The goal is to discover novel circulating immune complexes (ICx) in the serum of Lupus Nephritis (LN) as potential biomarkers. Protein A/G magnetic beads or C1q-coated plates were used to capture ICx in the serum of LN, followed by the identification of immunoglobulin-binding proteins using liquid chromatography and tandem mass spectrometry (LC-MS/MS). Six related genomic-level databases were used for selecting potential biomarkers, following ELISA validation with independent samples.