Lung structure and function similarities between primary ciliary dyskinesia and mild cystic fibrosis: a pilot study

Abstract

BackgroundPrimary ciliary dyskinesia (PCD) and cystic fibrosis (CF) are increasingly compared. There are no chest magnetic resonance imaging (MRI) comparative studies of PCD and CF. We assessed clinical, functional, microbiological and MRI findings in PCD and mild CF patients in order to evaluate different expression of lung disease.MethodsTwenty 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.ResultsPCD 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 < 0.001). These findings were confirmed after data-control for diagnostic delay. Pseudomonas aeruginosa and Staphylococcus aureus were more frequent in CF than in PCD (p = 0.05 and p = 0.003, respectively).ConclusionsMRI 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.Electronic supplementary materialThe online version of this article (doi:10.1186/s13052-017-0351-2) contains supplementary material, which is available to authorized users.

Lung function in patients with primary ciliary dyskinesia: an iPCD Cohort study

“…Comparisons of lung function between PCD and CF are rare and the results have been unclear. Some studies concluded that FEV1 was similar in PCD and CF patients [31,40,41], while another reported that it was lower in PCD children compared to pancreatic-sufficient and -insufficient CF children [42]. Yet another study found that children with PCD had better FVC, but similar FEV1 to children with CF [43].…”

Bronchiectasis in PCD looks different to CF on CT scan

“…The structural changes seen on pulmonary CT scans from patients with Cystic Fibrosis (CF) and Primary Ciliary Dyskinesia (PCD), both causes of significant bronchiectasis, have been the basis of numerous previous reports [ 1 – 6 ]. More information on the range of these structural changes is available from patients with CF, due in part to the ability to detect CF by new born screening and because early treatment of this common genetic disease has the potential to prevent or retard the onset of bronchiectasis.…”

“…PCD is an important cause of bronchiectasis and there are several reports that describe the radiological features of PCD-bronchiectasis [ 2 – 6 , 8 ]. Most groups have used CF derived, scoring systems to describe these changes.…”

Lung function in primary ciliary dyskinesia: breaking the myth that this is a mild disease

“…Although computed tomography (CT) imaging has been used clinically in cystic fibrosis, studies reporting changes in PCD with specific relationships between structural and functional abnormalities are lacking. However, there is some evidence of similar magnetic resonance imaging (MRI) and lung function changes in PCD and cystic fibrosis subjects with mild pulmonary disease [13]. Inclusion of CT imaging and MRI is being encouraged in randomised controlled interventional trials in cystic fibrosis to allow improved assessments of cystic fibrosis disease progression [14].…”