Lymphoid neogenesis in chronic rejection

Purpose of review Although chronic rejection is currently one of the main causes of long-term allograft failure, its pathogenesis remains elusive, thereby preventing the development of effective therapy. Recent findings Recent advances in the comprehension of the pathophysiology of chronic inflammatory diseases could shed new light on the pathogenesis of chronic rejection. Lymphoid neogenesis is a mechanism responsible for the progressive organization of chronic inflammatory infiltrates into functional ectopic germinal centers, which has been recently evidenced in various pathological situations sharing a common feature: the failure of the immune response to eradicate the targeted antigens. Chronic rejection is such a situation as it results from a sustained alloimmune response against the donor's antigens that are constantly replenished by the grafted tissue. Accordingly, functional ectopic germinal centers develop within chronically rejected organs. Summary During chronic rejection, the graft is simultaneously the target and the site of elicitation of the alloimmune response.