Characterizing Mucociliary Clearance in Young Children with Cystic Fibrosis

BACKGROUND: This research characterized mucociliary clearance (MCC) in young children with cystic fibrosis (CF). METHODS: Fourteen children (5–7 years old) with CF underwent: two baseline MCC measurements (Visits 1 and 2); one MCC measurement approximately one year later (Visit 3); and measurements of lung clearance index (LCI), a measure of ventilation inhomogeneity. RESULTS: Median (range) percent MCC through 60 minutes (MCC60) was similar on Visits 1 and 2 with 11.0 (0.9–33.7) and 12.8 (2.7–26.8), respectively (p=0.95), and reproducible (Spearman Rho=0.69; p=0.007). Mucociliary clearance did not change significantly over one year with median percent MCC60 on Visit 3 [12.8 (3.7 – 17.6)] similar to Visit 2 (p=0.58). Lower percent MCC60 on Visit 3 was significantly associated with higher LCI scores on Visit 3 (N=14; Spearman Rho=−0.56; p=0.04). CONCLUSIONS: Tests of MCC were reproducible and reliable over a two-week period and stable over a one-year period in 5–7 year-old children with CF. Lower MCC values were associated with increased ventilation inhomogeneity. These results suggest that measurements of MCC could be used in short-term clinical trials of interventions designed to modulate MCC and as a new, non-invasive test to evaluate early lung pathology in children with CF.