Biotest Reverse Cells

[Trek Tech]

We routinely test our reverse cells daily for positive and negative reactivity. We use anti-D for our negative control with the reverse cell as they are Rh negative. This is the second month in a row that we have found reactivity with our A1 cells and anti-D. The negative control comes off very rough and when observed microscopically needle-like crystals are seen. Biotest tells me that there is only one other account besides us reporting this. I don’t know if others routinely perform a negative control with these cells. Perhaps you should consider doing so.

[SMW]

Reverse grouping cells are generally used to test patient/donor serum/plasma. Perhaps the problem is with the control material you are using and not the cells. Do you see the same reactions when testing with plasma/serum (i.e., not reagent materials), e.g., when running serum/plasma from an A patient/donor with the reagent A1 cells? The reactions you may be seeing may be due to an additive, preservative, etc. present in the reagent anti-D which is not present in donor/patient samples.

[Lcsmrz]

What does Biotest say to use as a negative control?

[Trek Tech]

It happens with saline and it happens with an A1 patient. When you look at the cells under the scope there are actual crystals in the bottle of reverse cells.

[NANCY AUGENSTEIN]

We have noticed the B cell button first has the appearance of being positive, but after excessive shaking it comes off negative with patients who are type B or AB.

We routinely test our reverse cells daily for positive and negative reactivity. We use anti-D for our negative control with the reverse cell as they are Rh negative. This is the second month in a row that we have found reactivity with our A1 cells and anti-D. The negative control comes off very rough and when observed microscopically needle-like crystals are seen. Biotest tells me that there is only one other account besides us reporting this. I don’t know if others routinely perform a negative control with these cells. Perhaps you should consider doing so.

[Trek Tech]

We use Biotest's A1 and B cells for reverse grouping in tube. For the past 6 months our cells "go bad" after 3 weeks. The negative control turns 1+ in either one, the other or both bottles. When you look at a drop microscopically there are needle like crystals in the bottles. Biotest has been great about overnighting a new set but this is getting very old. They tell us that there is only one other account with this problem but I have to believe that it happens more frequently. Most people do not run a "negative" control with their reverse cells. (I have even tried using an AB plasma as a negative). We are very small and don't get both an A or B everyday. We might see an AB once a week. I believe this should be reported to FDA as a purity and potency problem. Anybody have any ideas?

[adiescast]

I don't use Biotest reagents. We are a large institution and we do not run a negative control with our reverse cells. We see enough patients of different types each day to act as negative controls.

Do you see the crystals in a fresh bottle of reverse cells or only in the older bottles? It may be that there is a problem with their preservative solution. If they are not taking the problem seriously, then you may want to talk to FDA. You could tell Biotest first that they are not taking this seriously enough and you are considering bringing it to the attention of FDA. Have you asked to speak with a supervisor or just worked with the line staff at Biotest?

You may also want to look at purchasing the reverse cells from a different supplier if this is an on-going problem.

[L106]

I don't use Biotest reagents. We are a large institution and we do not run a negative control with our reverse cells. We see enough patients of different types each day to act as negative controls.

I understand your logic, and I'm sure you are doing this every day, but are you documenting that the reverse cells were "tested against known Positive and known Negative samples each day of use and reacted appropriately?" I think some inspectors would expect to see documentation of that testing (and the supervisory review of it.)

[adiescast]

Actually, to my knowledge there is no requirement for negative controls for reverse cells. Our manufacturer's insert only recommends positive controls. Ergo there would only be a need to document a problem such as the oneTrektech2 describes rather than daily (day of use) documentation of negtive reactivity with supervisory review.

This has gone through multiple inspections by CAP, AABB, and FDA.

Edited January 7, 2010 by adiescast
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[Trek Tech]

I don't use Biotest reagents. We are a large institution and we do not run a negative control with our reverse cells. We see enough patients of different types each day to act as negative controls.

Do you see the crystals in a fresh bottle of reverse cells or only in the older bottles? It may be that there is a problem with their preservative solution. If they are not taking the problem seriously, then you may want to talk to FDA. You could tell Biotest first that they are not taking this seriously enough and you are considering bringing it to the attention of FDA. Have you asked to speak with a supervisor or just worked with the line staff at Biotest?

You may also want to look at purchasing the reverse cells from a different supplier if this is an on-going problem.

The fresh bottles are fine. I did email them saying that I was concerned about the "purity and potency" (a statement directly from CGMP) of their product and that got their attention. They assure me they are working on the problem. They thought it was my storage. I sent them 6 months of my chart recorders from my Helmer fridges (which were perfect). Unless they come up with something soon I will have to switch back to Ortho. Sometimes you get what you pay for when you go for lower cost.

Thank you for validating my concerns.

[jtsbbtalk]

Hi Everyone,

First - I must identify myself as the technical manager at Biotest in the US.

I really appreciate Trektech working on this problem with us, as well as all your ideas for possible reasons for the problem. Trektech is seeing these crystals regularly, however there was only one lot where another account saw them as well. With such a rare occurrance (one customer/set of cells per a couple of hundred users and even more sets of cells) trying to do a root cause analysis has been very difficult. Since the crystals only appear at her site after 3 weeks of product use, our testing at different temperatures etc - takes at least 3 weeks .

I do understand the frustration, because I'm feeling it too. (I don't usually answer these!)

While our investigation team/QA/QC is working on this, does any one have any other thoughts on what might be causing this? Especially at just one site routinely?

Thanks!

[Mabel Adams]

This is ringing some bells but unfortunately I can't remember as much about it as I would like. I can picture the crystals. It was quite a few years ago (probably in the 90s) and since we only used cells from Immucor, it must have been their reagents. Likewise, the bottles would be fine when we received them but over time would develop these crystals. We were always shipping them back to them and then they wouldn't find the crystals. We were a smaller lab, using 2-3 sets of screening cells per month. We were in a very dry climate so I seem to remember we felt that contributed to the precipitation of these crystals. I seem to think they were an antibiotic (sulfa, maybe) added as a preservative and once Immucor changed something in their formulation, the problem went away. Sad. I used to have a better memory than this. Anyone else remember such an issue?

[TeachBB]

We have seen the same crystal-like interference with their screening cells. As they get older, it gets worse. It's almost as if it's a diluent degredation problem. We have had to take several sets out of use due to this very problem...

Perhaps we are the other facility Biotest speaks of.....

[TimOz]

Sounds like the diluent is the issue.

I am not sure what Biotest use, but most manufacturers use Alsever's solutuion. This diluent was developed after sodium citrate and Rous-Turner solutions as a blood collection anticoagulant and blood unit storage solution in about 1939. Dr. John B. Alsever devised it to be used at a 50:50 mix with whole blood. So this diluent was never designed as an IVD cell suspension reagent for 3 or 15% cells and the design is over 70 years old.

I am completely guessing here but crystal deposition in storage is likely to be the dextrose that is in Alsever's at 2.05%. The Sodium chloride (0.42%) and Sodium Citrate (0.8%) are unlikely to come out of solution at refrigeration temperatures.