exlimey

Tests on the adsorbed serum (with ZZAP-treated cells) give confidence that the are no underlying alloantibodies to common antigens. However, the use of allogeneic cells risks removal of a cold-reactive alloantibody to a high incidence antigen, e.g. anti-Vel, -PP1pK. A low risk, but still concerning. Does you facility also test the ZZAP-treated patient cells (now presumably DAT-negative) back against the patient's own serum ? This is ultimate proof that the cold-reactive antibody is an AUTOantibody and adds more confidence in the results of the adsorption with allogenic cells. I may b

Arguably the initial ABO discrepancy is proof of the presence of a cold-reactive antibody. If the DAT was positive, how do you determine that the autocontrol is valid ? Surely its just the same DAT-positive cells reacting with the antiglobulin reagent, or were the patient's cells treated to render them DAT-negative prior to testing ? Were the "zzap'd cells" autologous ?

Especially if the beast in question is largely IgM.

That's an excellent point. It always struck me as slightly odd that such critical testing is done by "drops" - a potentially highly variable volume. One certainly wouldn't see an HIV test kit give instructions like "Dispense two drops". Goes to show that the standard serological (tube) test is extremely tolerant of variation.

Wow. I perfectly understand the science, but that is an awful thing to put in a Directions for Use. A savvy Inspector could throw serious doubt on any tests performed using the supplied dropper. And why provide a dropper if it isn't good enough for the test ? The only way to meet this requirement to the fullest is to use a calibrated semiautomatic pipette.

Could be, but would probably still need some evidence of immunization, I think, maybe ? Examples of "auto anti-LW" are more often seen in the elderly, but I suppose they could be found in certain disease states (no mention of why a T & S is required for a 17-year old).

You win, Galvania ! The best answer so far. Very X-files.

Lots of options.....here are some that come to mind: Was pregnant, didn't know it, auto-terminated very early (heavy menstruation); transfused when she was very young and doesn't remember; ritual blood exchange - a "blood-brothers/sisters" sort of thing. I think there are even so-called "naturally occurring" examples of anti-D, which is just another way of saying "we don't know what caused the immunization." I'm sure others will add to this list. Interestingly, it does raise another issue: How much trust can one put into an oral and/or traditional medical record ?

Eek ! I hope they don't need transfusion.

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.