Rutten M, Ciet P, van den Biggelaar R, Oussoren E, Langendonk J G, van der Ploeg A T, Langeveld M
Department of Pulmonology, Erasmus University Medical Center, Rotterdam, The Netherlands.
Department of Radiology, Erasmus University Medical Center, Rotterdam, The Netherlands.
Orphanet J Rare Dis. 2016 Apr 26;11:50. doi: 10.1186/s13023-016-0425-z.
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.
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.
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.
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.
II型粘多糖贮积症（MPSII）患者经常因骨骼异常导致的限制性气道疾病以及气道不同水平（包括气管）的糖胺聚糖（GAG）积聚而出现呼吸困难。在本研究中，我们描述了成年MPSII患者气管和支气管狭窄的程度、呼吸过程中气道直径的变化以及这些阻塞对呼吸功能的影响。
纳入五名成年MPSII患者（平均年龄40岁）。进行了肺功能测试以及吸气和呼气胸部CT扫描。在吸气末和呼气末测量气管和主支气管的横截面积，并计算塌陷百分比。
所有患者均存在整个胸内气管和主支气管的弥漫性狭窄以及气管的严重呼气塌陷。在主动脉弓上方1厘米处，气管的中位塌陷百分比为68（范围60至77%），在主动脉弓水平为64（范围21 - 93%），主支气管左侧为58（范围26 - 66%），右侧为44（范围9 - 76%）。肺功能测试表明，这种气道塌陷导致所有患者出现阻塞性气道疾病，五名患者中有四名病情严重（用力呼气量<预测值的50%）。
在成年MPS II患者中，中央气道直径显著减小，呼气时气管和主支气管广泛塌陷。这种中央气道阻塞解释了MPSII患者严重的呼吸症状。
