# Clinical features and outcomes of childhood interstitial lung disease: a tertiary center experience

## TL;DR

This study examines the clinical features and outcomes of childhood interstitial lung disease in a Turkish cohort, emphasizing hypoxia as a key predictor of instability.

## Contribution

The study provides a detailed analysis of a large Turkish pediatric chILD cohort using the chILD-EU classification framework.

## Key findings

- Hypoxia was the strongest independent predictor of clinical instability in chILD patients.
- Surfactant dysfunction disorders and immune/environmental diseases were the most common subtypes identified.
- Ground-glass opacities were the most frequent radiological finding in chest CT scans.

## Abstract

Childhood interstitial lung diseases (chILD) constitute a rare and clinically complex group of disorders. This study aimed to characterize the clinical, radiological, and genetic features, as well as the outcomes, of chILD in a Turkish cohort classified according to the chILD-EU framework.

We retrospectively reviewed the medical records of 84 pediatric patients diagnosed with chILD between 2017 and 2024 at a tertiary referral center in Türkiye. Patients were categorized according to the chILD-EU classification. Clinical variables, imaging findings, genetic analyses, pulmonary function test results, and Fan severity scores were systematically assessed. Logistic regression analysis was performed to identify independent predictors of clinical instability.

The median age at diagnosis was 6.0 years (IQR: 1.1–12.9). Surfactant dysfunction disorders (A4) and immune- or environmental-related diseases (B2) were the most frequently identified subtypes. Hypoxia was observed in 36 of 84 patients (42.8%) and emerged as the strongest independent predictor of clinical instability (OR: 8.5; 95% CI: 2.2–33.0; p = 0.002). Pathogenic or likely pathogenic variants were identified in 18 of 84 patients (21.4%); among variant-positive cases, ABCA3 was the most frequently affected gene (3 of 18; 16.7%). Chest computed tomography was available in 82 of 84 patients, with ground-glass opacities being the most common finding, observed in 51 of 82 patients (62.2%). A decrease of at least one point in the Fan severity score was observed in 42 of 84 patients (p < 0.001). Mortality was 12 of 84 patients (14.3%) after a median follow-up of 3.2 years (range: 1.2–4).

This study presents one of the largest single-center pediatric chILD cohorts reported from Türkiye. It highlights the prognostic relevance of baseline hypoxia and underscores the importance of comprehensive radiological and genetic assessment in the management of chILD.