Large scale quantification of autoantibodies using array-based immunoabsorption method in idiopathic inflammatory myopathies (IIM) 3072

Abstract Description Autoantibodies are important biomarkers for diagnosis and diseases activity evaluation in IIM. Current immunoassays have limitations in terms of sensitivity and quantification. Here we developed an array-based immunoabsorption assay for large scale quantitative profiling of autoantibodies in sera of IIM patients. A panel of 28 myositis specific antigens (MSA) and associated antigens (MAA), including Jo-1, Mi-2, MDA5, TIF1-r, PL-7, PL-12, HMGCR, NXP2, SRP, SAE, Ro52, U1snRNP, KU, PM/Scl, et al, were fixed onto the 3D surface of microfluidic chips. Serum from IIM patients were first incubated with the chip to identify the antibodies reactive to the antigens, then the positive sera were diluted and pre-incubated with different amount of antigens before they were put on the new chips for reaction. The antibodies which specifically binding with the antigens will be inhibited from reacting with the antigens on chip. Using this method, we measured the levels of the 28 MSA and MAA antibodies in 135 IIM patients and 100 controls. A broad range of autoantibodies were detected with high prevelence in IIM, including anti-MDA5 (42.9%), anti-Ro52 (39.3%), anti-TIF1-r (31.1%), anti-SRP54 (11.1%), anti-PL12 (10.4%) and anti-Jo-1 (9.6%). Robust anti-MDA5 antibody were detected in 17 IIM with ILD had a median NFI of 5000 which were 100 higher than sera negative patients. Pre-absorption of the serum with MDA5 robustly inhibited the antibody binding specificity in a dose depended manner. Funding Sources N/A Topic Categories Technological Innovations in Immunology (TECH)