Impact of intraportal donor-specific leukocyte transfusion for adult ABO-incompatible liver transplantation.

Introduction. We have reported that repeated donor-specific leukocyte transfusions (DSLT) via the portal vein allow rapid reduction of immunosuppressants and decrease the occurrence of acute cellular rejection. Herein, we examined the immunological benefits of DSLT in adult ABO-incompatible living donor liver transplantation (LDLT). Materials and Methods. Ten adult patients (MELD score, 19.4 +/- 7.3; range, 12-29) underwent LDLT from ABO-incompatible donors from August 2003 to November 2007. The antirejection therapy included multiple perioperative plasmaphereses, splenectomy, and quadruple immunosuppression. In addition to these conventional approaches, we performed 4 intraportal administrations of DSLT after transplantation. Results. There was no humoral rejection in any patient. Two patients experienced mild cellular rejection requiring steroid pulse therapy. Both donor-specific immunoglobulin (Ig)M and IgG A/B antibodies in all patients decreased following transplantation by 16 fold. By flow cytometry, donor type of CD56+NK T cells existed in the liver graft showing macrochimerism at 1 month after liver transplantation. Furthermore, interleukin (IL)-10 production of Th2 type cytokines was up-regulated after transplantation. Three patients died of sepsis and infection. The 5-year survival rate was 70% by the Kaplan-Meier method. Conclusion. Adult ABO-incompatible liver transplantation can be performed with acceptable patient and graft survival rates with a low risk of antibody-mediated rejection using intraportal administration of DSLT. Donor type CD56+NK T cells may induce tolerance by a veto or an anti-idiotype network mechanism.