VTN and complement 3 glomerulopathy: The autoimmune causes of C3G include antibodies directed against the individual complement proteins Factor H, C3b, and Factor B. In addition, autoantibodies such as C3 nephritic factors (C3NeF), which bind to neoepitopes of the central AP C3 convertase, are most common; C4NeF and C5NeF have also been described (45–48).