HSCT-Based Approaches for Tolerance Induction in Renal Transplant

Renal transplantation has become the preferred treatment for end stage kidney failure. Although short-term graft survival has significantly improved as advances in immunosuppression have occurred, long-term patient and graft survival have not. Approximately only 50% of renal transplant recipients are alive at 10 years due to the toxicities of immunosuppression and alloimmunity. Emerging research on cell-based therapies is opening a new door for patients to receive the organs they need without sacrificing quality of life and longevity because of drug-based immunosuppression. Research has focused on inducing tolerance, a state in which the body accepts the transplant and graft function is stable. Cell-based therapies to facilitate chimerism and achieve tolerance in major histocompatibility disparate recipients have been developed in mouse, swine, canine, and nonhuman primate models. These findings are now being translated into the clinic in several trials currently underway. Protocols that use a combination of traditional therapeutic agents paired with cell populations including hematopoietic stem cells, regulatory T cells, and facilitating cells are being conducted with the objective to harness the donor immune system to protect the transplanted tissue. The benefits and feasibility of the clinical application of cell-based therapy has been demonstrated, and promising results have been achieved. Here we discuss the preclinical work that has led to the clinical application of the various approaches and a summary of the most current clinical data from groups throughout the world.