Combined detection of islet autoantibodies for clinical diagnosis of type 1 diabetes in the low-prevalence population


 
 
 Single positive islet autoantibodies (IAbs), sometimes detected in healthy individuals and low risk type 1 diabetes (T1D) patients, are considered to be irrelevant to the development of diabetes, making it difficult to diagnose and classify adult-onset diabetics.
 
 
 
 To determine the significance and clinical value of IAbs in T1D diagnosis in the low-prevalence population; and to explore whether electrochemiluminescence (ECL)-IAb detection assay can improve the clinical utility of IAbs in the immunodiagnosis of T1D in the low-prevalence population.
 
 
 
 A total of 633 newly-diagnosed adult-onset diabetic patients (≥18 years old) were divided into two groups according to their clinical phenotypes: 575 patients with age at diagnosis ≥35 years and body mass index (BMI) ≥ 24 kg/m2 were considered a low-prevalence population (population with a low prevalence of T1D) and the other 58 patients were considered a high-prevalence population. All the samples from 633 participants were tested with IAbs using standard radiobinding assays (RBA) and electrochemiluminescence (ECL) assay, in parallel.
 
 
 
 Compared with the high-prevalence population, fewer positive IAbs (94/575, 16.3% vs. 28/58, 48.3%) were detected in the low-prevalence population, and more of which (69/94, 73.4% vs. 9/28, 32.2%) were positive for a single IAb, with GADA being the most prevalent single-IAb. Single-IAb detection in the low-prevalence population did not always suggest T1D phenotype. Combined detection of IAbs by RBA and ECL assays had a significant clinical utility to distinguish autoimmune diabetes in the low-prevalence population with low BMI, poor β-cell function at the diagnosis, and an accelerated decline in β-cell function during the follow-up.
 
 
 
 Combined autoantibody detection by RBA and ECL assays improved differentiating autoimmune from non-autoimmune diabetes in the low-prevalence population.
