Stem Cell Transplantation in Living Donor Renal Transplantation for Minimization of Immunosuppression

Background. We present our experience of living-donor renal transplantation (LDRT) using pretransplant stem cell transplantation (SCT) where we have successfully achieved minimization of immunosuppression. Methods. Nine hundred sixteen patients underwent LDRT between 2007 and 2011: 606 under tolerance induction protocol (TIP) and 310 with our usual triple immunosuppression of calcineurin inhibitors (CNI), mycofenolate sodium (MMF), and prednisone (controls). The test group (TIP) was stratified into group 1, 1 haplomatch or greater (n=392), group 3, less than 1 haplomatch (n=214); controls were similarly stratified to group 2, 1 haplomatch or greater (n=179) and group 4, less than 1 haplomatch (n=131). The TIP consisted of donor-specific transfusion, adipose tissue-derived mesenchymal and hematopoietic stem cell transplantation, and nonmyeloablative conditioning with total lymphoid irradiation, cyclophosphamide, and rabbit-antithymocyte globulin. Posttransplant IS consisted of prednisone, CNI, or MMF, all in low doses. Results. Four-year patient survival was 93.5%, 90.7%, 88.7%, and 82.7% in groups 1 through 4, respectively, and death-censored 4-year allograft survival was 94.8%, 95.4%, 94.5%, and 74.6%, respectively. Mean serum creatinine (mg/dL) for groups 1 through 4, respectively, at 4 years was 1.26, 1.57, 1.29, and 2.1. The number of rejection episodes was highest in group 4 and lowest in group 1. Minimization of IS was successfully achieved in 82.9% patients in group 1 and in 61.7% patients in group 3, whereas no minimization in groups 2 and 4. Stem cell transplantations were safe. Conclusion. Stem cell transplantation is effective in IS minimization in LDRT resulting in good graft function and patient and graft survival at 4 years.