Characterization of Immune Cell Populations in Lupus Nephritis Using a SignalStar® Multiplex Immunohistochemistry Assay 2332985

Abstract Introduction Systemic Lupus Erythamatosis (SLE) is a chronic autoimmune disease characterized by dysregulated immune response, production of autoantibodies, and tissue damage. Lupus nephritis (LN) is a kidney disease caused by SLE. Many immune cell types are implicated in LN. In contrast to healthy kidney tissue, LN tissues have increased presence of B cells, macrophages, regulatory T cells (Tregs) and dendritic cells (DCs). Additional insights into these heterogenous immune cells in LN will be valuable for understanding disease progression and therapeutic strategies. Methods We interrogated normal and LN formalin-fixed, paraffin-embedded (FFPE) tissues using an 8-plex SignalStar® multiplex immunohistochemistry (mIHC) assay to compare total (CD68+), M2c (CD68+CD163+), and M2a (CD68+CD206+) macrophages, CD19+ and CD20+ B cells, and total (CD3+) and FoxP3+ regulatory T cells (Tregs). CD11c was used to mark dendritic cells (DCs). All stains were performed using Leica Biosystems BOND RX. Slide images were collected at 20X magnification using Akoya PhenoImager HT. Phenochart 1.1 software was used to define regions of interest and inForm 3.0 software was used to perform population analyses on regions of interest from tissue sections. Results We observed increased immune cell presence in LN tissues. B cells, identified with CD19 and CD20, were increased; the number of CD19+ compared to CD20+ B cells was higher in the LN samples. We also observed increased levels of subtypes of macrophages, M2c (CD68+CD163+) and M2a macrophages (CD68+CD206+), and increased CD3+ T cells. Conclusion The SignalStar® mIHC assay enables robust spatial analysis of SLE LN tissue samples. LN tissues show increased immune cell presence, with increased levels of CD19+ B cells, M2a and M2c macrophages, and CD3+ T cells. These cell types play roles in autoantibody production, debris clearance, and inflammation. Further studies of these cell types in LN will help with understanding disease progression and design of more effective therapeutics. Funding Source N/A Topic Categories Basic Autoimmunity (BA)