Post-Transplant Lymphoproliferative Disorder

Kim, Gheun Ho; Kang, Chong Myung

Abstract

Post-transplant lymphoproliferative disorder (PTLD) is a heterogeneous group of conditions characterized by Epstein-Barr virus (EBV)-driven lymphoid proliferation in the face of impaired T-cell immune surveillance. Most of PTLD are of B- cell origin. Sero-negative recipients of sero-positive organs, and recipients receiving OKT3 are at increased risk. The clinical features are multiple and varied and can range from a benign mononucleosis-like illness to a fulminant non- Hodgkin's lymphoma. Frequently, an extranodal presentation is found with a predilection for brain and allograft. The presentation of forms localized to the renal graft may be incidentally discovered during imaging of the kidney; because the masses may also produce a pressure effect on the collecting system, the patient may present with renal obstruction. To establish diagnosis of PTLD, tissue biopsy is necessary. The mainstay of treatment is immunosuppressive dose reduction. For patients failing to respond to a reduction in immunousppression, a second step of treatment can be used such as interferon alpha, chemotherapy, anti-CD20 antibody (rituximab), and EBV-specific cytotoxic T-cells. Chemotherapy is currently the most commonly used therapeutic alternative. Anti-viral drug therapy has been shown to be of very limited benefit and there are theoretical reasons why it may be ineffective. There appears to be a correlation between PTLD and EBV viral load measured by polymerase chain reaction (PCR) of the peripheral blood, and quantitative PCR may be a useful guide in the management of PTLD. Multicenter randomized trials and standardized diagnostic and therapeutic strategies are required to improve our understanding of PTLD.