ABSTRACT
BACKGROUND: Since December 2019, the SARS-CoV-2 pandemic significantly has impacted the medical community. When infected with SARS-CoV-2, most of the patients developed bilateral pneumonia. We have herein presented the atypical case of a patient who developed unilateral SARS-CoV-2 pneumonia, affecting only the second lung allograft re-transplanted (re-LTX). CASE PRESENTATION: A SARS-CoV-2 infection occurred in a 2-dose vaccinated patient with LTx with a history of second unilateral lung transplantation performed after an end-stage bronchiolitis obliterans syndrome. The first symptoms started with a flu-like syndrome, and the patient's clinical condition worsened with nonsevere acute respiratory failure requiring conventional oxygen therapy. Treatment consisted in administrating specific anti-SARS-CoV-2 monoclonal antibodies along with probabilistic antibiotherapy, anticoagulation, and steroids. On day 7, the patient was discharged from hospital. We aimed to assess this atypical unilateral pneumonia based on different explorations. A ventilation scintigraphy showed a severe ventilation decrease owing to end-stage bronchiolitis obliterans syndrome within the left first allograft, which may be associated with asymmetrical virus diffusion between the 2 lungs. We did not identify any other relevant differences with respect to the 2 donors' clinical characteristics. Using specific immunohistochemistry staining against angiotensin converting enzyme-2 receptor, the main known receptor for SARS-CoV-2 binding on airway epithelial cells, no staining difference was observed between the 2 lung biopsies that were collected at re-LTx from each lung. CONCLUSIONS: With the present case report, we aimed to highlight how this kind of unusual presentation may be caused by the difference of ventilation between the 2 lungs.