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galvania

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Everything posted by galvania

  1. galvania
    For tube testing using the "uniform procedure tube method" that CAP suggests, they reported the following results: 333 participants, mode 64, consensus range 16 to 256. For Gel testing "uniform procedure gel method", 138 participants, mode 256, consensus range 64 to 1024. Sorry but that range of results is just HUGE regardless of method. FIVE dilutions difference. Something tells me there is no standardisation in either method. Things like dilution medium can make a big difference as can the choice of cell phenotype used to carry out the titre. I hope individual labs are not getting that level of range when they repeat a titre! I also have never heard of CRP affecting results in gel; and I fail to see by what mechanism it could. I have, on the other hand, heard that transfusion during a period when the patient has a high CRP can be more likely to induce de novo antibody formation
  2. galvania
    Does the AABB state a reason, Treemoss?
  3. galvania
    I think you will all find that the manufacturers do indeed have something to say on the topic. Most IFUs (box inserts /package inserts) will have a disclaimer about products not being used in the way they were intended. So diluting cells from 5% to 1% would definitely come under 'off-label' use unless the manufacturer specifically says you can do this and specifies what you should use as a diluent
  4. galvania
    IFU means package insert. So, in your case, both methods are stated, provided they mean by '("if the test result is negative or doubtful and a test for weak D is required") that you then go on to perform an IAT using THIS reagent. If that is the case, and you actually DO that test, then you need to control both methods anna
  5. galvania
    First of all, what do you mean by M+? Do you mean it was microscopically (only) positive? If so, then really really weak. In the first test you washed 8 times. In the second, four times. My guess is that your final cell suspension in test 1 was weak to the point of almost non-existent, whereas in test 2 you would have had a decent quantity of cells. So the difference between very very weak and negative is possibly just down to that. Plus, tube technique is much more difficult to standardise anyway than gel. Plus it won't be clinically significant - why waste all that time and effort? anna
  6. galvania
    I would very much advise you to do a QC. Depending on how you dilute them and what you dilute them with, you may not get the results you expect! (Less relevant for tube testing though)
  7. galvania
    What is the IFU method for the anti-D you are controlling? If it says you should use it in IAT then you need to control the IAT. If it is for immediate spin, or 5 mins at RT then that is how you have to control it.....
  8. galvania
    I quite fancy an expedition to Loch Ness - with or without the monster......
  9. galvania
    Sorry - just seen this is UK. Do you have access to DC screening cards with anti-IgG, -IGM, and IgA?? (Sorry colleagues from the US - this will mean nothing to you)
  10. galvania
    Yes - however, I would have expected an increase in the reaction with the R2R2 cell in the enzyme-IAT and it did not move. Or did it go from a weak 1+ to a strong 1+. Even so - for a 1+ in IAT, I would expect a +++ in an enz-IAT for a 'normal' anti-D. Which country is this in?
  11. galvania
    Interesting. So, a qualified lab scientist can take on complicated nursing activities too......? OK - so who shall I practice on? any volunteers????????
  12. galvania
    I think doing enz-IAT is missing the point here. Usually one would expect an anti-D to react more strongly or at least AS strongly with papain-treated cells (2-step) than with non-treated cells in an IAT. Of course there are the odd exceptions and this is clearly one of them. So, provided your weak anti-D control is working correctly with the papainised cells, then it has to be patient-related rather than instrument/reagent related. I know it's a bit weird but I wonder if this anti-D is a mix of IgA and IgG and that sometimes the IgG component is not visible, and that the IgA part only reacts by IAT but not in papain. Having said that , I don't KNOW that an IgA antibody would not react in pap. I'm just surmising. Malcolm, do you know whether IgA antibodies would react in pap?
  13. galvania
    Sorry Malcolm. Mea Culpa. Can I plead old age and being very tired?
  14. galvania
    I don't suppose there is any possibility of seeing the images in the gel cards is there?
  15. galvania
    So how strong is the reaction in Coombs?
  16. galvania
    Are you using a one-step or a two-step enzyme technique?
  17. galvania
    What exactly do YOU mean by traceability in this context, Dahboud?
  18. galvania
    It depends what type of population you are testing. If you are testing patients, then ideally you need to have those antigens where antibodies may only react against homozygotes present in a double dose. It is almost impossible to do that with just two cells - regardless of whether you are testing in gel or in tube. So, three cells for patients. Two cells is fine for donors where very weak antibodies are less important
  19. galvania
    It is also important to check whether this patient has EVER been pregnant or had a transfusion.
  20. galvania
    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-
  21. galvania
    What needs to happen now is a thorough investigation of WHY this issue happened - not to apportion blame, but to ensure that it can never happen again due to an error in the lab
  22. galvania
    It depends what you have available. Here there are 'Coombs' cards (either poly or just IgG) for doing the DAT; most of the time a positive result would then be tested on a card that differentiates between IgG and complement or IgG, IgA, IgM and complement. Both of these two cards have a control on them which is the equivalent to your 'saline control'. I too have seen some lovely cold agglutinin disease samples that are positive across the board, saline control included
  23. galvania
    I would also go for the Variant D idea. On the Echo, you had once a neg and once a ? result. Well, the ? could be due to something other than a true reaction; or it might be that the particular D variant is detected by that clone but that the number of antigen binding sites is at the absolute limit of detection so that tiny differences in pipetting (say, in the length of time the cells were in contact with the antiserum, the exact cell suspension) could explain a difference between neg and ?. If the tube testing is done with a different clone, no problem at all in explaining that difference. She should of course be treated as Dneg until the molecular biology sorts it out. (Maybe she was B+ as a donor???
  24. galvania
    I like the sound of a weak B sub type. I have seen several such beasts and they can give very variable results. The best way to sort it out is of course some molecular biology; and if the patient is a secretor, you could do secretor status...... But never ever transfuse with group AB or B. That reaction with the B cells might just be a real anti-B. I know of one death that was caused through transfusing B in such conditions. Sorry. Can't give any details, but was not in Europe or the States....
  25. galvania
    You are quite right to be proud. Thanks for sharing it with us.
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