The exosome as a novel predictive/diagnostic biomarker of rejection in the field of transplantation.

Finding a non-invasive biomarker to monitor allograft status after transplantation could contribute to better control of the post-transplant status of transplant recipients and, if possible, could be used instead of invasive biopsy for proving rejection. On the other hand, reducing the dosage of immunosuppression or stopping lifelong use of them because of their severe side effects is an important goal in order to dispose of their severe side effects. The ability of exosomes as a biomarker of rejection and as a therapeutic strategy was investigated in the human kidney, heart, and lung transplantation or in transplantation models with interesting results. Moreover, the ability of exosome was assessed as antigen-presenting vesicles (APVs), in which exosomes can either participate in immune stimulation (semi-direct recognition) or immune suppression thereby, influence on the transplantation outcome. In this paper, authors try to provide comprehensive information about triple role of exosomes in the transplantation medicine. • Exosomal content are different between transplant recipients with rejection and those without rejection. • Exosomal content remarkably discriminate patients with rejection and those without rejection. • Exosomes could be novel biomarkers of rejection in transplantation. • Exosomes can both directly and indirectly activate T cells and therefore can participate in graft rejection/tolerance. • Exosomes as a therapeutic strategy promote the allograft survival time in the transplantation. [ABSTRACT FROM AUTHOR]