Cytokines and adhesion molecules in chronic rejection

Despite the increasing short-term success of clinical transplantation during recent years, many allografts, regardless of organ type, continue to be lost over the long term due to chronic rejection, despite improvements in immunosuppression and better patient management. Thus, as a long-term answer to an irreversible disease process, organ transplantation has not lived up to its potential. Although the host mechanisms leading to the process remain obscure, the progressive morphological changes evolving in the afflicted organs are well understood. Chronic rejection has long been thought to be an antibody-mediated event, as immunoglobulins and other circulating proteins are often associated with areas of vascular damage. It is becoming more clear, however, that a whole array of host defense factors, primarily, cytokines, lymphokines and adhesion molecules, are of critical importance in the process. This review summarizes various cytokines and their individual functions as well as adhesion molecules potentially involved in aspects of immune responsiveness, and placed in the context of chronic rejection.