ABSTRACT
Viral infections may trigger islet autoimmunity leading to type 1 diabetes (T1D) . We hypothesized SARS-CoV-2 infection is associated with presence of islet autoantibodies (IAb) in children. Between 8/2020 and 12/2021, ASK screened 47general population Colorado children aged 1-17 y for IAb to GAD, insulin, IA-2 and ZnT8 as well as antibodies to SARS-CoV-2 receptor binding domain (CoV-2 RBDAb) - a sensitive and specific marker of infection. Of those, 4172 (89%) have not previously received SARS-CoV-2 vaccine. During the study period, prevalence of CoV-2 RBDAb increased in unvaccinated from 1% to 58% and up to 100% among vaccinated. Among all children, the prevalence increased from 1% to 72% - an estimate of herd immunity (Figure) . Among the unvaccinated, prevalence of multiple or single high-affinity IAb did not differ between children positive vs. negative for CoV-2 RBDAb, respectively 1.23% (16/1297) vs. 1.00% (29/2875) , p=0.52. In multivariate logistic regression, presence of IAb was not associated with presence of CoV-2 RBDAb (OR=1.40, p=0.31) , adjusting for age, sex, race/ethnicity, and family history of T1D. While we found no association between past SARS-CoV-2 infection and islet autoimmunity, a confirmation in a larger population is warranted. Longer follow-up will help assess whether SARS-CoV2 infection accelerates progression from islet autoimmunity to diabetes.
ABSTRACT
Objective: Large-scale screening of the general population for islet autoantibodies (IAbs) to detect type 1 diabetes (T1D) has started worldwide. The standard screening method of separate radio-binding assay (RBA) for each IAb is an inefficient bottleneck. Furthermore, most positive results by RBA in screening of general population individuals without a clinical diagnosis of T1D are low-affinity and not predictive of future diabetes. Research Design and Methods: We have developed and validated a novel 6-Plex assay based on electrochemiluminescence (ECL) technology that combines in a single well high-affinity IAbs (to insulin, GAD, IA-2, and ZnT8), transglutaminase autoantibodies for celiac disease, and severe acute respiratory syndrome coronavirus 2 antibodies. The Autoimmunity Screening for Kids (ASK) provided 880 serum samples, from 828 children aged 1-17 years without diabetes who were previously tested for IAbs using single ECL assays and RBA assays. Results: Levels of all six antibodies in the 6-Plex ECL assay correlated well with respective single ECL assay levels. Similar to single ECL assays, the 6-Plex ECL assay positivity was congruent with the RBA in 95% (35/37) of children who later developed T1D and in 88% (105/119) high-risk children with multiple IAbs. In contrast, only 56% (86/154, P < 0.0001) of children with persistent single IAb by RBA were found to be positive by 6-Plex ECL assay. Of 555 samples negative for all IAbs by RBA, few (0.2%-0.5%) were positive at low levels in the 6-Plex ECL assay. Conclusions: The study demonstrated that the 6-Plex ECL assay compares favorably to the standard RBAs in terms of disease specificity for general population screening in children. The 6-Plex ECL assay was therefore adopted as the primary screening tool in the general population screening ASK program with advantages of high efficiency, low cost, and low serum volume.