Clinical findings, pathology, and outcomes of C3GN after kidney transplantation

C3 glomerulonephritis (C3GN) results from abnormalities in the alternative pathway of complement, and it is characterizedbydepositionofC3withabsentorscant Igdeposition. Inmanypatients,C3GNprogresses toESRD.The clinical features, pathology, and outcomes of patients with C3GN receiving kidney transplantation are unknown. Between 1996 and2010,weidentified21patients at our institutionwhoreceived a kidney transplantbecause ofESRD fromC3GN.The median age at the time of initial diagnosis ofC3GNat kidney biopsy was 20.8 years. The median time fromnative kidney biopsy todialysis or transplantationwas 42.3months.Of21patients,14(66.7%)patientsdeveloped recurrentC3GNintheallograft.Themedian timetorecurrenceofdiseasewas28months. Graft failure occurred in50% of patientswith recurrentC3GN,with a median time of 77months to graft failure post-transplantation. The remaining 50%ofpatients hadfunctioninggrafts, with amedian follow-upof 73.9months.Themajority of patients hadhematuria andproteinuria at time of recurrence. Three (21%)patientswerepositiveformonoclonalgammopathyandhada faster rate of recurrence and graft loss. Kidney biopsy at the time of recurrence showedmesangial proliferativeGNin eight patients andmembranoproliferativeGNin six patients.All allograft kidney biopsies showed brightC3 staining (2-3+), with six biopsies also showing trace/1+ staining for IgM and/or IgG. To summarize,C3GNrecurs in 66.7% of patients, and one half of the patients experience graft failure caused by recurrence.