ABSTRACT
Polyomavirus BK viral allograft nephritis is a great challenge in posttransplant management and graft survival because of difficulty in diagnosing and treatment. Initial treatment usually involves reducing immunosuppressive medications. However if concomitant acute rejection exist, it is more challenging in managing these patients, because acute rejection requires increase in immunosuppression. We present a case of a 35-year-old man who developed BK viral allograft nephritis and concomitant acute rejection 3 months after transplantation. BK viral allograft nephritis was missed in diagnosis and only pulse steroids for anti-rejection therapy was done. Initially, renal function was improved, but 4 months later, he presented with deterioration in renal function. Second renal biopsy showed BK allograft nephritis without rejection. BK viral DNA in plasma by PCR and urinary decoy cell were also positive. Reduction in immunosuppression by discontinuing mycophenolate mofetil stabilized the deterioration in renal function, however it failed to clear viremia.