Ortho Gel new prediluted cells formulation

[J Schuler]

We were seeing occasional reaction in screen cell 2. Now we are seeing it in screen cell 1. Has anyone been having problems with this cell now?

[Mary]

Yes, we have had several "false positives" on cell 1.

[janet]

Why do you think they are false positives as apposed to an antibody that seems to react only with that one cell?

We've had a couple since starting the new formual.....but we would get an occasional "unidentified" before too.

When we first started with the gel 6 years ago we were making up 0.8% from DBL 3% cells. We were having many reactions with S2 only......many were females and many of those females were childbearing age. Some were sent off to our reference lab along with a new aliquot of the cells.....they reproduced reaction with that cell only. We felt maybe it was in the Bg 'family'?!?!?

[Gerald]

This seems to be directly related with how long the screen cells have been at room temp.

All 5 of the positives that we have had with our current lot# were negative when repeated with a new set of cells (same lot#). They were also negative with our panel.

[Mary]

We had the same experience.

How long do you allow the reagent cells to be at room temp?

[RWOOD57]

Why does it react this way with just certain patients and not all patients, this problem can really get frustrating when your busy. Does ortho read this forum?

[babsglab]

I have no problems with cells because we are a small hospital (22 beds) and we put the cells away between use.

[babsglab]

I have no problems with cells because we are a small hospital (22 beds) and we put the cells away between use.

I will say I'm less than thrilled with the Ortho system- I only use their screening cells- all workups are done in tube with Immucor reagents.

Ortho used to set the standard for Blood Banking, now I think Immucor reagents are much better.

I wish Ortho would read this site.

[Mabel Adams]

Why do you suppose it is more likely to be screen cell 2--even on different lots? Just coincidence? I remember years ago reading of some ultra-sensitive method (polybrene maybe?) picking up anti-E antibodies that were not detectable by other methods that the author said were naturally occurring. I keep wondering if the cells can change with RT storage to somehow enhance the E antigen.

Has anyone reported this to Ortho yet?

[Kwenz]

We have also seen non-specifc reactions. Our last lot screen cell 2 gave us fits. All patients were negative with Ortho panels (A&, negative with panels using tubes with PeG. I had hoped it was only that lot but it happened again today. When I last called tech services, they said no one else had any problems. At least know I know we're not alone.

I'll also echo the problem with colds showing up (esp those homo only Ms) They cause a lot of problems as all of our techs are generalists and don't always think to look for that homo only reaction pattern.

I would say that the new formulation is no better than the old.

[Gerald]

I have called Ortho 3-4 times in the last 2 weeks. I was told that there has been other calls about this. I've had 5 occurrences on the current lot#, 4 on the 1st lot# we got after the reformulation.

Another question has come up in relation to this. Is it acceptable to qc 1 set of cells each day or does each set that's being rotated on the same day need qc done? I know different lot # would need to be, but what about if it's the same lot?

[Mabel Adams]

Usually I would say that only one vial needs to be QCd but with these current problems, different vials behave differently.

I talked to Ortho and they think it is because the cells are at RT too much so we will be refrigerating between uses more. They also suggested rotating the vials to me (daily I think) but I don't quite see the logic of that. It seems to me that they would spend just as much time at RT but it would be spread out over a longer period. And it would be a lot more confusing keeping track of QC and such. We will just put our rack in the fridge more than we were doing; I realize some places may not have that luxury. If that doesn't help, I will see how all of you that tried rotating vials thought it worked!

[Gerald]

I was rotating the cells at 24 hours. I'm now rotating at 12 hours and I haven't had any issues since.

[rcurrie]

Thanks, Gerald. We will give that a try. More reagent racks to QC! Although I think QC'ing one rack is okay legally (as long as the lots are the same), we QC each rack.

BC

[Mabel Adams]

This week I had a 36 yo head injury patient that recieved 1 unit 10 days prior show hazy reactions in gel. The weird thing was, there was a pattern to it! Certain cells were quite negative and others were really quite hazy with a sort of topline. There was no rouleaux detected in tube typing (patient A pos).

The panel almost fit anti-Jkb so I erred on the side of caution and got in Jkb neg units for him. I got a new specimen the next day for comparison and got the same screen results although weaker (pos in cells 2 & 3). It turns out he is Jka+b+ so I did not need the Jkb- units but I didn't know that at the time.

A tube screen was negative but I worried about a newly forming antibody that was partly IgM or something--especially in the Kidd system. He has been on TPN. Has anyone seen this sort of reaction in a patient on TPN or any other patient?

We can usually get rid of haze by respinning the sample. That didn't work.

[galvania]

Mabel - I have some questions for you?

1..What is TPN (sorry for my ignorance)

2..When you say 'gel' do you mean the MTS gel or are you talking about ortho?

3..What cells are you using?

Anna

[Mabel Adams]

TPN is total parenteral nutrition-an IV soup of proteins, lipids and glucose for patients that can't eat for a long period. They seem to give it over many hours per day so it is hard to get a sample without it being contaminated with it. I used to occasionally see positive DATs due to it. I don't know if it would affect gel or not.

In the US, the only gel system is MTS gel marketed by Ortho.

I am using Ortho's prediluted 0.8% screening and panel cells in the new diluent formulation.

Does that help?

[galvania]

Thanks for the clarification, Mabel. I get a bit confused sometimes a) because things aren't always called by the same name in British english (I grew up in the UK) and American English and because in Europe Ortho market a different card which has glass beads rather than gel - which people in Europe often wrongly still refer to as gel. The MTS cards that you have are equivalent to the DiaMed cards here in Europe. The reason I asked is because I know that from time to time we have had problems with the odd cell too, usually due to Bga (or any other of the Bg 'family'), but I also know that the buffering system is critical so maybe the new Ortho buffering system is less than ideal.

As for your patient, the TPN shouldn't normally have any effect, but then maybe if the buffering system of the cells is a bit 'off' then it might be enough to tip the balance. On the other hand, was the patient's Kidd group determined before or after transfusion? And have you done a DAT?

Anna

[Mabel Adams]

An auto control in gel (IgG) was quite negative so we didn't do a DAT. My experience is that the autocontrol in gel is a lot more sensitive than the tube DATs that we do. I guess I could have looked for complement. We have to keep our samples for 7 days post-transfusion, which is 10 days post-collection so we still had his pre-transfusion specimen. That is what we typed for the Kidd antibodies. I also typed the unit that we gave him then and it too was Jkb neg. I need to try to get another specimen on him and see if anything has changed by now.

[Yanxia]

Mabel Adams, I don't know whether you can get the prior donor's sample( the patient had transfused 10 days before). If the antibody is new developed it mybe induced by the antigens of this donor, so it can react with it . If it is possible, you can test the antigen to deduce a conclusion from it.