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Posts posted by exlimey
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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.
- mcgouc and David Saikin
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4 hours ago, David Saikin said:
I never considered my blood bank saline as a critical reagent for the reason that I could always use what was on hand for patient use. I would not have taken the irrigation product though. I would use the normal saline for infusion. Never had to do that but there was no reason I could not.
Wow, David, you must live a charmed life if you haven't been tripped up by "bad" saline sometime in your career. Certainly in the vast majority of cases the actual pH of saline has little impact, but there are lots of examples where changing the pH of a test system has deleterious effects. Most manufacturers of blood bank reagents and test platforms now specify pH ranges for saline, essentially requiring the use of buffered saline.
- Yanxia, Malcolm Needs and mcgouc
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19 hours ago, cswickard said:
Just to bring patient variability back into this conversation - we were repeating the antibody ID on a new titer specimen to see if the antibody remained the same (anti-E) - our current procedure. This time around the pt also appears to have an anti-Dia too - not always detectable on our current screens and panels. Testing of the current and previous specimen showed that the anti-Dia was there last time too and was even higher than the anti-E titer (4 for anti-Dia and 1 for anti-E) for both specimens.
Fun with patients every day.
You were unlucky tripping over an antibody to a to a low incidence antigen. Sometimes the fancy commercial panels are too fancy. Some of the antibodies to low incidence antigens are quite common and only remain undetected because regular red cell panels do not have the corresponding antigens.
In this situation, I would make every effort the get a blood sample from the putative father - a sometimes awkward and emotionally-charged situation. Test the father for Dia (and E while you're at it) and if negative, you don't have to continue to evaluate the potency of the antibody(ies).
Getting a sample doesn't always work, of course and there's always a risk that the "father" is not THE father.
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21 hours ago, Malcolm Needs said:
I agree, BUT, if the antibody identified in the previous sample has, for example, a specificity of anti-E, and you titrate using r"r red cells and get a titre of, for example, 64, and then the next sample gives a titre of 4, what do you do? At this stage, you have no idea whether the original titre of 64, or this titre of 4, is correct.
A valid position, BUT, how often is such a large discordance seen ? Probably not often. I'm sure there are statistics out in the ether somewhere.
Perhaps storing the previous sample, or series of samples would be useful - this would allow a logical investigation of any anomalous results. Repeating the titration every time is extra work and in most cases, of little value.
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While I agree that parallel testing of a previous sample and a current sample will potentially even-out the intrinsic variation in antigen expression of test cells, I would hope that a well-trained cadre of operators following a good SOP would get the same titration results (end-point) when testing the same sample time after time.
A vague, musty memory suggests to me that there are proficiencies along those lines - independent samples to be titrated, tested and the results reported. Perhaps that has gone the way of the dinosaurs?
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3 hours ago, applejw1 said:
- but I know when they report that an anti-Ge3 or anti-Vel was identified in the patient's sample that rare frozen-thawed cells must have been used at some point in the investigation, right?
And in the examples you suggested - probably with the strategic application of some chemical and/or exotic enzyme treatments. Totally out of control. Scandalous!
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2 hours ago, Malcolm Needs said:
Anyone would think I'm a pedant!!!!!!!!!!!!!!
Could be an antibody identification panel.
I really only responded so that I could smash more light bulbs.........
- Sandy L, Malcolm Needs, AMcCord and 1 other
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On 11/18/2016 at 1:57 PM, Darren said:
One antibody panel?
I'll put my Malcolm hat on: That's a red cell panel, not an antibody panel.☺
- Malcolm Needs and AMcCord
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17 hours ago, gagpinks said:
I was suspecting it could be anti Ce. How would you differentiate anti e from anti Ce ?
I wouldn't worry about the possibility that the auto/allo antibody is Ce. Since the patient is Rh-negative (rr), any transfusions would also be Rh-negative - the very great majority of which are also C-. Only a very small chance of finding a random r'r in your D- donor pool, not impossible, but remote.
I agree with Malcolm - hyperhemolysis (US spelling). These folk have wacky immune systems anyway and the massive dose of foreign antigens delivered by a transfusion can cause them to react in strange ways. Earlier workers used the term "bystander hemolysis".
I understand that even with very low hemoglobiin levels, avoidance of transfusion in these persons seems to be the best practice.
- Malcolm Needs and AMcCord
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17 hours ago, Cliff said:
Sure, here is our validation plan, we are still validating the process. I took out names and links to documents.
Thank you, Cliff. That's very interesting. I was wondering if you planned to do comprehensive phenotyping, and you are.
One comment: Super-strong, FDA-licensed reagents may not allow detection/demonstration of weakening of antigens. Perhaps a better way to detect weakening of antigens would be to use a weak and/or diluted reagent. You could even do comparative titrations and add up scores....
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14 hours ago, Cliff said:
We are validating that now. We were going to add in a K+ cord cell, but those were hemolyzing, so we'll type the recipient instead and if needed give them K-.
Cliff,
If you wouldn't mind, please explain what you are validating - not specifically how, but what elements are you evaluating.
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2 hours ago, SMILLER said:
I just have to observe here (being a mere generalist) that when an inspector finds us using ANY expired reagent or control anywhere else in the Lab, we would certianly be cited---regardless of any evidence of a "rash of patient morbidity/mortality due" to its use.
It seems odd that we expect less oversight for an area within the lab where the potential outcome of even one mis-interpretation of a test outcome could mean life or death for our patients.
Just sayin'...
Scott
I see your point SMILLER/Scott. It's a fair argument. I'm not advocating "less oversight", but merely acknowledgement that an immunohematology work-up often has a lot more "grey/gray" than the other pathology disciplines. As we all know, "antibodies don't read books" and sometimes it takes all of your resources and experience to resolve a serological problem, including the prudent use of expired materials (or frozen inventory).
One could argue that absolute prohibition of using expired reagents in such cases could potentially put a patient at more risk by leaving an issue unresolved. Using all of your tools, in-date or otherwise, to get a good answer might outweigh the regulatory implications.
As I alluded to earlier......I don't recommend front-line techs use expired reagents willy-nilly - they should be used surgically and by those skillful enough to recognize the limitations.
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1 hour ago, mrmic said:
Why not use outdated sera and cells for screening and then use the 1 in-date bottle to retest and use as test of record?
What about rare red cells and sera from commercial or patients that may be frozen in liquid nitrogen and used to help with antigen and antibody problems? Of course you would run controls.
Where have all the blood bankers gone? Who is writing these regs.? Have they been out of the lab too long?
There are patients waiting for us and our results.....Sometimes I think that the "regulators" feel obliged to fix problems that don't exist. Does anyone recall a rash of patient morbidity/mortality due to the use of expired reagents in the blood bank arena?
That being said, the use of such material should be restricted to those with the appropriate knowledge and expertise.
- dragonlady97213, seraph44, Gnapplec and 3 others
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14 hours ago, Clarest said:
I would like to know, as well. We're planning to change one regular panel to an enzyme panel and wondering how should the validation be done.
Clarest
Enzyme-treated cells can be very useful in the hands of expert serologists who know the pros and cons of their use. Routine use by front-line techs is probably ill-advised.
In this case, some level of feasibility testing might be useful before switching to an enzyme-treated panel, but I would hesitate to call it "validation". Each facility should determine if such a panel is useful to them, or if it would cause more problems that it would solve.
As I mentioned in earlier in this thread - I believe these are FDA-license reagents and they do not require validation.
- goodchild, Clarest and Teristella
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16 hours ago, sarara26 said:
I am switching from an Immucor antibody panel to a Quotient antibody panel and need to do a validation.
My personal opinion - no validation required.
You are switching from one FDA-licensed product to an equivalent. Unless you plan to use it in a fashion contrary to the manufacturer's instructions it's a business decision rather than one of quality or performance.
If you have an internal policy that directs you to "validate" in these situations, you should change that policy. Anything that an end user does to "validate" a commercial, FDA-licensed red cell panel is dwarfed by the process involved to get these products to the market.
Perhaps more important is that the replacement product suit your facility's specific needs. The typical antigenic make-up of the panel you select should reflect your particular testing requirements. For example....if you have lots of patients with anti- D, a panel with lots of D+ cells my not be very useful.
- Dansket, goodchild, Teristella and 2 others
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Interesting question - do rabbit red cells carry CD38 ?
I thought I heard/read that removal of anti-CD38 by adsorption was not successful using human cells (which we know carry CD38). Even if rabbit red cells do carry the marker, I assume the same would apply ?
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Jealous.........
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An interesting position; in practice, it would probably work fine. I am not a regulatory expert, but I thought that both IS crossmatches and electronic crossmatches are only permissible after a negative antibody screen. Obviously in the DARA/anti-CD38 cases this would not be so. You may be able to wordsmith your way around the constraint.
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17 minutes ago, Mabel Adams said:
I read a research paper in Transfusion on this drug that mentioned eluates being panreactive on these patients (at least the one they studied). http://onlinelibrary.wiley.com/doi/10.1111/trf.13069/full
I stand corrected, maybe.
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On 10/29/2016 at 11:18 PM, Mabel Adams said:
I am trying to decide on a policy of whether to do full genotyping or just K typing when we get their pre-treatment specimen. So far, most of the patients we have on the drug are not needing any transfusions (we still have fewer than 10).
Since your patients are NOT getting regular transfusions, I would hesitate to get full genotypes. If they switch over to being regularly transfused, it might be worth reconsidering, but you may paint yourself into a corner and find it necessary to "honor" the other DTT-sensitive antigens like Yt and Do. See DargonLady's comments above.
A K typing can be easily performed using monoclonal antisera, even after the first dose of drug and if the DAT is positive.
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On 10/29/2016 at 11:05 PM, Mabel Adams said:
I understand that eluates will contain the anti-CD38 so that won't really help unless there is a big difference in strength of reactions.
Since it has been reported that workers are unable to remove anti-CD38 by adsorption, I suspect that one would be unable to elute said antibody, rather similar to "HTLA" antibodies. An eluate could be free of anti-CD38 and therefore be testable, however, there are hundreds of reports of nonreactive eluates in patients with obvious hemolytic and/or serological transfusion reactions.
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1 hour ago, jayinsat said:
I say change your SOP to match your practice, as long as it has been validated, passes daily QC and doesn't contradict manufacturers requirements. I don't know of any transfusion services that wash the cell suspensions routinely anymore.
What do you mean by "validated" ? Have you actually validated your ABO grouping process?
DTT-Treatment of Screening Cells (Daratumumab/Darzalex)
in Transfusion Services
Posted
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.