CYTOKINES AND ORGAN-TRANSPLANTATION - A REVIEW

Cytokines regulate both aspecific inflammatory responses and specific immune responses. Inflammatory changes occur in the organ transplant a s a result of tissue trauma and ischemia/reperfusion in the organ dono r and at the time of transplant operation. There is a possibility that cytokines play a role in mediating theses changes. These aspecific in flammatory changes may not only affect graft function but also influen ce graft immunogenicity (enhanced MHC and adhesion molecule expression ) and thus, vulnerability to rejection. Cytokines orchestrate the spec ific immune response elicited by organ transplantation. Relevance of c ytokines to the rejection reaction is multifactorial in nature : 1) pr omotion of the proliferation an differentiation of specific alloreacti ve T and B cells clones and differentiation and activation of CTL and NK cells, 2) chemotactic effect and induction of the expression of adh esion molecules, 3) enhancement of MHC class I and II expression, and 4) direct cytotoxic effect on the target grafted cells. Therefore, mod ulation of cytokine activity either specifically (monoclonal antibody, soluble receptor, etc.) or aspecifically (cyclosporin, FK 506, Rapamy cin, steroids, etc.) is essential in controlling graft rejection. Dete rmination of circulating cytokines and cytokines measurement within th e biological fluids produced by an organ transplant may help in the di agnosis of rejection episodes and other complications following organ transplantation.