Evaluation of two different preconditioning regimens for ABO-incompatible living kidney donor transplantation. A comparison of splenectomy vs. rituximab-treated non-splenectomy preconditioning regimens

Abstract

Introduction: Although splenectomy has been employed in most documented protocols for ABO-incompatible kidney transplantation (ABO-ILKT), its utility is not yet determined. The aim of this study was to evaluate the long-term results of ABO-ILKT with splenectomy, and also compare the outcome of ABO-ILKT with splenectomy versus non-splenectomy.

Methods: We did a retrospective study of ABO-incompatible living donor kidney transplants at our institution and affiliated hospital between January 2001 and December 2006 (n = 70). All patients were treated with a combination of immunosuppressive drugs, including tacrolimus (FK), mycophenolate mofetil (MMF) and methylprednisolone (MP). Between January 2001 and December 2004, all patients underwent pretransplant double filtration plasmapheresis (DFPP) and splenectomy at the time of transplant (n = 46) (ABO-I-SPX group). Between January 2005 and December 2006, splenectomy was not performed and a protocol that involved pretransplant low-dose injection of rituximab was employed (ABO-I-RIT group). ABO-compatible living kidney transplants (n = 55) performed between January 2001 and December 2004 were employed as a control group (ABO-C group).

Results: Patient survival was 100% in all groups. Three-year graft survival was 98.2, 93.5 and 95.8% in the ABO-C, ABO-I-SPX and ABO-I-RIT groups, respectively. Five-year graft survival was 93 and 91.3% in the ABO-C and ABO-I-SPX groups, respectively. Renal allograft function was comparable among the three groups. However, compared to the ABO-I-RIT group, the incidence of acute antibody-mediated rejection (acute AMR) or chronic AMR was significantly higher in the ABO-C and ABO-I-SPX groups.

Conclusions: Although long-term outcome of the ABO-I-SPX group was excellent and showed no significant difference compared to the ABO-C group, splenectomy is not essential for successful ABO-ILKT. The rituximab-treated patients showed excellent short-term graft survival and renal function, and the incidence of AMR in the ABO-I-RIT group was significantly reduced compared to the ABO-I-SPX group.