De novo minimal change disease after ABO-incompatible kidney transplantation.

We report the clinical and pathological findings of a case of de novo minimal change disease (MCD) after ABO-incompatible living kidney transplantation. A 62-yr-old man with end-stage renal disease associated with type I diabetes received ABO-incompatible kidney transplantation from his 58-yr-old wife. Although allograft function was excellent immediately after surgery, massive proteinuria (35 g/d) appeared on post-transplantation day 5. After the allograft biopsy taken on post-transplantation day 6, he was treated with 12 cycles of plasma exchange, but the nephrotic-range proteinuria showed no remission. The biopsy specimen showed no significant pathological findings on light microscopy, but electron microscopy showed diffuse effacement of podocyte foot processes. Based on the diagnosis of de novo MCD, the patient received intravenous methylprednisolone pulse therapy, followed by high-dose steroid maintenance therapy. The steroid therapy induced complete remission of nephrotic syndrome and stable allograft function immediately, which was also maintained at one yr after the transplantation.