Severe tracheal and bronchial collapse in adults with type II mucopolysaccharidosis.
BACKGROUND
Mucopolysaccharidosis type II (MPSII) patients frequently suffer from dyspnoea caused by restrictive airway disease due to skeletal abnormalities as well as glycosaminoglycans (GAG) accumulation at different levels of the airway, including the trachea. In this study we describe the extent of the tracheal and bronchial narrowing, the changes in airway diameter during respiration and the effects of these obstructions on respiratory function in adult MPSII patients.


METHODS
Five adult MPSII patients (mean age 40 years) were included. Pulmonary function tests and in- and expiratory chest CT scans were obtained. Cross-sectional areas of trachea and main bronchi were measured at end-inspiration and -expiration and percentage collapse was calculated.


RESULTS
There was diffuse narrowing of the entire intra-thoracic trachea and main bronchi and severe expiratory collapse of the trachea in all patients. At 1 cm above the aortic arch the median % collapse of the trachea was 68 (range 60 to 77%), at the level of the aortic arch 64 (range 21-93%), for the main bronchi this was 58 (range 26-66%) on the left and 44 (range 9-76%) on the right side. The pulmonary function tests showed that this airway collapse results in obstructive airway disease in all patients, which was severe (forced expiratory volume <50% of predicted) in four out of five patients.


CONCLUSIONS
In adult MPS II patients, central airways diameters are strikingly reduced and upon expiration there is extensive collapse of the trachea and main bronchi. This central airways obstruction explains the severe respiratory symptoms in MPSII patients.
Department of Pulmonology, Erasmus University Medical Center, Rotterdam, The Netherlands.
M
M
Rutten
Department of Radiology, Erasmus University Medical Center, Rotterdam, The Netherlands.|Department of Paediatric Pulmonology, Sophia Children's Hospital, Erasmus University Medical Center, Rotterdam, The Netherlands.
P
P
Ciet
Department of Pulmonology, Erasmus University Medical Center, Rotterdam, The Netherlands.
R
R
van den Biggelaar
Center for Lysosomal and Metabolic Diseases, Erasmus University Medical Center, Rotterdam, The Netherlands.
E
E
Oussoren
Center for Lysosomal and Metabolic Diseases, Erasmus University Medical Center, Rotterdam, The Netherlands.|Division of Pharmacology, Vascular and Metabolic Diseases, Department of Internal Medicine, Erasmus University Medical Center, Rotterdam, The Netherlands.
J G
JG
Langendonk
Center for Lysosomal and Metabolic Diseases, Erasmus University Medical Center, Rotterdam, The Netherlands.
A T
AT
van der Ploeg
Center for Lysosomal and Metabolic Diseases, Erasmus University Medical Center, Rotterdam, The Netherlands. m.langeveld.1@erasmusmc.nl.|Division of Pharmacology, Vascular and Metabolic Diseases, Department of Internal Medicine, Erasmus University Medical Center, Rotterdam, The Netherlands. m.langeveld.1@erasmusmc.nl.
M
M
Langeveld
D000328:Adult; D000402:Airway Obstruction / Q000503:physiopathology; D001980:Bronchi / Q000473:pathology* / Q000503:physiopathology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D016532:Mucopolysaccharidosis II / Q000473:pathology* / Q000503:physiopathology; D012129:Respiratory Function Tests; D014132:Trachea / Q000473:pathology* / Q000503:physiopathology
Adults; Airway obstruction; Mucopolysaccharidoses; Mucopolysaccharidosis type II; Respiratory function tests; Respiratory system abnormalities/complications; Tomography; Trachea abnormalities; X-Ray computed