Successful prolonged rituximab treatment for post-transplant lymphoproliferative disorder following living donor liver transplantation in a child.

PTLD is a serious complication of immunosuppression in solid organ transplant recipients. The incidence of PTLD is significantly higher in pediatric recipients than in adult because children are often EBV-seronegative and they may develop primary EBV infection after transplantation. We herein describe a case of GI-PTLD who achieved a complete remission by prolonged rituximab, a chimeric monoclonal antibody against CD20, mono-therapy. A one-yr-old female underwent a LDLT for liver failure after having previously undergone the Kasai procedure for biliary atresia. At sixty days following the transplantation, GI-PTLD developed. Withdrawal of immunosuppression and a surgical resection were thus performed. A histopathological examination of tumor revealed atypical medium to large cell lymphoid proliferation with strong CD20 immunopositivity indicating their B-cell origin. Polymorphic PTLD was diagnosed. Rituximab was administered at a dose of 375 mg/m2 once a week, and the monotherapy resulted in a complete remission after 34 administrations. Based on this case, rituximab appears to be beneficial as a first-line therapy for PTLD.