Acute renal failure caused by hyperuremic acidemia in ABO-incompatible kidney transplant maintained with cyclosporine and high-dose mizoribine: a case report.

INTRODUCTION: The shortage of cadaver organs has led to expansion of living donor kidney transplantations with, 30% increase among ABO-incompatible cases in Japan and the use of marginal extended donors. Herein we have reported the outcome after an ABO-incompatible kidney transplantation from an aged living-related donor who suffered from mild diabetes mellitus and hypertension.

CASE REPORT: A 48-year-old man underwent ABO-incompatible kidney transplantation from his 76-year-old father, using anti-CD20 antibody induction, followed by cyclosporine (CsA), mycophenolate mofetil (MMF), and prednisolone. After the operation, MMF was switched to high-dose mizoribine (MZ). He was discharged from the hospital on postoperative day (POD) 28 with a serum creatinine (sCr) of 1.47 mg/dL. On POD 34 when the sCr was 8.14 mg/dL, his urine examination showed uric acid crystals with serum uric acid of 24.6 mg/dL. Biopsy findings showed no evidence of acute rejection but mild tubulointerstitial injury. Hemodialysis performed twice to reduce uric acid was accompanied by hydration. CsA/MZ was switched to tacrolims/MMF; benzbromarone, to febuxostat to treat hyperuric acidemia. On POD 58, sCr reduced to 1.75 mg/dL he was discharged. On POD 416, graft function was stable with sCr of 1.70 mg/dL.

CONCLUSION: Common side effect of MZ is hyperuricemia which presumably caused acute renal failure of this aged marginal donor kidney.