Screen cells vrs panel

[crisramirez]

I have a question here, and I would be glad if someone could give me information about that.

We got at our blood bank the next case

Screen cells I-II-III (standarized R1R1-R2R2-rr) positive in cell II

Then we ran a 11 cells in (column tecnology) Diamed and got the next results

1. 11 cells panel (not enzimatic treatment - IgG column) Negative

2. 11 cells panel (enzimatic treatment - NACL) positive, anti E

My point is...if the screen cell (IgG colum) is positive in cell II why the panel is negative..? Obviously, the 11 cells panel includes E positive cells and screen cells are have not been treated with any enzyme.

If someone could help It would be appreaciatte

best regards,

[rravkin@aol.com]

Chris,

What was the reaction strength of Cell II? Do you use Diamed column technology for your screen testing?

[Malcolm Needs ☆]

I agree with Ronald that the strength of the reaction with your screening cells is important.

The number of E antigen sites varies enormously (as it does with all antigens as a matter of fact), and it could be something as simple as the fact that the screening cells just happen to be at thew "high end" of this range.

On the other hand, it could also be that the screening cells just happen to also express an unknown antigen of low incidence that you are detecting by IAT, and that the anti-E detected with enzyme treated red cells is coincidental (I know, I know, I am hearing hoof beats and looking for zebras again)!!!!!!!!!!

:crazy::crazy:

Edited June 3, 2011 by Malcolm Needs
As ever, awful spelling!

[Liz]

crisramirez , this is a valid question and I agree with looking at the strength of cell II on the screening cells compared to the panel.

Malcolm, there are still spelling mistakes

[Malcolm Needs ☆]

crisramirez , this is a valid question and I agree with looking at the strength of cell II on the screening cells compared to the panel.

Malcolm, there are still spelling mistakes

Oh Liz - you KNOW is one of my many, many weaknesses!!!!!!!!!!!!!!!!

:haha::haha:

[dgibaud]

You also want to consider the freshness of the screen vs. the panel cells. Some antigens lose strength as they age.

Don

[David Saikin]

I have seen this phenomenon with the Ortho Screen Cell II (R2R2) also. Most of the time if I enzyme pretreat the panel is negative; about 30% of the time only the R2R2 cells react AND the patient is always E negative. I feel that I have no choice but to call it an anti-E reacting with homozygous cells. Even more interesting is the fact that if I make another vendor's panel into 0.8% cells it will invariably be negative - and only sometimes will enzyme pretreatment bring up reactivity with the R2R2 cells.

[crisramirez]

Hello,

Thank you for your replies...for those asking, Screen cells II (positive 2+).

and again.., when I ran the 11 cells panel results were

1.Negative in IgG column with no enzimatic treatment

2. positive anti E in Nacl column with enzimatic treatment.

thank you for your opinions

[crisramirez]

yeap...Diamed-Biorad tecnology

[John Eggington]

When you repeated the screen, did you use the same bottle of cells (not just the same batch). We've found that when cells start to 'go off' (for any number of reasons), they can begin to behave like enzyme treated cells; so if you use IAT cards you are, in effect, performing an enzyme IAT test - ideal for detecting weak Rh antibodies. If the effect is 'batch wide', it would seem more likely that the 'difference in antigen density' suggestion is more likley (although it would be nice to see some of Malcolm's zebras).

[profbaud]

You must be using Ortho gel technology. This problem pops up 2-3 times a year and I finally talked with Ann Steiner from Ortho after our state BB meeting and she says there is an association with Bg-EE on some R2R2 cells that causes this to occur that they can't explain. When this does happen, they eliminate that donor from the screening pool.

[Yanxia]

You must be using Ortho gel technology. This problem pops up 2-3 times a year and I finally talked with Ann Steiner from Ortho after our state BB meeting and she says there is an association with Bg-EE on some R2R2 cells that causes this to occur that they can't explain. When this does happen, they eliminate that donor from the screening pool.

What is Bg-EE, is it the Bg antigen and the EEantigen?

[rravkin@aol.com]

Chris,

Not withstanding the potential antigen expression differences of your reagent cells, do you have a transfusion history for this patient for the past three months and did you perform an auto control and/or a DAT?