Post-transplant lymphoproliferative disorder
|Post-transplant lymphoproliferative disorder|
|Classification and external resources|
Post-transplant lymphoproliferative disorder (PTLD) is the name given to a B-cell proliferation due to therapeutic immunosuppression after organ transplantation. These patients may develop infectious mononucleosis-like lesions or polyclonal polymorphic B-cell hyperplasia. Some of these B-cells may undergo mutations which will render them malignant, giving rise to a lymphoma.
In some patients, the malignant cell clone can become the dominant proliferating cell type, leading to frank lymphoma, a group of B cell lymphomas occurring in immunosuppressed patients following organ transplant.
The disease is an uncontrolled proliferation of B cell lymphocytes latently infected with Epstein-Barr virus. Production of an interleukin-10, an endogenous, pro-regulatory cytokine, has also been implicated.
In immunocompetent patients, Epstein-Barr virus can cause infectious mononucleosis in adolescents, which is otherwise asymptomatic in children during their childhood. However, in immunosuppressed transplant patients, the lack of T-cell immunosurveillance can lead to the proliferation of these EBV-infected of B-lymphocytes.
Depletion of T cells by use of anti-T cell antibodies in the prevention or treatment of transplant rejection further increases the risk of developing post-transplant lymphoproliferative disorder. Such antibodies include ATG, ALG and OKT3.
Polyclonal PTLD may form tumor masses and present with symptoms due to a mass effect, e.g. symptoms of bowel obstruction. Monoclonal forms of PTLD tend to form a disseminated malignant lymphoma.
PTLD may spontaneously regress on reduction or cessation of immunosuppressant medication, and can also be treated with addition of anti-viral therapy. In some cases it will progress to non-Hodgkin's lymphoma and may be fatal. A phase 2 study of adoptively transferred EBV-specific T cells demonstrated high efficacy with minimal toxicity.
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- Nourse, JP; Jones K; Gandhi MK. (May 2011). "Epstein-Barr Virus-related post-transplant lymphoproliferative disorders: pathogenetic insights for targeted therapy.". Am J Transplant 11 (5): 888–95. doi:10.1111/j.1600-6143.2011.03499.x. PMID 21521464.
- Haque T, Wilkie GM, Jones MM, Higgins CD, Urquhart G, Wingate P, Burns D, McAulay K, Turner M, Bellamy C, Amlot PL, Kelly D, MacGilchrist A, Gandhi MK, Swerdlow AJ, Crawford DH (Aug 2007). "Allogeneic cytotoxic T-cell therapy for EBV-positive posttransplantation lymphoproliferative disease: results of a phase 2 multicenter clinical trial." (PDF). Blood 110 (4): 1123–31. doi:10.1182/blood-2006-12-063008. PMID 17468341.