Islet Autoantibody TypesMark Differential Clinical Characteristics at Diagnosis of Pediatric Type 1 Diabetes.

We aimed to study whether islet autoantibody type marks differential characteristics at the time of type 1 diabetes (T1D) diagnosis. We studied 711 children with newly diagnosed autoimmune T1D. We compared demographic (sex, age, race/ethnicity), clinical (pubertal development, BMI percentile, diabetic ketoacidosis [DKA]) and laboratory (glucose, hemoglobin A1c [HbA1c], C-peptide, tissue transglutaminase antibodies [tTGA], thyroglobulin antibodies, and thyroid peroxidase antibodies [TPOA]) characteristics by presence/absence of autoantibodies to insulin (IAA), GAD65 (GADA)or IA-2/ICA512 (IA-2A). Islet autoantibodytiters were evaluated among the children positive for the relevant autoantibodytype. We used multivariable analysis to adjust for potential confounders. IAA+ was statistically associated with younger age (p  50 U/mL) (OR = 0.21, p = 0.026) but not with age, IAA status, IA-2A status, islet autoantibodynumber, or thyroid autoimmunity. None of the associations with IA-2A positivity was statistically significant in the multivariable analysis. In multivariable models,IAA titer was significantly associated with younger age (p = 0.006), DKA (p = 0.017) and higher tTGA levels (p = 0.002); GADA titer with female sex(p = 0.028), racial minority (p = 0.046) and TPOA positivity (p = 0.021); and IA-2A titer with older age (p = 0.001) and notbeing African-American (p = 0.024). Islet autoantibody type is associated with differential characteristics at diagnosis of pediatric T1D. Longitudinal and mechanistic studies are needed to evaluate T1D endotypes by autoantibody type. This article is protected by copyright. All rights reserved.