General population screening for type 1 diabetes using islet autoantibodies at the preschool vaccination visit: a proof-of-concept study (the T1Early study)

Abstract

ABSTRACTObjectiveType 1 diabetes (T1D) screening programmes testing islet autoantibodies (IAbs) in childhood can reduce life-threatening diabetic ketoacidosis. General population screening is required to detect the majority of children with T1D, since in >85% there is no family history. Age 3-5 has been proposed as an optimal age for a single screen approach.DesignCapillary samples were collected from children attending their pre-school vaccination and analysed for IAbs to insulin, glutamic acid decarboxylase, islet antigen-2, and zinc transporter 8, using Radiobinding/Luciferase Immunoprecipitation Systems assays. Acceptability was assessed using semi-structured interviews and open-ended postcard questionnaires with parents.SettingTwo primary care practices in Oxfordshire, UK.Main outcome measuresThe ability to collect capillary blood to test IAbs in children at the routine pre-school vaccination (3.5-4 years).ResultsOf 134 parents invited, 66 (49%) were recruited (median age 3.5y (IQR 3. 4-3.6), 26(39.4%) male); 63 provided a sample (97% successfully). Parents (n=15 interviews, n=29 postcards) were uniformly positive about screening aligned to vaccination and stated they would have been less likely to take part had screening been a separate visit. Themes identified included preparedness for T1D, and the long-term benefit outweighing short-term upset. The perceived volume of the capillary sample was a potential concern and needs optimising.ConclusionsCapillary IAb testing is a possible method to screen children for T1D. Aligning collection to the pre-school vaccination visit can be convenient for families and allows a universal approach without the need for an additional visit.KEY MESSAGESWhat is already known on this topic?Screening children for type 1 diabetes by measuring islet autoantibodies (IAbs) may reduce life-threatening diabetic ketoacidosis. The optimal age for screening children at a single timepoint has been proposed as age 3-5. Routine immunisations are given at a similar age.What does this study add?Aligning IAb testing with the pre-school vaccination visit (age 3.5-4y) is feasible and acceptable. Potential barriers and facilitators of this approach are explored.How this study might affect research, practice or policy?The routine vaccination programme is a potential opportunity to screen children for future type 1 diabetes, offering improved engagement and potentially reducing the costs associated with a screening programme; all of which need exploration in a large and definitive study.