Comprehensive cardiopulmonary assessment in α mannosidosis

Introduction: α Mannosidosis is an extremely rare, progressive, and complex lysosomal storage disease, characterized by mental retardation, hearing impairment, coarse facial features, skeletal abnormalities, and pulmonary involvement. While bone marrow transplantation has been the only therapeutic option to date, nowadays new treatment options are being explored, which may affect pulmonary and exercise capacity.

Aim and methods: To assess cardiopulmonary involvement in patients with α mannosidosis by pulmonary function tests, cardiopulmonary exercise testing, and low irradiation chest computed tomography (CT).

Results: Five patients aged 11 to 28 years were followed in our Respiratory-Metabolic Clinic. All five had pulmonary symptoms and received inhaled therapy. Three patients underwent bone marrow transplantation. Parenchymal lung disease was evident in 3/5 chest CT tests. Pulmonary function tests were abnormal in all patients and showed obstructive/restrictive impairment with air trapping. All five patients showed reduced peak oxygen uptake (median 23.1; range 20.4-32.2 mL/minute/kg, median %predicted 62; range %predicted 59-79).

Conclusions: Pulmonary involvement is a known complication in this rare disease. Comprehensive cardiopulmonary evaluation is feasible among these patients and may help in assessing disease progression and response to new treatment modalities.

Keywords: cardiopulmonary exercise testing; exercise capacity; α mannosidosis.