Post Transplant Lymphoproliferative Disorder (PTLD) occurs as a result of immunosuppression after transplantation but despite the name it should not be considered to be a single entity but a spectrum of poorly classified diseases varying from benign lymphocytic hypertrophy to rapidly growing and fatal lymphoma. Three variables determine PTLD: Epstein Barr Virus (EBV) status at transplantation; amount and type of immunosuppression used; and virus co-infection. There are many controversies in the literature over etiologic factors, histologic classification and staging of the disease. However these pale into insignificance beside the controversies over treatment of the disease.
Presentation of PTLD is very varied with the spectrum of PTLD including focal EBV infection with EBV DNA replication, hyperplastic lymphadenopathy, classical Non-Hodgkins B and T cell as well as Hodgkin’s, lymphomas. The incidence of PTLD varies with the type of organ transplant (highest with Intestine and Lung and lowest with living donor kidney transplants), as well as the cumulative immunosuppression. Therapeutic approaches to PTLD include chemotherapeutic strategies which yield 40% treatment related mortality, and more modern strategies involving biologic agents such as rituximab and adoptive T-cell therapies. Successful treatment involves many disciplines and requires the efforts of oncologists, haematologists, virologists and transplant specialists. Studies of therapies are hampered by the relative rarity of the disease and the resultant absence of randomised controlled trials. Apart from universal application of reduced immunosuppression, a consensus is emerging around the utility of early Rituiximab in CD20 positive tumours with subsequent chemotherapy in recurrent or unresponsive disease.