39 minutes ago, diplomatic_scarf said:

Thank you for replying.  Everything was done by gel card, we don't use the tube method.  Patient was typed A Pos. The antibody screen was 1+ positive on Screening cell 1 and 3, negative on Screening cell 2.  But when we did the Antibody Identification panel and Auto control , they were all negative. We repeated everything and got the same results.  We redrew the patient for a new specimen and got the same results. 

We sent out the specimen for an Antibody Identification at a reference lab. The result we got back was Anti-M. 

I am just wondering, why didn't our panels picked this up? Why only the screening cells were positive? What was the reasoning behind this? The panel and all our reagents have passed QC and are not expired. There was no signs of contamination in our specimen or reagents. Thank you. 

Reactivity with two of three cells effectively rules out the "antibody to a low incidence antigen" argument.

Is the supplier/manufacturer of the Screening Cells the same as the supplier/manufacturer of the panel ? If not, then I suspect formulation differences of the two products may be the answer, specifically pH of testing environment. 

3 hours ago, Malcolm Needs said:

Maybe it is a mixed cold and warm AIHA - rare, but they exist (I co-wrote a paper on a case), in which case the "cold" could be an auto-anti-H, or even just the normal auto-anti-H commonly found in group A plasma.  That would explain the weak reactions with group A red cells.

It's tough to see on the scanned panel sheets, but the D- group O panel cells are w+ reactive, equivalent reactivity to the crossmatched group A cells.

Agree with previous - looks like a warm autoantibody and it's important to see what, if anything is underneath. Adsorptions will be necessary. Interestingly, if I can read the results correctly, the antibody is showing a marked preference for D+ cells. It may have LW specificity, although 4+ is unusually strong for anti-LW.

I'm curious as to why there is "w+ incompatibility with all A pos units". I would have expected those to be 4+ reactive, also.

There may be several issues going on here.

6 hours ago, diplomatic_scarf said:

The antibody screen was positive.

All screening cells reactive, or some other pattern ?

1 hour ago, Malcolm Needs said:

I like explanation one very much exlimey.  Very many of the examples of anti-Vel I have encountered (and I have seen many, as I was working at the BGRL in London in the mid to late 1970's when Dr Bertil Cedegren was studying the percentage of Vel Negative donors in the Swedish population) had a high concentration of IgM, and a low concentration of IgG.

Exactly. And very likely to cause in vitro hemolysis in appropriate test systems (not to mention in vivo hemolyis). I remember doing many 2-stage EDTA tests, using fresh complement and poly AHG. Good times.

I think I may have met Dr. Cedergren when I was working at the BGRL in Oxford during the late 1980's.

I can't really explain your serological findings, but I agree with Malcolm's sentiment: "That stuff'll kill ya!" Anti-Vel is notoriously slippery and infamously dangerous.

Without a more detailed look at your results, I see a few remote possibilities:

1. The anti-Vel may have an IgM component that doesn't like the Gel, but does like the PEG test

2. There's possibly something underlying the anti-Vel, hence the "extra" reactivity

3. The unit you crossmatched is not actually Vel-, but another member of the Vel variant club

While the use of EDTA plasma basically eliminates the chance of detecting hemolytic antibodies (as Malcolm says above), some laboratories still use serum. It's possible some hemolysis might been seen in visual check before taking the serum-RBC-PEG reactants to IAT. One may also recognize loss of RBC volume after the washing process, if some of the cells were destroyed during the incubation phase.

On 12/24/2019 at 11:58 AM, Michelle L said:

Does anyone that uses Immucor's Elu-Kit II test the pH of their eluate once it turns blue? Or do you just go by the blue color indicator as being within the appropriate pH range?

1. Personally, I wouldn't do ANYTHING different/extra than the manufacturer recommends. You may inadvertently "modify" the process and find yourself in a corner that requires validation of your local modification. Yikes !

2. Typical eluate volumes are quite small - often too small to be measured with a pH probe. So I suspect, correct me if I'm off-base, that the pH has been checked using pH paper. If so, eyeballing the color of the pH paper is no better than eyeballing the color of the eluate.

And, as AMcCord suggests, while the blue color may vary, the differences in pH values of the different blues is very small. The manufacturer (Gamma/Immucor) has put a lot of effort into making the kit idiot-proof.

6 hours ago, pathlabtech said:

Here's the antibody screen:

Cell	IS	37C	AHG
SC 1	neg	neg	1+
SC 2	neg	neg	1+
Auto	neg	neg	neg

The possible interpretations are:

1. single warm antibody, antigen present on both cells

2. antibody to high prevalence antigen

3. complement binding by a cold antibody not detected at IS

Can someone explain interpretation #3? 

 

 

 

Interpretation #3 should only be considered if a polyspecific antiglobulin reagent was used, i.e., a "complement coat" will only be detected if the antiglobulin reagent used contains an anti-complement component. Even if that is the case, Interpretations #1 and #2 are far more likely.

1 hour ago, Malcolm Needs said:

As said above, we don't have to make this decision, as all of our units are typed for ABO, D, C, E, c, e and K.

What does the Blood Center do with the K+ units ? Throw them out, or only give them to K+ patients ?

16 hours ago, Mabel Adams said:

So the same logic applies as for E & c--avoid stimulating anti-V/VS during more routine transfusions to save yourself the option to have a compatible crossmatch during a crisis when you may be giving V/VS+ blood to save a life.  If the patient has already made anti-V/VS you can still choose to ignore it and give incompatible units because it is a lesser evil but we would mostly feel better if we could avoid giving crossmatch-incompatible blood because it would be hard in the moment to prove that there wasn't an additional antibody directed against a different low incidence antigen.  That's why we do AHG crossmatches I'd say.  Same argument against it of using a precious resource before the patient has made the antibody.

This is a very interesting thread, partly ethics, partly practical use of resources, and a large dose of "what if".  In the legal sense, the concept of "Prior Restraint" comes into play  - doing something to prevent a possible event regardless of probability.

So.....a not-so-unrealistic scenario:

The hospital has a patient with anti-K and is required to screen/type a number of units to fill a transfusion order. During the process some donors/donations are identified as K+. What should the facility do with those, knowing full well that they may stimulate an immune response in recipients ?

And.....discuss.....

16 hours ago, Malcolm Needs said:

"reagent quality anti-V and/or anti-VS are both like hen's teeth"

Unless you have the right contacts......

9 hours ago, Malcolm Needs said:

Anti-V and anti-VS have only ever caused very mild delayed transfusion reactions, and only ever caused a positive DAT, rather than clinically significant HDFN.

They may indeed "cause very mild delayed transfusion reactions", but to a multi-transfused (Sickle Cell Disease, SCD) patient, with often a multitude of other alloantibodies, what would be a typically mild reaction in a "normal" patient can be serious, even fatal in SCD patients, especially if it induces a hyperhemolysis event. SCD patients understandably have very fragile immune systems. It doesn't take much to upset the apple cart.

36 minutes ago, Mabel Adams said:

But I bet they make the V/VS positive unit crossmatch incompatible so you can't use it, right?  And that from a very limited pool of units.

They sure do, especially since many laboratories routinely use the super-sensitive assays like PEG-IAT or CAT (gel/bead technology) for crossmatches.

Most examples of anti-K are IgG, and therefore need an antiglobulin test to detect them. While enzyme-treatment of cells may or may not enhance reactivity of anti-K, it rarely turns an indirect agglutinin into a direct agglutinin. It does happen, but I've only seen it with Rh specificities where antigen density supports the process.

 

I presume that the "neutral cards" do not contain anti-IgG and therefore your findings are as expected/typical for most examples of anti-K.

2 hours ago, Baby Banker said:

Issitt says that the antigen expression is variable even in the same donor or patient.  I didn't see anything about sample age, but I just glanced over the entry.

I am Bg(a+) and my expression is usually quite strong; it got super strong after a bout of Infectious Mononucleosis.

I have seen my own cells react with examples of anti-Bga when the cells are fresh and then reactivity dwindle to nothing as cells from the very same collection tube age.

Definitely nonsense.

In my experience, antibodies to Bg antigens ONLY react with the freshest of cells, and only with individuals with unusually strong expression of the antigens, e.g., Bg(a+s). Even when the odds are stacked in your favor - fresh cells from an individual with a strong expression, you're only likely to get barely macroscopic results. It can be very frustrating to chase down one of these to identify it.

13 hours ago, fendi98 said:

Saline tube technique at 37, immediate spin = incompatible with 1+ reaction including auto control

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.

41 minutes ago, abillarn said:

Thank you all for the responses and input.. The reagent manufacturer does not really specify what reaction grade is acceptable to validate your Coombs reagent really did its job. We were in the process of making our procedure , just not 100 percent sure what grade , we were leaning on 2+.

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.

25 minutes ago, Malcolm Needs said:

Grrrrrrrrrrrrrrrrrrrrrrr!!!!!!!!!!!!!!!!!!!

Anyone know the name of this man and his relevance to this thread?????

 

What's wrong Malcolm ? You don't like the idea of using a Coombs Test to find Kell- blood ??

14 minutes ago, JPSCANNELL f. CROKE said:

2+ is the only result possible as you have a mixed cell population in the tube now (patient/donor + check cells).

The definition of a 3+ and 4+ is a clear background = not mixed field.

And 1+ is just too weak, something is wrong.

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.

4 hours ago, AMcCord said:

Liquid-in-glass, spirit only. We (the entire facility) got rid of mercury thermometers some years ago - safety hazard.

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.

On 4/19/2019 at 8:30 AM, AMcCord said:

Those things are not big budget items. Once they come, new thermometers go into service, old ones are removed and discarded, new certificate goes in notebook, old certificate goes into archive file. I decided a couple of years ago that I am too hard pressed for time to check calibrations on things like thermometers.

Do you use liquid-in-glass thermometers ? If so, spirit (alcohol) or mercury ?

1 hour ago, Malcolm Needs said:

exlimey, again I agree, but it depends where Jennifer G is based.

NHSBT used to give out units of blood containing anti-D (and some other antibodies, as long as they were weak), but that is no longer so.  Since variant CJD raised its ugly head, we are no longer able to take blood from donors who have themselves been transfused (there are a few strange rules about when the blood was given, etc, but that is beside the point).  Because of this, and the fact that donors cannot be relied upon to be 100% honest (or simply don't know), so that we don't know if the antibody is as a result of a transfusion, a pregnancy or "naturally occurring", we destroy any units containing antibodies of any sort (with RARE exceptions), in case the antibody is the result of a transfusion, and it gets out into our untransfused inventory.

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.

1 hour ago, Malcolm Needs said:

Totally agree exlimey, however, another question I have is, ws a DAT performed when the "anti-D" was detected?  I also have another suggestion, to go along with your question about platelets, and that is it could be that one of the units was from a donor with a DEL phenotype.  Unless elutions (obviously) or molecular techniques are used, this may never be known, but it is known that some types of DEL can cause primary stimulation, but that the anti-D produced in these circumstances is very weak.  As you say exlimey, as the patient is elderly (and ill), the patient's immune system could be compromised.

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.