Reliability of labeling red cell units with minor antigen historical results and process considerations.

Background: Several approaches are used by blood centers when providing minor (non-ABO/D) antigen-negative RBCs to hospitals. Details vary but include providing results on the unit labeling intended for clinical use without retyping or providing results on packing documents or via computer query requiring confirmation. Recent regulatory changes allow labeling with historical minor antigen results, defined as previously performed by the donor center on two different donations with results linked to the donor and confirmed concordant.