CP and systemic lupus erythematosus: We aimed to develop multiplex (MLP) assays of 6 biomarkers, namely adiponectin, neutrophil gelatinase-associated lipocalin (NGAL), monocyte chemoattractant protein-1 (MCP-1), kidney injury molecule-1 (KIM-1), ceruloplasmin, and hemopexin used in the Renal Activity Index for Lupus (RAIL) and establish MLP assays using the Milliplex MLP and the electrochemiluminescence Mesoscale Discovery (MSD) technology, to compare with the gold standard of established single immunoassays.