Inborn errors of immunity: a structured model for paediatric-to-adult transition of care.

The transition of care from paediatric to adult healthcare services is a vulnerable period for patients with inborn errors of immunity (IEI), a heterogeneous group of primary immunodeficiency disorders characterized by chronic immune dysfunction and significant morbidity. With advances in diagnosis and treatment, an increasing number of patients with IEI are now reaching adulthood, making the management of this transition a growing clinical priority. Inadequate transition is associated with medical complications, treatment non-adherence, discontinuity of care, increased healthcare utilization, and poorer long-term outcomes. Despite growing awareness, condition-specific and standardized transition guidelines for IEI remain largely absent, leaving clinicians without a clear framework to guide this critical phase. In this context, the present review proposes a structured, multidisciplinary transition protocol designed specifically for paediatric patients with IEI to support therapeutic adherence, continuity of care, and patient well-being. This practice-informed narrative review integrates a non-systematic appraisal of the available literature, expert clinical consensus, and the practical experience of a dedicated Italian centre. Central to this model are the early identification of patients eligible for transition, beginning around age 14, and the gradual involvement of a multidisciplinary team, with shared responsibility between paediatric and adult specialists throughout an overlap period of at least three years. Clear documentation, including a standardized clinical dossier and final transition report, along with measurable process and outcome indicators such as infection rates, follow-up adherence, and patient-reported quality of life, ensures continuity of care and ongoing support. The framework also addresses immunoglobulin replacement therapy options, including intravenous, subcutaneous, and facilitated subcutaneous immunoglobulin, which each offer distinct advantages depending on patient needs and life stage. Patient and caregiver empowerment, timely management of comorbidities, and regular reassessment of individual needs are core components. Although resource-intensive, the proposed model is designed to be adaptable to different healthcare settings. Limitations, including reliance on multidisciplinary resources and the absence of prospective validation, are acknowledged, and future research to evaluate its impact on clinical outcomes is warranted. Through coordinated, standardized strategies, this work aims to bridge the gap between paediatric and adult healthcare, reducing care discontinuity and supporting successful long-term disease management in adulthood.