Zesergio Melo

By Zesergio Melo, Juan A. Ruiz-Pacheco, Claudia A. Mendoza-Cerpa and Raquel Echavarria

Renal transplantation is currently the best alternative for patients with end-stage renal disease. Immune responses activated against the allograft are a decisive factor in transplantation outcomes and patient survival. Although short-term graft and patient survival have improved significantly as a result of better donor matching systems, novel immunosuppressive agents and enhanced care, long-term outcomes remain unfavorable and reflect sub-clinical injury caused by chronic rejection. The immune system lies at the intersection of immunogenic tolerance and graft failure; thus, it is a major determinant of pathology in the context of renal transplantation. During the early stages of transplantation increased expression of cytokines has been observed in addition to increased expression of adhesion proteins and immune cells. This early inflammatory response does not necessarily end in graft rejection, although this will depend on the severity of the inflammation. Activation of Toll-like Receptors (TLRs), damaging molecular patterns (DAMPs), and other components of innate immunity is key to the formation of atherosclerotic plaques and the development of autoimmune diseases. Initially the donor antigens are presented to the T lymphocytes of the recipient. This activation induces their proliferation, differentiation and cytokine production. Successful kidney transplant recipients need to develop immunologic tolerance against donor antigens. In this chapter, we address some of the innate and adaptive immune mechanisms associated with kidney transplantation; emphasizing their role in allograft rejection.

Part of the book: Pathophysiology

By Maritza G. Verdugo-Molinares, Marco Ku-Centurion and Zesergio Melo

This chapter focuses on the emerging field of exosomes in the context of reperfusion injuries. Exosomes, nano extracellular vesicles with diverse cargo, play a crucial role in cell-to-cell communication. Exosome quantity and content changes have been implicated in various pathologies, including kidney, brain, heart, and liver ischemia-reperfusion injury. Particularly, exosomes derived from mesenchymal stem cells (MSCs) have shown promising potential as a treatment approach. This chapter aims to provide a comprehensive understanding of exosome biogenesis, the role of organ-specific exosomes in reperfusion injury pathophysiology, and the advantages and prospects of exosome-based treatments. By exploring the multifaceted aspects of exosomes in reperfusion injuries, this chapter will contribute to the advancement of knowledge in this field.

Part of the book: Reperfusion Injuries