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Antibody-mediated rejection (AMR) of the cardiac allograft is a poorly defined and challenging diagno-sis for transplant recipients and their clinicians. Although even its very existence in heart transplantation was debated until relatively recently, improved immunopathologic and serological techniques to detect myocardial capillary complement deposition and circulating anti-HLA (human leukocyte antigen) antibodies have led to the detection of a spectrum of newly uncovered immunologic changes that characterize AMR. The earliest standardized clini-cal and pathological criteria for the diagnosis of AMR in heart transplantation became available in 2004, the result of a task force assembled by the International Society for Heart and Lung Transplantation (ISHLT). In 2006, the cri-teria were refined by the ISHLT Immunopathology Task Force (Table 1). These revisions provide 4 categories of diagnostic criteria: clinical, histopathologic, immunopatho-logic, and serological assessment.1 Despite these published criteria, currently>50 % of heart transplant centers make the diagnosis of AMR based on cardiac dysfunction and the lack of cellular infiltrates on the heart biopsy (precon-ference survey included in the ISHLT consensus article).