Correlation between Lung Clearance Index (LCI) and Cystic Fibrosis Severity Markers

אלעד בן-מאיר ^1,2 Joel Reiter ² Silvia Gartner ³ Iris Eisenstadt ⁴ Tomer Israeli ⁴ Reuven Tsabari ² David Shoseyov ² Alex Gileles-Hillel ² Natalia Simanovsky ⁵ Eitan Kerem ² Malena Cohen-Cymberknoh ²

¹Dept. of Pediatrics A, Edmond and Lily Safra Children’s Hospital, Sheba Medical Center, Ramat Gan, Israel
²Pediatric Pulmonary Unit and CF Center, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
³CF Center, Hospital Universitari Vall d' Hebron, Barcelona, Spain
⁴Dept. of Physiotherapy and CF Center, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
⁵Department of Radiology, Hadassah-Hebrew University Medical Center, Jerusalem, Israel

Introduction:

The lung clearance index (LCI) is a lung function parameter derived from multiple-breath washout test. LCI is a sensitive tool for the early detection of lung disease [1-7] and monitoring of treatment [8-10] in Cystic fibrosis (CF).

Several studies have demonstrated a significant correlation between LCI and CF severity markers including FEV₁[11-15] and high-resolution computed tomography (HRCT) [16-18].

Lower body mass index (BMI), CFTR mutation classes I-III, pancreatic insufficiency and exercise intolerance demonstrated by six-minute-walk-test (6MWT) are associated with worse lung disease and outcomes. The correlation between LCI and these severity markers has not been investigated to date.

Objective:

To evaluate the correlation between LCI and FEV₁, BMI, HRCT, CFTR mutation class, pancreatic status, chronic pseudomonas colonization and 6MWT.

Methods:

A cross-sectional study was conducted at Hadassah hospital, Israel and Vall d`Hebron hospital, Spain CF centers.

Demographic and clinical data (age, sex, BMI, genotype, pancreatic status) were collected. Spirometry, LCI and 6MWT were performed on a routine visit. HRCT, performed within one year of the visit, was scored according to the modified Brody score [19]. Correlation analysis performed between LCI and the severity markers.

Results:

One hundred and five patients (47 females, mean age 17.7±9.1 years, mean BMI%ile 54.7±28.5) were included in the study. A significant correlation between LCI and FEV₁ (r=-0.72;p<0.001) as well as between LCI and chest-HRCT (r=0.81;p<0.001), and between LCI and chronic pseudomonas colonization (p<0.01) was found.

Conclusion:

Our study supports the use of LCI for assessing and monitoring the progression of CF lung disease.