Forward (Cell) Grouping | Reverse (Serum) Grouping |
4+ | 2+ | 4+ | 0 | 4+ |
Most probable ABO type: Group A
Possible Causes: A(B) phenotype, patient cells coated with IgG, acquired B antigen.
Some strategies for resolution: Review patient history. Retype with monoclonal reagents made from another clone or human polyclonal reagents if available; perform an antibody screen to detect autoantibody; perform a direct antiglobulin test (DAT); or wash patient cells and retest.
Testing patient plasma with patient red blood cells
Patients who are truly group A, without any true B antigen, will demonstrate a negative auto control. Since there is no B antigen present on the patient's red cell and there is anti-B in patient plasma, no agglutination should form.
A antigen (No B antigen) | Anti-B | Negative |