Immunoglobulin A (IgA) nephropathy is an autoimmune disease characterized by the deposition of circulating IgA-containing immune complexes (IgA-ICs) in the glomerular mesangium, leading to mesangial cell proliferation, enhanced extracellular matrix production, and variable infiltration of inflammatory cells. Because IgA nephropathy carries a lifelong risk of progression to end-stage kidney disease, optimal therapeutic strategies to halt renal deterioration are needed.