Late conversion to everolimus complicated with necrotizing glomerulonephritis in a renal allograft recipient: case report.

Conversion from calcineurin inhibitors (CNI) to proliferation signal inhibitors (PSI), such as sirolimus or everolimus (EV), may improve the course of chronic allograft nephropathy. Herein we have presented a case of a kidney recipient with chronic cyclosporine (CsA) nephrotoxicity who was converted from CsA to EV at 5.5 years posttransplantation. There were no significant changes in immunofluorescence (IFL) or in electron microscopy (EM) in the preconversion biopsy. Two months after conversion, proteinuria and creatinine increased. The biopsy showed focal, segmental necrosis of the glomerular tuft with the formation of segmental cellular crescents and increased endocapillary cellularity. IFL showed granular deposits of IgG, IgM, and C3 mostly along the capillary walls; it was negative for C4d. EM revealed electron-dense deposits within the glomerular basement membrane (GBM) and in the subendothelial region with significant reduction in the capillary lumina due to GBM reduplication and widening of lamina rara interna with the formation of fibrillary structures therein: focal, segmental glomerulosclerosis. EV was withdrawn and we administered tacrolimus and steroid pulses with improvement. Five months after the withdrawal of EV, a third graft biopsy showed remission of the necrotizing glomerulonephritis. However, the patient demanded dialysis at 17 months after conversion to EV. We concluded that necrotizing glomerulonephritis with immune complex deposition in a renal allograft was possibly induced by late conversion from CNI to EV. Reconversion to CNI may be recommended in cases of PSI-associated posttransplantation glomerulonephritis but the long-term prognosis is uncertain.