Department of Pediatrics, Queen Silvia's Children Hospital, Gothenburg, Sweden.
Department of Pediatrics, Central Hospital, Skoevde, Sweden.
J Cyst Fibros. 2018 Mar;17(2):236-241. doi: 10.1016/j.jcf.2017.08.004. Epub 2017 Aug 16.
Data on long term variability of Lung Clearance Index (LCI) in Cystic Fibrosis (CF) is urgently needed to guide test result interpretation. Our aim was to evaluate LCI variability in clinically stable CF lung disease in school age children.
Paediatric patients, aged 6 to 17years, attending the outpatient CF clinic performed Multiple Breath Nitrogen Washout (Exhalyzer® D) and spirometry every third month over a period of one year. Clinical stability was assessed by the Cystic Fibrosis Clinical Score (CFCS) at each visit.
Twentyfive children were recruited: baseline median (range) FEV% pred. 91 (55-122)%, LCI 9.1 (6.4-18.6), CFCS 15 (12-23). A total of 107 visits were included in the study, of which 93% were defined as clinically stable. In clinically stable visits, within-subject variability of LCI and FEV% pred. were 10% and 16%, respectively. The upper limit of normal (ULN, 95% percentile) of LCI variability during clinical stability was 17%.
LCI within-subject variability was low and comparable to FEV% pred. which strengthen the use of LCI to monitor lung disease progression in CF patients. An increase in LCI >17% compared to previous LCI-measurement in clinically stable CF patients may therefore indicate early lung disease progression.
迫切需要关于囊性纤维化（CF）中肺清除指数（LCI）长期变异性的数据，以指导测试结果解释。我们的目的是评估学龄期 CF 肺部疾病中临床稳定患者的 LCI 变异性。
6 至 17 岁的儿科患者在门诊 CF 诊所就诊，每三个月进行一次多呼吸氮冲洗（Exhalyzer®D）和肺活量测定，为期一年。每次就诊时通过 CF 临床评分（CFCS）评估临床稳定性。
共招募了 25 名儿童：基线中位数（范围）FEV%预测值 91（55-122）%，LCI 9.1（6.4-18.6），CFCS 15（12-23）。共纳入 107 次就诊，其中 93%被定义为临床稳定。在临床稳定的就诊中，LCI 和 FEV% pred. 的个体内变异性分别为 10%和 16%。LCI 变异性的正常上限（ULN，95%百分位数）在临床稳定期间为 17%。
LCI 的个体内变异性较低，与 FEV% pred. 相当，这加强了使用 LCI 监测 CF 患者肺部疾病进展的能力。因此，与临床稳定的 CF 患者之前的 LCI 测量相比，LCI 增加>17%可能表明早期肺部疾病进展。
