In children with primary ciliary dyskinesia, which type of lung function test is the earliest determinant of decline in lung health: A systematic review

Abstract

Background: Primary ciliary dyskinesia is a rare genetic disorder characterized by recurrent sinopulmonary infections and worsening obstructive lung disease. Kidney and brain involvement is less common and is associated with overlapping ciliopathies/syndromes. The lungs are impacted early in the course of the disease, so it is vital to monitor lung function and recognize any decline by doing appropriate lung function tests. This systematic review compares different lung function tests and analyzes which one becomes abnormal earlier in the disease.Methods: A systematic review was conducted following the methodology in the "Cochrane Handbook on Systematic Reviews for diagnostic tests." The Preferred Reporting Items for Systematic Review and Meta-Analyses were used to report the results. The risk of bias assessment was done using "The Cochrane Handbook for Systematic Reviews tool for interventional studies." A meta-analysis was not performed due to the small sample size. All studies were analyzed by using Joanna Briggs Institute's critical appraisal tool.Results: After screening for the duplication of results and applying inclusion and exclusion criteria, 14 studies were assessed by reading the full texts. Out of these, eight were finally included in this systematic review. The total sample size from all studies was 165, including 80 males. All the studies used spirometry as a lung function test, whereas multiple breath washout was used in five studies. Other tests used for comparison were computed tomography (CT), magnetic resonance imaging (MRI), cardiopulmonary exercise testing, 6-min walk test, DLCO, maximal inspiratory pressure, maximal expiratory pressure, and PaO 2 . Lung clearance index (LCI) by multiple breath washout had a stronger association with the structural changes on CT/MRI than spirometry indices like forced expiratory volume in 1 s (FEV1) and forced expiratory flow at 25% to 75% of lung volume .Conclusions: Based on the evidence from this systematic review, LCI becomes abnormal earlier than FEV1 or FEF 25-75 and positively correlates with the findings

Pulmonary functions, nasal symptoms, and quality of life in patients with primary ciliary dyskinesia (PCD)

“…FEF 25−75 was in the lower limit of normal and LCI was increased, consistent with small airway obstruction. Previous studies found that LCI is more sensitive than FEV1 to detect early lung disease, and may correlate with CT findings 30,31 . In a study comparing PCD, CF and healthy controls, FEV1 was similarly reduced in PCD and CF, while FEF 25−75 and maximal expiratory pressure were lower in PCD 7 .…”

“…Previous studies found that LCI is more sensitive than FEV1 to detect early lung disease, and may correlate with CT findings. 30,31 In a study comparing PCD, CF and healthy controls, FEV1 was similarly reduced in PCD and CF, while FEF 25−75 and maximal expiratory pressure were lower in PCD. 7 In another study, abnormal LCI was found in nearly all 27 patients, including those with normal FEV1.…”

Primary Ciliary Dyskinesia: A Clinical Review

“…When performing MBW, worse ventilation inhomogeneity is associated with a longer time to equilibrate or clear the inert gas [28]. Recent studies have found that LCI detects abnormal lung function earlier than FEV 1 or FEF 25-75% in children with PCD (similar to what has been reported in CF); in a systematic review, LCI has correlated with imaging findings on high-resolution computed tomography (HRCT) and magnetic resonance imaging (MRI), making it a useful tool for longitudinally monitoring lung disease [29,30]. Work is underway to characterize genotype-phenotype relationships that may elucidate the variation in lung function in PCD, as lung function may be stable for long periods in some patients, but others experience more severe airway obstruction and more rapid decline in lung function.…”

Chronic Cough and Causes in Children

“…Primary ciliary dyskinesia is a congenital disorder caused by genetic mutations that affect the mucosal cilia structure of the airways and elsewhere [ 8 ]. Transient neonatal respiratory distress is common, and a cough is a major symptom with onset during infancy.…”

“…An anterior aortopexy was performed (Figure 3) w coughing and cessation of the prednisone. Primary ciliary dyskinesia is a congenital disorder caused by genetic affect the mucosal cilia structure of the airways and elsewhere [8]. Transie piratory distress is common, and a cough is a major symptom with onset Because the disorder affects several proteins of the cilia, this dysfunction c mobility of the cilia or cilia movement that is not coordinated to provide n iary clearance.…”