FH and complement 3 glomerulopathy: While C3G also is associated with serum autoantibodies to FH (17), the antibodies are reported to be of lower avidity for FH than in patients with autoimmune aHUS (23), to be directed at different FH epitope specificities located in the N-terminal region (23), and typically not to affect FH functional activity as measured in the hemolytic assay (17).