**4. Conclusions**

We describe a fairly mild COVID-19 case in a severely immunosuppressed LTX recipient with good evolution on empiric intravenous antibiotics only. Immunosuppressive therapy might have averted the cytokine storm and the progression of pulmonary disease typically observed in some SARS-CoV-2 infections of immunocompetent patients. Diarrhea is described as a common symptom, even as an isolated manifestation in COVID-19. We assume that immunosuppression may modify the clinical presentation of COVID-19 after SOT. Immunosuppression, in particular tacrolimus, may avert the strong immunological reactions and therefore prevent some of the sequalae of SARS-CoV-2. For this reason, typical respiratory symptoms consisting of a cough and shortness of breath may not always be observed in these patients, thus creating new challenges for infection control and preventing the spread of the disease. This is the beginning of a new infectious era, leading to a global health crisis wherein potential harms need to be anticipated as soon as possible. The increasing SARS-CoV-2 transmission and resultant emerging pandemic are still beyond human control because of the altered biologic characteristics that provide SARS-CoV-2 its virulence and thus this virus poses a real challenge for future drug development. Physicians treating COVID-19 should be encouraged to include their patients in randomized controlled trials in order to gain the clinical evidence so urgently needed in the care of patients suffering from severe COVID-19. Further studies are required to confirm the abovementioned hypothesis before immunosuppression may be safely proposed as a supportive treatment approach in immunocompetent and SOT recipients.

**Author Contributions:** All authors were equally involved in planning the study, collecting the information and drafting the manuscript and figures. All authors have read and agreed to the published version of the manuscript.

**Funding:** This research received no external funding.

**Conflicts of Interest:** The authors declare no conflict of interest.
