Session Time: 5:30pm-7:30pm
Presentation Time: 5:30pm-7:30pm
Location: Exhibit Hall E
Background: One of the key unmet needs in heart transplantation is an effective and accurate, non-invasive tool to diagnose acute and chronic heart transplant rejection. Here, we introduce a novel-imaging platform to accurately assess the microperfusion of cardiac allografts, as an indicator of acute cellular rejection, using contrast enhanced ultrasonography (CEUS).
Methods: Syngeneic and allogeneic heart transplantation was carried out using a murine transplant model. Recipient mice were injected intravenously with microbubble contrast agent (MicroMarker, Visual Sonics) at several time-points post-transplantation to assess microperfusion prior to rejection, at the time of rejection and following anti-rejection therapy. Allografts were subjected to non-linear contrast imaging, and high-resolution parametric perfusion maps were generated to depict microvascular perfusion. Activated endothelium and platelet accumulation in the grafts' microvasculature were evaluated through immunohistochemistry.
Results: Parametric microperfusion mapping allowed the robust detection of both acute and chronic heart allograft rejection demonstrated by a sharp decrease in the microperfusion of allografts as compared to the isografts (40%, 64%, 92% decrease in the microperfusion on days 4, 6 and 8 post-transplantation; p<0.05 for all experimental groups). In addition, we were able to predict allograft rejection by detecting a marked early reduction in microperfusion prior to marked histologic changes. Finally, our study showed a marked restoration of microperfusion following anti-rejection therapy. Our data indicate that early accumulation of platelets in the microvasculature results in a subsequent decline in perfusion of heart allografts.
Conclusion: High-resolution microperfusion mapping using CEUS of cardiac allografts represents an innovative and robust imaging platform for the non-invasive diagnosis of heart transplant rejection. These data have the potential to change the paradigm of diagnosis of rejection in solid organ transplantation.
To cite this abstract in AMA style:Fischer K, Ohori S, Meral F, Giannini S, Hoffmeister K, Athar H, Ichimura T, Smith R, Giverts M, Jolesz F, Abdi R. High-Resolution Perfusion Mapping to Detect Heart Transplant Rejection Using Contrast Enhance Ultrasound [abstract]. Am J Transplant. 2015; 15 (suppl 3). https://atcmeetingabstracts.com/abstract/high-resolution-perfusion-mapping-to-detect-heart-transplant-rejection-using-contrast-enhance-ultrasound/. Accessed August 4, 2021.
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