The case of BK virus infection in which it was difficult to differentiate from acute rejection.

BK virus (BKV) nephropathy is one of the major causes of allograft dysfunction or graft loss in kidney transplant recipients. Early diagnosis and timely reduction in immunosuppressant is important for proper treatment. We report a 35-yr-old male case of cadaveric renal transplantation with BK viral related tubulointerstitial nephritis complicated by acute rejection. The diagnostic biopsy showed severe inflammatory infiltrates, tubulitis, and peritubular capillaritis. Discontinuation of mycophenolate mofetil, prednisone pulse therapy, and r-globulin was successful in relieving allograft dysfunction.