Transition from Pediatric to Adult Care in Patients with Transfusion-Dependent Beta-Thalassemia in France: A National Study Concerning a Rare Disease.

Background/Objectives: Transfusion-dependent β-thalassaemia (TDT) is a lifelong condition requiring coordinated multidisciplinary care. In France, where the disease is rare, transition from pediatric to adult care remains poorly structured, potentially compromising adherence and long-term outcomes. Methods: This national retrospective study evaluated current transition practices and their clinical impact among young adults with TDT. Patients aged 20-25 years in December 2022 were identified from the national NaThalY registry. Those diagnosed and managed in France before age 15 were included. Clinical data were collected for the two years preceding and following transition. Transition practices were assessed using a standardized questionnaire sent to pediatric centers. Results: Thirty-four patients were included (mean transition age: 19 years). The rate of response to the questionnaire was 90.5%, with feedback from 19 centers. Only one-third of centers offered joint pediatric-adult consultations, and one-quarter provided transition-focused education. No written transition protocols were reported. Mean pre-transfusion hemoglobin levels were significantly lower after the transition (8.5 vs. 8.0 g/dL; p = 0.01). Ferritin levels showed a non-significant increase, with no statistically significant changes observed in hepatic or cardiac iron concentrations. Conclusions: This study demonstrates marked heterogeneity and limited formalization of transition practices in France. Development of structured, standardized transition pathways is urgently needed to ensure continuity of care and optimal disease management in adults with TDT.