CCL2 and IgA glomerulonephritis: IgG-ddIgA1 complexes from both patients with IgA nephropathy (IgAN-IgG-ddIgA1) and healthy controls (HC-IgG-ddIgA1) could induce the proliferation of mesangial cells and up-regulate the expression of multiple inflammatory cytokines, including IL-6, MCP-1 and CXCL1.