TFRC and kidney disorder: Immune complexes containing Gd-IgA1 are important in the pathogenesis of IgAN and IgAVN.[6] Gd-IgA1 is specifically detected in IgAN and IgAVN and not in other renal diseases.[6] Gd-IgA1, anti-Gd-IgA1 antibodies, and soluble Fc alpha receptor form immune complexes and bind to the transferrin receptor of mesangial cells, leading to mesangial cell activation and proliferation.