Black P N, Ching P S T, Beaumont B, Ranasinghe S, Taylor G, Merrilees M J
Dept of Pharmacology and Clinical Pharmacology, Faculty of Medical and Health Sciences, University of Auckland, Private Bag 92019, Auckland, New Zealand.
Eur Respir J. 2008 May;31(5):998-1004. doi: 10.1183/09031936.00017207. Epub 2008 Jan 23.
Small airways are the major site of airflow obstruction in chronic obstructive pulmonary disease (COPD). This is attributed to loss of elastin in alveoli and fibrosis in small airways. In the present study, it was hypothesised that changes to elastic fibres in alveoli might be paralleled by a similar reduction in elastic fibres in small airways. Tissue blocks from patients who had lobectomy for bronchial carcinoma were studied. Patients were classified as COPD (forced expiratory volume in one second (FEV(1)) < 80% predicted, FEV(1)/forced vital capacity (FVC) < 0.7) or controls (FEV(1) > or = 80% pred, FEV(1)/FVC > or = 0.7). Elastic fibres were visualised using Elastic van Gieson staining and the volume fraction (v/f) of elastic fibres was determined as a percentage of tissue volume using point counting. Elastic fibre networks were also visualised by confocal microscopy. The v/f for elastic fibres in alveoli was 18.6% for COPD and 32.8% in controls. In the airways the v/f was 14.6% for COPD and 25.5% in controls. FEV(1)% predicted was correlated with v/f in both alveoli and small airways. The volume fraction of elastic fibres was reduced to a similar extent in small airways and alveoli in chronic obstructive pulmonary disease and both were correlated with the extent of airflow obstruction. Loss of elastic fibres in small airways may contribute to the development of airflow obstruction in chronic obstructive pulmonary disease.
小气道是慢性阻塞性肺疾病（COPD）气流阻塞的主要部位。这归因于肺泡中弹性蛋白的丧失和小气道的纤维化。在本研究中，假设肺泡中弹性纤维的变化可能与小气道中弹性纤维的类似减少同时出现。对因支气管癌接受肺叶切除术的患者的组织块进行了研究。患者被分为COPD组（一秒用力呼气量（FEV₁）<预测值的80%，FEV₁/用力肺活量（FVC）<0.7）或对照组（FEV₁≥预测值的80%，FEV₁/FVC≥0.7）。使用弹性范吉森染色使弹性纤维可视化，并使用点计数法将弹性纤维的体积分数（v/f）确定为组织体积的百分比。弹性纤维网络也通过共聚焦显微镜进行可视化。COPD患者肺泡中弹性纤维的v/f为18.6%，对照组为32.8%。在气道中，COPD患者的v/f为14.6%，对照组为25.5%。预测的FEV₁%与肺泡和小气道中的v/f均相关。在慢性阻塞性肺疾病中，小气道和肺泡中弹性纤维的体积分数降低程度相似，且两者均与气流阻塞程度相关。小气道中弹性纤维的丧失可能导致慢性阻塞性肺疾病中气流阻塞的发展。
