Question

Robert Brown, transfusion ten years ago.

The pretransfusion 2-cell screen was negative using LISS. Group O Rh(D)-negative units were compatible when crossmatched at immediate spin and were released. RB was transfused with two units of RBCs during hip-replacement surgery.

One day following surgery, a delayed transfusion reaction was suspected because of a drop in hemoglobin. A transfusion reaction workup was requested. The pre- and post-samples were compared visually for hemolysis. The DAT on the post-reaction sample was microscopic positive. The posttransfusion antibody screen was 2+ positive with one of the screening cells (using LISS) at AHG. An antibody identification panel was performed.

1. What antibody is suspected? anti fya
2. How could you confirm the identification?

3. Why was the antibody screen negative in the pretransfusion testing?

Answer 1

1. What antibody is suspected?

Anti A, Anti B, rh

2. How could you confirm the identification?

RBC antibody screening or direct anti agglutination test. This test identifies specific antibodies present in the red blood cells of individual, who had blood transfusions.

3. Why was the antibody screen negative in the pre transfusion testing?

• due to presence allo-immunized RBC from the previous transfusion or
• the titer of  allo-antibodies are low
• because of minimal survival rate