Primary ciliary dyskinesia and mild cystic fibrosis: lung structure and function similarities

Abstract

Introduction: primary ciliary dyskinesia (PCD) and cystic fibrosis (CF) are increasingly compared. There are no chest magnetic resonance imaging (MRI) comparative studies of PCD and CF. Aims and objectives: we assessed clinical, functional, microbiological and MRI findings in PCD and mild CF patients in order to evaluate different expression of lung disease. Methods: 20 PCD (15.1 years) and 20 CF subjects with mild respiratory impairment (16 years, 70% with pancreatic insufficiency) underwent MRI, spirometry, and sputum cultures when clinically stable. MRI was scored using the modified Helbich system. Results: PCD was diagnosed later than CF (9.9 versus 0.6 years, p=0.03), despite earlier symptoms (0.1 versus 0.6 years, p=0.02). In the year preceding the study, patients from both groups underwent two systemic antibiotic courses (p= 0.48). MRI total scores were 11.6±0.7 and 9.1±1 in PCD and CF, respectively. FEV1 and FVC Z- scores were -1.75 (range, -4.6-0.7) and -0.6 (-3.9-1.8) in PCD, and -0.9 (range, -5.4- 2.3) and -0.3 (-3.4-2.5) in CF, respectively. No difference was found between lung function or structure, despite a higher MRI subscore of collapse/consolidation in PCD versus CF (1.6±0.1 and 0.6±0.2, p Conclusions: MRI is a valuable radiation-free tool for comparative PCD and CF lung disease assessment. Patients with PCD may exhibit similar MRI and lung function changes as CF subjects with mild pulmonary disease. Delay in PCD diagnosis is unlikely the only determinant of similarities.