An unusual cause of respiratory failure in a 25-year-old heart and lung transplant recipient

Sirolimus-Induced Pulmonary Alveolar Proteinosis in the Context of Hematopoietic Stem Cells Transplant Rejection: A Case Report

Pulmonary alveolar proteinosis (PAP) is a rare parenchymal pulmonary disease, characterized by the accumulation of surfactant material in alveoli. Rare cases of pulmonary alveolar proteinosis have been reported following the use of sirolimus. All published cases have been described following solid organ transplantation, and symptoms improved quickly after treatment's cessation. We describe a case of PAP secondary to sirolimus treating graft-versus-host reaction in a patient who received a stem cell transplant for chronic lymphocytic leukemia. Pulmonary alveolar proteinosis was cured after stopping sirolimus without any other therapeutic management. PAP can be a rare but serious side effect of sirolimus. It is important to rule out other causes of primary or secondary PAP before suggesting a toxic drug cause. The main challenge is to quickly diagnose this side effect to stop exposure to the toxic agent.

Sirolimus-induced secondary pulmonary alveolar proteinosis

Pulmonary alveolar proteinosis (PAP) is a rare pulmonary syndrome that is characterized by the accumulation of excess surfactant in the alveolar space, leading to impaired gas exchange. Sirolimus-induced PAP is an extremely rare entity that has only been described in the literature in a small number of case reports. We present a case of a 39-year-old female with acute lymphocytic leukemia who underwent stem cell transplant, complicated by graft-versus-host-disease (GVHD) involving the skin for which she was treated with steroids, photopheresis, sirolimus, and ruxolitinib. She was admitted to the intensive care unit (ICU) for acute on chronic hypoxic respiratory failure requiring intermittent mechanical ventilation. Computed tomography (CT) of the chest showed thickened inter- and intralobular septa with ground glass opacities and consolidation with a limited geographic pattern. Bronchoalveolar lavage fluid was stained with Periodic acid-Schiff (PAS), which was positive for extracellular proteinaceous material. Autoimmune studies including antibody levels for primary autoimmune pulmonary alveolar proteinosis (PAP) were negative. The patient was diagnosed with sirolimus-induced secondary PAP, and sirolimus was discontinued. A year later, she no longer required supplemental oxygen, and repeat CT imaging showed only faint residual disease. This is the only documented case of sirolimus-induced PAP in a stem cell transplant recipient and the first case reported in which the patient developed severe hypoxic respiratory failure requiring mechanical ventilation. In the right clinical context, PAP can be diagnosed with characteristic high resolution computed tomography (HRCT) findings, serum GM-CSF antibody levels, and bronchoscopy with bronchoalveolar lavage.