Ocular Involvement in Post-Transplantation Lymphoproliferative Disorder: A Rare Case with Rituximab Hypersensitivity

BACKGROUND Post-transplantation lymphoproliferative disorder (PTLD) is a heterogeneous group of lymphoid proliferative conditions that occur in transplant recipients under sustained immunosuppression. Rituximab is widely used as first-line therapy for PTLD. However, hypersensitivity reactions to rituximab are rarely reported in pediatric patients. CASE REPORT A 1-year-old boy underwent living-donor liver transplantation for biliary atresia using his mother's graft. Six years after transplantation, he presented with mild graft rejection and abnormal liver function tests. Cervical lymphadenopathy was also noted, accompanied by elevated Epstein-Barr virus (EBV) DNA levels. Following tacrolimus dose reduction, EBV DNA levels gradually declined. Two years later, he developed progressive right-eye visual impairment, and evaluation confirmed intraocular PTLD. Fundoscopy showed a mass in the iris-ciliary body of the right eye and mild elevation in the left eye. Despite administration of intraocular methotrexate and surgical intervention, the disease progressed. Rituximab (RTX) was discontinued due to hypersensitivity reactions. Subsequently, the patient received obinutuzumab, a third-generation anti-CD20 monoclonal antibody, which was well tolerated and resulted in undetectable EBV DNA levels and a reduction of intraocular inflammation. The patient is currently maintained off immunosuppressive therapy without evidence of graft rejection. CONCLUSIONS Intraocular PTLD is a rare condition that must be distinguished from other ocular pathologies in liver transplant recipients, and clinicians should suspect intraocular PTLD in such cases. Our summary integrates clinical insights regarding the manifestations and ocular involvement of intraocular PTLD. Patients allergic to rituximab may benefit from third-generation anti-CD20 monoclonal antibodies.