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exlimey

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Posts posted by exlimey

  1. Your comments are spot-on, Malcolm. A "reference range" is typically the expected result from normal individuals. This is fine for something like a platelet count or a creatinine quantitation (or any of the chemistries), but is absolute nonsense for an assay that has only two potential outcomes: Positive or Negative. I suppose "Indeterminant" might be a third option.

    Here's your Reference Range for Antibody Screens: Positive / Negative / Indeterminant

  2. 3 hours ago, Malcolm Needs said:

    We used to, when I first started working in a hospital, but, since the advent of vCJD, after which we could never be certain whether an allo-antibody had been caused by a transfusion or pregnancy (well, in a female anyway!!!!!!!!!), and so we no longer use a unit for transfusion if an allo-antibody is present in the circulation of the donor.

    Is this approach applied to rare units ? For example, a donor who is Kp(b-), with anti-Kpb in their circulation. Granted, such a unit would probably only go to someone who already had anti-Kpb, so technically there would be no impact (analogous to Mabel's anti-D scenario). Just curious.

  3. 22 hours ago, mimi03 said:

    We are seeing this quite often but sometimes it doesn't react with all ten donor cells on the Ortho panel but the reactivity really looks like an ARD.

    It's remotely possible that Ortho use different diluents for different cells. I remember a rumor that "fresh" cells are suspended in one kind of diluent, but frozen-thawed cells are in a similar diluent with a couple of extra chemicals to compensate for the freeze-thaw process. I think that frozen-thawed (deglycerolized) cells are sometimes used in emergencies when the scheduled donor(s) don't appear.

  4. I agree with all the previous comments. You cannot manage a transfusion reaction in a patient who has died from lack of blood.

    One thing to add: In the time before time......emergency release units were always O negs. However, today's practice has evolved in a risk-based manner and it is now accepted that O pos units can fulfil this function. Perhaps ironically, if the old practice had been employed in this case (use O negs), it would have been very unlikely that this patient would get a E+ unit.

  5. Any of the major laboratory suppliers can help with lab design and furniture, for a price, of course. VWR (Avantor) and Thermo-Fisher are probably top of the list. I think that Mabel is referring to "Herman Miller" - a longtime standard for labs and offices. I think they may sell direct or through the distributors.

    Good luck. Designing a new space can be both fun and frustrating. Nothing can ever be perfect, compromises always have to be made.

  6. I think you can just use basic 40% glycerol (in water). Glycerol is available from many sources. Use an equal volume of 40% glycerol to washed, packed red cells. Freeze @ -80 C is small aliquots. I don't remember the details of recovery, but it involves washing with a couple of different Saline concentrations, akin to deglycerolizing red cells for transfusion. The "Valeri Method" - see the article below.
     
    Vox Sang 2000;79(3):168-74.  An experiment with glycerol-frozen red blood cells stored at -80 degrees C for up to 37 years. C R Valeri 1G RagnoL E PivacekG P CassidyR SreyM Hansson-WicherM E Leavy
     
  7. 12 hours ago, Mabel Adams said:

    Maybe... if I move to the city to be nearer my kids.  I was thinking something like this would be good and even helpful.

    Moving seems to be very common after retirement, but It would be tough to leave Bend. Beautiful city and environs.

    I suggest fly fishing, but I'm biased. Lots of opportunities where you live, some of the more famous waters. Lots of mental stimulation, too (although not medical), with a heavy dose of Zen.

  8. 13 hours ago, Mabel Adams said:

    Forty years ago, we occasionally received a mislabeled unit, but I have seen only one since ARC started using more barcodes and related quality practices.  That unit was labeled O neg but retyped as O pos.  We finally had to return the unit to ARC, and they spiked it to test the contents which were O neg.  I think it was early in the Adsol years and we used to get a pedi unit that was CPDA-1 or maybe it had something to do with leukoreduction.  When it was collected, the person making segments was in the habit of cutting off the tubing and discarding it but needed to keep it on the CPDA-1 unit for making segments. He quickly realized his error, fished the discarded tubing out of the waste bin and reattached it to the unit, I think with a clamp.  Of course, he did not grab the tubing from the correct unit.

    Wow. That's bizarre.

    The routine retest of incoming materials detected the "transplanted" segments, only because of an Rh difference. If the transplants just happened to be the same ABO/Rh as the host - fairly good odds for an O+ to another O+, for example, it would be undetectable. I wonder how many times that's happened ? No way to know, I suppose.

  9. 15 hours ago, Baby Banker said:

    I don't know what the titer is for incompatible kidney transplant, but for hearts they prefer less than 1:4, but there are other criteria as well.  If the patient is less than 12 months old, they don't worry as much about the titer.  

    I think they won't consider a patient who is over 2 years old.

    Again though, that is for hearts.

    This is fascinating stuff. A lot of science, learned the very hard way, with a heavy dose of art. I don't envy those having to make these calls.

  10. 28 minutes ago, Neil Blumberg said:

    It's been done.  Depends on the ability to suppress the anti-A titer low enough through immunosuppressive drugs and plasma exchange, the usual preparative regimen.  Obviously ABO identical is best, but this is an alternative at some centers with experience doing these transplants.

    Thanks. Probably an unanswerable question: How low a titer is "low enough" ?

    A follow-up.....can one transplant an A1 kidney into an A2 patient with anti-A1 ?

  11. 1 hour ago, Baby Banker said:

    That's still a significant number of A subgroup kidneys to give B patients.  

    Patients who are type B and need a kidney transplant usually have to wait years, and sometimes die because no type B kidney is available.

    Agreed. No criticism was intended, I was just surprised at that approach.

    So by reading between the lines, the logic is that by transplanting a kidney from a donor with a weaker expression of A antigen (A2), the group B recipient/host is less likely to detect/reject it ? Did I get that correct ? Just curious, can one give a group A1 kidney to a group B patient who has a very low isoagglutinin titer ?

  12. I agree with Malcom - not much value, if any. I, too, have done many such noninformative adsorptions.

    In a recently-transfused patient, there is perhaps a very remote chance that (allo)adsorptions on an eluate would reveal a "only on the cells, not in the serum yet" newly formed antibody. This might be important if the clinicians suspect faster-than-normal red cell loss, but it would be very difficult to differentiate from the typical increased red cell demise seen in patients with warm autoantibodies.

  13. 5 hours ago, applejw said:

    Just last month, we had a unit from our supplier labeled as O+ but retype showed that it was AB+.  I personally don't mind re-typing units so that we can do an electronic crossmatch.

    WOW ! Just, wow. I really wasn't expecting to hear this. I can't imagine the multitude of failures involved in such an event. Of course.....if one was mislabeled (or mistyped), there's probably an equally badly mislabeled partner out there somewhere.

  14. 21 hours ago, MAGNUM said:

    We do not retype any antigen typings that come from the reference laboratory.

    20 hours ago, jshepherd said:

    We do not recheck ag typing. 

    12 hours ago, Ensis01 said:

    then believe their process and the label.

    Apologies in advance to the above for using their comments as examples.

    Just to stir-up a little controversy.......if we trust our Government-regulated/approved blood suppliers to have quality systems, get the correct answer and label accurately, why are in-coming Red Cell Units re-typed for ABO/Rh ?

    And....go......

  15. I believe the primary action of CDP is as a mild acid, thereby eluting bound IgG (reducing DAT) and denaturation of HLA/Bg antigens (removal of "unexpected reactivity").

    Perhaps the prolonged treatment time removed some of the sialic acid on the red cells and has inadvertently created cells that are easier to agglutinate, i.e., the equivalent of enzyme-treatment ?

  16. 12 hours ago, Byfaith said:

    with an optional recheck depending on the techs comfort level - say they screened many units for several antigens and were multitasking as well.

    Lots of users on this Forum are in the same place and I'm sure they have some good advice on how to approach this issue. However, I would be cautious of implementing an optional process that potentially calls into question the quality of previous work.

  17. 8 hours ago, Neil Blumberg said:

    Just the person you want operating on your brain or reading your prostate biopsy, no doubt.  Makes one proud to be a part of the same profession.  Not.  Pettifogging fool.  Perhaps he is nice to his dog and children.

    "Pettifogging".....an 'olde worde" that is so relevant today. Thank you for reminding me. I shall try to work it into as many conversations as possible.

  18. 16 hours ago, RRay said:

    I've had this come up before with incomplete transfusion history (transfusions at another facility) and with IV drug use / sharing needles.  Occam's razor?

    Agreed....history is always a wildcard.

    I had a case once where there a teenaged male individual had antibodies to red cells (I can't remember the specificity) with no apparent transfusion history. Later questioning revealed that the person was part of a "Blood Brothers" group who routinely and ritually exchanged blood through self-inflicted cuts. Each to their own.

  19. I was also thinking of a prior sensitization. A weird, barely detectable D+ phenotype may not generate a new immune response, but may be enough to reactivate the primed lymphocytes in an individual who's anti-D has faded into non-detectability. Tiny re-exposure and wham ! Nice, strong, clear-cut anti-D, apparently out of nowhere.

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