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Lymphoproliferative diseases (LPD) associated with Epstein Barr virus (EBV) infection cause significant morbidity and mortality in bone marrow and solid organ transplant recipients. To gain insight into LPD pathogenesis and to identify potential effective therapeutic approaches we investigated early molecular events leading to B cell transformation by gene expression profiling of EBV infected B cells from tonsils by Affymetrix microarray 72 hours post infection when the B cells hyperproliferation phase starts. Cell cycle and apoptosis were the most significantly affected pathways and enriched gene sets. In particular we found significantly increased expression of CDK1 and CCNB1 (cyclin B1) and of one of their downstream targets BIRC5 (survivin). Importantly the strong up regulation of the anti apoptotic protein survivin was confirmed in lymphoblastoid cell lines and 71 of EBV positive post transplant EBV LPD lesions scored positive for survivin. The validity of early transforming events for the identification of therapeutic targets for EBV LPD was confirmed by the marked anti proliferative effect of the CDK inhibitor flavopiridol on lymphoblastoid cell lines and by the strong induction of apoptosis by survivin inhibition with YM155 or terameprocol. Our results suggest that targeting of CDKs and/or survivin in post transplant EBV LPD by specific inhibitors might be an important approach to control and eliminate EBV transformed B cells that should be further considered. © 2013 Wiley Periodicals Inc.

Item does not contain fulltext Bone marrow involvement by lymphoma is considered a systemic dissemination of the disease arising elsewhere, although some tumors may arise primarily in the bone marrow microenvironment. Primary bone marrow lymphoma (PBML) is a rare entity whose real boundaries and clinicobiological significance are not well defined. Criteria to diagnose PBML encompass isolated bone marrow infiltration, with no evidence of nodal or extranodal involvement, including the bone, and the exclusion of leukemia/lymphomas that are considered to primarily involve the bone marrow. Twenty-one out of 40 lymphomas retrospectively reviewed by the International Extranodal Lymphoma Study Group from 12 institutions in 7 different countries over a 25-year period fulfilled the inclusion criteria. These cases comprised 4 follicular lymphomas (FLs), 15 diffuse large B-cell lymphomas (DLBCLs), and 2 peripheral T-cell lymphomas, not otherwise specified. The FL cases showed paratrabecular infiltration, BCL2 protein and CD10 expression, and BCL2 gene rearrangement. DLBCL showed nodular infiltration in 6 cases and was diffuse in 9 cases; it also showed positivity for BCL2 protein (9/10) and IRF4 (6/8). Median age was 65 years with male predominance. All but 3 FL patients were symptomatic. Most cases presented with cytopenias and high lactate dehydrogenase. Four patients (3 FL cases and 1 DLBCL case) had leukemic involvement. Most DLBCL patients received CHOP-like or R-CHOP-like regimens. The outcome was unfavorable, with a median overall survival of 1.8 years. In conclusion, PBML is a very uncommon lymphoma with particular clinical features and heterogenous histology. Its recognition is important to establish accurate diagnosis and adequate therapy. 01 februari 2012

Fifty-two cases of monomorphic post-transplant lymphoproliferative disorders (M-PTLD), developed in patients undergone solid organ or bone marrow transplantation, were studied by the application of the tissue micro-array (TMA) technology. They included 50 cases of diffuse large B-cell lymphomas (DLBCL) and 2 Burkitt lymphomas (BL). In order to evaluate the immune-profile a large panel of antibodies was applied including several new markers (Cyclin D2, Cyclin D3, p27, PKC-β, FOXP-1 and Survivin) identified as negative prognostic factors in DLBCL of the immunocompetent patient. Out of 50 DLBCL, 23 cases (46%) had an Activated B Cell (ABC) phenotype, 8 (16%) a Germinal Centre B-cell (GCB) phenotype, and 11 (22%) an Unclassified (UC) phenotype. In 8 cases (16%) the subtype was not demonstrable due to sub-optimal preservation or loss of the tissue core. FISH analysis detected BCL2 gene amplification and MYC rearrangement. EBV was identified in 32 cases (64%) performing immunohistochemistry (LMP-1) and in situ hybridization (EBER). Clinical data and follow-up were available in all cases of malignant lymphomas but one. Thirty-two patients died for progression of disease or complications related to transplant (bleeding, bacterial infections, and multi-organ failure); 17 patients are actually alive and disease-free. M-PTLD are aggressive lymphomas characterized by very poor outcome. The neoplastic process is stimulated by a prolonged immunosuppressive status which is capable to induce alterations of the immune system and allow EBV reactivation in previously infected patients. Indeed EBV infection seems to be the most significant risk factor to predict the development of a PTLD while age, sex, site of involvement and type of transplant do not have significant correlation. Furthermore DLBCL arisen in a setting of immunodeficiency share phenotypic and molecular features with DLBCL of the immunocompetent patient. In particular, the former shows a high incidence of BCL2 gene amplification and this aberration typically correlates with “non-GCB” phenotype. Also M-PTLD do express prognostic markers (PKC-β, cyclin D2, FOXP-1, and Survivin): notably, in our study, PKC-β and FOXP-1 were frequently expressed and they were predictive of a shorter overall survival even in lymphomas recognized to have a good prognosis (GCB-type). Given the fact that such molecules are detectable at the time of the diagnosis, we postulate whether a “tailored” or more specific therapy might be applied in the management of the immune-compromised patient.