exlimey
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Posts posted by exlimey
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My sympathies, Darren. That's a horrible situation.
It's generally accepted that the best way to minimize HUMAN error is automation (with the proviso that the systems are well designed). If a LIS allows post-dated entries, it would seem logical that "scanning" would be the best option to back-fill the missing data. And, probably a lot quicker.
If one is forced to perform manual data entry, the process should probably include a second check (verification), preferably by a second individual.
Either way, not fun for anyone. Good luck.
- donellda, John C. Staley and Ensis01
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Some caution may be appropriate. Most "colds" are indeed clinically insignificant and mere laboratory annoyances. Most of these are autoantibodies that can be avoided by pre-warming methods. However, some can be clinically important - there are examples of anti-Vel that behave exact as LaurieD describes, but are IgM, cold-reactive alloantibodies that can cause serious in vivo hemolysis. I think one case reported by Jill Storry was actually fatal. Another nasty beastie in this category is anti-P+P1+Pk (anti-Tja, in the old vernacular).
I would suggest that a Reference Laboratory take a look at the sample (the Blood Bank of Hawaii is close
), just to give some assurance that the troublemaker is "just a cold auto". Pre-warming without an antibody ID may be dangerous. Just my two cents.
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To paraphrase Malcolm: A proven responder may have "other stuff", too. A serological crossmatch is probably the best, and sometimes, the only way to detect it.
- AuntiS, Malcolm Needs, AMcCord and 4 others
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12 hours ago, diplomatic_scarf said:
I was just looking for printed materials for this air gap method, if any exist, so I can have something official for my reference. Thank you 🙏
From reading the previous comments, both old and new, it appears that the manufacturer (Ortho) does not specifically require the bubble and therefore nothing is in writing (the Directions for Use). You may be out of luck trying to find something to reference.
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I find it interesting that various users have been told/advised to use a pipette in a manner that may compromise the accuracy of the volume delivered. I'm sure the pipette instructions indicate to use vertically.
Thankfully, the serological assays that are used by the Transfusion Medicine field have a wide range of tolerance. The "1-drop to 1-drop" concept is horrifying to many other pathology disciplines.
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13 hours ago, Ensis01 said:
If two of three screening cells positive at 2+ but panels are negative I would recheck everything
Agreed. The initial results using the Screening Cells still need to be resolved. "Non-specific" probably won't be acceptable.
Please clarify - "Screening cell is positive with 2 lines(2+)". Does this mean that one, or two of the Screening Cells are reactive?
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On 3/18/2022 at 11:21 AM, John C. Staley said:
In all my years (30+) in blood banks and transfusion services I never QC'd panels and it was never addressed in any inspections/assessments. When ever the subject came up I figured that if you were not QCing every antigen on every cell you were doing little more than providing some random inspector with smoke and mirrors so they would think you are doing something worth while. A some point you need to trust the manufactures to do their job.
Agreed. Anything less than a full phenotype is useless. We don't even do that for Screening Cells, which are arguably a lot more important.
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18 hours ago, Sonya Martinez said:
I did check our IFU and they did specifically state to use glass tubes. No more arguments.
Excellent. It's not often that the IFU comes to our rescue.
- jayinsat, John C. Staley, AuntiS and 2 others
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This issue - the switch to plastic - seems to bubble up every few years (pardon the minor pun). When I was a puppy in my early years, last century, labs were already tossing around the idea to avoid potentially dangerous, sharp glass tubes. When broken, the plastic used for test tubes is also sharp, possibly worse that glass, as Malcolm suggests.
As others have mentioned, static is always an issue with the plastic version, rather than occasional with glass. Other than that, and in my experience, plastic test tubes tubes work almost as well as glass for serological testing. However, many "tube reagents" are not formulated for, or qualified in plastic. The Directions for Use/ Package Inserts may be restrictive.
Two points - personal opinion of a cranky old man:
1. One event does not indicate a trend - changing the whole system to address a single cut-finger incident is unreasonable.
2. The various safety apparatuses (however they be mis- or confusingly named) exist to limit institutional legal liability, i.e., prevention of legal action ("please don't sue us"). The workers' actual safety is often secondary.
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The classic WAA case - an autoantibody that prefers the presence of a normal e antigen on its target red cells. May or may not be compatible with e- (R2R2) cells, but often shows weaker reactivity, especially in it's early stages of development. By the time the autoantibody gets to the 4+ stage (complete, solid agglutination), there are rarely any weaker cells.
The question: Do you transfuse e- (R2R2), i.e., the "least incompatible" ?
From a rarity/inventory point of view, in the short term that may be manageable, but probably unsustainable long term. The decision gets more complicated when the patient is E-. One could argue that there's a significant chance that by transfusing "double-dose" E+ cells, you'll cause the patient to make anti-E. Oops. Next time around, the R2R2 option may be off the table.
And ultimately, as Petz opines, there's scant evidence to support that "least incompatible" cells (e- in the above case) survive in vivo any better than random cells.
- Yanxia and David Saikin
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On 12/3/2021 at 5:59 PM, John C. Staley said:
Was he residing in the UK? I lost track of him when he retired.
He passed peacefully in his home near Wilmington, NC.
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I'm in line with the above answers. A current diagnosis would be useful, especially to give us an idea if the aforementioned blood products (platelets, plasma) may be in play. There has to be some kind of more recent stimulus.
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On 9/15/2021 at 8:08 AM, AuntiS said:
Sorry - just saw this reply now.
Canadian Blood Services tests all donor units for K. If K negative, the donor end label has K- on it. If K positive, the end label doesn't have any K antigen testing information listed - the K+ status is only embedded in the donor unit phenotype barcode.
All donor units are treated the same - so the K+ units are available, as all other units are, but it is easy to select a K- unit for females of childbearing potential and who are on a drug like daratumumab.
sandra
Thanks, Sandra. As I'm sure you knew, I am aware of the answer - no way, no how are blood suppliers going to "discard" ~10% of their product. But I think it's important to consider the consequences of some of the now routine testing algorithms. No testing mean results are unknown, but once one has information, one may be required to take action. Many transfusion protocols for chronic users involve Rh (C/E) and K matching - there's another batch of donors whose (partial) phenotype is known and considered to be quite immunogenic. It goes on.
I do find it interesting that your system "hides" the K+ status, but openly prints the K- attribute on the label.
Another thought: If the K type of all of the patients were known, they could get the K+ units. The antigen frequencies should match up.
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On 9/10/2021 at 3:09 PM, applejw said:
I suggest to my techs during training that it may be prudent to test the last wash before preparing the eluate - especially when additional red cells are not available. I'm sorry to report that I have seen several elutions where the last wash never became negative..... usually with cord cells where the mom had a VERY strong antibody - even changing tubes with every wash. I'm sure that if I had had the patience and persistence, it might have become negative but I gave up at 10 washes.
At that point, you could probably test the Last Wash for specificity !!
You'd probably get the results you need.
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I have always run the eluate and last wash in parallel, but the question did make me think.
I appreciate the attempt to reduce (potentially unnecessary) work, but don't like the idea of doing two-stage testing (eluate first and then Last Wash, or the other way around). If this happens, you've lost any efficiency (and time) you believed you gained by not testing the eluate and Last Wash in parallel. However, the cautious approach to a low volume (rare) specimen may have some merit - checking the Last Wash first adds confidence that any eluate prepared from the washed cells will be more likely to be valid.
The two-stage testing concept has crept into the laboratory over the last couple of decades and is completely valid for follow-up or reflex testing. But.....one of my peeves: Reagents that suggest "Immediate spin, incubate negatives". If you're running a negative control anyway and/or most of your tests will be negative (DATs with anti-Complement reagents), you'll almost always be incubating, so why bother with the Immediate Spin ?
Bottom line: Do what the eluate kit manufacturer says (unless you've validated otherwise).
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3 hours ago, David Saikin said:
(maybe it's ok because the "new" method is read microscopically vs macro read for the classic method).
Hah ! Excellent point, David. I wonder how much emphasis should be put on those "microscopic" reactions, especially when the endpoint a titration is most often defined as the "last MACROscopic (or 1+) reaction"? How do the Powers-That-Be justify that little nugget ?
Can you imagine resulting-out a "change in titer" based on a microscopic reaction ? Talk about piling-on to the already acknowledged confusion level.
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An excellent discussion point. I think many others have similar questions and concerns. The have been several other threads on this forum with similar subject matter.
As an Old Fart, I feel obliged to spout some (un-referenced) history. Most of the original work on clinical significance of antibodies in pregnancies was done in the absence of potentiators and definitely before the use of (semi)automated test systems. I think it was a "saline-IAT" using 22% albumin (BSA) as a diluent. Most of those antibodies were anti-D, for obvious reasons. There's not much out there in the literature in terms of controlled or organized studies regarding other specificities. There are a fair number of one-of-a-kind case studies, but most of the stuff is retrospective analysis of data. Basically, other than anti-D, nobody really knows what an antibody titer means, but as Ensis01 suggests, detecting a change in titer (increase) may be more important.
In an era when basic tube shaking is going away, it only makes sense (we have no other option) to convert to the new techniques and equipment, but I suspect that it has the potential to further confuse an issue which already has enough confusion to (dis)satisfy everyone. I don't envy anyone handling this hairball.
As a last thought...the high-powered potentiators (and techniques) used today don't reflect what's going on in vivo. Arguably, if one ignored the 22% BSA diluent, the saline-IAT is a better mimic of the in vivo scenario.
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I am not aware of any LICENSED anti-Cob available in the USA. The American Red Cross system uses an unlicensed version for most of its Cob phenotyping requests. I believe Cob can be determined by the HEA BeadChip process (molecular typing). If you have a patient that needs Co(b-) red cells, I think those are your two options: PHENOtyping with an unlicensed reagent or units predicted to be Co(b-) by GENOtyping.
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My personal favorite Ch/Rg confirmatory test: Strong reactions with C4d-coated cells. Old school, but really cool to see.
- milahp and Malcolm Needs
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8 hours ago, lalamb said:
Believe this is in the new AABB standards.
If indeed two samples are mandated by standards, AABB or otherwise (I'm not doubting your information, lalamb), it would seem that from some of the responses here, many labs are going to have to re-tool their processes, including building such practices into their computer systems.
Anti-D in O positive patient, DAT+, no RhIg given
in Transfusion Services
Posted
Presumably predicted to be V-VS+ ? Might want to check on the hrB status, too.