Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton, UK.
NIHR Southampton Biomedical Research Centre, University Hospital Southampton NHS Foundation Trust, Southampton, UK.
Respir Res. 2018 Feb 20;19(1):31. doi: 10.1186/s12931-018-0734-y.
COPD is a complex, heterogeneous disease characterised by progressive development of airflow limitation. Spirometry provides little information about key aspects of pathology and is poorly related to clinical outcome, so other tools are required to investigate the disease. We sought to explore the relationships between quantitative CT analysis with functional, inflammatory and infective assessments of disease to identify the utility of imaging to stratify disease to better predict outcomes and disease response.
Patients from the AERIS study with moderate-very severe COPD underwent HRCT, with image analysis determining the quantity of emphysema (%LAA), small airways disease (E/I MLD) and bronchial wall thickening (Pi10). At enrolment subjects underwent lung function testing, six-minute walk testing (6MWT), blood sampling for inflammatory markers and sputum sampling for white cell differential and microbiological culture and PCR.
122 subjects were included in this analysis. Emphysema and small airways disease had independent associations with airflow obstruction (β = - 0.34, p < 0.001 and β = - 0.56, p < 0.001). %LAA had independent associations with gas transfer (β = - 0.37, p < 0.001) and E/I MLD with RV/TLC (β = 0.30, p =0.003). The distance walked during the 6MWT was not associated with CT parameters, but exertional desaturation was independently associated with emphysema (β = 0.73, p < 0.001). Pi10 did not show any independent associations with lung function or functional parameters. No CT parameters had any associations with sputum inflammatory cells. Greater emphysema was associated with lower levels of systemic inflammation (CRP β = - 0.34, p < 0.001 and fibrinogen β = - 0.28, p =0.003). There was no significant difference in any of the CT parameters between subjects where potentially pathogenic bacteria were detected in sputum and those where it was not.
This study provides further validation for the use of quantitative CT measures of emphysema and small airways disease in COPD as they showed strong associations with pulmonary physiology and functional status. In contrast to this quantitative CT measures showed few convincing associations with biological measures of disease, suggesting it is not an effective tool at measuring disease activity.
COPD 是一种复杂的、异质性疾病，其特征是气流受限的进行性发展。肺量测定法提供的病理关键方面的信息很少，与临床结果的相关性也很差，因此需要其他工具来研究疾病。我们试图探讨定量 CT 分析与疾病的功能、炎症和感染评估之间的关系，以确定影像学在分层疾病以更好地预测结局和疾病反应方面的效用。
来自 AERIS 研究的中重度 COPD 患者接受了高分辨率 CT（HRCT）检查，图像分析确定了肺气肿的数量（%LAA）、小气道疾病（E/I MLD）和支气管壁增厚（Pi10）。在入组时，受试者接受了肺功能测试、六分钟步行测试（6MWT）、血液采样以检测炎症标志物和痰液采样以检测白细胞分类和微生物培养及 PCR。
本分析共纳入 122 例患者。肺气肿和小气道疾病与气流阻塞有独立的关联（β=−0.34，p<0.001 和 β=−0.56，p<0.001）。%LAA 与气体转移有独立的关联（β=−0.37，p<0.001），E/I MLD 与 RV/TLC 有独立的关联（β=0.30，p=0.003）。6MWT 中行走的距离与 CT 参数无关，但运动性低氧与肺气肿有独立的关联（β=0.73，p<0.001）。Pi10 与肺功能或功能参数无任何关联。CT 参数与痰液中的炎症细胞均无关联。肺气肿越严重，全身炎症水平越低（CRPβ=−0.34，p<0.001 和纤维蛋白原β=−0.28，p=0.003）。在痰液中检测到潜在致病细菌和未检测到潜在致病细菌的患者之间，任何 CT 参数均无显著差异。
本研究进一步验证了定量 CT 测量肺气肿和小气道疾病在 COPD 中的应用，因为它们与肺生理学和功能状态有很强的关联。与这一点相反，定量 CT 测量与疾病的生物学测量之间几乎没有令人信服的关联，这表明它不是一种有效的测量疾病活动的工具。
