Clinicopathological analysis of the age-related differences in patients with Epstein-Barr virus (EBV)-associated extranasal natural killer (NK)/T-cell lymphoma with reference to the relationship with aggressive NK cell leukaemia and chronic active EBV infection-associated lymphoproliferative disorders

Takahashi E, Ohshima K, Kimura H, Hara K, Suzuki R, Kawa K, Eimoto T & Nakamura S for the NK‐cell Tumor Study Group
(2011) Histopathology 59 , 660–671 Clinicopathological analysis of the age‐related differences in patients with Epstein–Barr virus (EBV)‐associated extranasal natural killer (NK)/T‐cell lymphoma with reference to the relationship with aggressive NK cell leukaemia and chronic active EBV infection‐associated lymphoproliferative disorders Aims: Extranodal natural killer (NK)/T‐cell lymphoma (NKTL), comprising nasal NKTL and extranasal NKTL (ENKTL), is associated with Epstein–Barr virus (EBV). A bimodal age distribution was noted in NKTL patients. We examined the clinicopathological differences between two age groups of ENKTL patients (n = 23) and compared the findings with those of aggressive NK cell leukaemia (ANKL; n = 10) and monoclonal chronic active EBV infection‐associated T/NK‐cell lymphoproliferative disorders [chronic active EBV infection/TNK‐lymphoproliferative disorders (CAEBV/TNK‐LPD)] of NK‐cell type (n = 45). Methods and results: Distinct differences existed between elderly (>50 years; n = 13) and younger (≤50 years; n = 10) ENKTL patients; the latter showed a higher disease stage (P = 0.0286), worse performance status (P = 0.0244), more frequent B symptoms (P = 0.0286) and more frequent liver, spleen and bone marrow involvement (P = 0.0222, 0.0005 and 0.0259, respectively). Few clinicopathological differences existed between younger ENKTL and ANKL patients. Patients with monoclonal CAEBV/TNK‐LPD of NK‐cell type (n = 45) showed features similar to those in younger ENKTL/ANKL patients, except a more juvenile onset of CAEBV‐related symptoms and better prognosis. However, the onset age of overt leukaemia/lymphoma in CAEBV/TNK‐LPD patients and overall survival thereafter were similar to those in younger ENKTL/ANKL patients. Conclusions: ENKTL (≤50 years) is distinct from that in elderly patients and may encompass ANKL and overlap in the clinicopathological profile with NK‐cell type CAEBV/TNK‐LPD.     

Plasmablastic lymphoma may occur as a high-grade transformation from plasmacytoma

Plasmablastic lymphoma (PBL) is an uncommon aggressive lymphoma arising most frequently in the oral cavity of HIV-infected patients. Rare cases of PBL have been reported in extraoral sites, particularly extranodal sites, as well as in immunocompetent patients. We report an unusual case of PBL in a 69-year-old, HIV-negative non-immunocompromised man presenting with generalized lymphadenopathy. To our knowledge, this is the first case of PBL presented as primarily generalized lymphadenopathy in HIV-negative patients. Histologic examinations of cervical, inguinal and axillary lymph nodes demonstrated a neoplastic proliferation of large cells with extensive necrosis. The neoplastic cells formed sheets with a relatively cohesive growth pattern interspersed by small lymphocytes and plasma cells. The large tumor cells expressed MUM1, OCT-2 and BOB.1, and were negative for CD138, CD38, AE1/AE3, melan A, PLAP, S100, vimentin, CD117, CD30, ALK-1, leukocyte common antigen (CD45), T-cell, B-cell and histolytic markers, CD56, CD10 and BCL-6. The proliferation index by Ki-67 immunohistochemistry was approaching 100%. In situ hybridization for Epstein–Barr Virus-encoded RNA (EBER) was positive in large malignant cells. A diagnosis of PBL was made. These findings indicate that PBL should be included in the differential diagnosis of an HIV-negative, immunocompetent patient with generalized lymphadenopathy. The adjacent plasma cells were positive for CD138 and CD38 and show kappa-light chain restriction, but without EBER expression, raising the possibility of a preexisting or concurrent plasmacytoma and that the PBL may be a high-grade transformation from a preexisting plasma cell neoplasm following Epstein–Barr virus infection. Electron microscopy showed numerous circumferential long slender peripheral cytoplasmic projections in the large tumor cells, suggesting that some of the previously reported large B-cell lymphoma with cytoplasmic projections may actually be PBL.     

LMP1 antagonizes WNT/β-catenin signalling through inhibition of WTX and promotes nasopharyngeal dysplasia but not tumourigenesis in LMP1(B95-8) transgenic mice

Latent membrane protein 1 (LMP1) of Epstein-Barr virus (EBV) can induce cell transformation and tumourigenesis, but the mechanism is not understood. Previous studies have suggested that LMP1 acts through up-regulation of cellular proliferation pathways including the Wnt/β-catenin pathway, in which β-catenin is the central effector. Increased levels of β-catenin coupled with a decrease in E-cadherin lead to reduced cell adhesion. This pathway is antagonized by WTX (Wilms' tumour gene on the X chromosome), which can promote the ubiquitination and degradation of β-catenin. In the present study, we established L2/LMP1B(95 - 8) /EGFP transgenic mice to investigate the in vivo role of LMP1. Down-regulation of WTX and E-cadherin was accompanied by increased expression of β-catenin in these mice. Even though invasive tumours did not develop, dysplasia was seen in the nasopharynx and oropharynx epithelium of these transgenic mice. Analysis of LMP1(+) , WTX(+) , and LMP1 siRNA silenced HNE-1 cell lines demonstrated that WTX could exert a dominant role in LMP1-mediated WNT/β-catenin pathway regulation. This study indicates that LMP1 antagonizes the WNT/β-catenin pathway by inhibiting WTX, and this reduction in WTX is associated with epithelial dysplasia via regulation of the WNT/β-catenin pathway molecules E-cadherin and β-catenin. Further studies are required for a better understanding of the relationship between LMP1-mediated antagonization of the WNT/β-catenin pathway and tumourigenesis.     

Associations of serum EBV DNA and gammopathy with post-transplant lymphoproliferative disease

Abstract: Background: Post‐transplant lymphoproliferative disease (PTLD) is a life‐threatening complication of immunosuppression following transplantation. Epstein–Barr virus (EBV) and gammopathy in serum are associated with PTLD, but these two parameters have not been evaluated in parallel for their association with PTLD. Methods: We evaluated the incidence of EBV load positivity, gammopathy, and protein expression in sera from all PTLD patients diagnosed at our hospital during the past seven yr. Results were compared with those of a control group including matched transplanted patients who did not develop PTLD. Results: Seven of 10 PTLD patients presented EBV⁺ PTLD, for which five patients had detectable serum EBV DNA levels compared with none of 38 controls (RR between two groups =121, p < 0.0001). Five out of 10 patients had gammopathy at PTLD diagnosis compared with 5/38 controls (RR between two groups = 6.6, p = 0.022). Additionally, protein serum analysis by high‐resolution two‐dimensional gel electrophoresis and image examination failed to evidence specific abnormality in patients with PTLD compared with controls. Conclusions: Our results confirm an association between EBV in sera and gammopathy with PTLD, and highlight the high specificity of the former analysis. Whether a combination of both analyses will improve the clinical detection of PTLD remains to be evaluated in a larger prospective cohort study.     

Primary adrenal natural killer/T-cell nasal type lymphoma: first case report in adults

We report the first case of a primary adrenal natural killer (NK)/T-cell nasal type lymphoma in adults. The patient presented with an enlarging left adrenal mass and the initial concern was for adrenocortical carcinoma. Surgical resection revealed NK/T-cell lymphoma. Rapid recurrence in the contralateral adrenal gland was treated with a single cycle of chemotherapy before he died due to infectious complications and progressive disease. This case demonstrates the aggressive presentation of a novel subset of primary adrenal lymphoma that should be considered in the differential diagnosis of a rapidly enlarging adrenal mass.     

Immunophenotypic analysis of Epstein-Barr virus (EBV)-infected CD8(+) T cells in a patient with EBV-associated hemophagocytic lymphohistiocytosis

Hemophagocytic lymphohistiocytosis (HLH) is a severe and often fatal condition characterized by uncontrolled activation of T cells and macrophages. In Epstein-Barr virus (EBV)-associated HLH (EBV-HLH), the pathogenic roles of ectopic EBV infection in the T-cell population and of clonal proliferation of EBV-infected T cells has been described. However, the immunophenotype of EBV-infected T cells has not been fully characterized. Here we describe a case of EBV-HLH presenting with a massive clonal proliferation of CD8(+) T cells with TCR VB14. Analysis of in situ hybridization for EBV-encoded small RNA1 showed that only CD8(+) T cells harbored EBV in this patient. The EBV-infected TCR VB14(+) CD8(+) T cells exhibited unique immunophenotypic features including lacked CD5 expression and a markedly bright expression of HLA-DR. After initiation of treatment with prednisolone, etoposide, and cyclosporin A, the percentage of infected cells declined progressively in parallel with other serum markers such as ferritin. These findings suggest that lacking expression of CD5 on CD8(+) T cells with specific TCR VB may serve as a useful marker of dysregulated T-cell activation and proliferation in EBV-HLH.     

Human antibody titers to Epstein–Barr Virus (EBV) gp350 correlate with neutralization of infectivity better than antibody titers to EBV gp42 using a rapid flow cytometry-based EBV neutralization assay

Measurement of neutralizing antibodies to Epstein–Barr virus (EBV) is important for evaluation of candidate vaccines. The current neutralization assay is based on antibody inhibition of EBV transformation of B cells and requires 6 weeks to perform. We developed a rapid, quantitative flow cytometry assay and show that neutralizing antibody titers measured by the new assay strongly correlate with antibody titers in the standard transformation-based assay. Antibodies to EBV gp350 and gp42 have been shown to block infection of B cells by EBV. Using new assays to quantify antibodies to these glycoproteins, we show for the first time that human plasma contains high titers of antibody to gp42; these titers correlate with neutralization of EBV infectivity or transformation. Furthermore, we show that antibody titers to EBV gp350 correlate more strongly with neutralization than antibody titers to gp42. These assays should be useful in accessing antibody responses to candidate EBV vaccines.     

Periodontopathic bacteria and herpesviruses in chronic periodontitis

Periodontal disease involves complex interactions of microorganisms and host defenses. This work investigated the associations between putative bacterial pathogens, herpesviruses and chronic periodontitis. Subgingival samples were collected from 40 periodontally healthy individuals and from 40 patients with chronic periodontitis with probing depths of ≤3 mm or ≥6 mm. Multiplex and nested polymerase chain reactions were used to identify bacterial pathogens and herpesviruses. Porphyromonas gingivalis, Tannerella forsythia, Epstein–Barr virus (EBV) type 1, cytomegalovirus (CMV), Aggregatibacter actinomycetemcomitans and EBV type 2 were detected in, respectively, 95, 75, 72.5, 50, 12.5 and 10% of sites with probing depths ≥6 mm. P. gingivalis, T. forsythia, EBV‐1 and CMV were statistically associated with probing depths ≥6 mm. A. actinomycetemcomitans and EBV‐2 showed no association with periodontitis sites, and no significant associations were found for any of the test infectious agents and probing depths ≤3 mm. Our results confirm an association between P. gingivalis, T. forsythia, EBV‐1 and CMV, and chronic periodontitis. These infectious agents may play an important synergistic role in the pathogenesis of chronic periodontitis.