exlimey

Oops. Perhaps "Mia" is not as obsolete as I believed. Great article/reference.

Yes. In the examples I've seen, the usual the culprit is a gene re-arrangement that results in expression of the Dantu antigen. If I remember correctly, the P3BER clone does not react with Dantu+ cells. If it isn't mentioned in the Directions for Use, you could check with the technical people at Millipore/Bioscot. The presence of "Mia" (an obsolete umbrella term that can apply several "Miltenberger" antigens), already indicates that some MNS gene shuffling has occurred.

Do you mean used to MAKE the eluate or it being added to the test system ?

This scenario doesn't explain why the donor red cells react with the serum from most patients. For this to be a "low incidence antigen" issue, ALL of the patients would have to have an antibody to (probably) the same low incidence antigen. That is very unlikely. As Malcolm suggests, this sounds like an abnormality of the donor's red cells. I believe Hemo bioscience have a lectin kit, but it may only be available in the USA.

Those anti-Vels are sneaky !

NicolePCanada - I agree with both Ward_X and Malcolm's comments. There are definitely situations (patient groups, diagnoses) where a less sensitive methodology like LISS-IAT can be useful to work around "junk" that may be detected in Gel, Solid Phase or PEG test systems. But...they should be employed only by operators who understand the consequences of such actions, AND have the support of their medical staff.

The "Swiss Army Knife" approach to serological problem solving used to be fun. Having the ability to tinker with a variety of test methods and come up with your own conclusions was one of the addictive parts of immunohematology. Alas, that is no longer viable in today's era of validate everything and demonstrate competency several times a year. I used a lot of words to say: "If you don't use it, get rid of it".

I like your "neo-science" quote ! As the actual science has progressed, and the sensitivity of assays has increased, workers have encountered "-only" antibodies: albumin-only, enzyme-only, LISS-only, PEG-only, solid-phase-only, Gel-only. As you point out, if the older assays were that bad, we'd have patients dropping all over the place due to the presence of "missed" antibodies and false-negative crossmatches. My point about the "stickiness" is that the gel system is notoriously unforgiving with anything but completely normal, healthy, well-washed cells, preferably in the manufacturer's diluent. Throw anything at it that's little different and you risk incomplete or unsatisfactory centrifugation of red cells. I don't know if that specifically happens with Jk(a-b-) cells, but I have seen frozen/thawed cells behave badly. After reviewing the posts here , I think it's perhaps a little more worrying that jojo808's group may consider transfusion of "least-incompatible". I understand that needs must, but that's a dangerous proposition if one doesn't know the specificity of the antibody(ies) causing the incompatibility.

This may be a little heretical, but I think I would avoid the gel test in this case. Perhaps do the cross-matching in a test system that's not as sensitive ? Local policy permitting, of course. A plain old tube test would probably result in compatible crossmatches. The gel test system has probably not seen many cells with the Jk(a-b-) phenotype, and I also suspect that they're probably "sticky", especially if the cells have be frozen/deglycerolized.

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.

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.

All screening cells reactive, or some other pattern ?

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.

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.

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.

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

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.....

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

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. 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.

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.