RhD-negative red blood cells can be saved during liver transplantation in RhD-negative patients due to low risk of alloimmunization against RhD.

Background: Transfusion demand is high in liver transplantation (LT), and thus RhD-positive (RhD+) red blood cell concentrates (RBCs) are sometimes given to RhD-negative (RhD-) patients. Due to immunosuppression, these patients rarely produce anti-D. We investigated the rate of anti-D formation in RhD- patients undergoing LT who were transfused with RhD+ RBCs as well as the number of transfused RhD- and RhD+ RBCs.

Study design and methods: RhD-type and transfusion history of all patients undergoing LT between 2010 and 2023 were reviewed retrospectively. In RhD- patients, who received RhD+ RBCs, the results of antibody screening test (indirect antiglobulin test and with papain-treated test cells) and direct antiglobulin test were evaluated.

Results: Five hundred and twenty-seven patients underwent 576 LT. Eighty-seven patients were RhD-, of whom 42 were transfused with RhD+ RBCs. In 34 of them, an antibody screening test result was available more than two weeks after the last RhD+ RBCs transfusion. In two of them, a transient, weak anti-D antibody was detectable, which disappeared in the further course. Overall, 1352 RBCs were transfused to the 87 RhD- patients, 543 of those were RhD+. Most RhD+ RBCs were provided to men and elder women.

Discussion: Transient weak anti-D occurred in two RhD- male patients during LT after transfusion of RhD+ RBCs without evidence for a hemolytic transfusion reaction. To save stocks of RhD- RBCs, early transfusion of RhD+ RBCs to RhD- men and women beyond the childbearing age should be considered during LT.