MeganPLT

Hi All, to add to this antibody discussion a bit further - we test in parallel for reasons above (ie to rule out tech variability - detect a difference in titration which is the most important for the clinician) however, I am curious to know how blood banks titer when there are multiple antibodies present. We have a mom with 3 antibodies showing and one historical not showing and it's proving extremely difficult to separate out the different antigens using our 4 in date panels to do the titer studies. Should we just use one or two cells with the antigens and try to be consistent when the mom comes back in for titers (they are monitoring every 4 weeks right now) or try to divide out as best we can? what do you all recommend?!?!

This is not my area of expertise but did you ask the vendor for interpretation? I know the Duffy phenotype is based on few alleles, including the GATA box silencing mutation - so I would think there would be a couple factors to consider right? I would assume if the FyB allele is present, even if weak, you would want to call them FyB pos as a donor, but if it is a weak expression and as a recipient they could possibly make anti FyB you'd want that documented as well! I am curious if you come up with an answer... please let us know (looks like there were a lot of views for this string but no answers)! Sorry I can't be of more help!

@Brenda Hutson No that all makes perfect sense! I don't want you to have to dive into the antibody details if not needed; I appreciate you giving a well rounded review of the Erytra. (and I feel frozen/thawed samples have to be looked at with extra consideration as well!) About shying away from the big pictures - that is similar to what we do with the echos - we don't "blow it images up" because sometimes you can actually "over read" or start to question the reaction which is not good either - but it took us some time to get there and understanding it too has a camera algorithm to abide to! And as we have gained experience with the reaction images, it is easier to make that determination - sometimes going to the panel and sometimes knowing it is "safe" to call the screen image negative and feeling confident. Thanks for the additional details as it help me understand how the different instruments/methodologies work and gives an example of decision making for interpretation (since with any instrument, you will have to have that).

Great answer @AMcCord! I would just add - if you are just getting used to the echo or NEO - everyone has forgotten once and then they are really careful not to do it again; so don't beat yourselves up! I know I still check by ringing the vial like a bell at the beginning of my shift just to make sure! - Because - if the vial doesn't have the stirball and the person before you loaded it; it is stills works for the first couple hours or so until the red cells start to settle to the bottom of the vial!

Great Post All! Just one concern - Brenda, your last post mentioned missing weak antibodies and I know no one method is perfect (it's my mantra), but can you give us an example of which ones are weak/missed that are showing in PeG? And when you say questionable screen - do you repeat screens that have a history of antibody or just when they give you an equivocal result?? I've seen where others have done that during a transition period between switching methods - until they get use to it! And just since no one has mentioned it yet - we got a chance to look at the echo Lumena and have been fairly impressed with footprint and new and improve specificity (an issue solid phase has dealt with but seems to be getting better and hopefully much better on the Lumena!) and sensitivity has never been an issue for us with Echo. PS - @MaryPDX Thanks for the heads up on the Eflexis, I hadn't heard about that analyzer yet; but just keep in mind anything available in Europe usually takes 2-4 additional years for US to approve (from what I've seen in the past) so I wouldn't wait around for it!

To add onto what Malcolm stated as well - if we get unexpected reactivity in one method - we do use another method just to be sure - and if there is nothing there we usually monitor the patient with AHG XMs until the screen goes back to negative. We don't try to "chase something down" that isn't there or isn't "clinically significant." For example, we know we see more Jka's on echo that don't show up in other methods, but I am happy to identify them - the old philosophy "pay me now or pay me later," but we do see nonspecific reactivity. We've used manual gel, PeG, LISS, solid phase (echos) - and gel and echo seem to both have their issues with nonspecific reactivity but I do love when they "find the antibody first." I will also say that we treat our echos as AUTOMATION (not as a tech) everything goes on them; they are the first TOOL to do our workups, so we set our expectations to still do complex workups by bench. I couldn't imagine life without them. (we are a big hospital with lots of prenatals) However, when a complex antibody comes up or a screen is pos but the panel is unexplained or panagglutinin - we refer back to another method, and move on with life. I also don't believe in a "gold standard" in blood banking - everything is a tool to help aide in patient care (and safety). I think whatever method you choose to do primarily it is nice to have a flow chart or two - but of course they are not going to catch every scenario and there will always be exceptions. I'll try to get an attachment on here if I can! Nice thread!

The echo requires 250uL packed cells but this also allows for dead space and it doesn't use all 250 uL of packed cells. So after we finished testing with manual method, we took an aliquot of the red cells, spun them down, and only had about 150uL packed cells left over, but we tried it anyway and it worked just fine! (my BBTS said it's okay to try it if you have less, and if there wasn't enough sample you would get an X on the result and it would not be valid but if you get an interpretation it's fine). I'm trying not to over think this one... and CAP support said it was fine but I'll get it in writing from them if I have too.

I've had some inspectors that get really subjective on the standards and I always ask to call CAP "as a referee" or to get clarification of the standard - most of the time they are able to sort it out over the phone! When in doubt challenge the very same day they are questioning you. Sounds to me like your inspector is trying to understand the intent of the standard but may not be a practicing blood banker or they would know comparing IS XM to IgG crossmatch is not method correlation - I'd show them the technical manual in which explains the definitions of the two types of crossmatches and what they are used for - then hopefully the inspector would understand it's like comparing apples to oranges versus gala apples to golden crisp apples (for example gel AHG XM vs tube AHG XM for which the standard is intended). Just to cover ourselves as far as QC review goes - we wrote in our policy that QC is reviewed and passed and marked down on the daily maintenance record sheet and the medical director signs off on that sheet on a monthly basis - so the Medical Director is essentially reviewing that QC passes on a daily basis. If there was ever a QC failure, we have a seperate procedure for corrective action to document what we did to troubleshoot and when QC ultimately passed and the medical director signs off on all corrective actions documents as well. So maybe that might help for the future. It's absurd that the MD would have to look at every QC reaction on a daily basis! Good luck!

We use the 16 panocell from Immucor and it has 3-4 cells bracketed for the use of a "mini-panel" similar to the @ for ortho. However - if you look at the note at the bottom of the immucor panel it says this about the bracketed cells: "In those instances where a patient's serum is known to contain anti D, it may be desirable to perform antibody screening tests with D negative red cells. The panel cells whose vial numbers are set off by brackets [()] can be used together to form a three or four vial D negative antibody screening reagent. All bracketed cells must be used to construct a complete screening reagent" . The intent of the bracketed panel is not to perform antibody ID but to be used as an additional extended screen (especially if you use a 3 cell screen where cell 3 will be positive in cases of RhIg administraion). So we perform this "mini panel" as a screen - not as antibody identification. Remember - Screening cells are not required to have homozygous expression for antigens. Big distinction so I think people may be trying to use this for more than what it's intent is really for....like tbostock described above.

Great! I like your suggestion Donna - L106, Thanks! I also called CAP and they verified that we can use the manual- DAT survey (I meant to say DAT not J survey originally) on echo just like Donna suggested! They said that would be the easiest way since the automated method only does the IgG DAT (otherwise she said you could report out the automated method as solid phase IgG only - you could write it in (manufacturer is still Immucor) and make note in the comment section but that seems a bit confusing and I wouldn't want to fail on a technicality). Just another note - since this is really running as correlation - we would just looking for positive vs negative result, not grading, between tube and echo. I think the MD will be ok with this. We would still have to perform our parrellel/methods studies for the TRM.31450 CAP standard using our samples but that won't be a problem. The only thing I am worried about now is the stability of the DAT samples from the survey - they can't be hemolyzed or the monolayer will fail on the echo.... I guess we can just try it out and see how it goes. Usually they hold up much better than the JAT samples (we even let our students test the old DAT surveys from 6 months ago and they work in tube).

Our facility has decided to start running IgG DATs on our echo (for cords and investigation of warm autos) but there is one snag in the road - neither CAP or API offer an Automated DAT survey at this time - so what do other facilities do? We have a couple ideas but would love to hear what others are doing to stay proficient if running DATs on any automation... 1. Old school blind comparison? - procure blind samples from another facility near by that performs DATs on automation 2. Use the samples from the J (manual) CAP survey on the instrument - but how to report it out on the survey??? 3. Other suggestions????

HI Michaele, without going to much into the LIS world/language - I am wondering which LIS you use and how you set your system up to NOT do the IS XM. Logically like everyone else is saying the computer is validated to not let an ABO incompatibilty slip pass but our rules are set up as such we can't move on without entering IS grid results....? Any suggestions? Also, we are not electronically crossmatching yet but even if we were to go there I have heard the the rules are set in the truth tables to not allow electronic crossmatch if AHG crossmatch is required due to positive screen....any body have any suggestions for how to set up rules to just let the computer be the ABO crossmatch but not miss doing the IgG portion of the crossmatch? Good Topic no matter what type of AHG crossmatch you're doing ...

At our hospital facility we do not require Rh type to be performed prior to patient receiving RhIG therapy antenatal in an outpatient setting, but we do for patients that are admitted - It's part of CAP requirement TRM.40785. We have many doctor's office accounts for prenatal workups and it's up to the doctor to determine the Rh status of the patient. Then they sent the pt to our outpatient lab to recieve RhIg. Truly a transfusion service cannot "require" anymore testing than what the doctor orders. So if their order is for Rh immunoglobulin therapy - that's all they get - even if our facility has no Rh type on them. (I will say that 90% of the time we have a past history or a type and screen is ordered concurrent with the order for RhIG therapy). As far as standards go AABB Transfusion Journal vol 41,2001 committee report update from the 1990 SSCC report has recommended guidelines for prenatal testing in which First and subsequent prenancies should have ABORh and screen (with ABID workup for pos screen) tested on initial visit, and all D neg pregnancy should have testing before RhIg therapy. FYI - they also recommend that only when Rh is clearly positive (>/=2+) should the woman be considered D+. Thought that was interesting.

Currently our facility and our sister hospital (TriHealth in Cincinnati, Oh) does not but we are currently discussing this matter. If you perform electronic crossmatches, it IS a CAP standard to perform testing on a second phelebotomy (we still do tube crossmatches). It is only a matter of time before the standard is required for all samples that have the potential to be used for transfusion (pretransfusion testing) no matter what method is used to do crossmatches, so you might want to jump on the band wagon soon. It is the safest practice - and from what I heard, not too terribly difficult to implement in a hospital setting - when you explain to nursing the risks vs benefits of a redraw (which everyone hates). It is also possible to use EDTA samples from hematology from a seperate encounter (on same day as type and screen) which will reduce the amount of redraws needed. And most people needing blood have a CBC drawn around the same time ... so you just have to be able to prove it was from a different time of draw.

Solid phase is your primary method - you get a positive screen - let's say 1+ rxn on both, you run the ABID panel and auto/c or DAT and it's negative - what do you do?