Immune-mediated rejection occurs when the recipient’s immune response targets antigens carried by donor tissue or cells. This attack can progressively impair graft function and viability, making donor-recipient matching and immune management important considerations. Recognizing this mechanism helps clinicians distinguish an immunologic complication from injury caused by preservation, circulation, infection, or other problems.
Graft failure may also follow ischemia, thrombosis, infection, inadequate integration, or other technical and biological problems. These mechanisms damage transplanted tissue through pathways that are not necessarily equivalent to rejection. Separating them matters because the appropriate response may involve immunosuppressive treatment, surgical intervention, infection-related care, supportive management, or retransplantation.
Distinguishing rejection from ischemic, thrombotic, infectious, integration-related, or other technical injury is clinically important because poor graft performance does not identify the cause by itself. Mechanism-focused evaluation supports a more appropriate choice among immunosuppression, surgery, supportive care, infection management, or retransplantation, rather than assuming that every decline reflects rejection.
Clinicians assess suspected graft failure through several complementary sources: functional testing, imaging, laboratory biomarkers, and, when necessary, biopsy. Using more than one type of evidence helps evaluate graft performance and investigate whether rejection or another injury process is responsible. This structured assessment provides the basis for deciding what intervention or support is appropriate.
Biopsy has a selective role rather than serving as the only assessment method. When functional testing, imaging, and laboratory biomarkers do not adequately clarify the problem, clinicians may use tissue examination to help distinguish rejection from other causes of graft dysfunction. Its place in the workup reflects the need to match diagnostic intensity to the unresolved clinical question.
Management depends on the mechanism identified during evaluation. Immunosuppressive treatment addresses immune-mediated injury, whereas surgical intervention may be relevant to technical problems; supportive care and retransplantation are additional options in appropriate circumstances. Linking treatment to cause helps clinicians avoid treating every failed graft as rejection and keeps management responsive to the underlying problem.
Graft failure research extends beyond rescue after dysfunction appears. The topic informs work on donor matching, graft preservation, and immune tolerance, all aimed at improving graft survival. These priorities connect clinical assessment with prevention and long-term transplantation outcomes, while providing context for studying both immune-mediated and nonimmune causes.