exlimey
Content Type
Store
Profiles
Forums
Blogs
Calendar
Gallery
Downloads
Glossary
Links Directory
Questions
Jobs
Posts posted by exlimey
-
-
On 4/29/2022 at 11:30 AM, David Saikin said:
When you say assay, that is, to me, a test, like Type and Screen. Yes, we are using the same reagents but they are being used differently (automation vs manual). Your QC in this instance validates the entire test system.
But, but, but....you said "We QC the reagents". The equipment/instruments are qualified and deemed functional through calibration/certification/validation, and presumably, preventative maintenance.
-
-
1 hour ago, AuntiS said:
In Canada, our standards also add a requirement to clearly labelled/segregated area:
CSTM 3.2.1.7
Contamination of blood components or blood products from patient samples, reagents and/or tissue products shall be avoided by ensuring that blood components and blood products are stored in designated storage equipment or in clearly labelled segregated areas within the storage equipment.(See guidance statement below:
Physical barriers are needed to prevent contamination of blood components and blood products from other materials stored in the same equipment or area.
Examples of physical barriers include a leak-proof shelf or container (preferably with a lid), clearly labeled to reflect the contents. If the physical barrier is a shelf, blood components/products should be stored above any potential contaminants (reagents, patient samples, etc.).)sandra
Very interesting, Sandra. I completely understand the intent of the regulations and I appreciate that first impressions of cleanliness of blood products are important. However, it appears that in an arguably overzealous attempt to keep everything "clean", the fact that the outside of any blood bag is not sterile is completely overlooked. The air to which the exterior of blood products are exposed (refrigerated or room temperature) is not sterile. But....this is not relevant because the product inside the bag is supposed to be sterile and appropriate precautions are used during infusion events.
That being said, I like a clean, orderly and well-labeled refrigerator !
-
Please forgive my ignorance.....but do the regulations require facilities to "perform QC" on the reagents or the assay ?
-
16 hours ago, L.C.H. said:
OK, follow-up as promised with results of the D chip - and I have some reading up to do on these.
Overall predicted RhD phenotype: D+ (weak partial)
Alleles:
- RHD*weak partial 4.0 encodes p.201Arg and p.223Val
- Hybrid RHD*D111a-CE(4-7)-D does not encode D but encodes partial C as part of r'S haplotype
The report includes a reference: "Experience with RHD*weak D type 4.0 in the USA," Blood Transfusion 2018:6: 1-3.
Presumably predicted to be V-VS+ ? Might want to check on the hrB status, too.
-
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.
- Ensis01, donellda and John C. Staley
-
3
-
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.
-
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, Ensis01, Marilyn Plett and 4 others
-
7
-
All of the above are excellent suggestions. I will have to get up earlier to contribute.
- Arno, Malcolm Needs, John C. Staley and 3 others
-
3
-
3
-
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.
-
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.
-
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?
-
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.
- Ensis01 and Baby Banker
-
2
-
-
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.
- jayinsat, albaugh, John C. Staley and 7 others
-
10
-
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.
- David Saikin and yan xia
-
2
-
-
-
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.
-
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.
-
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.
-
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.
-
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).
-
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.
Storing Saline Cubes
in Transfusion Services
Posted
Interesting discussion. Yes, cardboard can carry dirt and/or insects, but to imply that the presence of such on supplies like saline cubes creates a risk to patients and staff is an extreme stretch. We don't live in a vacuum and most of us spend time outdoors with the dirt and bugs every day (potentially bringing them inside with us). A wipe with a damp paper towel should be sufficient to clean an obviously soiled outer container.
If you talk to the manufacturer of the saline, I'm sure they would argue that the outer box is not merely a convenient shipping container, but also an integral part of the product itself, designed to support the flexible primary container and get the best performance from the product. After all, they've designed in a nice little tear-out section that creates a perfect hole for the spigot/tap.