**2. Discussion**

Organ transplantation is a definitive and curative treatment for end-stage organ disease. The preferred source of organs is from the deceased. Particularly in developing countries, organ harvesting is more from living donors. Although the morbidity and mortality rates for living donors are extremely low, completely healthy individuals are exposed to medical, surgical, psychological and sometimes to economic risks.

While organ transplantation will continue to be the definitive treatment for the present and foreseen future, the statistical evidence revealing the gap between demand and supply and the experience of the global medical community has clearly shown that even the centers with best figures of organ supply are far from meeting the growing need. Therefore the scientific world has arrived at a point to think and search for alternative solutions and different therapeutic modalities for end-stage organ diseases. An overview of the present state of organ transplantation suggests that future interest and work will be focused on three major points:

a.increasing the frequency, safety and outcome of traditional transplantation activities. This would cover research to discover ways of expanding donor pool, especially cadaveric, and innovative work for longer and safer preservation of harvested organs and methods that would help to obtain better graft and survival rates. Weissenbacher and associates have reported the beneficial effects of ex-vivo/ex-situ hypothermic and normothermic machine perfusion in the transplantation of liver, kidney, intestine and pancreas. The beneficial effects include viability, organ utilization and improved initial graft function. The authors have considered the potential role of normothermic regional perfusion to re-condition donors after circulatory death organs before retrieval. Machine perfusion presents superiority over the traditional cold preservation method. Since organ preservation is an essential aspect of the transplantation process, these developments provide hope for better organ quality and longer viability [1].

In solid-organ transplant, cell therapy is used as an immunomodulation therapy or as a functioning graft. The beneficial effects of cell therapy in solid-organ transplantation are long-term kidney allograft survival and avoiding the well-known adverse effects of immunosuppressive drugs. Cell-based therapy in solid organ transplant is indicated for the treatment of ischemic reperfusion injury, for the prevention of chronic allograft nephropathy and induction of long-term allograft tolerance. Immunoregulatory cells act when it is necessary for immune suppression and there are several mechanisms by many pharmacologic targets [2].

