A multiply transfused 52-year-old male was admitted to the ED with severe bleeding. His admission hemoglobin was 6.3 g/dL. The physician ordered 6 units of RBCs STAT. The patient's pretransfusion ABO grouping results are as follows: Anti-A Anti-B A1 cells B cells Patient Results 4+ 0 2+ 4+ Which of the following scenarios are consistent with the serologic findings in this case? Please select the single best answer
O An A2 with an anti-A1
O Abnormal serum proteins resulting in rouleaux formation
O An alloantibody reactive at room temperature
O A cold autoantibody
O All of the above