Understanding Pulmonary Fibrosis in Pediatric Interstitial Lung Disease: A Comprehensive Analysis.

BACKGROUND

Childhood interstitial lung diseases (chILDs) encompass a wide range of rare, chronic respiratory disorders, with pulmonary fibrosis (PF) being the clinical entity closely associated with mortality and morbidity.

RESEARCH QUESTION: What is the prevalence and radiologic spectrum of PF in children with chILD, and how is it associated with pulmonary function and clinical characteristics?

STUDY DESIGN AND

METHODS

This multicenter, retrospective observational cohort study used data from the Turkish Childhood Interstitial Lung Disease Registry as of January 2024. An experienced radiologist reviewed the chest CT scans for PF findings. Patients were divided into 2 groups based on the presence or absence of PF findings, and their clinical and demographic data were analyzed.

RESULTS

A total of 404 patients (47.5% female) from 25 centers were included. The median age was 137 months (interquartile range [IQR], 24-376 months). The median z score for weight was -1.02 (IQR, -8.8 to 6.88), and the median z score for height was -0.59 (IQR, -7 to 6.45). The median FEV1 was 68% (IQR, 16%-127%), and the median diffusion capacity of the lungs for carbon monoxide (Dlco) was 66% (IQR, 21%-132%). The PF findings were as follows: reticular abnormalities, 34.9% of patients; cystic abnormalities, 21% of patients; traction bronchiectasis, 19.8% of patients; architectural distortion, 14.4% of patients; and honeycombing, 2.5% of patients. Two groups were compared based on the presence (n = 183) or absence (n = 221) of PF findings; the group with fibrotic findings showed a higher age and lower z score for weight (P < .05). Although no differences were found in PFT parameters between groups (P > .05), Dlco was lower in the fibrotic group (P = .015). The prevalence of PF was higher in patients with diffuse parenchymal lung disease (DPLD) group A disorders than in those with DPLD group B (P = .014).

INTERPRETATION: Our results show that PF is a common complication in chILD and becomes more pronounced with age, underscoring the importance of early detection. The higher rate of PF findings in patients with DPLD-A disorders suggests that children with surfactant dysfunction or alveolar developmental abnormalities may be at an increased risk of PF developing. PF may be more common in children with a lower Dlco score, with a DPLD-A disorder, or of an older age.