In all my years performing lab inspections, I never really thought of this...

Most labs will QC their MTS IgG cards using the IAT method (QC serum w/ antibodies and screening cells) of course, but I don't see labs performing QC with the direct AHG method using IgG coated cells. And, of course the maunfacturer's instructions are vague.  What are others doing and how have other accreditation agencies (I'm with COLA) interpreted the QC requirements for the IgG cards for indirect and direct AHG testing?

The cards need to be run with a positive and negative control specimen.  they do no require the use of sensitized cells.  the igg cards use the antibody screening cells with a pos and neg serum/plasma.  I don't find the directions vague.  FDA requires all gel cards be tested day of use with a positive and negative (this includes those cards used for ABORh and AB testing).

We do run IgG DAT's on ProVue for Cord Blood testing.  We make our own positive (O Pos donor cells coated with IgG) and negative controls since there are no manufctured controls for this.  It seems like this is more in the way of QC'ing the method since Antibody Screen QC QC's the IgG reactivity of the Gel cards.

So as a negative control do you use an IgM antibody or just a cell that is not sensitized?  Seems to me that is like running a B cell as the negative control for A1 lectin (instead of an A2 cell).  Does it matter for a positive control to have the antibody "preattached" or let it attach in vitro in the gel card - seems like you are testing the same thing - your card is detecting IgG sensitization.

Edited December 30, 201410 yr by David Saikin

So as a negative control do you use an IgM antibody or just a cell that is not sensitized?  Seems to me that is like running a B cell as the negative control for A1 lectin (instead of an A2 cell).  Does it matter for a positive control to have the antibody "preattached" or let it attach in vitro in the gel card - seems like you are testing the same thing - your card is detecting IgG sensitization.

 

So our negative control is just an unsensitized cell.  This may be overkill as the QC we do with Positive and Negative antibody screen actually QC's the IgG reactivity of the gel card.

Edited December 30, 201410 yr by Sandy L

We run positive and negative control for screening cells using positive and negative antibody screening specimens which can be used as reactivity of the surgiscreen. 

 

We also run positive DAT and negative DAT specimens (Pos=rh Pos donor coated with anti-D, Neg=uncoated donor cells). We make suepension of this cells with MTS 2 plus and MTS 2 and run  it on IgG gel card. 

this way you are testing your MTS diluents also. (Once we had negative control came up positive and it was due to contamination of MTS 2 reagent).

  I do the same as Eagle Eye above except we buy Alba-QC and take one of the tubes that is Rh positive and just add our Anti-D. This has always worked well. We have been inspected by CAP and Joint Commission and nobody has questioned us doing it this way. i also do AABB assessments and this works for that inspection also.

We do the same as Sandy L.

I do the same as Eagle Eye above except we buy Alba-QC and take one of the tubes that is Rh positive and just add our Anti-D. This has always worked well. We have been inspected by CAP and Joint Commission and nobody has questioned us doing it this way. i also do AABB assessments and this works for that inspection also.

Kathy,

Could you provide more detail as to how you convert an Rh positive AlbaQ-Chek vial to give it a positive DAT?

I've tried adding as little as 5ul of ORTHO BioClone anti-D to vial 2 or vial 4. When testing on ProVue, this results in an "unwanted positive Rh control" when tested with the A/B/D Reverse Grouping gel card as well as a positive DAT with the anti-IgG gel card.

Edited January 25, 201510 yr by Dansket

The brief time period that we ran cord bloods on our ProVue, we did the same thing that Kathyang did.

We added a bit of anti-D to the AlbaQ vial 4 and ran an IgG-DAT on vials 2 & 4, to have neg/pos QC for the MTS 2 Solution.

Now that we stopped doing cord bloods we only do Type and Screens with vials 1, 2, and 3 for QC. Those three vials encapsulate all the QC requirements.