Supplementary Material for: ISPAD Clinical Practice Consensus Guidelines 2024: Screening, Staging, and Strategies to Preserve Beta Cell Function in Children and Adolescents with Type 1 Diabetes

Introduction This guideline serves as an update to the 2022 International Society for Pediatric and Adolescent Diabetes (ISPAD) consensus guideline on staging for Type 1 Diabetes (T1D). Key additions include an evidence-based summary of recommendations for screening for risk of T1D and monitoring those with early-stage T1D. In addition, a review of clinical trials designed to delay progression to Stage 3 T1D and efforts seeking to preserve beta cell function in those with Stage 3 T1D is included. Lastly, opportunities and challenges associated with the recent United States Food and Drug Administration (FDA) approval of teplizumab as an immunotherapy to delay progression are discussed. WHAT IS NEW • Stages 1, 2a, 2b, 3a, 3b, and 4 T1D are being used in clinical, research, and regulatory settings. • General population screening programs for T1D are expanding in both research and clinical settings. • Effective screening and monitoring programs include individualized education, psychological support, and metabolic surveillance for those identified with islet autoantibodies. • The anti-CD3 monoclonal antibody (teplizumab) has been approved by the U.S. FDA to delay progression from Stage 2 to Stage 3 T1D • These insights emphasize that trials and effective screening and treatments in early-stage T1D need to be inclusive for all children and young people irrespective of geographic location and health systems.