Forward (Cell) Grouping
Reverse (Serum) Grouping
Unexpected reactions (including rouleaux) in reverse grouping.
Most probable ABO type: Group A
Possible causes: A2 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; or perform saline replacement techniques.