[A novel electrochemiluminescence method for detecting insulin autoantibody]

Area of Science:

• Immunology
• Clinical Chemistry
• Biotechnology

Background:

• Insulin autoantibodies (IAA) are important biomarkers for type 1 diabetes mellitus (T1DM).
• Accurate and efficient detection methods are crucial for diagnosing T1DM and identifying at-risk individuals.
• Existing methods may have limitations such as radioactivity or lower sensitivity.

Purpose of the Study:

• To establish and validate an electrochemiluminescence (ECL) method for insulin autoantibody (IAA) detection in China.
• To evaluate the clinical application value of the developed ECL method for IAA detection.

Main Methods:

• Proinsulin was labeled with Sulfo-tag and biotin.
• Serum samples were incubated with labeled proinsulin and then captured using a Meso Scale Discovery (MSD) streptavidin plate.
• Detection was performed using an MSD electrochemiluminescence instrument, with optimized conditions including antigen concentration, serum acidification, and incubation times.

Main Results:

• The ECL method demonstrated high reproducibility and consistency with microplate radioimmunoassay (agreement rate: 93.7%, Kappa value: 0.858, correlation coefficient r=0.749).
• The assay showed good diagnostic performance with an area under the curve (AUC) of 0.764.
• A significantly higher positive rate of IAA was observed in T1DM patients (52.73%) compared to healthy controls (0.76%).

Conclusions:

• The established ECL method for IAA detection is highly sensitive, specific, and user-friendly.
• The method avoids radioactive contamination, offering a safer alternative.
• The ECL assay demonstrates significant clinical application value for IAA detection, particularly in the context of T1DM.