Comparison of the lung clearance index in preschool children with primary ciliary dyskinesia and cystic fibrosis

Abstract

<b>Background:</b> Previous studies have shown that the lung clearance index (LCI) determined by multiple-breath washout (MBW) is sensitive to detect early lung disease in preschool children with cystic fibrosis (CF). In preschool children with primary ciliary dyskinesia (PCD), data on the onset and severity of lung disease and on the sensitivity of the LCI as a noninvasive quantitative outcome measure remain limited. Therefore, we hypothesized that&nbsp;MBW feasible and sensitive to detect ventilation inhomogeneity in preschool children with PCD. <b>Methods:</b> This was a prospective cross-sectional multicenter study and included preschoolers with PCD and preschoolers with CF and healthy controls. LCI was determined using nitrogen MBW, and compared between the three groups. <b>Results:</b> LCI was determined in 27 children with PCD, 34 children with CF and 30 healthy controls (mean age, 4.8 years; range, 2.2 – 6.9 years). The LCI in preschool children with PCD was increased (median, 9.1; CI 95%, 8.6-10.3) compared to healthy controls (median, 7.0; CI 95%, 6.7-7.1), (P &lt; 0.0001), but did not differ from preschool children with CF (median, 8.6; CI 95%, 8.4-9.7), (P = 0.71). The feasibility in the PCD group was 93.1% and was similar to that in the CF group (91.9%) and in healthy controls (85.7%), (P = 0.55). Interpretation: This study demonstrates early onset of lung disease in preschool children with PCD and indicates that lung disease severity in PCD may be similar to that in CF during preschool years.&nbsp;These data support a need for early diagnostic monitoring and therapy and suggest the LCI as a noninvasive diagnostic tool and as a potential endpoint in clinical trials&nbsp;testing early interventions.