Division of Respiratory Medicine, Department of Paediatrics, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland.
Department of Paediatric Pulmonology, University Children's Hospital of Ruhr University Bochum at St. Josef-Hospital, Bochum, Germany.
Thorax. 2021 Jul;76(7):681-688. doi: 10.1136/thoraxjnl-2020-215504. Epub 2021 Jan 27.
Lung clearance index (LCI) is a promising lung function outcome in individuals with primary ciliary dyskinesia (PCD). The impact of events clinically important for individuals with PCD, such as pulmonary exacerbations, on LCI is unknown.
We conducted an international, multicentre, observational cohort study to assess the association of LCI and risk of pulmonary exacerbation, specific changes in LCI during pulmonary exacerbation and global variability of LCI across four visits every 4 months. Ninety individuals with PCD, aged 3-41 years, underwent nitrogen multiple-breath washout (MBW) and spirometry measurements. The association of LCI and pulmonary exacerbations was assessed by Cox proportional hazards and random-effects regression models.
We obtained 430 MBW and 427 spirometry measurements. In total, 379 person-years at risk contributed to the analysis. Per one unit increase (deterioration) in LCI, the risk of future pulmonary exacerbation increased by 13%: HR (95% CI), 1.13 (1.04 to 1.23). If LCI changed from a range of values considered normal to abnormal, the risk of future pulmonary exacerbations increased by 87%: 1.87 (1.08 to 3.23). During pulmonary exacerbations, LCI increased by 1.22 units (14.5%). After pulmonary exacerbations, LCI tended to decline. Estimates of variability in LCI suggested lower variation within individuals compared with variation between individuals. Findings were comparable for forced expiratory volume in 1 s.
On a visit-to-visit basis, LCI measurement may add to the prediction of pulmonary exacerbations, the assessment of lung function decline and the potential lung function response to treatment of pulmonary exacerbations.
肺清除指数（LCI）是原发性纤毛运动障碍（PCD）患者有前途的肺功能指标。对 PCD 患者具有临床重要意义的事件（如肺部恶化）对 LCI 的影响尚不清楚。
我们进行了一项国际性、多中心、观察性队列研究，以评估 LCI 与肺部恶化风险、肺部恶化期间 LCI 的特定变化以及每 4 个月进行 4 次的 LCI 整体变异性之间的关联。90 名年龄在 3-41 岁的 PCD 患者接受了氮多次呼吸冲洗（MBW）和肺活量测定。通过 Cox 比例风险和随机效应回归模型评估 LCI 与肺部恶化的相关性。
我们获得了 430 次 MBW 和 427 次肺活量测定值。总共有 379 人年的风险参与了分析。LCI 每增加一个单位（恶化），未来肺部恶化的风险增加 13%：HR（95%CI），1.13（1.04 至 1.23）。如果 LCI 从正常范围变为异常范围，未来肺部恶化的风险增加 87%：1.87（1.08 至 3.23）。在肺部恶化期间，LCI 增加了 1.22 个单位（14.5%）。肺部恶化后，LCI 呈下降趋势。LCI 变异性的估计值表明个体内的变异性低于个体间的变异性。1 秒用力呼气量的发现结果相当。
在就诊间的基础上，LCI 测量可能有助于预测肺部恶化、评估肺功能下降以及肺部恶化治疗的潜在肺功能反应。
