exlimey
Content Type
Store
Profiles
Forums
Blogs
Events
Frequently Asked Questions
Gallery
Downloads
Glossary
Links Directory
Questions
Jobs
Vendors
Posts posted by exlimey
-
-
16 hours ago, Christy Spence said:
We use 1:9 dilution of QC antisera (anti-D & anti-c) upon arrival / prior to use. "Periodically" and "weak antibodies" are way too vague...
Again, continuing my earlier thread: Rh antigens are very stable and may not be representative of deterioration of other antigens.
-
14 hours ago, pinktoptube said:
Why can't they just be treated like the screening cells? Run a positive and negative control day (same that you use for the screen) of use.
Are you suggesting that one tests every panel cell every day of use ?
-
21 hours ago, Eagle Eye said:
1:4 dilution of anti-Fya on the day of putting into use and on the day of expiration...
Continuing my earlier thread: That approach doesn't check those cells that are Fy(a-).
-
11 hours ago, dragonlady97213 said:
From what I've read, the antibody uses an IgG4 backbone. Using Immucor's GammaClone that doesn't pick up IgG4 alloantibodies should work, but I haven't seen anything verifying that.
Apologies, I now remember you posted that earlier. The mind is a terrible.....wait, what was I saying..........
It's IgG4 nature and use of the Immucor/Gamma reagent won't help much if it's causing direct agglutination before the antiglobulin phase, especially in reverse typing.
-
18 hours ago, DPruden said:
It's a CAP checklist item.
TRM.42650 Monitored Temperature The temperature of refrigerators is monitored in a manner that will mimic the temperature characteristics of a component stored in the device.
NOTE: For example, placement of the temperature sensor probe in liquid with heat transfer characteristics similar to blood, and a volume similar to the smallest units stored, is recommended, but other procedures are also acceptable. The correct placement for the temperature sensor is controversial. Some experts recommend leaving the sensor exposed to air, some recommend enclosing it in liquid, and some recommend enclosing it in an aluminum block.
Perfect ! Thanks for the reference.
So...a follow-on question: Who determined that 10% glycerol is a "liquid with heat transfer characteristics similar to blood" ? At least one user on this site is using 30% glycerol.
-
11 hours ago, dragonlady97213 said:
In testing all panel cells react 4+ at RT to 2+s at Anti-IgG. The RT reactivity is also seen in the reverse type. Further testing looked as if papain treated RBCs absorbed the reactivity.
IgM, IgG or both ?
-
20 hours ago, spavlis said:
I believe.....Thermometers are placed in solutions similar to the components of blood.
10% glycerol solutions is determined to be similar to blood.
Is that an official rule, standard, regulation, or something contrived that we've all convinced ourselves is true ?
-
Just curious....why glycerol ? Does the refrigerator manufacturer require you to use it ?
-
On 3/10/2017 at 10:10 AM, mollyredone said:
We could show them our antigen typing worksheets so they could see the different lot numbers. We keep two years of antigrams, although most of anti-sera testing is IS (3%) now, only Fya and Fyb are AHG, which we validated in gel.
Fair enough. I was picturing the results living with each patient record, but if you're antigen screening donors and the results are kept together, that would be easy.
-
59 minutes ago, Malcolm Needs said:
You will be surprised to learn that most of the inspectors for this particular regulator have never stepped foot over the threshold of a transfusion laboratory prior to inspection!!!!!!!!!!!!!!!
Unfortunately, I'm not surprised. I would consider myself lucky to get an inspector who even knows blood groups.
-
1 hour ago, John C. Staley said:
This topic keeps popping up periodically and I find it both interesting and frustrating. My personal view, as stated in previous discussions on the topic, is that what ever you do is little more than smoke and mirrors in an attempt to pacify some regulator. I'm sure that's also why the manufacturer puts such nonsense in their package inserts. They claim specificity for many antigens yet it is acceptable to confirm the reactivity of a select few!! I'm sure that can be rationalized but it still makes no sense to me.
Well said. Smells like trying to fix a problem that doesn't exist. Or perhaps an attempt by regulators to align Blood Bank work to other pathology departments which do instrument-performed assays in a assembly-line fashion. Blood Bank doesn't fit.
-
3 hours ago, mollyredone said:
What we do is use the current cells for our QC for our antigen typing, using a heterozygous cell as a positive control for whatever antigen we are testing. That seems periodic to me.
Very clever ! I like that idea, but suspect it would be a real pig to collect, collate and hand over said results to an inspector.
-
On 3/7/2017 at 9:07 AM, AMcCord said:
We dilute anti-K 1:20 with 6% albumin and run a K antigen positive and negative cell for QC every day of use.
More Devil's Advocate: That only tests the K antigen - a very stable structure. What about other antigens that are more likely to and are known to deteriorate over time - Lea, Leb, Fyb, to name but a few ?
The only value to testing a K- cell against a diluted antisera is to check the DAT on the chosen panel cell, i.e., it's potential to cause a false-positive. You could simply do a DAT instead.
I'm certainly not suggesting that everyone completely phenotype their Screening Cells and Panel Cells each day (or periodically). I'm all in favor of a minimalist approach to this issue, and it appears that similar testing algorithms are acceptable to inspectors.
I really just wanted to highlight the flaws in this whole concept, from both the regulatory side and that of the users. And.....don't forget.....the manufacturer's of the red cell reagents have a huge amount of stability data.
- Ensis01, goodchild, Malcolm Needs and 4 others
-
7
-
On 3/3/2017 at 9:08 AM, SMILLER said:
We use a dilution of our regular QC sera and run and document Pos and Neg QC results when we receive a new lot number.
Scott
Just to clarify and to play Devil's Advocate: Your facility's interpretation of "periodic(ally)" is once upon arrival ?
And, apparently, according to LaurieU, that met at least one JC inspector's requirements. Sounds too good to be true.
- John C. Staley and goodchild
-
2
-
I agree with the previous responses. I would cease and desist with routine microscopic reading - you don't read the gel tests microscopically. Perhaps keep the microscope around just in case there's an odd case where it MIGHT be useful, but I suspect that it will just collect dust.
-
On 2/14/2017 at 8:15 AM, BankerGirl said:
The thought process was that if the co-signer is not qualified to administer blood, then they would not be knowledgeable enough to know exactly what they were verifying.
Forgive my ignorance.....I don't work in a hospital. In your facility, does the process of administering of other drugs require the concurrence of two "qualified individuals" at the bedside ?
-
21 hours ago, KLCarter said:
Thanks JHH1999. That makes perfect sense. that explanation with a validation of the extended expiration date should be sufficient. (I hope!)
Everything JHH1999 writes is sound, and perfectly laid out. I like cake, too.
I would, however, caution that one may get some regulatory push-back if one attempts to "validate" an extended expiration date on material that comes with a date assigned by the manufacturer.
-
20 hours ago, Malcolm Needs said:
An excellent post JHH1999, however, if I made the cake today, with milk that had a use by date of tomorrow, there would be grave doubt as to whether the cake would be edible today, let alone in a few days time!!!!!!!!!!!!!
Malcolm - I was told (by Diana Brazier, of MRC/BGRL/BPL-D) that good serologists are often very good cooks. Are you suggesting you fall to either of the extreme sides of the Bell curve?
-
Oh, my. I can't even begin to imagine what such a document would look like. There is so much grey/gray in transfusion medicine, especially in the testing realm, that any document would be as complicated and of as little use as the US Tax Code.
For example:
Positive DAT - abnormal; except when one or more of the following conditions exist: [add your list of 50+ reasons for a positive DAT]
You would be listing so many ifs, ands, or buts, that any document would be practically useless.
My vote echoes MOBB: Use the "get-of-jail" phrases like "as appropriate" and "where such exist".
-
That's a new one for me too.
Microscopically detectable auto-anti-P1??? I think someone had a little too much coffee.
-
13 hours ago, TreeMoss said:
We do report ours as an antibody to the preservative in the Ortho cells.
For clarification: These are NOT "antibodies to the preservative". If that were the case, they would be neutralized in the presence of the preservative and have absolutely no impact on the serology (except maybe coating RBCs with immune complexes).
They are antibodies that react with RBCs only in the presence of a specific co-factor.
- AMcCord, Malcolm Needs and Yanxia
-
3
-
16 hours ago, jemarass said:
Hello!
We had a patient this morning have a positive antibody screen, so we sent her off for antibody ID which came back negative. I repeated the screen from the original sample and obtained the same results, had the patient redrawn and again same results. We use quotient screen cells, where as our blood center uses ortho. Has anyone come across a case where a patient has an antibody to the reagent? Was this proven in anyway? Patient has an order for 2 units of blood but with no specific antibody available to screen for, I am stumped as to how to call it a compatible crossmatch if we don't know what is causing the positive reactions.
Thank you!
There are lots of reports of antibodies that appear to need a "co-factor" to react. These are technically not "an antibody to a reagent", as Vikman suggests, but antibodies that only react in the presence of specific chemicals or ingredients in the test system.
In this case, it appears that there are differences in formulation of the Quotient and Ortho reagent cells. Quotient has something in their diluent that Ortho does not (and probably the other way around). That "something" facilitates the detection of the ingredient-dependent antibody.
As to proving it, I think your test results and that of the other lab already give enough evidence. I have heard of labs that "wash" their screening cells to remove that original diluent and then re-test. You may be able to do that, but bear in mind that if you are doing a gel-test of some sort, the magic ingredient may be in the gel.
As to the crossmatch problem, may I presume that the cells from the candidate units are not suspended in Quotient diluent ? They might be compatible because the cell suspensions lack the magic ingredient (but see my caveat above).
-
10 hours ago, Vikman said:
I would definitely suggest using 2 drops of cells to 8 drops of DTT. You will lose cells in the washing process.
If one does as suggested (by AABB TM and Hemo) - 1 drop of PACKED CELLS to 4 drops of DTT, you should be able to make at least 15 - 20 drops of a 3% cell suspension after treatment and washing.
To make 1 drop of packed cells from a commercial red cell suspension, you typically need to centrifuge down 20 - 25 drops.
-
On 1/28/2017 at 0:52 AM, David Saikin said:
It was noted at the time that somewhere, somehow in its manufacturing process it was neutralizing the reagent anti-D.
I vaguely remember that one. There are lots of anecdotes of funky results that were ultimately blamed on the saline in use at the time.
More recently, there have been reports of excess ozone in "blood bank saline" causing inactivation of the S antigen. Apparently ozone is bubbled through saline to sterilize it. In colder months the warehouse is cold and the ozone does not dissipate as quickly. In the summer months it's not so much of a problem.
- David Saikin and mcgouc
-
2
Ortho Panel Cells -Quality Assurance
in Transfusion Services
Posted
An interesting twist ! One could look at it that way.
Red cell products ultimately do deteriorate and that's why they must have an expiration date. Hemolysis is often the first visual clue. However, that doesn't mean that all of the antigens have suddenly become unrecognizable; it just means some of the older cells in the vial have popped. Studies have been published demonstrating that antigens remain stable many days/weeks after official expiration.
Manufacturers do have oodles of stability data - both static (in-house) and following shipping. Typically a unit of red cells that is turned into a red cell product has at least an eight-week expiration. This allows for manufacturing and shipping to the end users who then usually have five-weeks left on the expiration. In reality, those expiration dates could be longer, but the manufacturers deliberately give themselves a buffer period, just in case.
The wildcard in this whole process and issue upon which the regulatory agencies focus is shipping. How do the end users know that something horrible didn't happen to the material ? An unanswerable question. Even though the manufacturers have shipping stability data, they can't possibly foresee and test every odd, weird situation. One could argue that Ortho have less faith in their shipping process than other suppliers, hence the requirement for periodic QC.