Identification of distinct subgroups of EBV-positive post-transplant diffuse large B-cell lymphoma.

Post-transplantation lymphoproliferative disorder is an aggressive complication of transplantation, most frequently of diffuse large B-cell lymphoma morphology and associated with Epstein-Barr virus (EBV) infection/reactivation. In this study the microenvironment of EBV+ (n=23) and EBV- (n=9) post-transplant non-germinal center B-cell diffuse large B-cell lymphoma was characterized. Of EBV+ cases somatic hypermutation analysis, gene expression profiling, and extensive phenotyping were performed. Our results demonstrated variable cytotoxic T-cell infiltration and significantly increased CD163+ M2 macrophage infiltration in EBV+ compared with EBV- post-transplant diffuse large B-cell lymphoma. On the basis of IgM staining and hypermutation analysis, two EBV+ post-transplant diffuse large B-cell lymphoma subgroups were identified: IgM+ tumors lacking somatic hypermutations and IgM- tumors harboring somatic hypermutations. IgM- tumors arose late following transplantation (median interval: 16 months), mainly in kidney recipients. IgM+ tumors on the other hand arose early (median interval: 3 months, P-value=0.0032), almost exclusively following stem cell transplantation and were associated with worse outcome (median survival 1 month for IgM+ versus 41 months for IgM- tumors, log-rank/Wilcoxon P-value 0.07/0.04). Notably, IgM+ tumors were characterized by plasma cell features (monotypic kappa/lambda expression, high MUM1 expression, and partial CD138 expression) and a high proliferation index. Consistent with the plasma cell phenotype, unfolded protein response signaling was upregulated. In contrast, IgM- EBV+ post-transplant diffuse large B-cell lymphoma did not express kappa, lambda, IgD, or CD138 and expressed limited MUM1. In these tumors T-cell signaling was enhanced associated with increased T-cell infiltration compared with IgM+ cases. Overall, our results allow further molecular classification of EBV+ post-transplant diffuse large B-cell lymphoma and provide a rationale for the use of subtype-specific-targeted therapies (eg, bortezomib in IgM+ tumors). Our findings also provide a biological basis for the clinical differences between post-transplant lymphoproliferative disorder following solid organ and stem cell transplantation, which are regarded as different disorders.

Association of 150-kDa oxygen-regulated protein with vascular endothelial growth factor in proliferative diabetic retinopathy.

PURPOSE: 150-kDa oxygen-regulated protein (ORP150), a member of heat-shock protein family located in endoplasmic reticulum (ER), has a critical role in secretion of vascular endothelial growth factor (VEGF). We investigated expression levels of ORP150 and correlated these levels with VEGF and total vitreous antioxidant capacity (TAC) in proliferative diabetic retinopathy (PDR). We also examined expression of ORP150 in retinas of diabetic rats and in human retinal microvascular endothelial cells (HRMEC). METHODS: Vitreous samples from 40 PDR and 20 non-diabetic patients, epiretinal membranes from 14 patients with PDR, retinas of rats and HRMEC were studied by enzyme-linked immunosorbent assay, immunohistochemistry and Western blot analysis. RESULTS: We showed a significant increase in expression of VEGF and ORP150 in vitreous samples from PDR patients compared with controls (p < 0.0001 for both comparisons). Total vitreous antioxidant capacity (TAC) levels were significantly lower in patients with PDR than those in controls (p < 0.0001). Vascular endothelial growth factor (VEGF) and ORP150 levels in PDR with active neovascularization were significantly higher than that in inactive PDR (p = 0.016; p = 0.011, respectively). A significant positive correlation was observed between levels of ORP150 and levels of VEGF (r = 0.42; p = 0.001). In epiretinal membranes, ORP150 was expressed in vascular endothelial cells and stromal cells. We also demonstrated colocalization of the nuclear cell proliferation marker Ki67 and ORP150 in endothelial cells of pathologic new blood vessels. 150-kDa oxygen-regulated protein (ORP150) levels were significantly increased in rat retinas after induction of diabetes. Vascular endothelial growth factor (VEGF) and the pro-inflammatory cytokines interleukin-6 (IL-6) and tumour necrosis factor-α (TNF-α) induced upregulation of ORP150 in HRMEC. CONCLUSION: These results suggest a role for ORP150 in PDR angiogenesis.

Correction to: Secondary B-cell lymphoma associated with the Epstein-Barr virus in chronic lymphocytic leukemia patients.

[This corrects the article DOI: 10.1007/s12308-016-0273-8.].

Differential expression and localization of human tissue inhibitors of metalloproteinases in proliferative diabetic retinopathy.

PURPOSE: Tissue inhibitors of metalloproteinases (TIMPs) block the catalysis by matrix metalloproteinases (MMPs) and have additional biologic activities, including regulation of cell growth and differentiation, apoptosis, angiogenesis and oncogenesis. We investigated the expression levels of all the four human TIMPs and correlated these levels with those of MMP-9 and vascular endothelial growth factor (VEGF) in proliferative diabetic retinopathy (PDR). METHODS: Vitreous samples from 38 PDR and 21 nondiabetic control patients and epiretinal membranes from 14 patients with PDR and 10 patients with proliferative vitreoretinopathy (PVR) were studied by enzyme-linked immunosorbent assay, Western blot analysis and immunohistochemistry. RESULTS: Tissue inhibitor of metalloproteinases-1, TIMP-4, MMP-9 and VEGF levels were significantly higher in vitreous samples from PDR patients than in nondiabetic controls (p < 0.0001 for all comparisons), whereas TIMP-2 and TIMP-3 levels did not differ significantly. TIMP-1, TIMP-4, MMP-9 and VEGF levels in PDR with active neovascularization were significantly higher than those in inactive PDR (p < 0.0001, 0.001, 0.013, 0.004, respectively). Significant positive correlations existed between levels of TIMP-1 and levels of TIMP-4 (r = 0.37; p = 0.004), MMP-9 (r = 0.65; p < 0.0001) and VEGF (r = 0.59; p < 0.0001), between levels of TIMP-4 and levels of MMP-9 (r = 0.61; p < 0.0001) and VEGF (r = 0.62; p < 0.0001) and between levels of MMP-9 and VEGF (r = 0.62; p < 0.0001). TIMP-1 and TIMP-3 were expressed in vascular endothelial cells in PDR epiretinal membranes and in myofibroblasts and leucocytes in PDR and PVR epiretinal membranes. CONCLUSION: The differential expression of TIMPs in PDR suggests that among the 4 TIMPs, TIMP-1 and TIMP-4 may be possible biomarkers of disease activity.

Unbalanced Vitreous Levels of Osteoprotegerin, RANKL, RANK, and TRAIL in Proliferative Diabetic Retinopathy.

PURPOSE: We investigated the expression of the proinflammatory and proangiogenic factor osteoprotegerin (OPG) and its ligands, receptor activator of nuclear factor-κB ligand (RANKL), tumor necrosis factor-related apoptosis-inducing ligand (TRAIL), and the receptor RANK in proliferative diabetic retinopathy (PDR). MATERIALS AND METHODS: Vitreous samples from PDR and nondiabetic control patients and epiretinal membranes from PDR patients were studied by enzyme-linked immunosorbent assay, immunohistochemistry, and Western blot analysis. RESULTS: Vascular endothelial growth factor, OPG, and soluble RANK levels in vitreous samples from PDR patients were significantly higher than that in nondiabetic controls. Soluble TRAIL levels were significantly lower in PDR patients than that in nondiabetic control, whereas soluble RANKL levels did not differ significantly. RANKL, RANK, and TRAIL were expressed in vascular endothelial cells, myofibroblasts, and CD45-expressing leukocytes in PDR epiretinal membranes. CONCLUSIONS: Dysregulated expression of OPG/RANKL/RANK pathway and TRAIL might be related to inflammation and angiogenesis in PDR.

Secondary B-cell lymphoma associated with the Epstein-Barr virus in chronic lymphocytic leukemia patients.

Up to 10 % of chronic lymphocytic leukemia (CLL) patients present with aggressive secondary B-cell lymphoma (most frequently diffuse large B-cell lymphoma, DLBCL) which may be clonally related to the CLL (i.e., Richter transformation, RT, 80 % of the cases) or de novo (20 % of the cases). Several genetic lesions associated with RT have already been identified, but the potential role of the Epstein-Barr virus (EBV) has been largely overlooked. In this study, we describe six CLL patients who developed a secondary EBV-positive (EBV+) B-cell lymphoma (five DLBCL, one Hodgkin lymphoma) and compare their clinicopathological characteristics to ten CLL patients with EBV-negative (EBV-) secondary B-cell lymphomas (all DLBCL). All 16 patients had a history of iatrogenic immunosuppression or chemotherapy. Eighty percent had received fludarabine as part of the CLL treatment. Most secondary lymphomas were clonally related to the previous CLL (3/4 EBV+, 7/7 EBV- cases tested). Notably EBV+ RT was associated with a trend for older age at onset (median 72 vs. 63 years, p value >0.05), longer interval between CLL and RT diagnosis (median 4.2 vs. 2.9 years, p value >0.05), and shorter overall survival (median 4 vs. 10 months, p value >0.05). These differences were not significant, probably due to small sample size. Immunohistochemical profiling suggested more frequent overexpression of TP53 and MYC in EBV- compared to EBV+ secondary lymphoma. Based on this small retrospective single center series, we hypothesize that EBV+ RT may constitute a separate subgroup of RT. Larger series are required to validate this suggestion.

Clinicopathologic comparison of plasmablastic lymphoma in HIV-positive, immunocompetent, and posttransplant patients: single-center series of 25 cases and meta-analysis of 277 reported cases.

Plasmablastic lymphoma (PBL) is a rare B-cell non-Hodgkin lymphoma often associated with Epstein-Barr virus (EBV) infection. To gain insight in this aggressive lymphoma subtype, the clinicopathologic characteristics of 25 unpublished single-center PBLs (2 in acquired immunodeficiency syndrome patients, 11 in immunocompetent individuals [IC-PBL], 12 in transplant recipients [PT-PBL]) and of 277 reported PBLs were summarized. In the reported series, PBL patients were predominantly male (77%) with a median age at diagnosis of 46 years (range, 1.2 to 87 y). The majority of the biopsies (66%) was EBV positive. Extranodal presentation was most frequent (88%, of which 35% were oral, 18% gastrointestinal, 12% cutaneous). PBL was diagnosed in acquired immunodeficiency syndrome patients (50%), immunocompetent individuals (35%), and transplant recipients (14%). These subgroups differed in age at diagnosis (median: 41, 64, 47 y, respectively), primary localization (oral, oral, cutaneous, respectively), EBV positivity (75%, 50%, 67%, respectively), CD45 expression (31%, 33%, 70%, respectively), and C-MYC aberrations (78%, 44%, 38%, respectively). Ann Arbor stage I, EBV positivity, CD45 expression, and lack of C-MYC aberrations were associated with better outcome (P<0.05). Our series of IC-PBL and PT-PBL cases revealed differential expression of CD10 (0% vs. 42%, respectively), CD56 (22% vs. 42%, respectively), TP53 (67% vs. 8%, respectively), and BCL2 (88% vs. 25%, respectively). Gene expression analysis of 5 of our PT-PBLs revealed upregulation of DNMT3B, PTP4A3, and CD320 in EBV-positive PT-PBL and suggested a role for cancer/testis antigens. The results of this retrospective study suggest different pathogenic mechanisms of PBL in different immunologic settings and a potentially important impact of EBV and CD45 on prognosis.

Clinicopathological characteristics of posttransplant lymphoproliferative disorders of T-cell origin: single-center series of nine cases and meta-analysis of 147 reported cases.

T-cell or natural killer (NK)-cell posttransplant lymphoproliferative disorder (T-PTLD) is a rare but severe complication after transplant. Here we present the clinicopathological features of a single-center series of nine cases. Additionally, we summarize the clinicopathological findings of 147 cases of T/NK-cell PTLD reported in the literature in an attempt to define subtype-specific characteristics. T/NK-cell PTLD occurs in patients of all ages, usually extranodally, and most frequently after kidney transplant. Organ specific incidence, however, is highest following heart transplant. Approximately one-third of T-cell PTLDs are Epstein-Barr virus (EBV)-related, with peripheral T-cell lymphoma, not otherwise specified (PTCL, NOS) being the most prevalent EBV-associated T-cell PTLD. A male predominance is observed, which is most striking in the EBV(+) group, particularly in PTCL, NOS. With a median posttransplant interval of 72 months, T-cell PTLDs are among the late-occurring PTLDs. Of the most common T-cell PTLDs, anaplastic large cell lymphoma (ALCL) has the best prognosis, whereas PTCL, NOS and hepatosplenic T-cell lymphoma (HSTCL) have the worst prognosis. EBV(+) cases seem to have a longer survival than EBV(-) cases, suggesting a different pathogenetic mechanism.