Although we did extended Rh and Kell typing for all cases with a non-negative antibody screen, we did not routinely do this for patients with a negative antibody screen.
Based on recent cases of rare phenotypes in the Rh system (e.g. r’r’), we will proactively test such patients most likely for this.
Extended Rh (C, c, E, e) and Kell typing should be done on all patients meeting the any of the following criteria:
- D-negative phenotype
- Positive antibody identifications (not nonspecific)
- Non-negative antibody screens
Standards for Blood Banks and Transfusion Services, AABB, Current Edition, Bethesda, MD, USA