We prepare our elutions with Immucor's Elu-kit and have validated them in gel, which works great - both in testing and volume needed for the antibody identification. However, recently, we have seen a few interesting cases in which the patient is in the process of making an antibody and the antigen positive cells react with definite positive reactions (2+). However, on a majority of the antigen negative cells, there are definite junky, repeatedly-reactive, weakly positive reactions. After several weeks, the eluate 'settles down' to just the original antibody identified and the junky reactions are gone. Has anyone else had this experience or can explain what we are seeing?

When you say the eluate "settles down" after several weeks, do you mean you are retesting the same eluate a couple of weeks later or making an eluate from a new sample collected several weeks later--or even making a new eluate from the original sample after the sample is several weeks old?

The patient has come in as a new encounter. We type and screen the new sample and the patient eventually reflexes to an eluate. New sample, new eluate preparation and testing.

I can't figure out why you are even doing an elution. Does the patient have an autoantibody? If the autocontrol is negative, then I can't see you doing anything but a straightforward antibody ID panel (with select cells if necessary).

BC

I am assuming you are still finding a pos DAT at the later visit so that is why you do a repeat eluate.

I have read that many people that start making alloantibodies also temporarily make some autoantibody. It is almost like the immune system "ramps up" generally at this time.