Table 1.

Donor- or product-specific variables that may impact RBC alloimmunization

Product collection/processing – Time between collection and processing – Efficiency of leukoreduction – Number of residual platelets remaining in the RBC unit after processing – Other considerations, including donor's health status

Storage considerations – Length of storage – Type of anticoagulant preservative solution utilized – Strain-specific genetic characteristics affecting blood storage – Gender of donor

RBC clearance rates after transfusion – Potentially impacted by many donor and recipient factors

RBC antigen specific factors – Degree to which the antigen is viewed as foreign by the recipient – Availability of T-cell help – Antigen copy number