BACKGROUND: The extent to which changes in lung function are due to natural variability in patients with primary ciliary dyskinesia (PCD) is unknown. We aimed to assess intra-individual variability in forced expiratory volume in 1 s (FEV1) derived from spirometry to define the extent to which the observed changes were due to test variability in clinically stable PCD patients. METHODS: PROVALF-PCD (Prospective Observational Multicentre Study on Variability of Lung Function in Stable PCD Patients) was a large international prospective cohort conducted in 2017-2019. We included patients aged ≥5 years who were clinically stable at two or more consecutive visits and provided spirometry-derived lung function measurements. To calculate the upper limit of normal (ULN), we fitted an unadjusted multilevel mixed-effect model, and to determine the absolute change in FEV1 z-scores, we calculated the coefficient of repeatability (CR). We performed sensitivity analyses by stratifying relative change by age (adults versus children), number of measurements (at least four), and time between measurements (<4 months apart). RESULTS: We included 252 participants from 12 countries with confirmed or highly likely PCD. We included 1028 FEV1 measurements from patients in stable state. The ULN for relative change between two measurements of FEV1 was 25%. Test variability remained high in all sensitivity analyses. The CR was 1.88 FEV1 z-score. CONCLUSIONS: Changes in intra-individual FEV1 >25% between visits in stable PCD patients lie beyond the expected test variability and therefore could be considered physiologically relevant. These findings inform the selection of end-points for pulmonary intervention trials in PCD, as they suggest that FEV1 is not a sensitive test for monitoring lung health in PCD.

• Publication type
• Journal Article MeSH

Primary ciliary dyskinesia (PCD) is a genetic disorder associated with recurrent and chronic respiratory infections due to functional defects of motile cilia. In this study, we aimed to elucidate inflammatory and proliferative responses in PCD respiratory epithelium and evaluate the effect of Azithromycin (AZT) on these responses. Airway basal cells (BCs) were isolated from nasal samples of Wild-type (WT) epitope of healthy donors and PCD donors with bi-allelic mutations in DNAH5, DNAH11 and CCDC39. Cells were expanded in vitro and stimulated with either Lipopolysaccharide (LPS) or vehicle control. Post stimulation, cells were treated with either Azithromycin (AZT) or vehicle control. Cell proliferation was imaged in real-time. Separately, BCs from the same donors were expanded and grown at an air-liquid interface (ALI) to generate a multi-ciliated epithelium (MCE). Once fully mature, cells were stimulated with LPS, AZT, LPS + AZT or vehicle control. Inflammatory profiling was performed on collected media by cytokine Luminex assay. At baseline, there was a significantly higher mean production of pro-inflammatory cytokines by CCDC39 BCs and MCEs when compared to WT, DNAH11 and DNAH5 cells. AZT inhibited production of cytokines induced by LPS in PCD cells. Differences in cell proliferation were noted in PCD and this was also corrected with AZT treatment.

• MeSH
• Azithromycin * pharmacology   MeSH
• Cytokines MeSH
• Epithelial Cells MeSH
• Humans MeSH
• Lipopolysaccharides toxicity   MeSH
• Ciliary Motility Disorders * MeSH
• Cell Proliferation MeSH
• Inflammation drug therapy   MeSH
• Check Tag
• Humans MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• Azithromycin * MeSH
• Cytokines MeSH
• Lipopolysaccharides MeSH

INTRODUCTION: In primary ciliary dyskinesia (PCD) impaired mucociliary clearance leads to recurrent airway infections and progressive lung destruction, and concern over chronic airway infection and patient-to-patient transmission is considerable. So far, there has been no defined consensus on how to control infection across centres caring for patients with PCD. Within the BEAT-PCD network, COST Action and ERS CRC together with the ERN-Lung PCD core a first initiative has now been taken towards creating such a consensus statement. METHODS: A multidisciplinary international PCD expert panel was set up to create a consensus statement for infection prevention and control (IP&C) for PCD, covering diagnostic microbiology, infection prevention for specific pathogens considered indicated for treatment and segregation aspects. Using a modified Delphi process, consensus to a statement demanded at least 80% agreement within the PCD expert panel group. Patient organisation representatives were involved throughout the process. RESULTS: We present a consensus statement on 20 IP&C statements for PCD including suggested actions for microbiological identification, indications for treatment of Pseudomonas aeruginosa, Burkholderia cepacia and nontuberculous mycobacteria and suggested segregation aspects aimed to minimise patient-to-patient transmission of infections whether in-hospital, in PCD clinics or wards, or out of hospital at meetings between people with PCD. The statement also includes segregation aspects adapted to the current coronavirus disease 2019 (COVID-19) pandemic. CONCLUSION: The first ever international consensus statement on IP&C intended specifically for PCD is presented and is targeted at clinicians managing paediatric and adult patients with PCD, microbiologists, patient organisations and not least the patients and their families.

• Publication type
• Journal Article MeSH