A large European registry study provides the first systematic assessment of how frequently pulmonary fibrosis occurs in children with childhood interstitial lung disease (chILD) and what impact it has on disease progression and outcomes.
Childhood interstitial lung disease (chILD) refers to a group of rare lung disorders affecting children. One possible complication is pulmonary fibrosis – a process in which lung tissue becomes remodelled and scarred. Until now, it was unclear how often fibrosis develops in children with chILD, how it affects disease progression, and what implications it has for survival.
For the study, first author Prof. Matthias Griese (CPC-M, Munich site of the German Center for Lung Research) and his team analysed data from the European chILD Registry. The registry includes children and adolescents from 23 countries, with more than 1,000 cases collected over a period of up to 20 years. Each diagnosis is reviewed by an expert panel according to standardised criteria, including CT imaging and, where available, tissue samples. This systematic approach is important because the term “fibrosis” has not always been applied consistently in clinical practice.
Significantly reduced lung function
The findings are clearer than expected: pulmonary fibrosis is not a rare feature in chILD. Depending on the definition used, approximately one in five children showed fibrotic changes, while even stricter criteria identified fibrosis in around one in nine children. These results indicate that fibrotic changes already play a more important role in childhood lung disease than previously assumed.
More importantly, fibrosis has a substantial impact on disease progression. Children with fibrotic changes consistently showed worse outcomes. Their lung function – measured by forced vital capacity (FVC) – remained around 15–20% lower than in children without fibrosis. This difference was not only a short-term finding but remained stable over several years.
Higher risk of death or lung transplantation
The study also revealed differences in survival. Children with pulmonary fibrosis had a significantly higher risk of death or requiring lung transplantation during follow-up. This association remained even after adjusting for factors such as age, sex, and body mass index (BMI). Interestingly, a higher BMI was associated with a more favourable prognosis – a finding that is consistent with observations from other chronic lung diseases.
Importantly, the results were consistent regardless of whether the broader registry definition or stricter criteria used in clinical studies were applied. This supports the robustness of the findings and shows that the association is not dependent on a specific definition of fibrosis.
Implications for clinical practice
The study highlights several important implications for patient care. First, fibrotic changes in children with chILD should be systematically assessed using standardised criteria. Second, the presence of fibrosis provides important prognostic information and helps identify patients at higher risk of an unfavourable disease course. Third, the findings emphasise the need to further investigate antifibrotic treatment approaches in children.
For children aged six years and older, one antifibrotic medication is currently approved. Other antifibrotic therapies are currently mainly used in adults but could potentially become relevant for affected children in the future. Their efficacy and safety in paediatric populations should be investigated in clinical trials.
The study highlights three key messages:
Original publication:
Griese M, Reu-Hofer S, Ley-Zaporozhan J et al. chILD-EU collaborators; Schwerk N, Seidl E. Prevalence and disease trajectories of pulmonary fibrosis of childhood interstitial lung disease: a register-based, multicentre observational study. The Lancet Respiratory Medicine. 2026 Jun 24:S2213-2600(26)00052-4. doi:10.1016/S2213-2600(26)00052-4. Epub ahead of print. PMID: 42341791.
