A New Luminescence Assay for Autoantibodies to Mammalian Cell–Prepared Insulinoma-Associated Protein 2

摘要

>OBJECTIVE—Insulinoma-associated protein 2 (IA-2) is a major autoantigen in type 1 diabetes, and IA-2 autoantibodies are routinely detected by a liquid-phase radioimmunoprecipitation assay. The present experiments were initiated to develop a new assay that does not require the use of radioisotopes or autoantigens prepared in bacteria or by in vitro transcription/translation.>RESEARCH DESIGN AND METHODS—IA-2 luciferase fusion protein was expressed in mammalian cells and assayed for autoantibodies by liquid-phase luciferase immunoprecipitation.>RESULTS—Our study showed that there was no significant difference between the luciferase immunoprecipitation and the radioimmunoprecipitation assays in sensitivity and specificity, and comparison of the two assays revealed a high correlation coefficient (R² = 0.805).>CONCLUSIONS—The luciferase system offers a robust, inexpensive, nonradioactive method for the detection of autoantibodies to mammalian cell–prepared IA-2 and could be of practical value at the clinical level.