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ABO/ Rh Testing- MTS gel vs. Tube


KBBB

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Hi,

I have worked in several other hospitals that did MTS gel Antibody Screens and panels, but did ABO/Rh testing by tube. It was because the tube testing is cheaper (and of course faster). We only have one MTS centrifuge. What are your opinions on the comparisons of the gel and tube methods for ABO/Rh testing on patients and retypes on units?

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I have been fighting off the Ortho Rep for about a year now because he would like for us to evaluate the ABO/Rh gel cards. Simply put, I can do an ABO/Rh less than 5 minutes, the gel takes 10 just to centrifuge the card. If we are doing a crossmatch on someone with no previous record, you have to wait at least 15 minutes before you even know what their type is. You also introduce a new diluent into the mix as well so I worry about the techs mixing them up (not sure what the difference in the two are). All of the techs here are generalist and there is not a tech dedicated to just blood bank so use of time is important here. I will continue to use tube for as long as I can. Just my 2-cents!;)

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I VOTE FOR TUBE TOO

The reason is same as Vic. I don't know the sensitivity difference, but I think we do forward and reverse type in ABO ,so we can find the subtype by it, although the method we use not dest the antigen.

As to D antigen, we all know too sensitive is not a good point in receipt.

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Vic,

Diluent 2 plus contains EDTA while Diluent 2 does not.

Agreed on the time issue. We use the MTS cards for our ABO/Rh, but retypes are performed in tube. In emergency situations it is common for techs to "do a quick tube type/rh" so the crossmatch can be started quicker.

Edited by Deny Morlino
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Hi,

I have worked in several other hospitals that did MTS gel Antibody Screens and panels, but did ABO/Rh testing by tube. It was because the tube testing is cheaper (and of course faster). We only have one MTS centrifuge. What are your opinions on the comparisons of the gel and tube methods for ABO/Rh testing on patients and retypes on units?

I agree tube method is a lot faster and cheaper, one can even perform an IS XM while waiting for Antibody screen hoping it would be negative :). The only advantage of having a second method (gel method) would be if you do electronic XM on patients with no history and only one tech on shift. With one centrifuge multiple patients and phone calls good luck on setting up ABO types before it's time to centrifuge AB Screen cards. I myself prefer setting up ABO typing one patient at a time even if I've set up AB Screens on multiple patients. I would not suggest gel typing on donor re-types I'd rather do slide method (as far as I know this is still an acceptable practice) and use tube on re-typing Rh Neg.

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I love ABORh testing in gel. My hospital is very small, all techs are generalists. I don't have any one that can determine mixed field in the ABD tube test. In gel it is obvious - and needs to be investigated. More expensive - not by much anymore; definitely more time consuming - you have to be able to generate a type fast (tube). You have to perform Weak D on cords bloods, but I even do that in gel. It standardizes almost everything, though I don't care for using 10uL of packed cells - I can't validate that. I can antigen type using 25uL of exhorbitantly overpriced antisera. I can do direct coombs' tests (and the complement check cells are always 4+); There are cards available outside the usa with all types of possibilities. I actually read an article where a group in remote Africa had validated the Kleihauer-Betke using gel (but lost sensivity with very small bleeds). Questionable cards may be preserved for future interpretation. The cards go in regular waste, not biohazard - my solid biowaste is down 60%. I like it more than I thought because it is more versatile than I thought. Capture has its excellent points also. If you are going automated, Immucor offers more choices - Ortho has the Provue.

Edited by David Saikin
I can spell?
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Thanks for the input. There is no BB computer, so no computer crossmatches and no automation. As to the expense, I haven't done the cost analysis yet, but time is money too. No cord bloods (not that kind of hospital).

Antigen typing isn't an issue yet since we are just starting up the transfusion service and won't be doing panels in the beginning. I just barely started working there and working on this project (week #2) We can get Ag typed units from the blood center. We also won't be doing DAT's at first (other than maybe for any transfusion reactions...figuring that all out). I suspect the number of DAT's ordered is low.

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We use the gel for everything. I agree with David that you can see what generalists are questioning. We also have all generalists in the Blood Bank. The pricing for the ABO gel is actually not any more expensive than the reagents since our reagent prices are high. We haven't had a problem with mixing of diluents since Diluent 2 is only used for auto controls and complete crossmatches. We also only need to complete QC by one method.

If there is a real question about the ABO, we will go back to tube.

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I agree with Deny and others about using the Gel primarily: We use the MTS cards for our ABO/Rh, but retypes are performed in tube.

We don't have generalists our staff is dedicated, and I know they appreciate the gel method for its many advantages.

Even the tiniest Labs in the country are using gel for convenience.

Liz

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We have found the anti-D reagent in the ABD/Reverse cards is more sensitive than the tube anti-D. We do routine ABO/Rh's in gel cards, in the emergent situation we use tube reagents.

Our cost has gone up considerably on traditional tube reagents and fortunately we have a ProVue. It has freed up some hands on tech time so we are able to concentrate on other tasks (such as answering the phone 1,000 times/day).

Our techs are mostly generalists with only a handful of seasoned (read middle-aged) bloodbankers that have a lot of BB experience.

Generalists love ABD's in gel, esp on the night shift when they are doing 10,000 things at a time and covering multiple benches.

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David, Are you using A/B/D monoclonal cards for CORD?

I love ABORh testing in gel. My hospital is very small, all techs are generalists. I don't have any one that can determine mixed field in the ABD tube test. In gel it is obvious - and needs to be investigated. More expensive - not by much anymore; definitely more time consuming - you have to be able to generate a type fast (tube). You have to perform Weak D on cords bloods, but I even do that in gel. It standardizes almost everything, though I don't care for using 10uL of packed cells - I can't validate that. I can antigen type using 25uL of exhorbitantly overpriced antisera. I can do direct coombs' tests (and the complement check cells are always 4+); There are cards available outside the usa with all types of possibilities. I actually read an article where a group in remote Africa had validated the Kleihauer-Betke using gel (but lost sensivity with very small bleeds). Questionable cards may be preserved for future interpretation. The cards go in regular waste, not biohazard - my solid biowaste is down 60%. I like it more than I thought because it is more versatile than I thought. Capture has its excellent points also. If you are going automated, Immucor offers more choices - Ortho has the Provue.
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We also use the gel for everything except unit retypes and retypes on new patients (2nd specimen). When we first looked at the gel we didn't think we would use the ABD cards, but the convenience for batching routines is great.

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for your RH neg CORD specimen---you perform weak D testing on gel??? How about AB Positive patient, do you run control card? I know new revision indicates that there is no need to run control card but under limitation it talks about CORD specimen. So I think it would be wise to run either control card or use ABD monoclonal and reverse card.

One more question: Do you run weak D in IgG gel card for all your Rh NEG patient or only prenatals???

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This thread is interesting because it shows the direction of blood bank testing towards automation. Sure, today we may utilize these gel cards manually but this is just a stepping stone towards blood bank automation and I think that we should understand that we are witnessing the threshold of blood bank automation; for better or for worse. I have heard arguments from both sides, for and against automation, but as a spectator the whole process is exciting to see. One of the biggest concerns with blood bank automation is accountability; as David Saiken has posted in a previous thread CAP requires 100% correct results in blood bank; this statement pertaining mainly to ABO/Rh testing. When your patient population will continue to grow and have no prior history pertaining to ABO/Rh type accountability is a very big priority when automating a blood bank.

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This thread is interesting because it shows the direction of blood bank testing towards automation. Sure, today we may utilize these gel cards manually but this is just a stepping stone towards blood bank automation and I think that we should understand that we are witnessing the threshold of blood bank automation; for better or for worse. I have heard arguments from both sides, for and against automation, but as a spectator the whole process is exciting to see. One of the biggest concerns with blood bank automation is accountability; as David Saiken has posted in a previous thread CAP requires 100% correct results in blood bank; this statement pertaining mainly to ABO/Rh testing. When your patient population will continue to grow and have no prior history pertaining to ABO/Rh type accountability is a very big priority when automating a blood bank.

Very good point!

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Hi,

I have worked in several other hospitals that did MTS gel Antibody Screens and panels, but did ABO/Rh testing by tube. It was because the tube testing is cheaper (and of course faster). We only have one MTS centrifuge. What are your opinions on the comparisons of the gel and tube methods for ABO/Rh testing on patients and retypes on units?

Interesting Question - One that will be discssed at the ASCLS Region III meeting being held September 22-24, 2010. In Savannah. On Wed. Sept. 22,2010 Jill Dennis of Thomas University will be giving an update on gel vs. tube. For more information on this meeting you can contact: brussell@mcg.edu or go the ASCLS webpage and look up events for September. Hope to see you there.

CBates

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We use both gel and tubes. Gel on the ProVue and tubes when performing any testing manually.

Gel IS more sensitive than tubes, but if you know that, you will be fine. If we get a 2+ or less in gel for the D, the patient is considered Rh Negative. (Usually they are a weak/partial D when that happens).

Gel does cost more and takes more time, but you can definitley see mixed field and can save the results for someone to look at later. (And that's a good thing when you have generalists in the BB!!)

Denise

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Hi Denise - Have you done a correlation with Weak D's and 2+ gel D rxs? Most of my pts who have historically been weak D in tubes are 3-4+ in gel.

We did not perform a formal correlation, but when we had known weak D's or when we do get a 1-2+ reaction, we repeat it in tubes and it is negative at IS and 3-4+ at IAT phase. We've probably seen over 20 of them in the last 2 years.... not a whole lot, but enough to add to our procedure that if you see a weak anti-D reaction in gel, call them Rh Negative...

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