Background: Mastocytosis is characterized by the accumulation of abnormal mast cells in various organs. Data on the prevalence of mastocytosis are heterogeneous, with the condition’s prevalence estimated to be between 9.6 and 23.9 per 100,000 inhabitants. Patients may present signs and symptoms that can severely impact quality of life (QoL), but reported data are scarce. Thus, we performed a nationwide study to estimate the prevalence and to assess the management and burden of adults with mastocytosis in France according to physician assessments. Methods: We developed an online survey comprising 25 questions investigating various aspects of mastocytosis and asked 6,239 physicians to respond. Data concerning physician characteristics and the number of patients followed were used to estimate overall prevalence. To assess patients’ QoL, we focused on the presence of signs and symptoms and the patients’ burden specifically in those with either indolent systemic mastocytosis (ISM) or mastocytosis in the skin (MIS). Results: Between July 11, 2023, and September 1, 2023, 1,169 physicians (18.7%) completed the survey. These physicians managed 4,121 mastocytosis patients, corresponding to an estimated prevalence of mastocytosis of 8.5 per 100,000 in France. In the ISM/MIS population (representing 76% of mastocytosis patients), 53% presented moderate to severe symptoms (mainly skin, digestive and general symptoms). Overall, physicians indicated that there was substantial burden associated with these symptoms in almost all fields of QoL analyzed. Conclusions: Our results provide further evidence of the burden associated with mastocytosis and highlight the need to improve QoL in these patients.

Introduction: The prognosis of cystic fibrosis (CF) has dramatically changed over the past decade in France, mostly due to global improvements in specific care. Currently, the majority of French CF patients are adults, meaning they went through a transition process from a pediatric CF center to an adult CF center. To determine the impact of that transfer on clinical evolution, we report the transition procedure of our CF center in Lyon. Materials and Methods: From January 2006 to December 2016, 117 CF patients went through a standardized transition process from the pediatric to the adult CF center of Lyon. We compared the clinical evolution of the patients over 3 periods starting the year before transfer and ending the next year after transfer. Clinical data taken into account were FEV1%, BMI, pulmonary colonization, number of antibiotic courses, and number of days of hospitalization per year and outpatient visits per year. Results: No significant differences were observed between respiratory and nutritional status, pulmonary colonization, number of antibiotic courses, and numbers of hospitalizations and visits when comparing the 3 periods of observation (the year before, the year after and the next year after transfer) around transition. Conclusion: The standardized procedure of transition in Lyon is associated with the maintenance of a stable clinical status of our CF patients.