Table 18. Example of an Unexpected Reaction in Reverse Typing. | Anti-A | Anti-B | A1 cells | B cells |
| Patient Results | 4+ | 4+ | 1+ | 0 |
Most Probable ABO Type: Group AB
Possible Causes: A2B patient with an anti-A1, abnormal serum proteins resulting in rouleaux formation, a room temperature reactive alloantibody, or a cold autoantibody.
Some Strategies for Resolution:
- Perform an antibody screen
- Test patient cells with anti-A1 lectin
- Perform saline replacement techniques
