Childhood interstitial lung disease survivors in adulthood: a European collaborative study.

Background: Interstitial lung disease (ILD) is rarer in children (chILD) than adults, but with increasing diagnostic awareness, more cases are being discovered. chILD prognosis is often poor, but increasing numbers are now surviving into adulthood.

Aim: To characterize chILD-survivors and identify their impact on adult-ILD centers.

Methods: European study (34 adult-ILD and chILD centers) reporting incident/prevalent cases of chILD-survivors from January to July 2023. Epidemiological, clinical, physiological and genetic data were collected.

Results: 244 patients were identified with median (years) (IQR) age at diagnosis 12.5 (6-16), age at study inclusion 25 (22-33), 51% male, 86% non-smokers, median %-predicted FVC and DLCO 70 (47-89) and 48 (32-75) respectively; 32% were prescribed long-term oxygen; 227 (93%) were followed-up in adult centers whereas 17 (7%) never transitioned. Commonest diagnoses (82%) were chILD category B1, 35% (sarcoidosis, hemosiderosis, connective tissue disorders, vasculitis); A4, 21% (surfactant-related); B2, 14% (bronchiolitis obliterans, hypersensitivity pneumonitis); Bz, 13% (unclassified-ILD). Bz patients had the worst functional status. 60% of all patients were still being prescribed corticosteroids. Re-specification of diagnosis and treatment were made after transition for 9.8% and 16% of patients respectively. Not all chILD diagnoses were recognized in adult-ILD classifications.

Conclusion: chILD survivors are seen in most adult-ILD centers and only a minority continue follow-up in pediatric centers. Survivors have a significant loss of lung function. The heterogeneity of their etiologies and therapeutic requirements has a real impact on adult-ILD centers. Re-specification of diagnosis and treatment may contribute to precision and personalization of management.