AB0905 DEVELOPMENT OF A NEW COMPREHENSIVE ASSAY KIT FOR MYOSITIS-ASSOCIATED ANTIBODIES AND MYOSITIS-SPECIFIC ANTIBODIES EXAMINATION OF CLINICAL USEFULNESS IN INFLAMMATORY MUSCLE DISEASES

Background Inflammatory muscle diseases are systemic inflammatory disorders that affect not only muscles but also skin, joints, lungs, and heart. Dermatomyositis (DM) polymyositis (PM) characterized by the production of antibodies. Measurement these antibodies is useful for diagnosis, classification disease type, evaluation activity, prognosis prediction, determination therapeutic strategy. However, sensitivity specificity vary depending on measurement method, some autoantibodies can be measured in limited laboratories. Objectives We developed a novel comprehensive assay kit myositis-associated with aim developing rapid simple detection method myositis-specific or related autoantibodies. we used proteome-wide antibody screening quantification wet protein arrays consisting proteins synthesized from human cDNA library (HuPEX). examined whether this clinically compared to enzyme-linked immunosolbent (ELISA). Methods Sera 47 patients diagnosed suspected were measure (anti-ARS, anti-MDA5, anti-TIF1-γ, anti-Mi-2, anti-SRP, antibodies) myositis-related (anti-U1RNP, anti-Ku, anti-PM-Scl, anti-mitochondria using (HuPEX) results ELISA, which commercially available immunoprecipitation autoantibodies（anti-OJ, anti-Zo antibodies). Autoantibodies undetectable ELISA positive array subjected immunoprecipitation. In immunoprecipitation, primary added solution containing an antigen form antigen-antibody complex solution. Next, secondary immobilized beads adsorb beads. Finally, was eluted SDS analyzed SDS-PAGE. Results cases, clinical diagnosis DM 26 PM 20 inclusion body myositis 1 case. available, cases anti-ARS (17 DM, 3 PM), 5 anti-MDA5 (Amyopathic DM), case anti-TIF1-γ (DM), 2 Mi-2 (1 anti-RNP (PM), (PM). Compared eighteen system all other 100% concordant. addition, could detected anti-OJ system. Of 6 whose anti-HMGCR antibody-positive antibody-positive, consistent diagnosis. Furthermore, among 4 who anti-SS-A anti-SRP positive, anti-Ku anti-Ki Those samples confirmed Conclusion Collectively, vitro proteome reveal may provide biomarkers. References [1]Mimori T, idiopathic myopathy:an update pathophysiological significance. Curr Opin Rheumatol, 2007. 19: p. 523-529 [2]Fukuda E, et al. Identification characterization recognized germ cell mAb TRA98 array. Genes Cells, 2021. 26(3): p.180-189. Acknowledgements: NIL. Disclosure Interests None Declared.