Table 1: C3 glomerulopathies.

Diseases EM-findings Alternative pathway abnormalities Disease specific treatment options Dense deposit disease (i) Osmophilic wavy dense deposits within GBM, mesangial matrix, tubular BM (i) Autoantibodies (C3Nef, FHAA, FBAA, C3-convertase AA) (ii) Mutations/genetic variations (CFH, CFI, CFB, MCP) (i) Infusion of fresh frozen plasma (ii) Plasmapheresis (iii) Eculizumab (iv) Immunosuppressive treatment (in case of autoantibodies) C3 glomerulonephritis (i) Mesangial, subendothelial, subepithelial and intramembranous deposits (i) Mutations/genetic variations (CFH, CFI, MCP) (ii) Autoantibodies (C3Nef, FHAA) (i) Eculizumab (ii) Immunosuppressive treatment (in case of autoantibodies) CFHR5 nephropathy (i) Mesangial, subendothelial, subepithelial deposits (i) CFHR5-mutation (i) No treatment of proven efficacy (ii) Plasma exchange associated with good outcome Familial C3 glomerulopathy (i) MPGN type III (ii) Subendothelial, subepithelial deposits (i) Familial hybrid CFHR3-1 gene autosomal dominant inheritance (i) No treatment of proven efficacy

Abbreviations: C3: complement component 3, CFHR5: complement factor H related protein 5, CFH: complement factor H, CFI: complement factor I, MCP: membrane cofactor protein, FHAA: factor H autoantibody, FBAA: factor B autoantibody, (G) BM; (glomerular) basement membrane, MCP: membrane cofactor protein.