Pulmonary function testing in children's interstitial lung disease.

The use of pulmonary function tests (PFTs) has been widely described in airway diseases like asthma and cystic fibrosis, but for children's interstitial lung disease (chILD), which encompasses a broad spectrum of pathologies, the usefulness of PFTs is still undetermined, despite widespread use in adult interstitial lung disease. A literature review was initiated by the COST/Enter chILD working group aiming to describe published studies, to identify gaps in knowledge and to propose future research goals in regard to spirometry, whole-body plethysmography, infant and pre-school PFTs, measurement of diffusing capacity, multiple breath washout and cardiopulmonary exercise tests in chILD. The search revealed a limited number of papers published in the past three decades, of which the majority were descriptive and did not report pulmonary function as the main outcome.PFTs may be useful in different stages of management of children with suspected or confirmed chILD, but the chILD spectrum is diverse and includes a heterogeneous patient group in all ages. Research studies in well-defined patient cohorts are needed to establish which PFT and outcomes are most relevant for diagnosis, evaluation of disease severity and course, and monitoring individual conditions both for improvement in clinical care and as end-points in future randomised controlled trials.

Lung clearance index-triggered intervention in children with cystic fibrosis - A randomised pilot study.

HYPOTHESIS: Using increase in the lung clearance index (LCI) as a trigger for bronchoalveolar lavage (BAL) and associated antimicrobial treatment might benefit clinical outcomes in children with cystic fibrosis (CF). METHODS: A 2-year, longitudinal, interventional, randomized, controlled pilot study with quarterly visits in 5-18 years old children with CF. LCI and z-scores for the forced expired volume in 1 s (zFEV1) and body mass index (zBMI) were obtained at every visit, CF Questionnaire-revised (CFQ-R) yearly and BAL and chest computed tomography at first and last visit. Children in the intervention group had BAL performed if LCI increased >1 unit from a fixed baseline value established at first visit. If the presence of a pathogen was documented in the BAL fluid, treatment was initiated/altered accordingly. RESULTS: Twenty-nine children with CF were randomized to the control (n = 14) and intervention group (n = 15). The median (interquartile range) number of BAL procedures per child was 2.5 (2.0; 3.0) and 6.0 (4.0; 7.0) in the control and intervention group, respectively. There was no significant difference between groups in slope for the primary outcome LCI; difference was 0.21 (95% confidence interval: -0.45; 0.88) units/year. Likewise, there was no significant difference between groups in slope for the secondary outcomes zFEV1, zBMI, CFQ-R respiratory symptom score and the proportion of total disease and trapped air on chest computed tomography. CONCLUSIONS: LCI-triggered BAL and associated antimicrobial treatment did not benefit clinical outcomes in a small cohort of closely monitored school-age children with CF.

Long-Term Lung Function and Exercise Capacity in Postinfectious chILD.

Background: Severe postinfectious diffuse pulmonary disease may clinically mimic other entities of children's interstitial lung disease and is clinically challenging comprising various disease severities despite treatment. Long-term lung function trend and physical capacity in children with postinfectious diffuse pulmonary disease are rarely reported. We investigated trends in pulmonary function by long-term follow-up and assessed physical capacity in such patients. Methods: We performed a descriptive, single-center follow-up study in children with biopsy-verified postinfectious diffuse pulmonary disease. Patients with completed primary treatment course were eligible for follow-up, including pulmonary function and exercise (VO2peak) testing. Results: Thirty patients with postinfectious diffuse pulmonary disease were identified and included. Median (range) age at diagnose was 27.5 (2-172) months after a mean lag time of 23 months. H. influenzae and rhinovirus were the most frequent pathogens. Fifteen patients were available for follow-up after mean (range) 7.6 (2-15) years of treatment completion. Lung clearance index (LCI2.5), forced expiratory volume in 1 second (FEV1), and bronchodilator responsiveness were abnormal in 80%, 53%, and 44%, respectively. Diffusion capacity for monoxide was abnormal in 7% and total lung capacity in 33%. Only 8% demonstrated low VO2peak, while 40% reported difficulties during physical exertion. Longitudinal data on spirometry (n = 14) remained unchanged from end of treatment throughout follow-up. A significant association was found between zLCI2.5 and zFEV1 (multiple linear regression; r 2 = 0.61; P = 0.0003). Conclusion: Postinfectious diffuse pulmonary disease in children carries a varying degree of chronic pulmonary impairment with onset of symptoms in the first months of life and a typical considerable lag time before diagnosis. Follow-up several years after the initial injury demonstrated moderate-to-severe peripheral airway impairment although no further lung function decline was found years after completion of treatment. Despite acceptable VO2peak, a considerable proportion struggled during heavy exercise.