Background
Patients seeking vascularized composite allotransplantation (VCA) often had devastating injuries requiring multiple blood transfusions to ensure acute patient survival Transfusions carry significant risk for sensitization against human leukocyte antigen (HLA), which may preclude patients from transplant due to a positive crossmatch, or lead to increased risk of rejection and graft loss While massive transfusion, defined by the administration of >10 units of red cells in 24 hours, is often required in these patients, its effects on sensitization are largely unknown.
Methods
We assessed all patients who underwent laboratory screening for potential upper extremity transplantation under our IRB-approved protocol from 2011–2015 Data on potential sensitizing events as defined by the solid organ transplantation literature were abstracted We then used Wilcoxon rank sum and Fisher's exact tests to assess differences between patients who underwent massive transfusion versus those who did not.
Results
Eighteen patients were identified The massive transfusion group (n=9, 50%) was 100% male; mean age=262±54 years at time of injury and 324±127 years at time of cPRA The non-massive transfusion group was 778% male and included 2 patients with a congenital arrest of the hand; mean age=236±185 years at time of injury and 307±117 years at time of cPRA Of the massive transfusion patients, 4 underwent transfusion with â‰∞17 units of PRBCs and/or whole blood, one had a positive cPRA, 8 had cPRA=0, and no patients reported being exposed to any other sensitizing events Of the 9 patients who did not undergo massive transfusion, 1 had a positive cPRA and had been pregnant, 8 had cPRA=0, and 1 reported an additional sensitizing event (pregnancy) Our sample size of 18 patients provided 73% power to detect a PRA difference of 20% between the massive transfusion and control groups We found no evidence for a significant difference in cPRA value distribution (p=0936) or odds of increased PRA (p=0765) between study groups.
Conclusions
Massive transfusion does not necessarily result in sensitization and preclude VCA Additional research will be needed to better understand massive transfusion and its impact on HLA antibody formation.