Antibody-mediated rejection without acute graft dysfunction in adult ABO-compatible heart transplantation: a case of accommodation

Humoral rejection in heart transplantation is associated with graft dysfunction, circulating anti-donor antibodies and C4d deposits in endomyocardial biopsies. Detecting C4d capillary positivity is of diagnostic and prognostic value. C4d positivity can be found in solid-organ transplants in cases of "accommodation," a form of humoral rejection without graft dysfunction. Accommodation might reflect a change in antibodies or in the antigen, or the graft acquiring a resistance to injury by antibodies and complement. We present a case of accommodation in the setting of adult ABO-compatible orthotopic heart transplantation, which was diagnosed according to the recently introduced ISHLT criteria for humoral rejection: despite this immunologic profile, the patient never showed signs of graft dysfunction. Physicians should be aware of the accommodation phenomenon so they can identify this subset of patients and assess its long-term effects on chronic rejection and outcome in transplanted patients.