Introduction
Primary ciliary dyskinesia (PCD), a rare genetic disorder that is
characterized by recurrent respiratory infection and pulmonary
dysfunction, has historically been viewed as a mild respiratory
condition [1]. However, recent data suggest that
PCD disease can seriously impair lung function in children of preschool
age. In fact, in some children PCD can worsen rapidly and lead to
greater decline in lung function during childhood than occurs in
pediatric cystic fibrosis (CF) patients [2-4].
Frequent respiratory tract infections appear to be important factor of
pulmonary disease progression in PCD patients [5],
while also causing repeated hospitalizations that adversely affect
quality of life of patients. Moreover, results of one European study
revealed that 70% of PCD patients who did not receive regular treatment
accumulated more than 50 outpatient visits before diagnosed[6].
Respiratory management of PCD patients is critical in order to prevent
irreversible lung damage and appropriate treatment will likely prevent
or slow progression of lung damage once a diagnosis is established[5]. Current PCD treatment mainly follows CF and
non-CF bronchiectasis treatment recommendations, with azithromycin (AZM)
maintenance therapy known to exert beneficial anti-inflammatory effects
when use to treat CF and non-CF bronchiectasis [7,
8]. RCTs examining azithromycin versus placebo demonstrated increases
of percent predicted forced expiratory volumes (ranged from 2.95% to
6.2%) in AZM-treated CF patients and two studies of azithromycin
treatment in adult non-CF bronchiectasis lasting 6 and 12 months showed
similar results [9, 10]. For a long time, there
were only anecdotal reports of benefit from macrolide antibiotic
(Clarithromycin, erythromycin, and azithromycin) in PCD patients[11, 12]. Recently, an international BEAT-PCD
consensus statement for infection prevention and control was published
in order to improve diagnosis and treatment [13].
Besides, the recently well-designed randomized, placebo-controlled trial
showed that significantly improvement of pulmonary exacerbations in PCD
patients that received 6-month AZM treatment regimens as compared to
those receiving a placebo, while measurements of pulmonary function
indicators revealed no significant intergroup differences in changes of
predicted FEV1, FVC and FEF25-75 values[14]. Nonetheless, treatment outcomes of pediatric
PCD patients receiving AZM are unclear, since studies abovementioned
conducted to date have been focused either on adults or included both
children and adults.
Here, we describe clinical outcomes of AZM-treated pediatric PCD
patients based on longitudinal follow-up periods of 3.1 years on average
(4 months to 9.4 years). The aim of the study was to evaluate effects of
long term AZM treatment on pulmonary disease status of pediatric PCD
patients through retrospective analysis of clinical follow-up data
conducted at the largest pediatric pulmonary treatment center in China.