Patient's antibody workup 4 months ago revealed Anti-e and Anti-C.  Patient's blood type is historically O Pos and is the same on the current specimen.  Current specimen antibody workup appears to be an Anti-D and Anti-C.  With a positive Autocontrol and a negative DAT.  Explanations please!

What's the diagnosis and what technique do you use for DAT?

Female or male? Being treated for ITP?

Are you certain that the anti-C and anti-e were alloantibodies in an R2R2, and not auto-antibodies in an R1R1, or that the anti-e (at least) wasn't an auto-antibody in an R2r, with the anti-C being an alloantibody all along?

What is the ethnicity of the patient? That information would help too. DIII individuals are strongly D+, but often make anti-D, but are also G-, and can make an anti-C+G that can mimic an anti-C+D.

The patient is a Latin American female. The auto control was negative. DAT is also negative. The patient is an oncology patient. She hasn't received IvIg.

You've said the autocontrol is positive and negative, which is correct?

What is this patient's Rh phenotype?

(DIV could also look like a normal D+ and make a nice anti-D)

Has she received any blood or platelets in the last 4 months?

Was the patient transfused within the last 3 months?? Anti-C and Anti-D are actually an Anti-G. What is the Rh type of the patient?

My first instinct was anti-G. I've seen it (once)