Beyond Infections: Clinical and Genetic Spectrum of Pediatric Immune Dysregulation Disorders

Aim: Primary immune regulatory disorders represent a rapidly expanding subgroup of inborn errors of immunity.Unlike classical infectionpredominant immunodeficiencies, these disorders may initially present with autoimmunity, lymphoproliferation, cytopenias, dermatologic disease, allergy, enteropathy, hemophagocytic lymphohistiocytosis, or malignancy. Materials and Methods:We conducted a retrospective single-center observational cohort study of children with genetically confirmed diseases of immune dysregulation who had been followed at a tertiary pediatric immunology center between 2005 and 2025.Patients were included if their molecular diagnosis was classified under the International Union of Immunological Societies (IUIS) category of diseases of immune dysregulation.Demographic, clinical, genetic, therapeutic, transplant-related, and outcome data were extracted from the medical records and analyzed descriptively.Results: Twenty-one children were included.Parental consanguinity was frequent (71.4%), and more than half of the cohort had a family history of primary immunodeficiency (57.1%).A substantial diagnostic delay was observed, with a median delay of 28 months (interquartile range, 8-105.5).The most common IUIS subcategory was regulatory T-cell defects (52.4%), followed by familial hemophagocytic lymphohistiocytosis syndromes with hypopigmentation (19.0%), autoimmune lymphoproliferative syndrome (14.3%), susceptibility to Epstein-Barr virus and lymphoproliferative conditions (9.5%), and immune dysregulation with colitis (4.8%).The main clinical features were lymphoproliferation (76.2%), hematologic abnormalities (66.7%) and autoimmunity (52.4%).Notably, malignancy was documented in 2 patients (9.5%).Antimicrobial prophylaxis was administered in 90.5% of the patients, immunoglobulin replacement in 66.7%, conventional immunosuppressive therapy in 38.1%, and biological or targeted therapy in 33.3%.Hematopoietic stem cell transplantation (HSCT) was performed in 8 patients (38.1%); immune reconstitution was achieved in all of the surviving transplant patients.Conclusion: Pediatric diseases of immune dysregulation frequently present with non-infectious manifestations, particularly lymphoproliferation, cytopenias, autoimmunity, and dermatologic findings.Recognition beyond infection-centered warning signs, the integration of genetic testing, and the individualized use of targeted therapies or HSCT may improve care for this heterogeneous group of disorders.