To E or not to E? That is the ?

[Dawn M]

I am new to this site, but thought I would pick some BB brains.

63 y/o female GI bleed presented to OPD for 2 units rbcs on 8/17/03, MTS screen neg. Shen then returned 9/12/03, and an anti-E was identified (1+), pt typed as E neg. She recieved 1 unit E neg xmatch comp rbcs without incident.

She returned 12/5/03 with a micro DAT(PS and IgG), and a 3+ anti-E in the eluate, 4+ anti-E in her serum. She had not been transfused since the 1 E neg rbc on 9/12. At this time, we retyped her for E, and she now is m+ for E Ag.

The transfused unit had been retyped for E, and the DAT on the donor unit was neg.

Specimen was sent to reference lab for sub-group testing, but they were unable to perform molecular testing.

The patient has since been transfused with 4 units E neg rbcs without incident.

Any ideas?

[John C. Staley]

My first thought is too much microscope! :wink: What commercial anti-E are you using that requires reading with a microscope? Could the patient have been transfused at anyother facility between 9/12/03 and 12/5/03? One last question, was a control of the last wash run with the eluate and was it negative? (I'm assuming the answer is yes but I had to ask.)

[Dawn]

I agree that the E phenotyping is suspicious. As for the anti-E in the eluate, it could be residual antibody, but it could also be some sort of weird autoantibody that just looks like anti-E but really isn't.

These types of problems are so frustrating!

[John C. Staley]

Our local reference lab really likes the phrase " xxx like antibody". Example, we told them it looked like an anti-e and three days later they reported "anti-e like antibody". Ya gotta love it. :roll: