Therapies Used by Children With Primary Ciliary Dyskinesia: A Natural History Study.

Introduction: Primary ciliary dyskinesia (PCD) management has not been systematically evaluated and is largely empirical.

Methods: Pediatric participants with PCD were enrolled in a prospective, longitudinal, multicenter, observational study. Therapies were recorded at annual visits and categorized by type. Age-related trends in prevalence of therapies were described by serial cross-sectional analyses. Generalized estimating equations analyzed covariates affecting prevalence of certain therapies and whether these covariates impacted oral antibiotic courses.

Results: A total of 137 participants completed 897 visits over 13 years. All but one received ≥ 1 antibiotic courses during study participation, most often cephalosporins (74%) or amoxicillin-clavulanate (73%). Thirty-one percent reported chronic azithromycin use. Per participant, there was an average of 2.3 (SD = 2.2) oral antibiotic courses annually. The rate of reported antibiotic courses at the 6 United States sites was 2.6 times higher compared to the Canadian site (p < 0.001). As patients got older, they were more likely to report use of amoxicillin-clavulanate (p < 0.001), chronic azithromycin (p < 0.001), fluroquinolones (p < 0.001), inhaled steroids with long-acting beta-agonists (p = 0.010), and hypertonic saline (p < 0.001). Compared to outer dynein arm defects, those with inner dynein arm/microtubular disorganization defects reported increased use of chronic azithromycin (p = 0.011) and inhaled steroids (p = 0.015).

Discussion: Older participants and those with inner dynein arm/microtubular disorganization defects reported more therapies likely due to disease progression and more severe phenotypes, respectively. We report that a wide range of therapies are used in PCD without disease-specific studies defining benefits and risks.