C3d positive DAT pre and post on suspected transfusion reaction

[milesd3]

last night we had a febrile suspected transfusion reaction which the pathologist determined was not a transfusion reaction. We are a small rural hospital and we don't do more than antibody ID.  In this case the AB screen was negative, the patient was redrawn and pre and post ABO Rh and screens were performed with everything looking good except the DAT's were positive 2+ on the pre transfusion sample and 1+ on the post.  Both DAT samples were negative with IGG only and positive with IGG/C3d.  I called our blood provider in hopes they could work this up as the patient is supposed to get more blood soon and I was afraid as to what night happen.  the nice lady informed me that working up compliment isn't something that is done.  I'm horribly confused with this as the work-up was at the request of our pathologist.  She mentioned taht compliment coating the RBC's was more than likely due to some medicine she was taking ans suggested I simply inform the patiens Dr. to premedicate with Tylenol and Benadryl.  Could someone please explain this to me as it seems comflicting.

Thanks

[David Saikin]

You can't elute complement from the red cells - besides which it is non-specific (though I wonder if there was an ab that fixed complement - Jk comes to mind - if it might be possible to elute it off even if the IgG DAT was neg.  Just a thought. 

 

Whenever I have dealt with a reaction on a patient with a pre and post + DAT we routinely performed the complete (ahg) xm on the pre and post specimens just to be thorough.  There is not much else you can do. 

[galvania]

Yes, David - I have seen an anti-Jka that was giving a C3d only pos DAT and was eluted (weakly!!) off of red cells.  But it doesn't sound like this is  the cause in this case as the DAT was already pos before.

I too would firstly carry out a crossmatch using pre- and post-transfusion serum on the units that were transfused.

And I wouldn't worry too much either!