Transfusion requirements and alloimmunization to red blood cell antigens in orthotopic liver transplantation.

Background and Objectives: Orthotopic liver transplantation (OLT) has been associated with high blood transfusion requirements. We evaluated the transfusion needs and frequency of alloimmunization to RBC antigens among OLT recipients pre- and post-transplantation.
Materials and Methods: We reviewed the medical records of patients who underwent a first OLT between January 2007 and June 2017. Transfusions given only during the perioperative period, defined by 1 week before OLT until 2 weeks following OLT, were included in this study. Records were reviewed in June 2019 for updated antibody testing results.
Results: A total of 970 patients underwent OLT during the study period. The median age of patients was 57 years; 608(62.7%) were male. During the perioperative period, transfused patients received an average of 10.7 (±10.7) RBC units, 15.6 (±16.2) thawed plasma units and 4.1 (±4.3) platelet units. At the time of OLT, a total of 101 clinically significant RBC alloantibodies were documented in 58(5.98%) patients. Fifty-three of these antibodies were directed against Rh blood group antigens. Twenty-two (37.9%) patients had more than one alloantibody. Patients with alloimmunization before OLT (N = 58) received perioperatively comparable number of RBCs to non-alloimmunized patients (10.5 ± 10.6 vs. 9.6 ± 10.7; p = 0.52). There was no significant difference in perioperative or intraoperative RBC transfusion between patients with one alloantibody and those with multiple alloantibodies. Only 16 patients (16/737; 2.17%) developed new alloantibodies at a median of 61 days after OLT. The overall alloimmunization rate was 9.8% (72/737), and female patients were more likely to be alloimmunized.
Conclusion: Blood transfusion requirements in OLT remain high. However, the rate of RBC alloimmunization was not higher than the general patient population.
(© 2021 International Society of Blood Transfusion.)