Enzyme replacement therapy stabilizes obstructive pulmonary Fabry disease associated with respiratory globotriaosylceramide storage

Fabry disease is an X-linked glycosphingolipidosis caused by a deficiency of α-galactosidase A, a lysosomal enzyme. Symptoms in hemizygous males and heterozygous females are due to lysosomal storage of globotriaosylceramide in the central and peripheral nervous system, vascular endothelium, cardiac valves and myocytes, gastrointestinal tract, and renal epithelium. Pulmonary involvement is also a recognized manifestation of Fabry disease, but histopathological evidence of pulmonary lysosomal storage is scant. We report a 51-year-old woman with a G43R α-galactosidase A mutation and normal spirometry testing 2.5 years prior to presentation, who experienced a dry, nonproductive cough that persisted despite treatment with antibiotics and bronchodilators. Spirometry demonstrated a mixed restrictive/obstructive pattern as well as impaired gas exchange. Patchy ground-glass pulmonary interstitial infiltrates were found on plain radiography and computerized tomography. She underwent an open lung biopsy that demonstrated peribronchiolar fibrosis and smooth-muscle hyperplasia. Prominent inclusion bodies of the bronchiolar/arteriolar smooth muscle and endothelium were present. Electron microscopy indicated the inclusion bodies were lamellated zebra bodies consistent with globotriaosylceramide storage. Enzyme replacement therapy (ERT) with agalsidase-beta was instituted. Since initiation of therapy, she occasionally has a dry cough but markers of obstructive lung disease have remained stable in the past 4 years. This report demonstrates that pulmonary involvement in Fabry disease is due to lysosomal storage, and suggests that ERT is capable of stabilizing pulmonary Fabry disease. However, progressive worsening of her total lung capacity indicates that ERT cannot reverse the ongoing process of fibrosis also seen in Fabry disease.