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I am sorry if this has been discussed previous... I searched and didn't find anything.  Quick question...

We are transfusion service that performs DAT's using poly-clonal IgG... if it is positive, we run the mono-clonal IgG, however, we do not run the C3d.    How many of you would and/or do run the complement control cells for DAT QC in addition to Check Cells?  

 

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With a positive poly on a DAT, we only run the anti-IgG here.  But we send the specimen out to a nearby lab for the Compliment.  We do not do the anti-compliment as we do not want to pay for the QC material that we would have to buy (and mostly waste when it outdates).

Scott

 

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TRM.40200 DAT Controls Phase II
When performing an antiglobulin test with anti-IgG or polyspecific antiglobulin reagents, IgG-coated red blood cells are used as a control in all negative antiglobulin tests. NOTE: IgG-coated red blood cells must be used to confirm all negative antiglobulin test results when the antiglobulin reagent used for testing has anti-IgG reactivity. Tests found negative by tube methodology must be verified by obtaining a positive test result after adding IgGcoated (control) red blood cells. If a licensed blood typing system is used that does not require
verification of negative test results using IgG-coated red blood cells, an appropriate quality control procedure must be followed, as recommended by the manufacturer.
Evidence of Compliance:
✓ Records of testing that include control results confirming negative antiglobulin tests

TRM.40210 DAT Phase II
When performing an antiglobulin test with anti-C3 antiglobulin reagents, C3-coated red
blood cells are used as a control in all negative antiglobulin tests.
NOTE: Complement-coated red blood cells must be used to confirm all negative antiglobulin
test results when the antiglobulin reagent used for testing has anti-C3 reactivity. Tests found
negative by tube methodology must be verified by obtaining a positive test result after adding C3-
coated (control) red blood cells.
If a licensed blood typing system is used that does not require
verification of negative test results using C3-coated red blood cells, an appropriate quality control
procedure must be followed, as recommended by the manufacturer. If a polyspecific antiglobulin
reagent is used, refer to checklist item TRM.40200.
Evidence of Compliance:
✓ Records of testing that include control results confirming negative antiglobulin tests

**********************************************************************************************************************************************

I was cited for this years ago. I called CAP and was told that because poly AHG has anti-C3 reactivity as well as anti-IgG reactivity, both had to be confirmed. In addition to this std, she also referred me to the all common checklist which requires that we perform QC on reagents every day of use. So unless the manufacturer of our reagent had some other recommended QC procedure for C3 reactivity, we were required to use the complement coated cells. I put a standing order in for C3 coated cells that day, sent the confirmation email to CAP and my citation was considered corrected on site. I would assume that AABB would view this in a similar way, not to mention CLIA.

When we do a DAT, we are looking for both anti-IgG and anti-C3 activity.  If the DAT is positive with poly and anti-IgG, that doesn't preclude anti-C3 activity. If you aren't doing QC for the anti-C3 activity of your poly AHG, how can you demonstrate that your reagent is reacting properly? If you send all DATs out to check for C3 activity, then you would only have to QC the anti-IgG activity and your reference lab would be responsible for the C3 activity. 

Having said all that.....have I ever seen a failure with the C3 activity? Nope and I don't expect to. I've given students anti-C3b, -C3d reagent that's outdated by years and it still works just fine. But that's irrelevant and not how the game is played. We don't do very many DATs, but that's also irrelevant. So, I stock the C3 coated cells. Cost of doing business. I find ways to save in other areas.

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I have never seen that interp for polyahg requiring IgG and C3 sensitized cells.  It seems to me that the final sentence of referring to TRM.40200 allows the use of the IgG sensitized cells to document the reactivity of your poly reagent.  I know I am not the only one who interprets this.  I will f/u w CAP on this.

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Regardless of a particular regulatory requirement concerning DAT QC,  I believe that one must at the least follow manufacturer's recommendations for a particular system.  For our Ortho BioClone polyspecific, the procedure requires both types of sensitized cells for positive controls.  This makes sense to me.  And besides showing that the cell-washer is working properly, one has to prove that the reagent can give a positive with both compliment- and IgG-sensitized cells.

Scott

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I have heard from CAP on this question - and I quote:

" Mr. Saikin

If you are using polyspecific reagent, you are only required to confirm negative results with IgG-coated red cells.  C3-coated red cells are only required with anti-C3 reagents are used (sic).  The last sentence in the note for TRM.40210 states that if polyspecific reagent is used, the TRM.40200 applies.  I hope this helps.

Regards,

Sarah Fabian, MLS(ASCP)"

If you use polyahg, you only need to run IgG check cells to confirm negatives.

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But...but...but...

polyspecific reagent DOES contain anti-C3...

(And I do not think that Ms. Fabian would suggest ignoring any manufacturer's recommendations contrary to her quote above.)

 

Scott

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My interpretation: Users of POLYSPECIFIC antiglobulin reagents are obliged to verify performance each day of use, i.e., QC should involve use of IgG-coated cells AND Complement-coated cells. This gives the user confidence that the reagent is performing as expected.

During routine testing, addition of IgG-coated cells to negative tests is sufficient to verify that the IAT was performed correctly - correct/effective washing, the antiglobulin reagent was added and is reactive, etc.

If it were a requirement to add IgG-coated cells and complement-coated cells to every negative IAT using polyspecific antiglobulin, it would be necessary to run everything in duplicate - one set would get IgG-coated cells and the other set would get complement-coated cells. I don't think that is the case.

Edited by exlimey
Typo

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