Below is a summary of two recent articles from the European Respiratory Journal looking at lung function in PCD: 1) Sejal Saglani wrote an editorial entitled “Lung Function in Primary Ciliary Dyskinesia: Breaking the Myth that this is a Mild Disease” and Florian Halbeisen, et al co-authored a paper entitled “Lung Function in Patients with Primary Ciliary Dyskinesia (PCD): an iPCD Cohort Study.”

The Halbeisen, et al iPCD study compared a measure of lung function, Forced Expiratory Volume in 1 second (FEV1), across three groups: a normal control group, an international group of 991 PCD patients, and a UK group of 5904 Cystic Fibrosis (CF) patients. The data analysis was performed in 2016 and published in 2018. The study showed that reduction in FEV1 increases with age for both PCD and CF patients compared to the normal control group. FEV1 was reduced by the same amount for both PCD and CF patients through childhood (age < 17 years). In late adolescence and early adulthood, the degree of impairment differed with PCD patients showing less FEV1 reduction than CF patients. Above age 30 the FEV1 reduction in PCD patients and CF patients again became similar.

Several conclusions were drawn from this study. It refuted the idea that PCD is a relatively mild disease. In fact, the reduction in FEV1 in the PCD and CF patient groups were similar at all ages with the exception of the young adult group. Significant reductions in FEV1 PCD patients early in life highlights the need for early diagnosis and appropriate disease management from infancy. A more significant FEV1 reduction with age in PCD seems to be correlated with low Body Mass Index (BMI) indicating the importance of nutrition management for PCD patients as is currently standard for CF. Certain PCD ciliary defects, for example microtubular defect, seem to be associated with steeper FEV1 reductions with age than other PCD ciliary defects. This points out the need for early testing of PCD patients to determine their specific type of ciliary defect, and perhaps initiating more aggressive treatment for patients that are predisposed to a more severe reduction in lung function with age.

This study demonstrates the advantages of patient registries and large, multi-center research efforts in PCD. Studies currently underway of potential PCD treatments, including inhaled hypertonic saline to improve airway clearance, or sustained use of azithromycin as an anti-inflammatory and anti-infective, will allow researchers and clinicians to determine whether these therapies improve PCD patient outcomes.

The full text articles are available via the following links:

http://erj.ersjournals.com/content/52/2/1801365

http://erj.ersjournals.com/content/52/2/1801040?ijkey=1497b04bd94e61f1454865667b94ef1aec570dab&keytype2=tf_ipsecshahttp://erj.ersjournals.com/content/52/2/1801040?ijkey=1497b04bd94e61f1454865667b94ef1aec570dab&keytype2=tf_ipsecsha

Richard Vassar
PCD Foundation