A pretransfusion antibody screen is positive with both screening cells, but the patient's autocontrol is negative. What is the most appropriate next laboratory action?
1Report the screen as negative because the autocontrol is negative and no alloantibodies are detectable, but first verify that the antibody screen cells cover all clinically significant antigens
2Issue uncrossmatched group O red cells for all future transfusions without further serologic investigation, as this is the safest approach for patients with possible antibodies
3Perform antibody identification and select antigen-negative, crossmatch-compatible red cells when indicated [CORRECT]✓ 정답
4Repeat only the ABO forward type using a different anti-A reagent to confirm the patient's blood group
해설
A positive screen with a negative autocontrol is compatible with an alloantibody pattern. The laboratory should identify the antibody and use its specificity to guide selection and serologic crossmatching of donor red cells.