Transplantation tolerance may be defined as normal graft survival sans immunosuppression, maintaining intact immunity. Tolerance induction (TI) strategies include induction of chimerism and/or clonal deletion. Donor specific transfusion (DST) and stem cells (SCs) have come-up as TI. In this parallel 2-armed open labeled study under non-myeloablative conditioning with DST as first arm and SCs as second arm, without using conventional immunosuppression. Monitoring included SCr (mg/dL), DSA and MLR. Protocol biopsies were planned after 100 days and yearly in willing patients. In event of rejection/DSA/MLR, rescue immunosuppression was planned. Patient survival for the first 2 years was 100% in both arms; at 5 years post-transplant 80% with SC and 90% with DST. Death-censored graft survival for 1st year was 100 % in both arms, and at 5 years, 80% with SC and 70% with DST. Mean SCr was 1.52 with SC and 1.97 with DST. Five patients from SC-arm and 3 from DST-arm had successful TI. MLR was negative in both groups. DSA appeared in 2 patients of SC without graft dysfunction and 4 of DST causing graft dysfunction. Thus SCs facilitate TI in LDRT under non-myeloablative conditioning.
