Pediatric-to-adult transition of care in patients with surfactant metabolism disorders.

Genetic disorders of surfactant metabolism, caused by pathogenic variants in the surfactant related genes (SRG) SFTPB, ABCA3, SFTPC and NKX2-1, were long considered as diseases of the neonate and the infant, with an outcome measured in weeks or months. Advances in neonatal intensive care, increased awareness, earlier molecular diagnosis, structured management and pediatric lung transplantation have generated a growing population of adolescents and young adults living with a surfactant metabolism disorder. In the largest European survey of childhood interstitial lung disease (chILD) survivors, surfactant-related disorders accounted for about one in five patients now followed in adult centers. These patients must leave pediatric services that have often known them for many years, entering adult respiratory care systems which are primarily around fibrotic lung disease of the older adults: a setting where SRG diseases are rarely recognized. No literature is specifically devoted to transition in surfactant metabolism disorders. Therefore, this review brings together three bodies of evidence: the pediatric natural history of SFTPB, ABCA3, SFTPC and NKX2-1 related disorders; specificities of SRG ILD surviving into and/or presenting in adulthood; the general principles of transition in rare disease, including the recent European Respiratory Society (ERS) statement on transition of care in chILD and what each implies for this group. Finally, the patient and family perspective were discussed, based on very sparse qualitative research. A proposed framework and a research agenda were suggested.