Proficiency testing for automated DAT

[MeganPLT]

Our facility has decided to start running IgG DATs on our echo (for cords and investigation of warm autos) but there is one snag in the road - neither CAP or API offer an Automated DAT survey at this time - so what do other facilities do? We have a couple ideas but would love to hear what others are doing to stay proficient if running DATs on any automation...

1. Old school blind comparison? - procure blind samples from another facility near by that performs DATs on automation

2. Use the samples from the J (manual) CAP survey on the instrument - but how to report it out on the survey???

3. Other suggestions????

 

[Auntie-D]

We get control material from Switzerland I think...

[L106]

Megan - Since CAP does not offer an automated DAT survey (as far as I know), my suggestion would be a variation of the #2 option in your list:

 

1.  Perform your regular manual proficiency testing on the CAP-DAT Survey samples (and report your results to CAP.)

 

2.  Then perform the DAT testing on the CAP-DAT Survey samples on your Echo instrument.

 

3.  Don't submit your Echo results to CAP.  Rather, keep the results in a file.  When you get the results report from CAP, compare the report with your Echo results, document whether your Echo results were satisfactory, and have your Pathologist Medical Director sign and date this (and return it to your file.)

 

Donna

[MeganPLT]

Great! I like your suggestion Donna - L106, Thanks!

 

I also called CAP and they verified that we can use the manual- DAT survey (I meant to say DAT not J survey originally) on echo just like Donna suggested!  They said that would be the easiest way since the automated method only does the IgG DAT (otherwise she said you could report out the automated method as solid phase IgG only - you could write it in (manufacturer is still Immucor) and make note in the comment section but that seems a bit confusing and I wouldn't want to fail on a technicality). Just another note - since this is really running as correlation - we would just looking for positive vs negative result, not grading, between tube and echo. I think the MD will be ok with this.  We would still have to perform our parrellel/methods studies for the TRM.31450 CAP standard using our samples but that won't be a problem.

 

The only thing I am worried about now is the stability of the DAT samples from the survey - they can't be hemolyzed or the monolayer will fail on the echo.... I guess we can just try it out and see how it goes. Usually they hold up much better than the JAT samples (we even let our students test the old DAT surveys from 6 months ago and they work in tube).

[galvania]

You also have to be very careful if reagents that CAP (or anyone else) uses for a survey have been validated for use by one method, the results obtained in another method might not be valid at all.

[Eagle Eye]

Also hoe much specimen do you need to run DAT on ECHO? Pack cells???

[MeganPLT]

The echo requires 250uL packed cells but this also allows for dead space and it doesn't use all 250 uL of packed cells. So after we finished testing with manual method, we took an aliquot of the red cells, spun them down, and only had about 150uL packed cells left over, but we tried it anyway and it worked just fine! (my BBTS said it's okay to try it if you have less, and if there wasn't enough sample you would get an X on the result and it would not be valid but if you get an interpretation it's fine). I'm trying not to over think this one... and CAP support said it was fine but I'll get it in writing from them if I have too.

[BankerGirl]

I just saw this post, and in the event that you do not know this, API now has an automated DAT survey available.  Last I heard, it was not yet accepted by CAP, but they were to evaluate the results from 2016 and make their determination.

[Dansket]

I have been running the CAP Survey DAT for years on ProVue without any failures.  CAP provides 3 samples in sealed vials.  We thoroughly resuspend the contents of the vials and then pour the entire contents (2-3ml) of the vials into individually labeled tubes.  Centrifuge the tubes for 15 seconds (in the same centrifuge we use for tube testing).  Specimens are now ProVue-ready for testing.