Primary Ciliary Dyskinesia in Adult Bronchiectasis - Data from the German Bronchiectasis Registry PROGNOSIS

Science and Research

BACKGROUND: Primary ciliary dyskinesia (PCD) is a rare genetic disorder caused by the malfunction of motile cilia and a specific etiology of adult bronchiectasis of unknown prevalence. A better understanding of the clinical phenotype of adults with PCD is needed to identify individuals for referral to diagnostic testing. CLINICAL RESEARCH QUESTIONS: What is the frequency of PCD among adults with bronchiectasis; how do people with PCD differ from those with other etiologies; and which clinical characteristics are independently associated with PCD? STUDY DESIGN AND METHODS: We investigated the proportion of PCD among the participants of the German Bronchiectasis Registry PROGNOSIS, applied multiple imputation to account for missing data in 64 (FEV(1)), 58 (breathlessness), 26 (pulmonary exacerbations), and 2 subjects (BMI), respectively, and identified predictive variables from baseline data using multivariate logistic regression analysis. RESULTS: We consecutively recruited 1,000 patients from 38 centers across all levels of the German healthcare system. Overall, PCD was the fifth most common etiology of bronchiectasis in 87 subjects (9%) after idiopathic, post-infective, COPD, and asthma. People with PCD showed a distinct clinical phenotype. In multivariate regression analysis, the chance of PCD being the etiology of bronchiectasis increased with the presence of upper airway disease (chronic rhinosinusitis and/or nasal polyps; aOR, 6.3; 95% CI 3.3-11.9; P < .001); age < 53 years (aOR, 5.3; 95% CI 2.7-10.4; P < .001); radiological involvement of any middle and lower lobe (aOR, 3.7; 95% CI 1.3-10.8; P = .016); duration of bronchiectasis > 15 years (aOR, 3.6; 95% CI 1.9-6.9; P < .001); and a history of Pseudomonas aeruginosa isolation from respiratory specimen (aOR, 2.4; 95% CI 1.3-4.5; P = .007). INTERPRETATION: Within our nationally representative cohort, PCD was a common etiology of bronchiectasis. We identified few easy-to-assess phenotypic features, which may promote awareness for PCD among adults with bronchiectasis.