Although considered a relatively mild disease, primary ciliary dyskinesia (PCD) has now been shown to affect lung function at an early age, similar to cystic fibrosis (CF), according to the results of an international PCD cohort study that were published in the European Respiratory Journal.
The investigators compared lung function derived from spirometry of patients with PCD with normal reference values and published data from patients with CF. Using the Global Lung Function Initiative 2012 for 991 patients (504 women and 487 men) from the international PCD cohort, they calculated z-scores and percentage of predicted values for forced expiratory volume in 1 second (FEV1) and forced vital capacity (FVC). Associations with sex, age, country of residence, diagnostic certainty, body mass index, organ laterality, and age at time of diagnosis were assessed in linear regression models.
Lung function in patients with PCD was reduced compared with reference values in both sexes and in all age groups. Children 6 to 9 years of age exhibited the smallest impairment: (FEV1 z-score, –0.84; 95% CI, –1.03 to –0.65 and FVC z-score, –0.31; 95% CI, –0.51 to –0.11).
Compared with patients with CF, FEV1 was similarly reduced in children 6 to 9 years of age (91%; 95% CI, 88%-93% in the PCD group and 90%; 95% CI, 88%-91% in the CF group), but was less impaired in young adults 18 to 21 years of age (79%; 95% CI, 76%-82% in the PCD group and 66%; 95% CI, 65%-68% in the CF group).
In individuals with PCD, children between the ages of 6 and 9 years had the best lung function, whereas adults had the worst. Moreover, results varied across the countries involved in the study.
The investigators concluded that the results suggest that PCD affects lung function beginning early in life, thus highlighting the importance of early, multidisciplinary, and standardized care as well as evidence-based treatments.
Halbeisen FS, Goutaki M, Spycher BD, et al. Lung function in patients with primary ciliary dyskinesia: an iPCD cohort study [published online July 26, 2018]. Eur Respir J. doi:10.1183/13993003.01040-2018