Ortho Screen Cells False Pos.

[BBB in Alaska]

I am going to try my hardest to not make this a book..... Has anyone had problems with false positives with Ortho screen cells?? We are having them here in our lab and unfortunately this is a very small hospital and we don't do panels so then we have to send out the patients blood and then the other hospital calls back woth negative....so ortho recommended we keep the cells in the fridge always (didn't help) This also happened at the hospital I worked at before which was clear across the country and ortho said there were peolpe that hand antibodies to the gel and recommended we do a dilution with the MTS solution after we had done panel A and B and come up with neg. Recently we started using the new lot number of screen cells as soon as we get them , because they just don't seem to last. Oh, and a co-worker of mine was recently at another hospital and talked to their BB person and ortho had them cover their screen cells with construction paper to protect them from the light, and cover the top of the incubator....they said by the way, this didin't help!!!:mad: So, now I am ready to tell ortho good bye.....and go back to tubes!!! ANY IDEAS!????

[marvy1]

I have seen many examples of weak to 1+ examples on screening cells and 0.8% panels in Gel. Since their reformulation this has become a fact of life. The reformulation seems to bring up a lot of "garbage". If there is no clear specificity, we rule out using "home-made" 3% diluted to 0.8% cells which almost always are clean negative.

[David Saikin]

All of us gel users have been victims of this phenomenon . . . I do reference work for other hospitals and when we have the same lot of screening cells, we get the same results. I have found that most of these 1-2+ reactions with no specificity are enzyme sensitive . . . makes me think they are HTLA's (chido/roger/knopps/mccoy). Since I am duplicating other institution's results, I find the recommendations of keeping cells refrigerated/protected from light/etc have no merit (at least for me). I report these out as "ANTIBODIES TO THE ROUTINELY ENCOUNTERED BLOOD GROUP SYSTEMS HAVE BEEN RULED OUT" . . . we would give gel ahg crossmatch compatible red cells (if necessary). It seems the capture system also is experiencing phenomena of this nature . . . this is what happens when sensitivity is increased.

[dmpollock]

You might want to switch to 3-4% cells instead of prediluted, and make them up fresh every day. It is very easy. Where I used to work we used to do this and never had problems. We used plastic screwtop tubes for the cells (the same as sendout samples)

Preparation of 0.8% Screen Cells I and II (prepared daily)

1. Label two test tubes "I" and "II," and label both with the date prepared.
   
2. Pipette 300 µl of corresponding 3% screen cells into each.
   
3. Add 300 µl MTS Diluent 2 to each
   
4. Centrifuge 60 seconds.
   
5. Decant supernatant.
   
6. Pipette 900 µl MTS Diluent 2 into each tube.
   
7. Mix before each use.
   

[tbostock]

Yes, many frustrations with that here too. We have tried keeping them in the refrig, as well as trying their "protecting from light exposure" theory, and we have seen no improvement.

To save panels, if we have a positive antibody screen that looks like a false positive (weak reactions, usually only in one cell), we repeat them on freshly diluted Surgiscreen cells. If they are negative, we do not proceed to a panel.

[jhaig]

Same problems here in upstate NY. It seems like every third lot or so I get some type of 'scratchy' results, usually only one cell in the Ortho A and B 0.8% panels. I've also seen it enough in the pre-diluted screening cells, so I've looked into switching to Immucor's Panoscreen cells. These have to be pre-diluted to use in gel, but it's pretty easy. So far, I've run 50 patients with known antibodies and have had excellent correlations. Dumping Ortho's 'improved' formulations could always be an option. Any else have experience with Immucor's Panoscreen cells?

[Mabel Adams]

At my prior workplace we switched last spring to routinely diluting Immucor's 3% screening cells and it worked like a charm. Still the occasional weird cell on pre-diluted panel A, but we switched to 3% additional panels so we could dilute up our own cells for any follow-up testing. The panels were always less of a problem than the screen cells.

At my current workplace, we had a terrible time with this recently although we have not had the trouble until now that others have had since the reformulation. We are keeping the screen cells in the box they come in while out on the counters and that seems to have helped this time.

[Nancy L.]

We have had the same aggravating problems as well. Ortho has been less than helpful. They didn't return our phone calls and when we were able to get ahold of them they claimed that we must be contaminating the cells. It was months before they even acknowledged that there was an issue and that other people were experiencing the same things. They then suggested keeping them in the refrigerator. That didn't help at all. For the last couple of months we have been keeping them in their box anytime they're not actively being used. This seems to have helped since we've had no problems since we started that. I'm sorry to hear it hasn't helped most of you. We're glad to have a respite from this aggravation as we were getting very close to scrapping ortho altogether. They're still "on probation" in our book. I'm not nearly as aggravated about the difficulties with the reformulated cells as I am about the incredibly poor customer service. Wow - it feels good to vent!

[Eagle Eye]

our current lot is been giving us pos(1+) reaction with cell #2 and most of the time panel is negative. SOme time we get cell#4 and 6 positive. WE got a new lot and we repeated those patient and we got negative result and those patient's antibody screen is negative with immucor 3% diluted to 0.8%.

[bbbirder]

We have had many problems with the pre-diluted cells lately, so we switched to diluting up Immucor cells daily. Now only a very rare false positive and time wasted on a panel (for a while we were getting 3-4 each day.) Problems of false positives happened even with very fresh cells, over multiple lots of the Ortho cells.

I like the comment that they are on "probation". We get a new lot this week, and will try one more time before permanently switching to diluting our own cells.

Linda Frederick

[AMcCord]

We also dilute Immucor Panoscreen with good results.

[bxcall1]

We have also encountered some of the same issues, but then again, in the past couple of months I have ID'd 3 anti Jka's that reacted only with the homozygous cells. I was originally resistant to the gel but am starting to become a convert.

[bbbirder]

My issue is not with gel, but rather with the 'reformulated' diluent for the 0.8% cells from Ortho. In the last few weeks and months with have chased down too much garbage. Since pre-diluting our own cells, this has stopped. I don't think it has altered our ability to detect clinically significant antibodies.

Linda Frederick

[bxcall1]

I guess the point that I failed to address is that sometimes these 'garbage cells' that come up positive without apparent antibody specificity may indeed be in indication of something that is sigificant (or may soon be significant if/when the titer increases).

With this said, I too have wasted plenty of time working things up that turn out to be nothing. On the other hand, I certainly don't want the bench techs dismissing reactivity as 'trash' just because it doesn't fall neatly into a pattern on the antigram.

[Churchi]

We have had problems ever since the reformulation of the Ortho cells. Now I routinely run a DAT on the screen cells each morning - if they look hazy or have jagged button I grab another set. I hope they can work out the formula issues soon - we love gel but it's not very cost effective to have to go through screen cells like this!

[PammyDQ]

We use 0.8% Ortho Surgiscreen. Occasionally we will get a positive reaction(w+ to 1+) with a resulting negative panel with 0.8% Ortho Panel A (I will repeat the original screen to rule out contamination at this point). We will report the screen as "Positive" and the Antibody Identification as "No Antibody Identified". We will perform a gel crossmatch on such patients, and leave it at that. Naturally we would check our screening cells for donors positive for Kpa, Jsa, Cw, V, Lua etc. and if the positive cell corresponds to one of these, make sure our panel also includes it, or find a selected cell(s) to identify or eliminate these. Sometimes this appears to be "garbage" cell (seeing the same reaction with more than 1 patient) and other times these patients return at a later time with an antibody now stronger and identifiable.

Another phenomenon we have encountered several times is apparent antibodies to the antibiotics in the screening cell/ panel cell preparation.

Ortho 0.8% Surgiscreen and Panels contain Trimethoprim/Sulfamethoxazole. Ortho 3% Surgiscreen and the 3% Immucor Panocell 16 contain

Chloramphenicol/Neomycin Sulfate/Gentamycin Sulfate.

One red flag for this is positive reactions on all 3 screening cells with compatible crossmatches in gel. Repeating screen with washed cells, and/or repeating with cells that contain a different antibiotic in it's suspension may reveal this as a possible reason for positivity.

Edited December 27, 2008 by PammyDQ
added sentence :)

[Mabel Adams]

So when you turn out this reactivity as "No antibody identified" do you require that patient have antiglobulin XMs the rest of his life or just that one visit?

[Karen Olsen]

We have been Gel users for over ten years and have chosen not to use the pre-diluted .8% screen and panel cells. I can't tell you how many times I have been so thankful for this decision as I receive letters from Ortho with issues and as I read on BB Talk Forum of issues!! I did try the .8% Ortho panel when it first came out but had nothing but frustration :cries:with it and went back to diluting our own cells. We love Gel as long as we stick to our guns on this.

[PammyDQ]

I've been at this institution for 7 years and it's only been an occasional problem with "miscellaneous" reactivity with the 0.8% Surgiscreen cells, which have been in use for a few years before I came here.

In recent memory, we have had 2 antibody patients reacting with a particular PANEL cell of a particular lot that was negative for their known antibody, without any additional antibody being ID'd.

One practice we have here is aliquoting a small amount of each screening cell to be used during our shift. This prevents constant re-entering of the vials, which can result in contamination and possible unexpected reactivity. Also, if an unexpected reaction should occur and it appears to be "junk" we will repeat the screen with an unopened vial of cells.

Mabel, generally speaking, we would continue with gel crossmatches for these patients even if future screening is negative. We must assume that the reactivity is due to a low frequency antigen.

[Patty]

Don't you think it's about time for ORTHO to start putting their reagent in bottles that protect the reagent from light if they think that is the culprit?

[PammyDQ]

Don't you think it's about time for ORTHO to start putting their reagent in bottles that protect the reagent from light if they think that is the culprit?

I thought the "light" issue had to do with false NEG results, especially with Anti-E?

I'd hate the bottles to be opaque, then it'd be a pain to observe for discoloration and hemolysis.

As I stated before, our institution has had some "junk" on occasion, but certainly not often enough for us to be discouraged in the product overall!

[jhaig]

Don't you think it's about time for ORTHO to start putting their reagent in bottles that protect the reagent from light if they think that is the culprit?

Good luck finding your Ortho rep. to address this issue. I'm not sure I have one anymore.:cool: