The T1DWATCH Study: a Screening for Type 1 Diabetes Autoantibodies in Children for Early Detection and Intervention.

This study aims to identify early-stage type 1 diabetes (T1D) in children aged 2-6 and 8-10 years through autoantibody (Ab) screening, genetic and immunological analyses, and to evaluate the effectiveness of educational interventions, as well as the feasibility and acceptability of their implementation.

It is a prospective cohort study involving 2,169 children attending primary healthcare centres in the Barcelonès area. Eligible participants will be those engaged in routine paediatric preventive programe with parental informed consent. The screening process consists of three visits: Visit 1: Capillary blood collection for 3 T1D related Ab (3-screen ELISA). Visit 2: Confirmation of positive results through a new venous blood sample to determine single T1D related Ab and metabolic tests (fasting glucose, HbA1c, C-peptide), HLA, imme cell study. Visit 3: Risk stratification based on Ab presence: Group A (negative), Group B (one positive Ab, at risk of T1D), and Group C (two positive Ab, diagnosed at stage 1 or 2). Immunological and metabolic changes will be monitored, and screening effectiveness will be assessed in terms of sensitivity, specificity, and false positive/negative rates. The association between HLA genotype and Ab positivity will be analysed using logistic regression. A cost-effectiveness analysis will be conducted alongside a qualitative evaluation of parents' and stakeholders' perceptions regarding the screening process.This study will provide evidence to optimise early T1D detection and its implementation in primary care.