Update on chronic rejection after intestinal transplant. An overview from experimental settings to clinical outcomes

Chronic rejection affects the long-term survival of solid-organ transplants, accounting for an incidence of between 5% and 10% after intestinal/multivisceral transplant. Because of unclear symptoms and signs and endoscopic findings, the diagnosis is often delayed. Presently, allograft removal represents the only available therapy due to the absence of effective pharmacologic approaches. Extensive research, through animal models, has been performed over the past 20 years to clarify the complex immune- and nonimmune-mediated mechanisms behind the development of chronic allograft enteropathy, with the aim of elucidating how to avert chronic rejection. The role of donor-specific antibodies and the way to challenge them in the clinic have gained acceptance among transplant centers as one of the main steps to prevent chronic rejection, although no common protocol exists that can be applied in a systematic fashion. The adjunct of a liver graft when retrans planting is needed in a sensitized recipient due to its protective effect against humoral immunity. Multicenter studies and clinical trials are required to better understand the pathogenesis of chronic rejection and to find the therapeutic answer to this clinical query.