Anti-CD38

[WisKnow]

Does anybody know if "antigen typed" cord cells are commercially available in the U.S. for use instead of us treating our screen and panel cells with 0.2M DTT when working on multiple myeloma patients receiving Anti-CD38 or Daratumumab?

[Mabel Adams]

Back in the day, they used to include a vial of O cord cells with panels.  I believe they quit because they had not had a practice of getting consent to use those cord cells.  I imagine it would be quite a headache to set up a system for getting consent and the parents might expect to be reimbursed for the commercial use of their baby's cells.  If I am remembering correctly, I doubt that anyone will be producing cord screen cells any time soon in the US. 

[WisKnow]

Thank you Mabel! That means we will continue to use 0.2M DTT treated cells. 

[David Saikin]

Mabel is right on with her reply

[exlimey]

Mabel is quite correct - I also remember that there were a number of ticklish "administrative" issues.

A more technical note: Since the volume red cells from one cord are small, I suspect the the products that were distributed were POOLS of cord cells. That is the only way that the manufacturers could have enough volume to make a viable product.  A pool would mean a mix of phenotypes and the product wouldn't be much for the application suggested by WisKnow.

Edited July 11, 2016 by exlimey

[Lingkwyz]

I wish I could get me one of those 0.2M DTT-treated cells. Our institution is currently serving one patient under DARA. fingers crossed.

[dot]

I was wondering where could I get the 0.2M DTT-treated cells?  We are starting to get patients that are taking the Anti-CD38.  I've looked on Ortho web site but couldn't find anything. 

Thanks in advance. 

[WisKnow]

6 hours ago, dot said:

I was wondering where could I get the 0.2M DTT-treated cells?  We are starting to get patients that are taking the Anti-CD38.  I've looked on Ortho web site but couldn't find anything. 

Thanks in advance. 

Hi dot!

I am not sure if there are 0.2M DTT treated cells readily available commercially if that is what you meant. We prepare our 0.2M DTT and use it to treat the positive cells we selected for antibody workup. It's a piece of work because you have to set up 0.2M DTT quality control by picking a heterozygous E and a K+ cell, antigen type them before and after treatment with 0.2M DTT. Kell group is destroyed by it. So after everything has been ruled out, we still recommend K negative unit.

[WisKnow]

6 hours ago, dot said:

I was wondering where could I get the 0.2M DTT-treated cells?  We are starting to get patients that are taking the Anti-CD38.  I've looked on Ortho web site but couldn't find anything. 

Thanks in advance. 

 

9 hours ago, Lingkwyz said:

I wish I could get me one of those 0.2M DTT-treated cells. Our institution is currently serving one patient under DARA. fingers crossed.

I am not sure if there are 0.2M DTT treated cells readily available commercially if that is what you meant. We prepare our 0.2M DTT and use it to treat the positive cells we selected for antibody workup. It's a piece of work because you have to set up 0.2M DTT quality control by picking a heterozygous E and a K+ cell, antigen type them before and after treatment with 0.2M DTT. Kell group is destroyed by it. The antibody identification is performed using the treated cells and after everything has been ruled out, we still recommend K negative unit.

[Lingkwyz]

6 hours ago, WisKnow said:

 

I am not sure if there are 0.2M DTT treated cells readily available commercially if that is what you meant. We prepare our 0.2M DTT and use it to treat the positive cells we selected for antibody workup. It's a piece of work because you have to set up 0.2M DTT quality control by picking a heterozygous E and a K+ cell, antigen type them before and after treatment with 0.2M DTT. Kell group is destroyed by it. The antibody identification is performed using the treated cells and after everything has been ruled out, we still recommend K negative unit.

Thanks for the info WisKnow. Still hoping we get us one of those.

[Mabel Adams]

Does anyone know how long the DTT treated cells are stable?  Our reference lab makes them up as needed as I expect we will, but it would be interesting to know if you could store them for a few days or weeks. They might be able to freeze them as they do rare cells.  I doubt they would last long due to lack of preservatives.  As I recall, if we dilute 3% cells to 0.8% in the Ortho diluent 2 that lacks preservatives they are to be discarded after one day.

[exlimey]

On 9/10/2016 at 7:31 PM, Mabel Adams said:

Does anyone know how long the DTT treated cells are stable?  Our reference lab makes them up as needed as I expect we will, but it would be interesting to know if you could store them for a few days or weeks. They might be able to freeze them as they do rare cells.  I doubt they would last long due to lack of preservatives.  As I recall, if we dilute 3% cells to 0.8% in the Ortho diluent 2 that lacks preservatives they are to be discarded after one day.

On the surface, "stability" of red cell products appears quite simple. However, there are a huge number of variables to consider, especially the age of the cells when put into use. Chemical- or enzyme-treatment of those cells adds another huge wildcard - it certainly voids the original expiration date assigned by a commercial supplier.

One approach may be to treat cells of a known/fixed age, suspend them in a commercially available red cell preservative, and then test the untreated (in the same preservative) and the treated for the presence/absence of a variety of antigens over the course of a few days or weeks. Ideally one would test all the "clinically relevant" antigens. Or, one could choose those antigens that are thought to be less stable over time. The best serological way to detect weakening of antigens would be to prepare serial dilutions of the test reagents and run titirations against the untreated and treated versions of the test cells.

It's a lot of work and all the commercial suppliers have done it for all of their current red cell products. However, I doubt that they will ever supply  DTT-treated cells since the market is so small and potential profit very limited.