Sirolimus-induced secondary pulmonary alveolar proteinosis

Stephanie Wang; Elinor Lee; Ryan Lau; Tisha Wang

doi:10.1016/j.rmcr.2021.101566

Sirolimus-induced secondary pulmonary alveolar proteinosis

Respir Med Case Rep. 2021 Dec 15:35:101566. doi: 10.1016/j.rmcr.2021.101566. eCollection 2022.

Authors

Stephanie Wang¹, Elinor Lee^{1

2}, Ryan Lau³, Tisha Wang^{1

2}

Affiliations

¹ Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, USA.
² Division of Pulmonary, Critical Care, and Sleep Medicine, Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, USA.
³ Department of Pathology, University of California, Los Angeles, USA.

Abstract

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.

Publication types

Case Reports