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StevenB

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StevenB last won the day on April 29

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About StevenB

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  1. Lol...I like the way you think, Malcom, but I don't have control over those decisions. Being a reference lab though, we push our efforts when testing referred samples. Micro reads are part of our routine if the patient has been transfused or pregnant within the last 3 months. Testing in PEG however is optional and PEG is notorious for revealing micro reactivity which often can not be identified. Having said that, I have on many occasions identified micro only, clinically significant antibodies in PEG. Would I recommend a hospital blood bank read micro? No, I wouldn't.
  2. Thanks yan....the macro negative reaction in PEG at IAT was with the unadsorbed plasma and was tested with Immucor’s murine monoclonal Gamma Clone IgG. As Mabel pointed out, this reagent does not detect IgG4 and the anti-CD47 is....evidently.... an IgG4 antibody. In my hands, it was microscopic reactive so I believe in the future we will drop that read when faced with these patients.
  3. Mabel was kind enough to share this sample with our lab as we had not had the pleasure of seeing one of these. The sample was limited and it technically was not a referral, so my work was centered on getting to know anti-CD47. The patient forward typed as an A with no issues (I've heard the forward type can at times be affected), but reverse typed as an O, with 2+ reactivity in the A1 and A2 reverse cells. The patient typed Rh positive; no reactivity noted in the Rh control. The DAT was micro positive with poly specific AHG, heavy-chain IgG (HC) and C3, but was not interpret-able due to a micro positive saline control. Warm washing x4 with 37C saline resolved the positive saline control and still demonstrated micro reactions in the previously mentioned AHG sources. Interestingly, the reactivity was actually slightly stronger than the initial testing. Initial antibody testing was 2+ reactive in saline at initial spin, 3+ in saline at 37C spin (post 30 minute incubation) and 3-4+ reactive in saline at IAT with HC IgG, 3-4+ reactive in PEG at IAT (4+ reactions with the Rh negative cells tested as compared to 3+ reactivity with Rh positive cells; consistent with reports in literature), and 4+ reactive with papain treated cells (carryover reactivity was noted as a "no spin read" was 3+ and agglutination was noted prior to the addition of HC AHG). Testing with Immucor's murine monoclonal IgG Gamma Clone in PEG at IAT was macro negative, micro positive. Alloadsorption x2 (using 2 volumes of cells to one volume of plasma) onto papain-treated R1R1 and rr cells of known phenotypes (we usually do R1, R2 and r cells, but with the limited sample I dropped the R2 adsorption) removed the initial spin reactivity and confirmed the patient was group A. Alloadsorptions x3 were 1+ reactive in saline at 37C, and 3+ reactive at IAT using the HC IgG. x4 adsorptions yielded the same results. Out of curiosity, I did run a D-- cell with the x4 and it was nonreactive at 37C, but 2+ reactive at IAT. For fun, I performed titration studies on both the R1 and rr x4 adsorptions (saline, 60 minutes 37C incubation). Macro reactivity at 37C was noted at 1:32 in both samples, but technically they had a titer of 4 (1st observed 1+ reaction). At IAT, both samples had a titer of 16,384.... AFTER 4 adsorptions! A recent report in IMMUNOHEMATOLOGY stated that using equal volume (cells:plasma) adsorptions onto papain-treated cells x3 and x4 resulted in "the majority" of the samples being nonreactive in saline at initial spin and in PEG at IAT. Lastly, I did perform EGA treatment of the patient's red cells to see its affect on the positive DAT. The micro reactivity was removed following a 1min. 30sec treatment of the patient's cells, but since the sample was way beyond the manufacturer's specimen recommendation, I'm not totally confident in the observed results. Net result: It looks like alloadsorptions will be needed to resolve any observed ABO discrepancies due to reverse cell issues and PEG testing with Immucor's murine monoclonal Gamma Clone, with a macro only read, would resolve any the issue of detecting underlying alloantibodies. Thanks much Mabel for sharing this sample with us!
  4. Antibody reacts consistently with all cells tested, including a phenotypically "matched" cell, but is nonreactive with the patient's autocontrol is indicative of an antibody to a high frequency antigen. Is initial testing in Gel, solid phase, LISS, PEG? The reason I ask is that in my experience, HTLA antibodies tend to show variable reactivity in tube, but can react more uniform in Gel testing (just guessing the same would be true for solid phase). Chido/Rodgers are possibilities; U is not as the patient is s+. Ena is a possibility as are Ge:2 and Ge:4.
  5. For me, it's completely dependent upon the results I obtained in my serum/plasma testing and the amount of eluate I have to test.
  6. We use cold and cold, not that it would have mattered in this case. It would have been interesting to see what a Lui Freeze eluate would have yielded. What did your ARC come-up with if you don't mind my asking?
  7. It is a bit annoying that the manufacturers do not have grades below 1+ as we see these all too often. However, we never interpret these reactions as 1+ as that would not be consistent with the manufacturer's parameters. When faced with this reactivity, we will record +w or w+ and define these reactions as being less than 1+ on the worksheet. For titers in Gel, I would think this would be an important distinction as the end point for a titer is the last 1+ result, not the last result that demonstrates reactivity. That could easily be a 2 to 3 tube difference and may present the physician with information that is not totally accurate.
  8. Just curious...what type of eluate did you perform and if Acid, did you use cold saline and wash solution when prepping the patient's cells?
  9. Interesting topic. In just a few posts, it is easy to see there is a variety of ways labs approach the "how often are elutions performed" question and under what circumstances. I too agree with Malcolm; in the presence of AIHA and a positive DAT, most likely you will get off a panagglutinin every time you perform an elution. Once this occurs, there is no point in performing additional elutions on a routine basis. In the patient though who has a positive DAT and is transfused on a regular basis, and has a negative eluate (yes, this does occur) the elution question is a bit different. Technically, any transfusion can result in the production of an alloantibody that may or may not present itself in a hemolytic fashion. It is possible to have a "delayed serologic transfusion reaction" that shows no signs or symptoms of a hemolytic process. In this scenario, the idea of not doing an elution on a regular basis because it has never revealed anything in the past, may result in missing a newly formed, clinically significant antibody that is only detectable in the eluate. Not performing an eluate in this scenario is not without risk and should not ever become "policy" without proper overview of the clinical situation.
  10. Not that I'm aware of, Scott. The words "only" and "all" would tend to make me say No.
  11. Ideally it is great to rule-out with at least one homozygous expression, but it is not always practical. The anti-K scenario is a prime example as discussed, but for those of you who insist on a homozygous cross-out: Do you really delay an identification of an anti-D and a potential transfusion, just to rule-out anti-E and anti-C? Most hospitals do not have access to r'r' or r"r" cells, so would you insist that the sample be sent to a reference laboratory for resolution? Ruling-out with heterozygous examples is an acceptable practice when the situation warrants it. Obviously, one should look at the "big picture" and if you are seeing reactivity consistently with only a homozygous expression of a certain antigen, then you wouldn't want to ignore that and rule-out on only a heterozygous expression (or 3 for that matter). My advice though: When doing a heterozygous cross-out make sure you are using a technique that is considered an enhancement for the antibody in question and if in doubt, either call your local reference laboratory for advice or ship it to them for resolution.
  12. StevenB

    AntiD

    A titre of 512 is not due to a standard dose of RhiG, no matter how recent....straight from the vial perhaps, but not from the vein. I agree with Malcolm; this seems more like a secondary response.
  13. Our first experience with Darzalex was with a patient who was receiving an "experimental drug" for MM. The tech ran ton of cells, 4 of which were cord cells. All 4 cord cells reacted similarly to the other cells tested. I've read somewhere where it is thought that anti-CD38 didn't react with cord cells, but we don't support that position. In regards to the .2M DTT treatment of cord cells not having an impact on Kell Sys. antigens, I've never come across any literature that would support that position.
  14. StevenB

    AntiD level

    In regards to frequency, if the titer is less than 16 we recommend performing titers every 4 weeks after 18-20 weeks gestation, then every 2 weeks at the 34th week. As usual, Malcolm is spot on!
  15. Fight to keep your 10 days at a minimum! There is no scientific basis to move the expiration to the 3 day standard for the untransfused, non-pregnant patient. Personally, even 10-14 days is too short!
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