Background: Posttransplant lymphoproliferative disorder (PTLD) is one of the most severe complications after transplantation, caused by uncontrolled proliferation of Epstein-Barr virus (EBV)‐positive B‐cells in the setting of chronic immunosuppression. The 2008 World Health Organization classification for lymphoid malignancies divides PTLD into four major categories: early lesions, polymorphic PTLD, monomorphic PTLD and Hodgkin PTLD. The treatment and prognosis depend on histology. The cornerstone of PTLD therapy includes reduction/withdrawal of immunosuppression, monoclonal anti CD-20 antibody (rituximab) and chemotherapy.
Cases: We experienced a PTLD with EBV infection in pediatric renal transplant recipient at our hospital. The patients were 10 year-old boy who received allograft kidneys from his brother. He was found positive IgM EBV serological but PCR EBV was negative before transplant. The donor kidney was EBV – seronegative. The induction immunosuppression with Basiliximab and maintenance with Steroid + Mycophenolate mofetil + Tacrolimus. He was diagnosed at 6 months after transplantation, with high EBV load and the organ involvement was spleen. The pathological diagnosis was polymorphic PTLD. The treatment included immunosuppressive reduction, after that adjust immunosuppression therapy, from MMF to Everolimus combined with anti-CD20 monoclonal antibody (Rituximab) 375mg/m2 x 4 doses. After treatment, PCR EBV was negative, no seen spleen tumor. However, 2 month later, the kidney function was decreased, he had BKV infection. We stopped everolimus and use IVIG for treatment. After six months, the serum creatinine was stable and PCR EBV and BKV was negative. 
Conclusions: This is a case of PTLD with EBV infection treated successfully with Rituximab and immunosuppressive reduction in pediatric renal transplant recipients. Early diagnosis and appropriate treatment is neccessaty for patient survival and long term graft survival.