Antibody-mediated rejection in heart transplantation: case presentation with a review of current international guidelines

Abstract

Antibody-mediated rejection (AMR) (humoral rejection) of cardiac allografts remains difficult to diagnose and treat. Interest in AMR of cardiac allografts has increased over the last decade as it has become apparent that untreated humoral rejection threatens graft and patient survival. An international and multidisciplinary consensus group has formulated guidelines for the diagnosis and treatment of AMR and established that identification of circulating or donor-specific antibodies is not required and that asymptomatic AMR, that is, biopsy-proven AMR without cardiac dysfunction is a real entity with worsened prognosis. Strict criteria for the diagnosis of cardiac AMR have not been firmly established, although the diagnosis relies heavily on tissue pathological findings. Therapy remains largely empirical. We review an unfortunate experience with one of our patients and summarize recommended criteria for the diagnosis of AMR and potential treatment schemes with a focus on current limitations and the need for future research and innovation.

Figure 1

Antibody-mediated rejection characterized by endothelial cell swelling and numerous macrophages filling vascular spaces.

Figure 2

(a) Antibody-mediated rejection, high power. Longitudinal section of capillary with mild endothelial cell swelling and macrophages accumulating in lumen. (b) Immunoperoxidase staining with CD68 highlights the macrophages.

Figure 3

Antibody-mediated rejection, high power. C4d decorates endothelial cells in this immunoperoxidase-stained slide.