Primary immunodeficiencies predisposed to Epstein‐Barr virus‐driven haematological diseases

Epstein‐Barr virus (EBV), a ubiquitous human herpesvirus, maintains lifelong subclinical persistent infections in humans. In the circulation, EBV primarily infects the B cells, and protective immunity is mediated by EBV‐specific cytotoxic T cells (CTLs) and natural killer (NK) cells. However, EBV has been linked to several devastating diseases, such as haemophagocytic lymphohistiocytosis (HLH) and lymphoproliferative diseases in the immunocompromised host. Some types of primary immunodeficiencies (PIDs) are characterized by the development of EBV‐associated complications as their predominant clinical feature. The study of such genetic diseases presents an ideal opportunity for a better understanding of the biology of the immune responses against EBV. Here, we summarize the range of PIDs that are predisposed to EBV‐associated haematological diseases, describing their clinical picture and pathogenetic mechanisms.     

Epstein–Barr Virus Expression in Classic Hodgkin Lymphoma in an Indian Cohort and its Association with Clinical and Histomorphological Parameters

Epstein Barr virus (EBV) associated Hodgkin lymphoma (HL) has been defined as cases with clonal EBV infection, EBV genome and gene products in the Reed Sternberg cells. We evaluated the prevalence and clinico-pathological association of EBV in North Indian HL patients. Eighty-eight cases of histologically confirmed classic HL were evaluated for EBV by both IHC expression of LMP1 and real time PCR on formalin fixed lymph node tissue. The expression pattern was analyzed for any association with clinical and histomorphological parameters. Nodular sclerosis subtype was seen in 79.5% patients and mixed cellularity was seen in the remaining patients. Ninety percent of the cases were positive for EBV. The detection rate of EBV by IHC was higher. The EBV positive cases presented with higher disease stage (p < 0.05). The presence of histomorphological features like granuloma formation (5/5), atypical lymphocytes (8/8), histiocyte clusters (26/28), large area of necrosis (11/12), less prominent inflammatory response (25/27) was associated with EBV positivity (p > 0.05). In our study population a high proportion of HL cases showed positivity for EBV indicating a pathogenic role. The positivity was independent of age, gender and histological subtype. Further evaluation of EBV positivity in modulation of tumor immunity may provide insights into variable treatment outcome in EBV positive cases.     

Epstein Barr virus-positive mucocutaneous ulcer of the colon associated Hodgkin lymphoma in Crohn's disease

Epstein Barr virus(EBV) positive mucocutaneous ulcers(EBVMCU) form part of a spectrum of EBV-associated lymphoproliferative disease. They have been reported in the setting of immunosenescence and iatrogenic immunosuppression, affecting the oropharyngeal mucosa,skin and gastrointestinal tract(GIT). Case reports and series to date suggest a benign natural history responding to conservative management, particularly in the GIT. We report an unusual case of EBVMCU in the colon, arising in the setting of immunosuppression in the treatment of Crohn's disease, with progression to Hodgkin lymphoma18 mo after cessation of infliximab. The patient presented with multiple areas of segmental colonic ulceration,histologically showing a polymorphous infiltrate with EBV positive Reed-Sternberg-like cells. A diagnosis of EBVMCU was made. The ulcers failed to regress upon cessation of infliximab and methotrexate for 18 mo. Following commencement of prednisolone for her Crohn's disease, the patient developed widespread Hodgkin lymphoma which ultimately presented as a life-threatening lower GIT bleed requiring emergency colectomy. This is the first report of progression of EBVMCU to Hodgkin lymphoma, in the setting of ongoing iatrogenic immunosuppression and inflammatory bowel disease.     

Diagnosis of Hodgkin lymphoma in the modern era

The Hodgkin lymphomas are a family of unique lymphoma subtypes, in which the nature of the neoplastic cell was enigmatic for many years. Much of the mystery has been solved, with all forms now considered to be of B-cell origin, in most cases of germinal centre derivation. Today we recognize Hodgkin lymphoma as an eponym that encompasses multiple entities. One of the unifying themes is the major contribution from the tumour microenvironment. Both the character of the neoplastic cells and the nature of the immune environment are critical to accurate diagnosis. Moreover, an understanding of the molecular alterations that characterize both the neoplastic cells and their microenvironment have led to therapeutic advances, targeting both neoplastic and reactive components. Other conditions may foster a similar inflammatory milieu and lead to lymphoproliferations that mimic the Hodgkin lymphomas. In this review we provide an update on the diagnostic features of the various subtypes and include additional information relevant for prognostic evaluation and investigation of potential therapeutic targets. Additionally, we also discuss those conditions that often cause confusion in diagnosis and need to be distinguished from the Hodgkin lymphomas.     

Combination of SAHA and bortezomib up‐regulates CDKN2A and CDKN1A and induces apoptosis of Epstein‐Barr virus‐positive Wp‐restricted Burkitt lymphoma and lymphoblastoid cell lines

Epstein‐Barr virus (EBV) latent proteins exert anti‐apoptotic effects on EBV‐transformed lymphoid cells by down‐regulating BCL2L11 (BIM), CDKN2A (p16^INK4A) and CDKN1A (p21^WAF1). However, the potential therapeutic effects of targeting these anti‐apoptotic mechanisms remain unexplored. Here, we tested both in vitro and in vivo effects of the combination of histone deacetylase (HDAC) and proteasome inhibitors on the apoptosis of six endemic Burkitt lymphoma (BL) lines of different latency patterns (types I and III and Wp‐restricted) and three lymphoblastoid cell lines (LCLs). We found that the combination of HDAC and proteasome inhibitors (e.g. SAHA/bortezomib) synergistically induced the killing of Wp‐restricted and latency III BL and LCLs but not latency I BL cells. The synergistic killing was due to apoptosis, as evidenced by the high percentage of annexin V positivity and strong cleavage of PARP1 (PARP) and CASP3 (caspase‐3). Concomitantly, SAHA/bortezomib up‐regulated the expression of CDKN2A and CDKN1A but did not affect the level of BCL2L11 or BHRF1 (viral homologue of BCL2). The apoptotic effects were dependent on reactive oxygen species generation. Furthermore, SAHA/bortezomib suppressed the growth of Wp‐restricted BL xenografts in nude mice. This study provides the rationale to test the novel application of SAHA/bortezomib on the treatment of EBV‐associated Wp‐restricted BL and post‐transplant lymphoproliferative disorder.     

A rare case of Epstein‐Barr virus‐associated hepatosplenic smooth muscle tumors after kidney transplantation

A 27‐year old caucasian male was diagnosed 2.7 years after kidney transplantation with Epstein‐Barr virus (EBV)‐associated smooth muscle tumors in liver and spleen. The reduction in immunosuppression and conversion from tacrolimus to sirolimus did not lead to a regression of the tumors. Additionally, the patient developed a cellular rejection of his renal allograft, which was successfully treated. A combined approach with stereotactic radiofrequency ablation (SRFA) and surgical resection was effective in the treatment of the tumors.     

Remission of Epstein‐Barr virus‐positive post‐transplant lymphoproliferative disorder by conversion to everolimus in a kidney transplant recipient

Post‐transplant lymphoproliferative disorder (PTLD) is a fatal complication of transplantation. There is no clear consensus on the treatment of PTLD. In most cases, the pathogenetic mechanism of PTLD involves the Epstein‐Barr virus (EBV). We report the case of an elderly kidney transplant recipient who developed EBV‐positive monomorphic T‐cell PTLD 14 years after transplantation. Conversion from conventional immunosuppressants to everolimus induced complete remission of PTLD accompanied by a decrease in blood EBV‐DNA level without chemotherapy.     

Prevalence of hepatitis B virus infection in non‐Hodgkin lymphoma: a systematic review and meta‐analysis

Background and aim: A recent meta‐analysis has demonstrated an association between hepatitis C virus and non‐Hodgkin lymphoma (NHL). There is also evidence on the association between hepatitis B virus (HBV) and NHL. The aim of this study was to evaluate this evidence using a meta‐analytic approach. Methods: We searched the MEDLINE database from 1962 to 2008 for case–control studies that have reported the association of HBV with NHL. We calculated the odds ratio (OR) and 95% confidence intervals (CI) to assess the prevalence of HBV infection and pooled the results using three different statistical models. Results: Our search yielded 12 studies with 11 studies (3262 NHL patients, 1 523 205 controls) evaluating HBV infection in NHL and one study (3888 HBV‐infected individuals, 205 203 controls) that had investigated for NHL in HBV infection. The OR of detecting HBV infection in NHL when compared with the control population was 2.56 (95% CI, 2.24–2.92) by the fixed effects model; 2.61 (95% CI, 2.29–2.98) by the exact method and 2.67 (95% CI, 2.04–3.49) by the random effects model suggesting a high prevalence of HBV carrier state in lymphoma. There was evidence of statistical heterogeneity which disappeared after exclusion of retrospective studies on sensitivity analysis. Conclusions: The results of this study suggest a possible causal relation between HBV infection and NHL which needs to be confirmed by experimental and epidemiological studies. In countries where prevalence of HBV infection is 1% or more, it may be prudent to screen patients with NHL for occult HBV infection.     

Hepatitis B virus and risk of non‐Hodgkin lymphoma: An updated meta‐analysis of 58 studies

Previous studies have focused on the relationship between hepatitis B virus (HBV) infection and non‐Hodgkin lymphoma (NHL). However, the results remain inconsistent and somehow conflicting in different subgroups. The aim of this study was to combine the findings of independent studies to comprehensively assess the association between HBV and NHL using a meta‐analysis. Relevant studies were identified through structured keyword searches in PubMed, EMBASE and the China National Knowledge Infrastructure (CNKI) database, and 58 studies with a total of 53 714 NHL cases and 1 778 591 controls were finally included. Pooled estimates indicated a significantly increased NHL risk in HBV‐infected individuals (summary odds ratio [sOR]: 2.50; 95% confidence interval [CI]: 2.20‐2.83) regardless of the study design (case–control studies: sOR: 2.47; 95% CI: 2.16‐2.82; cohort studies: sOR: 2.64; 95% CI: 1.78‐3.91). Considerable heterogeneity was observed across studies that was primarily attributed to the NHL subtypes (meta‐regression: P < .05). Overall, B‐cell NHL (sOR: 2.46; 95% CI: 1.97‐3.07) presented a stronger association with HBV infection than T‐cell NHL (sOR: 1.67; 95% CI: 1.34‐2.10). Within the B‐cell NHL subtypes, HBV infection was significantly associated with diffuse large B‐cell lymphoma (DLBCL, sOR: 2.06; 95% CI: 1.48‐2.88) and follicular lymphoma (FL, sOR: 1.54; 95% CI: 1.11‐2.12), but not with chronic lymphocytic leukaemia/small lymphocytic lymphoma (CLL/SLL) and Burkitt lymphoma. The results of this meta‐analysis support a positive link between HBV infection and NHL development. Further investigations for the mechanisms underlying HBV‐induced NHL are warranted.     

Prognostic Role of the Expression of Latent-Membrane Protein 1 of Epstein–Barr Virus in Classical Hodgkin Lymphoma

The prognostic impact of the presence of Epstein–Barr virus (EBV) in classical Hodgkin lymphoma (cHL) is controversial. Previous studies reported heterogeneous results, rendering difficult the clinical validation of EBV as a prognostic biomarker in this lymphoma. The objective of this study was to evaluate the survival impact of the expression of EBV Latent-Membrane Protein 1 (EBV-LMP1) in tumoral Hodgkin–Reed–Sternberg (HRS) cells of primary diagnostic samples of cHL. Formalin-Fixed Paraffin-Embedded (FFPE) lymph node samples from 88 patients with cHL were analyzed. Patients were treated with the standard first-line chemotherapy (CT) with Adriamycin, Bleomycin, Vinblastine and Dacarbazine (ABVD) followed by radiotherapy. The Kaplan–Meier method and the Cox proportional hazards model were used for carrying out the survival analysis. In order to investigate whether the influence of EBV was age-dependent, analyses were performed both for patients of all ages and for age-stratified subgroups. In bivariate analysis, the expression of EBV was associated with older age (p = 0.011), mixed cellularity subtype cHL (p < 0.001) and high risk International Prognostic Score (IPS) (p = 0.023). Overall survival (OS) and progression-free survival (PFS) were associated with the presence of bulky disease (p = 0.009) and advanced disease at diagnosis (p = 0.016). EBV-positive cases did not present a significantly lower OS and PFS in comparison with EBV-negative cases, for all ages and when stratifying for age. When adjusted for covariates, absence of bulky disease at diagnosis (HR: 0.102, 95% CI: 0.02–0.48, p = 0.004) and limited disease stages (I–II) (HR: 0.074, 95% CI: 0.01–0.47, p = 0.006) were associated with a significant better OS. For PFS, limited-disease stages also retained prognostic impact in the multivariate Cox regression (HR: 0.145, 95% CI: 0.04–0.57, p = 0.006). These results are of importance as the early identification of prognostic biomarkers in cHL is critical for guiding and personalizing therapeutic decisions. The prognostic role of EBV in cHL could be modulated by the type of CT protocol employed and interact with the rest of presenting features.