Patrícia Valério, Nephrology Department, Centro Hospitalar de Setúbal, Setúbal, Portugal
Rita Veríssimo, Kidney Transplantation Unit, Hospital de Santa Cruz, Centro Hospitalar de Lisboa Ocidental, Lisboa, Portugal
Francisca Silva, Nephrology Department, Centro Hospitalar do Funchal, Funchal, Portugal
Alexandra Atalaia, Pharmaceutical Services, Hospital de Santa Cruz, Centro Hospitalar de Lisboa Ocidental, Lisboa; 5Imaging Department, Centro Hospitalar de Lisboa Ocidental, Lisboa. Portugal
Tiago Saldanha, Pharmaceutical Services, Hospital de Santa Cruz, Centro Hospitalar de Lisboa Ocidental, Lisboa; 5Imaging Department, Centro Hospitalar de Lisboa Ocidental, Lisboa. Portugal
André Weigert, Kidney Transplantation Unit, Hospital de Santa Cruz, Centro Hospitalar de Lisboa Ocidental, Lisboa, Portugal

Objective: The purpose of this report was to describe the clinical features of mammalian target of rapamycin inhibitors (mTORi) pulmonary toxicity in kidney recipients. Material and methods: We analyzed clinical, analytical, and image data of all kidney recipients who were immunosuppressed with everolimus or sirolimus, between 2013 and 2018. Results: From a pool of 379 recipients, 12 presented evidence of mTORi-induced hypersensitivity pneumonitis. The median age at onset of pneumonitis was 62.8 years. The majority had chronic graft dysfunction, with a median serum creatinine of 1.9 mg/dL. All patients were under mTORi for at least 2 years. The most common symptoms were cough and fever. Chest computerized tomography documented ground-glass opacities and lower lobe involvement in all patients. Two required mechanical ventilation, one of which died (the only dead in this series). Conclusions: The size of this sample does not allow inferring about risk factors or prognosis predictors. However, most patients were male, with chronic graft dysfunction and exposure to mTORi for at least 2 years. MTORi-induced pneumonitis is rare but potentially fatal. It should be included in the differential diagnosis of pulmonary conditions in these patients.

Keywords: Hypersensitivity pneumonitis. Mammalian target of rapamycin inhibitors. Kidney transplantation. Pulmonary toxicity.