Inherited factor H dysfunction and complement-associated glomerulonephritis in renal grafts of first and second transplantations

A 38-yr-old man with factor H dysfunction and unknown glomerular disease received first and second renal transplantations (Tx) from living-related donors. His examination showed a low percentage activity of factor H (31%). Factor H dysfunction has been known to be associated with type II or III membranoproliferative glomerulonephritis (MPGN), haemolytic uraemic syndrome and IgA GN. The first graft from his mother showed diffuse mesangial deposit of IgA. His son has had IgA GN and his data also revealed a low percentage activity of factor H (33%) He and his son both showed a low activity of C3. Moreover, his father, who was the donor of the second Tx, had a low percentage activity of factor H (25%), and presented with mild glomerular deposit of C3 at operation, while he has been healthy through his entire 67 yr of life. Each of them had a low percentage activity of factor H. These findings through three generations suggested the inheritance of factor H dysfunction. The patient presented with proteinuria 3 months after the first Tx. At the first biopsy 30 months after the first Tx, light microscopy revealed minor glomerular abnormalities with electron dense deposits in subepithelial, intramembranous and mesangial regions, while immunofluorescence showed massive glomerular deposits of C3. In the second biopsy 51 months after the first Tx, the glomerulonephritis developed mesangial proliferation and crescent formation, accompanied by more massive C3 deposit and intramembranous, mesangial and subepithelial dense deposits. He then required redialysis. At the second and third biopsies within 2 months after the second Tx, the renal graft showed similar findings to the first biopsy after the first Tx. He perhaps presented with a recurrence of complement-associated GN, showing an atypical form of MPGN after Tx. These findings suggest that factor H dysfunction may play an important role of a certain pathogenesis of GN.