exlimey

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."

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.

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.

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.

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........

My interpretation: Users of POLYSPECIFIC antiglobulin reagents are obliged to verify performance each day of use, i.e., QC should involve use of IgG-coated cells AND Complement-coated cells. This gives the user confidence that the reagent is performing as expected. During routine testing, addition of IgG-coated cells to negative tests is sufficient to verify that the IAT was performed correctly - correct/effective washing, the antiglobulin reagent was added and is reactive, etc. If it were a requirement to add IgG-coated cells and complement-coated cells to every negative IAT using polyspecific antiglobulin, it would be necessary to run everything in duplicate - one set would get IgG-coated cells and the other set would get complement-coated cells. I don't think that is the case.

PEG-IAT is arguably the most sensitive tube test currently in widespread use. For this reason you're more likely to see concurrence with your Echo/Neo results if you use PEG for supplementary testing, i.e., the sensitivity of the two assays are perhaps the closest (LISS being less-sensitive). However, there's still a chance that the Echo/Neo will detect something that is not detected in PEG (or LISS). I wonder what Immucor would say if you decided to use another manufacturer's PEG reagent ?

I think the term "Chav" has recently become popular. Even more recently, calling someone "a right old Neymar" is not very flattering. As the Irish writer George Bernard Shaw once said: "England and America are two countries divided by a common language."

Wow. Thank you for that information. That certainly could influence the concern some of the medics demonstrate. Is the surgical room also chilled ?

That is exactly the theoretical risk that concerns the medical staff, but in my non-medical, laboratory-based opinion, the risk is extremely low. Extreme testing protocols (below 30 C) for cold-agglutinins are rarely informative, often having very specious clinical relevance. Does anyone really know what the results mean ? How high must a titration be to be significant ? If you look hard enough, you can find cold-reactive autoantibodies in most people, hence why routine testing protocols now deliberately avoid test phases below 37 C. Modern, super-sensitive test systems (PEG-IAT, CAT) don't even allow tests below 37 C and openly admit that IgM antibodies may not be detected (typically the form that "colds" take). Even with these "deficiencies" they still are licensed/approved for antibody detection and ID. If a patient is in such a dire situation that they're undergoing radical surgery, with the selective use of hypothermia and/or by-pass procedures, the least of their worries is a cold agglutinin. The easy fix to the transfusion of "cold blood" is a blood warmer, but obviously this would be contraindicated during hypothermic processes.

Perhaps I'm a little naive, but I find some of the "old time" logic somewhat illogical. I appreciate that a unit of red cells being transfused would potentially be "cold" - 1 - 6 C at the start of infusion, i.e., might cause a cold-agglutinin issue, but almost immediately, the infused portion would equilibrate to the temperature of the circulating blood. Additionally, the unit itself would start to warm-up to room temperature. Certainly additional problems could arise from "by-pass" procedures, but are the devices\pumps "cold" - 1 - 6 C ?? I suspect they operate at room temperature, nowhere close to refrigerator temperatures. After all that rambling, I meant to say that I don't why anyone would test "cold autoantibodies" at temperatures below that of typical (surgical) rooms. However, I'm sure there is a a whole library of circumstantial, anecdotal evidence supporting such extreme testing protocols.

Does the MTS gel card you typically use contain polyspecific antiglobulin reagent (anti-IgG + anti-complement) or does it just contain anti-IgG ? I think most users are using anti-IgG cards, and if that is the case, they're already dealing with the "Is it possible to miss a complement binding IgM antibody early on by using IgG only." issue.

RESt = Rabbit Erythrocyte Stroma - basically stabilized red cell membranes from rabbits. There is absolute no DTT in RESt.

I just answered this question. My Score PASS

I read on the Internet that if a person sinks in water and drowns, they're proven to be a witch........