Jump to content

Arno

Members
  • Posts

    81
  • Joined

  • Last visited

  • Days Won

    19
  • Country

    Switzerland

Everything posted by Arno

  1. Here are some thoughts 1. Prophylatic anti-D given after pregnacy loss despite her D pos type and not communicated further (but sounds like the event is too old to support this option right?) 2. Can be an anti-LW instead which looks like auto anti-D (reacting stronger with D pos cells) 3. Other blood derived product given (e.g. IVIG) containing anti-D but the reaction strentgh does not support this hypothesis 4. D variants alloimmunized during first pregnancy with D pos fetus
  2. This thread is pretty old but as it comes up again.... this "air gap" is required to avoid having the Anti-Human Globulin (AHG) present in the gel matrix getting partly "neutralized" by the excess of human immunoglobulin from the plasma. Keep in mind that plasma is full of various human Immunogloblins which will be recognized by the rabbit AHG. This "partial" neutralization may weaken the reaction indeed. Same as in tube but there is no washing step requires as the air gap is there to prevent this neutralization. Once cells are sensitized after the 37°C incubation step, the card is spun and the AHG will catch the Ig bound to the RBCs leading to positive reaction.
  3. Is the buffer used for preparing the RBC suspension for X-Match the same as for the AC? If not, this patient may have an additional Ab to a buffer component?
  4. Not that I am aware of. There are publications reporting an increase of DAT positive samples amongst Covid-19 patients. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7414594/ According to the authors, the eluate (IgG) reacts only with cells from Covid patients and this state is likely to be transient (related to hyperinflammation in these patients).
  5. I don't want to advertise any specific company but in this webinar available O-D (https://info.bio-rad.com/ww-IHD-transfusion-w6-registration-lp.html), various methods are discussed (pros/cons) on how to overcome the anti-CD38 interference. I thought it could be insteresting in the context of this thread.
  6. Sorry to hear this Malcolm. My most sincere condolences.
  7. Guidelines in Australia are pretty similar to the UK guidelines as far as I can see. https://anzsbt.org.au/wp-content/uploads/2018/06/GuidelinesforTransfusionandImmunohaematologyLaboratoryPractice_1ed_Nov20_.pdf They require as well a second ABO typing.
  8. Hi! I do not know which gel card supplier you are using, but the one I “know” use 50ul of A1 and B cells with 25ul of plasma and an incubation at 37°C for 15 minutes. And all of this in an AHG gel card of course… having previously checked as well there is no additional antibody that could interfere (result from mother if available/antibody screening result). Hope it helps.
  9. I just answered this question. My Score PASS  
  10. I hereby forward you the link to the registration page => https://info.bio-rad.com/ww-IHD-transfusion-w-registration-lp2.html?WT.mc_id=201015029401 You'll see that if cannot make it for the live session (due to time difference), the recording will be made available about 1 hour after the live session using the same link that will be sent to you by email and you will have the opportunity to watch it at any time (and an unlimited number of times...).
  11. In this context (post transfusion with DAT pos, screening neg), would be worth running/trying an elution?
  12. Should be HbS negative as decreasing the proportion of HbS (compared to HbA) prevents complications/crisis of SCD related to vaso-occlusion. So not only for crisis but to prevent the crisis. https://onlinelibrary.wiley.com/doi/full/10.1111/bjh.14346
  13. Thank you for your feedback - much appreciated. This confirms my understanding and what I have read so far on this topic. Thanks again.
  14. Hi there! I hope you are all doing well. The Italian blood transfusion society has made the screening of Covid-19 patient for IgA deficiency systematic before the transfusion of convalescent plasma. http://isbtweb.org/fileadmin/user_upload/Italy.pdf Would like to know what is your position in this regards and is there any similar existing guidelines? Thank you in advance
  15. Yes indeed different pH, different suppliers may explain such a behavior (some anti-M are enhanced with acidification of plasma). In addition, Anti-M often shows dosage effect but I believe you have antigen M double dose cells on your panel too. What are the phenotype of the 2 cells reacting in screening and the one not reacting? Is your patient antigen M negative? It also exists the anti-M1 (the M1 antigen belongs to the MN CHO collection) that reacts with some M positive cells and stronger with M/N positive cells (M1 is expressed on M positive cells) and it can be, though rarely, produced by antigen M positive patients.
  16. First of all, if the cassette Ctl is positive, the blood type result is invalid (esp. the D antigen typing) . Looks like a (warm) AIHA and several rounds of adsorption (allo with enzyme treated cells or auto, depends on date of previous transfusion, how much RBCs are available and possibility to "clean them up" using ZZAP for instance) may bring some clarity here to check if there is an underlying antibody.
  17. In addition to what has been nicely explained by Malcolm, it could be as well an example of Sd(a++) cell (commonly named "super Sid") reacting with a weak anti-Sda. The Sda antigen is not a LFA (expressed on more than 90% of cells) though some cells "overexpresse" it. Anti-Sda usually gives weak/DP reactions and can be neutralized using urine (contains soluble Sda substances). Other weak antibodies may behave the same way, e.g. anti-P1 reacting against "strong P1" cells only. However, that does not change at all what Malcolm said "I wouldn't expend too much time or energy trying to sort out the exact specificity. In all cases of such an antibody, as long as you cross-match by the same method as you used in detecting the presence of the antibody in the first place, it would be quite safe to give cross-match compatible blood."
×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.