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Detection of Type 1 Diabetes Autoantibodies in Thai Individuals
Using Chemiluminescence Immunoassay
Sarocha Suthon1,2, Papatsara Rodvinit3, Tassanee Narkdontri1,2, Nipaporn Teerawattanapong1,5
,
Saranya In-nag1,2, Saowaluck Thonglilitchowong1,5, Watip Tangjittipokin1,5*
1 Siriraj Center of Research Excellence for Diabetes and Obesity, Faculty of Medicine, Siriraj Hospital, Mahidol
University
2 Siriraj Center of Research Excellence Management, Faculty of Medicine, Siriraj Hospital, Mahidol University
3 Department of Biochemistry and Molecular Biology, Faculty of Medical Science, Naresuan University
4 Department of Immunology, Faculty of Medicine, Siriraj Hospital, Mahidol University
5 Research Division, Faculty of Medicine, Siriraj Hospital, Mahidol University
*Corresponding Author E-mail: watip.tan@mahidol.ac.th
Background: Methods: Results: Conclusion: 96 Abstract
Type 1 diabetes (T1D) is a chronic autoimmune disorder characterized by the destruction of
pancreatic beta cells, leading to insulin deficiency. A key diagnostic marker for T1D is the
presence of autoantibodies. However, T1D exhibits heterogeneity, with patients classified
as either autoantibody-positive or -negative. This classification is clinically significant, as it
informs disease progression and therapeutic strategies. The enzyme-linked immunosorbent
assay (ELISA) is the current gold standard for autoantibody detection but is time-consuming,
labor-intensive, and costly. Chemiluminescence immunoassay (CLIA) offers a more efficient
alternative, yet manufacturer-defined cut-off values may not suit all populations, such as Thai
individuals. This study aims to estimate new cut-off points for autoantibodies in Thai T1D
patients using CLIA.
Sixty-eight clinically diagnosed T1D patients were included, comprising 63 autoantibody-
positive and 5 autoantibody-negative individuals. Autoantibodies against GAD65, IA2, and
ZnT8 were measured using both ELISA and CLIA. Receiver operating characteristic (ROC)
analysis was performed to assess the area under the curve (AUC), sensitivity, specificity, and
accuracy for each antibody.
The CLIA-based detection yielded the following AUC values: GAD65 – 0.835 (95% CI: 0.733–
0.936), IA2 – 0.735 (95% CI: 0.564–0.906), and ZnT8 – 0.787 (95% CI: 0.621–0.954). The revised
population-specific cut-off for GAD65 was determined to be ≥5 IU/mL, providing a specificity
of 80.00%, sensitivity of 76.19%, and accuracy of 76.47%. For IA2, the cut-off was also ≥5
IU/mL, yielding 80.00% specificity, 53.97% sensitivity, and 55.88% accuracy. ZnT8 showed a
cut-off value of ≥5 AU/mL, with 80.00% specificity, 65.08% sensitivity, and 66.18% accuracy.
The findings demonstrate that CLIA represents a viable alternative to ELISA for autoantibody
detection in T1D, with the potential to reduce diagnostic time, labor, and cost. Population-
specific cut-off values improve diagnostic performance, supporting CLIA’s use in Thai clinical
settings. Larger studies are needed to further validate these findings.
Joint Conference in Medical Sciences 2025