Posttransplant Lymphoproliferative Disorders

Abstract

<jats:p>Posttransplant lymphoproliferative disorders (PTLDs) are a group of diseases that range from benign polyclonal to malignant monoclonal lymphoid proliferations. They arise secondary to treatment with immunosuppressive drugs given to prevent transplant rejection. Three main pathologic subsets/stages of evolution are recognised: early, polymorphic, and monomorphic lesions. The pathogenesis of PTLDs seems to be multifactorial. Among possible infective aetiologies, the role of EBV has been studied in depth, and the virus is thought to play a central role in driving the proliferation of EBV-infected B cells that leads to subsequent development of the lymphoproliferative disorder. It is apparent, however, that EBV is not solely responsible for the “neoplastic” state. Accumulated genetic alterations of oncogenes and tumour suppressor genes (deletions, mutations, rearrangements, and amplifications) and epigenetic changes (aberrant hypermethylation) that involve tumour suppressor genes are integral to the pathogenesis. Antigenic stimulation also plays an evident role in the pathogenesis of PTLDs. Plasmacytoid dendritic cells (PDCs) that are critical to fight viral infections have been thought to play a pathogenetically relevant role in PTLDs. Furthermore, regulatory T cells (Treg cells), which are modulators of immune reactions once incited, seem to have an important role in PTLDs where antigenic stimulation is key for the pathogenesis.</jats:p>

Post-transplant lymphoproliferative disorders: From epidemiology to pathogenesis-driven treatment

“…Among malignancies occurring in transplanted persons, the incidence of PTLD varies according to several risk factors, such as type of transplant, age of recipient, and duration and type of immunosuppression treatment [6][7][8]. The entire PTLD spectrum includes lymphoproliferative entities varying from reactive hyperplasia to malignant lymphoma.…”

EBV-positive post-transplant lymphoproliferative disorder presenting as primary diffuse large B-cell lymphoma of the central nervous system

“…The most commonly used pathologic classification of PTLD is the World Health Organization (WHO) classification, which divides PTLD into four categories: early lesions, polymorphic PTLD, monomorphic PTLD, and Hodgkin lymphoma/Hodgkin lymphoma-like (HL/HL-like) PTLD [8]. Early lesions are characterized by reactive plasmacytic hyperplasia and polyclonal B cell proliferation.…”

“…Monomorphic PTLD is further subdivided into B-cell and T-cell neoplasms. The majority of monomorphic PTLD cases (> 80%) are B-cell neoplasms with the most common subtype being diffuse large B-cell lymphoma [3,8]. The latter category closely resembles Hodgkin lymphoma.…”

“…Epstein-Barr virus (EBV) infection is present in the majority of PTLD cases and is believed to play a central role in the development of PTLD. Studies have indicated that the pathogenesis of EBVassociated PTLD is related to EBV's ability to transform and immortalize B lymphocytes [6,8]. The clinical manifestations of PTLD vary from nonspecific symptoms such as fever, to enlargement of lymph nodes or organ-specific dysfunction.…”

Plasmacytic Post-transplant Lymphoproliferative Disorder – Case Report

“…7 Rituximab, an anti CD20 monoclonal antibody, can be used effectively to treat them. 8,9 Other types of PTLD are rare and only 4% of them show plasma cell differentiation. 7,10 We would therefore like to present our patient with PTLD of duodenum with plasma cell differentiation.…”