Regamey Nicolas, Ochs Matthias, Hilliard Tom N, Mühlfeld Christian, Cornish Nikki, Fleming Louise, Saglani Sejal, Alton Eric W F W, Bush Andrew, Jeffery Peter K, Davies Jane C
Department of Gene Therapy, National Heart and Lung Institute, 1B Manresa Road, London SW3 6LR, UK.
Am J Respir Crit Care Med. 2008 Apr 15;177(8):837-43. doi: 10.1164/rccm.200707-977OC. Epub 2008 Jan 24.
Structural alterations to airway smooth muscle (ASM) are a feature of asthma and cystic fibrosis (CF) in adults.
We investigated whether increase in ASM mass is already present in children with chronic inflammatory lung disease.
Fiberoptic bronchoscopy was performed in 78 children (median age [IQR], 11.3 [8.5-13.8] yr): 24 with asthma, 27 with CF, 16 with non-CF bronchiectasis (BX), and 11 control children without lower respiratory tract disease. Endobronchial biopsy ASM content and myocyte number and size were quantified using stereology.
The median (IQR) volume fraction of subepithelial tissue occupied by ASM was increased in the children with asthma (0.27 [0.12-0.49]; P < 0.0001), CF (0.12 [0.06-0.21]; P < 0.01), and BX (0.16 [0.04-0.21]; P < 0.01) compared with control subjects (0.04 [0.02-0.05]). ASM content was related to bronchodilator responsiveness in the asthmatic group (r = 0.66, P < 0.01). Median (IQR) myocyte number (cells per mm(2) of reticular basement membrane) was 8,204 (5,270-11,749; P < 0.05) in children with asthma, 4,504 (2,838-8,962; not significant) in children with CF, 4,971 (3,476-10,057; not significant) in children with BX, and 1,944 (1,596-6,318) in control subjects. Mean (SD) myocyte size (mum(3)) was 3,344 (801; P < 0.01) in children with asthma, 3,264 (809; P < 0.01) in children with CF, 3,177 (873; P < 0.05) in children with BX, and 1,927 (386) in control subjects. In all disease groups, the volume fraction of ASM in subepithelial tissue was related to myocyte number (asthma: r = 0.84, P < 0.001; CF: r = 0.81, P < 0.01; BX: r = 0.95, P < 0.001), but not to myocyte size.
Increases in ASM (both number and size) occur in children with chronic inflammatory lung diseases that include CF, asthma, and BX.
气道平滑肌（ASM）的结构改变是成人哮喘和囊性纤维化（CF）的一个特征。
我们调查了慢性炎症性肺病患儿是否已存在ASM质量增加的情况。
对78名儿童（中位年龄[四分位间距]，11.3[8.5 - 13.8]岁）进行了纤维支气管镜检查：24名哮喘患儿，27名CF患儿，16名非CF支气管扩张症（BX）患儿，以及11名无下呼吸道疾病的对照儿童。使用体视学方法对支气管活检的ASM含量、肌细胞数量和大小进行定量分析。
与对照受试者（0.04[0.02 - 0.05]）相比，哮喘患儿（0.27[0.12 - 0.49]；P < 0.0001）、CF患儿（0.12[0.06 - 0.21]；P < 0.01）和BX患儿（0.16[0.04 - 0.21]；P < 0.01）的ASM占据的上皮下组织中位（四分位间距）体积分数增加。哮喘组中ASM含量与支气管扩张剂反应性相关（r = 0.66，P < 0.01）。哮喘患儿的中位（四分位间距）肌细胞数量（每平方毫米网状基底膜的细胞数）为8204（5270 - 11749；P < 0.05），CF患儿为4504（2838 - 8962；无显著差异），BX患儿为4971（3476 - 10057；无显著差异），对照受试者为1944（1596 - 6318）。哮喘患儿的平均（标准差）肌细胞大小（立方微米）为3344（801；P < 0.01）,CF患儿为3264（809；P < 0.01），BX患儿为3177（873；P < 0.05），对照受试者为1927（386）。在所有疾病组中，上皮下组织中ASM的体积分数与肌细胞数量相关（哮喘：r = 0.84，P < 0.001；CF：r = 0.81，P < 0.01；BX：r = 0.95，P < 0.001），但与肌细胞大小无关。
在包括CF、哮喘和BX在内的慢性炎症性肺病患儿中，ASM（数量和大小）均增加。
