Jyoung

I would question why your system let you issue blood on a patient with an antibody that was not cross matched through AHG phase. Our system (HCLL) sees anti-D as a level three antibody and would have never let us tagged the unit unless it was emergency issued.

Two things spring to mind - one simple and the other chasing zebras. Firstly, is your Dil2 at the same temperature as your PBS? If the PBS is at a slightly warmer temperature than your Dil2, it could just be that the red cells are already coated in a "cold reacting" antibody and that the change in temperature is sufficient to cause spontaneous agglutination. Secondly, it could be that your patient's red cells are low in sialic acid, and that something in the Dil2 is causing them to clump. Have you tried typing them for the M and N antigens?

I found in the package insert for the MTS Diluent 2.  It lists Trimethoprim and Sulfamethoxazole as preservatives.  These are antibiotics and maybe some patients build antibodies to these drugs. Not sure but seems like this is what was going on in my case.

I had never heard of it either until after attending a SCAB conference a few months ago.  Apparently you can add Combs AHG (IgG) to bind to the antibodies that are causing a positive DAT.   This will then block those antibodies from reacting when phenotyping a patient through the AHG phase. How or why this doesn't block the antigen when phenotyping I do not know? But I was told it doesn't.  I was also told this technique is mainly used for those patients with a strong postive DAT, where the DAT is still reacting after treatment with EGA.
 
Thanks,

That made me burst out laughing. In America that would be a very vulgar statement indeed !