHG. I agree with donellda - LUI eluate is a very easy procedure and one of the best for ABO incompatility. With the baby's H & H dropping is a sign that there is an incompatiblity. Is the mother breast feeding? ABO antibodies are in the mother's breast milk and can still be adsorbed by the baby. I hope the incompatiblity is self limiting and the baby does well. If the antibody is identified, let us know about the out come. Link to comment Share on other sites More sharing options...
galvania Posted February 4, 2008 Share Posted February 4, 2008 The high bilirubin might have nothing at all to do with blood group antibodies of course......Even a 1+ DAT doesn't really sound high enough to warrant a morbidity state sufficient to need an exchange transfusion. Are you sure of your Coombs technique? Link to comment Share on other sites More sharing options...
Yanxia Posted February 5, 2008 Share Posted February 5, 2008 If the red cells have stronger B antigens be destroyed in the cord cells then we get the neg DAT result, the 2nd sample is one day later there were new cells be produced so DAT is weak pos.This is just a hypothesis.In China a majority of ABO HDN have weak or neg DAT, we du heat elution, DAT and plasma antibodies test to detect it, the most important is elution. Link to comment Share on other sites More sharing options...
galvania Posted February 6, 2008 Share Posted February 6, 2008 This is for Shily - do you ever have a situation where the DAT is weak but the baby needs an exchange transfusion; and the ONLY reason for the baby's anaemia/high bilirubin is ABO HDN? Link to comment Share on other sites More sharing options...
Yanxia Posted February 6, 2008 Share Posted February 6, 2008 This is for Shily - do you ever have a situation where the DAT is weak but the baby needs an exchange transfusion; and the ONLY reason for the baby's anaemia/high bilirubin is ABO HDN?Almost all the ABO HDN I know its DAT is not stronger than 1+. If this is differ to you have found, maybe because the anti-globulin we used is different or the method. We just wash the cells three times then suspended in saline to 3%-5% concentrate, and one point cells to two points reagent, immediatly centrifuge, then monitor macroscopically. Tomorrow is China's lunar new year, happy new year! Link to comment Share on other sites More sharing options...
galvania Posted February 6, 2008 Share Posted February 6, 2008 Dear ShilyHappy New Year to you also. I think I did not explain my question clearly. What I was curious to know is this - How many babies with ABO HDN need an exchange transfusion in China? thank you Link to comment Share on other sites More sharing options...
Yanxia Posted February 7, 2008 Share Posted February 7, 2008 In our hospital , there will be 3600 babies be born every year, and in those babies just one or two need exchange transfusion.In the 3600 babies the O mother with not O baby is more than 30%.When I study in blood center, they will encounter ABO HDN very often,the teatcher said there will not strong DAT in ABO HDN, because the baby's antigen is weak and the soluble blood type antigen in lots of person's plasma. Link to comment Share on other sites More sharing options...
galvania Posted February 7, 2008 Share Posted February 7, 2008 thank you Shily. Link to comment Share on other sites More sharing options...
Yanxia Posted February 7, 2008 Share Posted February 7, 2008 It is my pleasure. Link to comment Share on other sites More sharing options...
Mabel Adams Posted February 8, 2008 Share Posted February 8, 2008 Happy New Year Yanxia! Link to comment Share on other sites More sharing options...
Mabel Adams Posted February 8, 2008 Share Posted February 8, 2008 Can someone explain how prozone would interfere with a direct coombs? It seems like the Fc portion of the antibody attached to the cells would still be available for the anti-IgG to attach to even if all the antigen sites on the red cell were full due to the high titer of the antibody.Also, I have read and done some small studies myself that most non-O babies of O moms have mom's ABO antibodies in their plasma/serum and on their red cells even if they have no symptoms of HDN and have a negative DAT. John Judd said that looking for the ABO antibody in cord blood was really only diagnostic if the expected one was missing. Then you needed to look elsewhere for the cause. If you find ABO antibodies in the cord blood, you don't know for sure whether it is the cause or an innocent bystander. Link to comment Share on other sites More sharing options...
galvania Posted February 8, 2008 Share Posted February 8, 2008 Mabel - I am sure you are right about prozone not being an issue. And I agree that you will often find a positive DAT and IgG ABO antibodies in newborns - obviously the more sensitive the technique you use the more likely you are to find them. I have only ever seen 2 cases in my life of ABO HDN where the baby was severely affected enough to require transfusion. Both mothers were from the Middle East (can't remember where exactly - too long ago) and both were group O. In both cases the DAT on the baby was strongly positive. I see that we have a contributor from Saudi Arabia on the forum - I would be interested to hear his input on this, as ABO HDN is known to be more frequent in Arab women. Link to comment Share on other sites More sharing options...
Yanxia Posted February 8, 2008 Share Posted February 8, 2008 Thanks Mabel!Galvania, you have seen 2 cases of ABO HDN ,the DAT of the baby was strongly positive.That is so strange to me to hear that. Did you do the enhanced DAT test? Link to comment Share on other sites More sharing options...
Mary Posted February 8, 2008 Share Posted February 8, 2008 Happy Chinese New Year! Link to comment Share on other sites More sharing options...
galvania Posted February 8, 2008 Share Posted February 8, 2008 Shily, what do you mean by an 'enhanced' DAT test? These were both cases I saw in London about 20 years ago! 2 cases in about 35 years is not very many!! Link to comment Share on other sites More sharing options...
Yanxia Posted February 14, 2008 Share Posted February 14, 2008 The enhanced DAT test will examine the result microscopically.In Chinese people there is not ABO HDN its DAT stronger than 2+ macroscopically, so see your post I feel surprising. Link to comment Share on other sites More sharing options...
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