Vikman

Yes you can for sure have an antibody to a reagent. I have seen it a few times against 0.8% Ortho reagents in GEL. We still primarily test in tube at my reference lab but when I do go to GEL, I tend to dilute out 3% Immucor cells instead of using the Ortho 0.8% cells to avoid any issues. I know in your case Ortho cells were negative but can definitely be directed against quotient cells.

I would definitely suggest using 2 drops of cells to 8 drops of DTT. You will lose cells in the washing process.

I work at a reference lab and I have personally worked up many Dara patients. I have had to DTT treat reagent cells only once to remove the reactivity caused by it. Every other instance I have been able to complete rule-outs/rule-ins in LISS. Maybe as these patients are on the drug for longer we will have to start DTT treating cells more but as of now it hasn't been as big of an issue as it was thought to be last year when this all started(at least for us). Has anyone else noticed this too? Could be we are just lucky with our patients.