Ortho Gel Testing

[speedwalker2k]

This is a question to all gel system users:

Our blood bank uses the Ortho Gel System for ABO/Rh, antibody screens & panels. We seem to have a lot of trouble with weak reactions & have been working hard to resolve this problem. Rouleaux is a contributing factor, as well as cold antibodies. We always make sure that we spin our EDTA tubes for 10 minutes, which has helped somewhat. We now do a lot of prenatal type & screens & have noticed that we are getting a lot more weak reactions. A lot of these weak reactions are haze/hazy, which could indicate rouleaux, but this is not always the case. When working these up, we rarely find an antibody. My question to everyone out there, is do you use Ortho Gel & do you have a lot of weak reactions, especially with pregnant women? I think that there may be an interfering substance (perhaps protein?) with the prenatal type & screens. Any ideas or help on this issue?

[Malcolm Needs ☆]

I can't honestly say that e have noticed this.

[galvania]

Malcolm - the cells you use in the UK are not the same as those used in the US. Could perhaps be relevant.

[Malcolm Needs ☆]

Could well be Anna.

[LIMPER55]

we also have a constant problem with the number 2 screening cell (3 cell screen) being hazy or one plus positvie.

the panel is usually all negative. the technical support claims we are the only ones having this problem.

yes-the pregnant specimens are prone to this-but not exclusively

[Bill]

We have a significant prenatal workload and have problems with weak reactions that turn out to be nothing; but, the issue is not seen in just the prenatal patients--across the board: prenatal, preop, oncology patients. Lately, we have had 2+ reactions with Ortho Scrn 2 (2 cell screen) that turn out to be nothing.

[Malcolm Needs ☆]

This thread is extremely similar to one begun by LaraT23 "Problems with cell#2 ortho screen cells".

In no way am I moaning about the similaritiy of the thread, but in both threads people have stated that Ortho say that "nobody else has had this problem". It is this (Ortho's responce) that I find very worrying.

Am I the only one who thinks that Ortho should look a bit closer into just what is happening (and, just maybe, be a bit more honest in saying that there is a more widespread problem)?

:confused::confused:

[RR1]

This thread is extremely similar to one begun by LaraT23 "Problems with cell#2 ortho screen cells".

In no way am I moaning about the similaritiy of the thread, but in both threads people have stated that Ortho say that "nobody else has had this problem". It is this (Ortho's responce) that I find very worrying.

Am I the only one who thinks that Ortho should look a bit closer into just what is happening (and, just maybe, be a bit more honest in saying that there is a more widespread problem)?

:confused::confused:

Malcolm, there are other companies that make these statements with equipment, reagents - and lab folk I have spoken to over the years just accept these, probably because it is easier than trying to find out the exact cause of the problem, especially as we are all under time constraints with trying to run our depts.

[Malcolm Needs ☆]

Malcolm, there are other companies that make these statements with equipment, reagents - and lab folk I have spoken to over the years just accept these, probably because it is easier than trying to find out the exact cause of the problem, especially as we are all under time constraints with trying to run our depts.

I quite agree and in no way am I "picking" on Ortho, or exonerating other companies in the same position.

[Likewine99]

We see this occasionally and find with pregnant patients that it is often a cold. Instead of doing the whole panel we often do a tube (LISS) screen or a prewarm screen.

We get a fair amount of rouleaux, not necessarily on pregnant pts but the is easily resolved. Remember gel is a tool on our tool belts, you could also repeat the screen with PEG or whatever other enhancement media you have.

If we can't resolve the reaction we call it "all common clinically significant abs r/o" and these pts would receive an AHG xm if they needed a transfusion.

[angie]

Is this problem observed only with ortho gel cards or also with diamed too. Is the solid phase grp system like Galileo better than the gel cards? looking forward to ur opinion.

[speedwalker2k]

That is all so helpful, thanks for responding. It looks as though we will have to make some kind of policy to troubleshoot these hazy gel reactions! I will run it by my supervisor. Too bad that is causes so much extra work to resolve this issue!

[speedwalker2k]

Maybe I should print all these responses out & mail them to an Ortho representative? Thank you to all that have responded. I am new to this & was not aware that there was a similar thread. I will be sure to be more careful in the future.

[David Saikin]

I have seen this problem spradically, but not with my patients - my referral hospitals are finding these 1+w rx in gel. Interestingly, if I have the same lot of cells, I can repeat these reactions. I usually get a negative panel, BUT I have found that most of these are enzyme sensitive. My feeling is that these are som HTLA-like antibody, since I can repeat the results from off-site. If I use an ortho panel to do the id's I will sometimes get a cell or 2 that reacts, but with no specificity. If I use a different vendor's panel, 99% of the time they are totally negative, but a few will also give that spurious w+ reactivity.

[nancanne]

We are just starting to do comparison studies before beginning use of gel. Already out of about 5 patients, we have encountered a 1+ reaction in Screen Cell II with no corresponding reaction in the tube test. We have to send out antibody identifications--came back as nothing. This will be a huge problem for us if it is this common.

[speedwalker2k]

David,

That is very interesting. I think that you may be onto something! I think that the gel system is very sensitive, but doesn't always pick up clinically significant antibodies. Another question, while we are on this subject, is about the centrifuge for the gel cards. We do an RPM check every day, but do not know of any other maintainance. Do you do anything more on your centrifuge? We use 15-40 mins as our incubation time, as that is what the package insert instructs you to do. Bottom line on all this workup on certain patients...it really seems like a lot of work for no significant antibody outcome. I am hoping that we can resolve this issue.

[speedwalker2k]

Nancanne,

I hope that this thread will help you when deciding what to choose in your comparison study. It has become a very big problem for us, since we now have a large population of prenatal profiles that we have recently taken on as our workload. I will continue to look into this & will welcome all the feedback that I can get. Good luck on your comparison studies...keep me posted!

[Antrita]

We have been having a lot of probelms in the past 6 months with weak looking reactions, especially with Cell 2. We are looking into automation this year and the Immucor Echo is looking better and better.

Antrita

[shelleyk482]

We are changing our primary method from manual gel to the TANGO. In doing our parallel studies we have had numerous cases of nonspecific reactions in gel that did not show on the TANGO; we sent these to a reference lab and without exception the reference lab did not identify a clinically significant antibody.

Yesterday, while training, we ran a patient on gel and the antibody screen was negative however the TANGO antibody screen was 3+ positive. Another tech repeated the gel screen and 3 of us (all with > 15 years experience each) called the screen negative. We then increased the plasma:rbc ratio and extended the incubation time to 45 minutes and was able to get a 2+ positive gel screen. The gel antibody panel was inconclusive, the TANGO panel was a clear cut anti-K. In reviewing the patient's history, we had done antibody screens 2 other times in the past 6 month, all negative, luckily she did not receive a transfusion either time and according to both her and her physician, she has not been transfused nor has she been pregnant (fullterm or miscarriage) during this time frame.

My staff is insisting on running all tests by both methods until our pathologist signs off on the validation, which I totally agree with-- they have lost confidence in the gel methodology. It has caused a lot more work than necessary with the numerous nonspecific reactions and then to have it miss an anti-K was the last straw in our facility.

[speedwalker2k]

Shelleyk,

That news is very disturbing to me! I know that our gel system has not picked up on anti-M antibodies, but they ended up being clinically insignificant. We too have had to extend our incubation period to pick up on things. Thank goodness that the patient that you mentioned was not harmed in any way! We have experienced so many nonspecific reactions in gel. When running the same patients with LISS, we usually get negative reactions. Thanks for sharing your experience. This will really help me as I delve deeper into this issue!

[cplatt36]

We use gel for both Type and Screens and have had a recent rash of patients with multiple myeloma causing us problems with the gel screens, but not always with the type. So I had everyone start adding plasma to the patient control cells in the screen, to pick up interference due to colds or protein. If the control is positive the screen must be redone using tube. This may help you.

[AMcCord]

We were having quite a few non-specific reactions, fuzzy, hazy etc. also. Pregnant ladies and Onc patients were the worst (and the majority of our patients! inconvenient to say the least). We started diluting up our 3-4% undiluted screen cells fresh each morning to 0.8% with MTS diluent 2 and using those for our antibody screens. That greatly reduced the problems we were having. We switched to Echo/solid phase in January and do not see many non-specific reactions in that same patient population. I had a conversation middle of last year with the supervisor of the reference lab we use about the 'gel problem'. She said that they have been receiving a significant number of samples that behave this way - funky in gel and negative with other methods. She also feels that the non-specifics could be 'formerly known as' HTLAs and/or white cell related antibodies. The problem seemed to get worse after Ortho's last reformulation of their prediluted cells. They were addressing complaints that the method was not sensitive enough. Now the method seems to be picking up stuff we'd all rather not see.

My recommendation is to dilute up your own cells. The hassle of doing that is small for the reward of many fewer problem antibody screens.

[speedwalker2k]

AMcCord,

That is all so helpful, I think that is a great way to alleviate this problem! Thank you so much for sharing your experience. Funny how the gel seems to pick up nonspecific reactions, yet it can also miss some clinically significant ones. I agree that these issues are a lot more common, now that Ortho has had a reformulation of their screening & panel cells.

[Geri Bollman]

our currrent lot of ortho 0.8% screening cell #2 is reacting with patients who also react with the BG+ cells on the panels, so i suspect there is some Bg on that cell.

Are your speicmen centrifuges ancient? We had noisy old things and switched to Helmer Quikspins in April 2008. They spin plastic tubes in 2 minutes (8000g). they were such a morale booster for our BB after years of spinning for 7+ minutes in extremely noisy centrifuges..

I think that we have had less nuisance antibodiies because of the Quikspins.

[AMcCord]

We use a StatSpin for gel specimens that spins 7200 rpm for 2 minutes 10 sec and were still getting fuzzies until we started diluting our own cells. Maybe a few more RPMs forces them into submission.