Case Report: COVID-19 Infection of a Transplanted Heart Simulating Cellular Rejection.

Contemporary reports showed that solid organ transplantation patients who contract SARS-CoV-2 infection have a high mortality rate. There are sparse data about recurrent cellular rejections and the immune response to the SARS-CoV-2 virus in patients after heart transplantation. Herein, we report a case of a 61-year-old male post-heart transplant patient who tested positive for COVID-19 and developed mild symptoms 4 months after transplantation. Thereafter, a series of endomyocardial biopsies showed histologic features of acute cellular rejection despite optimal immunosuppression, good cardiac functions, and hemodynamic stability. Demonstration of SARS-CoV-2 viral particles by electron microscopy in the endomyocardial biopsy confirmed the presence of the virus in the foci of the cellular rejection, pointing to a possible immunologic reaction to the virus. To our knowledge, there is limited information regarding the pathology of COVID-19 infection in immunocompromised heart transplant patients, and there are no well-established guidelines for treating such patients. Based on the demonstration of SARS-CoV-2 viral particles within the myocardium, we concluded that myocardial inflammation visible on endomyocardial biopsy might be attributed to the host's immune response to the virus, which mimics acute cellular rejection in newly heart transplanted patients. We report this case to increase awareness of such events post-transplantation and to add to knowledge regarding the management of patients with ongoing SARS-CoV-2 infection that proved to be challenging.