Proposed laboratory diagnostic workflow in the Italian national screening program for type 1 diabetes

Population screening for type 1 diabetes (T1D) using pancreatic islet autoantibodies is increasingly recognized as a promising strategy to reduce diabetic ketoacidosis and identify individuals during the presymptomatic stages of the disease. In Italy, Law 130/2023 and the implementing decree of November 6, 2025 established a national multi-year screening program for T1D and celiac disease in the pediatric population. The program proposes screening of children aged 5-6 years using capillary blood samples and standardized immunometric assays. The implementation of this program will require extensive involvement of clinical laboratories and a standardized diagnostic pathway capable of ensuring analytical reliability, harmonization, and efficient integration between regional and reference centers. The proposed model combines decentralized population screening performed in regional laboratories using high-throughput combined autoantibody assays with a centralized confirmatory strategy based on antibody-specific testing and referral of discordant or inconclusive samples to national reference laboratories employing alternative analytical platforms. Children with confirmed autoantibody positivity are subsequently referred to pediatric diabetes centers for metabolic staging and longitudinal monitoring. Beyond describing the screening pathway, the proposed workflow addresses key challenges that remain only partially standardized in existing international programs, including harmonization of laboratory procedures, confirmatory testing strategies, and integration between regional and reference laboratories. Harmonization strategies, including participation in collaborative research initiatives and national quality assessment programs, will be essential to ensure analytical reliability and support the effective implementation of population-based T1D screening in Italy.