exlimey
Content Type
Store
Profiles
Forums
Blogs
Events
Frequently Asked Questions
Gallery
Downloads
Glossary
Links Directory
Questions
Jobs
Vendors
Everything posted by exlimey
-
I concur with the autoantibody conclusion. However, unless you've neglected to tell the forum important details about this case, this work-up should have stopped at a negative antibody screen (in cards). I'm more concerned about why are you doing lots of extra work - especially an enzyme panel. And, why, oh, why are you using a "primitive", "insensitive" tube test when the super-sensitive card tests are negative /compatible? If this is a "normal" work-up, I believe your testing algorithm needs attention.
-
Do you plan to grade/record your antiglobulin control cell reactions ? If "YES", then you will need to define an acceptable range. Most workers simply use a check mark to signify satisfactory performance (hence "Check Cells"). In the absence of specific instructions and/or ranges from the antiglobulin control cell manufacturers, I favor the position suggested above by AuntiS: Macroscopic agglutination.
-
What's wrong Malcolm ? You don't like the idea of using a Coombs Test to find Kell- blood ??
-
The avidity/reactivity of freshly-prepared antiglobulin control cells may be sufficiently high that the obligatory mixed-field result is not seen. The agglutination matrix of the sensitized cells often incorporates the un-sensitized test cells - a clear background is very possible. Some workers believe that 2+ is too strong and that 1+ with antiglobulin control cells is the prefect result and allows detection of a decrease in sensitivity of the assay.
-
That's interesting. The last time I purchased spirit thermometers, we were unable to certify them (we didn't pony-up the extra $$$ for NIST-traceable versions). We had serious linearity issues between the ice-point and the working temperature. The mercury replacements had perfect linearity, but I understand the concern regarding mercury.
-
Do you use liquid-in-glass thermometers ? If so, spirit (alcohol) or mercury ?
-
Interesting. My perspective is from the USA. I assume then that the donors with detectable antibodies are permanently deferred ? That must put a hurt on the supply of Rh-.
-
Another remote possibility: Passive anti-D from one of the transfused units ? Most facilities are shy about transfusing red cells from donors with antibodies, but some of the savvy hospitals will get "favorable pricing" on Rh- units with anti-D. Since the Rh- unit (with anti-D) is typically going to an Rh- patient, the presence of the antibody is not usually a clinical problem, but may turn up as a laboratory anomaly. The amount of residual plasma in today's red cell products is very low, but a strong anti-D might show up post-transfusion and would probably only be seen be temporarily. You would have to look the timing of the transfusions and collection/detection of the anti-D-containing specimens. If you see a pattern, your blood supplier may be able to determine if any of the transfused units were from donors with anti-D.
-
Excellent points. The diagnosis, i.e., the reason for transfusion, might also give a clue. I also thought about RH-IG, but I can't think of a traditional use for that product in an elderly patient.
-
It might be a transient autoanti-LW, only reacting with D+ cells. Genuine examples of anti-D are usually more persistent than the situation you outline, but never say never. An elderly person's immune system may work in unpredictable ways. On a related tangent....if it is a "real" anti-D, I would wonder about the source of immunization - I'm assuming D- RBCs were transfused. You do not mention platelet transfusions.
-
CORD BLOOD NOT MATCHING HEEL STICK TYPE
exlimey replied to Texas Lynn's topic in Transfusion Services
Nice !!! Old School. -
If by "odd antigen" you mean a low incidence/frequency antigen on that specific A1 cell/donor, it should be easy to resolve using another A1 cell (or set of Reverse Cells) - the forward and reverse would compliment each other. However, if everyone is having problems with this patient, it's unlikely to be the reverse cell(s). Is the GI bleed due to ulcers ? H. pylori, perhaps. I think I read that some folks with H. pylori make cold autoantibodies.
-
So the A1 cells are reactive, but the O cells are nonreactive. Interesting. I would have guessed autoanti-H, but that doesn't fit. Have you tested A2 cells ? Might be a weird compound antibody like anti-HI - needs the presence of both antigens to react well. Have you looked at something simpler, like anti-M, for instance ? The DAT results suggest IgM/complement binding, but as you imply, further testing is required.
-
I agree - sounds like a cold auto, probably IgM. The IgG-gel cards are not exactly good at detecting IgM antibodies, Perhaps that's the reason for the nonreactive screens ? What do O cells do in your standard version of the "reverse"?
-
Where are the lights ?
-
Along the same lines......the basis of my personal safety approach: "If it's wet, and NOT yours, don't touch it."
-
saline expiration date
exlimey replied to KLCarter's topic in Immunohematology Reference Laboratories
My two cents: One CALENDAR month........If you open something on the 15th, it expires on the 15th of the next month, regardless of how many days are in the current month. But...... you have to be careful to not open something on the 29th, 30th or 31st of January..., or the 31st if the next month has 30 days.... -
I'm sure there are lots of variations between both Complement content of sera and the number "binding sites" on red cells. I suspect others on this site can provide references. This is assuming you are using the same antiglobulin reagent each time: To even out the variations, I suggest you use a pool of Complement sources (3 - 5). You may also consider using a similar pool of red cells. This may help lot-to-lot consistency. Ideally, in a perfectly-controlled world, one should use the same Complement source(s)and red cell source(s) each time you prepare a batch.
-
Darkening of panel cells-possible contamination?
exlimey replied to KBBB's topic in Immunohematology Reference Laboratories
Interesting. I like the "no one else is having a problem" line - the implication being that the problem is a result of something done by the end user. Random contamination (darkening) seems to be the bane of red cell manufacturers. Often, the randomness is exactly as you describe: one vial bad, another of the same batch is fine. It's very difficult to pin down a cause - could be their storage solution, could be inadequate sterilization of the containers/droppers, could be shipping, etc. I doubt there will be any resolution. I would send them pictures and ask for replacements. -
Darkening of panel cells-possible contamination?
exlimey replied to KBBB's topic in Immunohematology Reference Laboratories
Is the supplier of the affected panels the same as your source for Red Cell Storage Solution (Alsevers)? -
An EXCELLENT question Darren ! I look forward to some interesting debate.
-
Antibody Evaluation
exlimey replied to Muhammad Awwal's topic in Immunohematology Reference Laboratories
I agree with Malcolm - the IgG/IgM nature of the antibody is not relevant, and I would avoid tests with enzyme-treated cells in patients with confirmed WAIHA, especially after adsorption procedures. I know that some workers also avoid PEG when testing adsorbed serum in these cases, opting instead for LISS or even saline antiglobulin tests on the adsorbed serum. -
Short (facetious) answer: $$$$$$$$$ Long answer - my opinion - Facilities required or choose to follow AABB Standards (and therefore get an inspection) are required to pay for/buy said standards. At the very least, they are "institutional members" that pay an annual membership fee. The AABB Standards are very different from the Technical Manual (in which the universal, public domain procedures reside). I may be wrong, but I think the standards get some kind of tacit approval by the FDA, whereas the TM gets peer-review. Of course, both documents/books are available to anyone for a fee......
-
Thank you, Johnv. I know the science.
-
Isn't it fascinating that we're "allowed" to deliberately use a less-sensitive assay when "we" feel it appropriate? Offhand, I can't think of anything similar in other path disciplines. Anyone ? Anyone ? And..... go........
