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galvania

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galvania last won the day on January 7

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About galvania

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  • Birthday 05/09/1955

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    Jazz, birdwatching, gym
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    Castelletto di Vernasca, Italy
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    ex teacher/BMS in transfusion science. Now retired

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  1. If you are seeing a lot of weak results in your anti-D well that subsequently turn out to be negative, I suspect the reason to be one of manipulation rather than anything serological. I would guess that NONE of these babies are group O. I am guessing that you are seeing carryover from your anti-AB. It can happen that if cards are stored somewhere where condensation can take place then drops of antiserum can condense into the reaction chamber and 'jump' into the next well or even next 2 wells when you remove the aluminium. This can cause false positive results. I suggest you check the cards before pipetting in them and see if there are any signs of these drops. Don't use the cards if there are and look for another place to store them
  2. what is the baby's DAT? Is it anaemic? Jaundiced?
  3. Beware of using reagent antisera to do your QC. The buffers in the reagents can interact with the buffers in the cells and, if using anything other than tube, the buffers in the support medium. You may get false positive results
  4. IF it looks like a real reaction and it's only one cell then it may well be an antibody against an LFA. If you send a good sample from the patient together with the cell concerned to your reference centre, they may be able to identify it for you - although that's on an interest-only basis
  5. Oh I quite agree Malcolm - just that those two possibilities need to be taken into account with this type of reaction
  6. or it might have been anti-buffer or cold 'rubbish'......
  7. Cliff - I cant see where to edit my e-mail address. It is now <removed by admin>. And no - I have no problem that anyone in the forum can see this
  8. Sorry, have only just seen this. Now that I am retired >I no longer check my e-mails every day. (yes, that does say day, not hour. I know the youngsters will find that totally unbelievable). Anyway, if you suspect the presence of rouleaux it can be very difficult to differentiate between rouleaux and agglutination in gel although rouleaux does tend to have a pink haze about it. Even more difficult if BOTH are present…. I would not try to elucidate this in gel. I would do this in a tube and look at the result down a microscope (one of the few times where I think use of a microscope is justified) and then you can visually see the difference. As for the other part of the question - normal saline can interfere with the buffers used in the gel itself - regardless of the technique used (IAT, direct agglutination etc). This can lead to unagglutinated cells 'hanging' in the gel and this gives a rosy appearance which can be quite strong. It does not always happen but when it does can be mistaken for a positive result. A negative result can be interpreted as a true negative - saline will not weaken a result in a direct agglutination test. As an aside to Cliff, I didn't get an email notification but that could be because I have not updated my e-mail address!!!!! Will do so as soon as posible. Have changed countries too. Am now in Italy
  9. There is absolutely no problem testing for Ch/Rg in gel. And although it should not be ok to use 50ul plasma instead of 25, actually it does SOMETIMES enhance very weak antibodies. There have been times when I have done this successfully. You will not however find it in the official instructions for antibody screening/identification and this should never be done as a routine technique
  10. Well you carry on doing just that then klsmith, seeing as you had ONE example where it came up with something that would have otherwise been missed, and you clearly think that that justifies it. Actually why not put up enzyme IATs routinely as well. But please do not complain when you have to put up panels on 90% of your samples and get inconclusive results on all of them
  11. This issue has been going on for years. The complement coated cells are produced artificially. The method used is designed to be used to show positive reactivity with anti-C3 in a tube technique. It is not designed to show absence of reactivity in anti-IgG, neither in a tube, or even less in gel. Indeed the method used will ALWAYS show an unwanted positive reaction in anti-IgG if you use gel. CAP are aware of this - enough people have complained about this over the years. Why they don't do something about this is a mystery to me
  12. Except that we are talking about patients here that have anti-B in their own plasma already. We are not talking about patients who have no detectable anti-B in their plasma. So we are talking about a patient who groups as an A in the forward group and has a ++ reaction in B cells, due to anti-B. So if he receives group A plasma, yes, he will receive some anti-B - which will be diluted out by his own plasma which already contains anti-B……….. Realistically, I think it is a question of comparing risks, benefits and the amount of work. In this case, what are the chances that this is an ABwk patient? - Very low What is the risk, if this patient is an ABwk, of transfusing this patient with group A blood? None. On the contrary it is better than transfusing with group AB What is the risk, if this patient is an ABwk, of transfusing this patient with group A plasma? very little as the patient already has a considerable amount of his own anti-B in his plasma What is the risk, if this donor is an ABwk, of transfusing to a group A patient? Very little as the amount of B antigen present is so small How much work do you need to do to be 100% sure that this type of reaction belongs to a patient who is really a group A and not ABwk? As an absolute minimum genotyping, possibly complete sequencing. Long delays and $$$$$$$$$$$$$$$.
  13. And never EVER , under ANY circumstances look at gel tests under a microscope or a magnifying glass - unless you want to call absolutely everything positive and waste everybody's time
  14. and you would - I hope - transfuse with group A, so if you wrongly called it a group A, rather than an AB, it would actually be better for the patient. I know of at least one case where an ABel was transfused with group AB blood and died as a result of a transfusion reaction. And if this is a donor, the amount of B antigen present MIGHT cause a minor reaction if transfused to a group A patient but would not do any serious harm. An what percentage of those weak reactions with B cells will actually be caused by this phenotype anyway? Probably less than patients having antibodies against LFAs that are not picked up in the antibody screen and who have a minor reaction due to the incredible bad luck of receiving a unit of blood that just happens to have the antigen
  15. I would just like to add another comment to this discussion. CAT is NOT the best method for looking for weak ABO antigens or antibodies.
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