We had a cancer outpatient typed for platelets the other day. She has historically typed as an A pos, but now types as a very obvious, very clean O pos. We had the patient redrawn with the same results. Furthermore, after calling other hospitals, we found that we we are not the first hospital to see the same phenomenon in this patient. Previously, she has typed as an A at another hospital, then typed as an O some months later. Four days ago she was typed in our lab as an A. What could cause this? Is it possible that some of the chemotherapeutic drugs could cause an A to appear as an O? Other info: The patient is being treated for a myelodysplastic cancer. She has NOT had a bone marrow or stem cell transplant. She claims to have not received any blood products in the past four days. (4 days ago she typed as an A) Her blood smear showed junky looking red cells; lots of hypochromia, a lot of size varience, pappenheimer bodies, etc. This mystery is driving me crazy!
