New-Onset IgG Autoantibodies in Hospitalized Patients with COVID-19 [Autoantigen V2]. New-Onset IgG Autoantibodies in Hospitalized Patients with COVID-19 [Autoantigen V2]

We developed three different protein arrays to measure IgG autoantibodies associated with Connective Tissue Diseases (CTDs), Anti-Cytokine Antibodies (ACA), and anti-viral antibody responses in 147 hospitalized COVID-19 patients in three different centers. Overall design: Protein arrays were constructed by coupling antigens to carboxylated magnetic beads. Arrays consisting of conjugated beads were then used to probe hospitalized COVID-19 patient serum samples, healthy control samples, and autoimmune prototype samples to identify autoantibodies. Samples were run in duplicate except one sample (UP67 D7) which was run in quadruplicate. for A Luminex FLEXMAP 3D® system was used to quantitatively measure autoantibody reactivity in each sample in units of mean flourescent intensity (MFI). Positive antibody hits were statistically identified by a 5 standard deviation cutoff calculated from the MFI of healthy controls.