Reversible Chronic Interstitial Nephritis Induced by Tacrolimus
—Tacrolimus Chronic Interstitial Nephritis

Calcineurin inhibitors (CNI) are potent immunosuppressive agents in prophylaxis against graft rejection and autoimmune diseases including primary glomerulopathies. Previous research showed reversible; acute afferent arteriolar vasculopathy and irreversible chronic interstitial fibrosis associated with CNI nephrotoxicity. In this case report we describe a patient, with minimal change disease, that had developed chronic and progressive renal disease while receiving therapeutic dose of Tacrolimus. His serum creatinine had reached 537 umol/L and his nephrotic state worsened. Kidney biopsy showed chronic interstitial nephritis. Tacrolimus was discontinued and he was treated with 1 mg/kg prednisone in addition to Mycophenolate mofetil (MMF) 1 g twice daily. By the 2^nd month; serum creatinine returned to normal and by the 3^rd month serum albumin too. After 1 month of therapy; the dose of Prednisone was tapered down gradually till 5 mg daily by the end of 3^rd month. Moreover, the dose of MMF was reduced to 500 mg X2 by the end of 3^rd month. After 2 years of follow up; he remained stable and without relapse of NS or renal failure. In conclusion, reversible renal disease, due to chronic interstitial nephritis can be induced by CNI which is amenable to treatment with Prednisone and MMF.