Absence of Epstein-Barr viral encoded RNA (EBER) in primary cutaneous t-cell lymphoma

Increased Levels of Plasma Epstein Barr Virus DNA Identify a Poor-Risk Subset of Patients With Advanced Stage Cutaneous T-Cell Lymphoma

INTRODUCTION

Outcomes in advanced stage (AS) cutaneous T-cell lymphomas (CTCL) are poor but with great variability. Epstein-Barr virus (EBV) is associated with a subset of non-Hodgkin lymphomas. Frequency of plasma EBV-DNA (pEBVd) detection, concordance with EBV RNA (EBER) in tumor tissue, codetection of plasma cytomegalovirus DNA (pCMVd), and prognostic effect in AS CTCL are unknown.

PATIENTS AND METHODS

Patients (n = 46; 2006-2013) with AS CTCL (≥IIB) were retrospectively studied. pEBVd and pCMVd were longitudinally measured using quantitative real-time polymerase chain reaction. EBER in situ hybridization (ISH) was performed on tumor samples. Survival from time of diagnosis (ToD) and time of progression to AS was assessed.

RESULTS

Plasma EBV-DNA and pCMVd were detected in 37% (17 of 46) and 17% (8 of 46) of AS CTCL patients, respectively. pCMVd detection was significantly more frequent in pEBVd-positive (pEBVd(+)) than pEBVd(-) patients (35% vs. 7%; P = .038). Tumor tissue for EBER-ISH was available in 14 of 17 pEBVd(+) and 22 of 29 pEBVd(-) patients; 12 of 14 (85.7%) pEBVd(+) patients were EBER(+) versus 0 of 22 pEBVd(-) patients. Frequency of large cell transformation (LCT) tended to be greater in pEBVd(+) patients, but was not significant (10 of 14 pEBVd(+) vs. 10 of 23 pEBVd(-); P = .17). No notable differences in rates of increased levels of serum lactate dehydrogenase (LDH) were observed (17 of 17 pEBVd(+) vs. 27 of 29 pEBVd(-)). pEBVd detection was associated with significantly worse survival from ToD (P = .021) and time of progression to AS (P = .0098).

CONCLUSION

Detection of cell-free plasma EBV-DNA was highly concordant with the presence of EBERs in tumor tissue, predicted survival independent of LDH and LCT, and should be further studied as a biomarker in AS CTCL.

Evaluation of the Association Between Epstein-Barr Virus and Mycosis Fungoides

INTRODUCTION

Mycosis fungoides (MF) is the most common cutaneous T-cell lymphomas. Despite extensive studies, etiopathogenesis of MF is unknown. Environmental, infectious and genetic factors have been proposed as potential risk factors of MF. Herpes virus family members, especially Epstein-Barr virus (EBV), have been among the viral factors of interest in recent years. The aim of this study was to investigate the possible association of EBV infection with MF.

MATERIALS AND METHODS

This case-control study was performed on skin biopsy samples of 57 MF patients referred to Pathology Department of Mashhad Emam Reza Hospital from 2000 to 2011 and also on 57 melanocytic nevus samples matched with patients for age and sex. The presence of EBV in samples was evaluated by polymerase chain reaction. Statistical analysis of the data was conducted with the Statistical Package for the Social Sciences version 11.5 (SPSS Inc., Chicago, IL, USA).

RESULTS

In this study, out of 57 MF samples, there were 34 male and 23 female patients, with male:female ratio of 1.04. Mean patient age was 51.4 years. There were 22 and 4 positive cases of EBV in the case and control groups, respectively. Chi-square statistical test showed that EBV was significantly higher in case group than control (P = 0.000). There was no correlation between the presence of EBV in samples with lesion type, age and gender of the patients.

CONCLUSION

According to our study results, EBV is a likely etiologic agent or potential promoter in the pathogenesis of MF.

Epstein-Barr virus: dermatologic associations and implications: part II. Associated lymphoproliferative disorders and solid tumors

Epstein-Barr virus (EBV) was the first human virus to be associated with oncogenesis. Over the past few decades, cumulative research has revealed that latent EBV infection may be implicated in the pathogenesis of a heterogeneous group of lymphoproliferative disorders and malignancies occurring in both immunocompetent and immunocompromised hosts. Many of these diseases have either primary or secondary cutaneous manifestations. Serologic studies and EBV-encoded RNA in situ hybridization stains have been used to show the association of EBV with disease; while these findings may imply a role, they do not equate with causation. In part II of this continuing medical education review, the salient features of EBV-associated lymphoproliferative disorders and solid tumors are detailed.

Role of infectious agents in cutaneous T-cell lymphoma: facts and controversies

The etiology of cutaneous T-cell lymphoma (CTCL) remains unknown, with potential infectious causes having been explored. This contribution evaluates the evidence suggesting an infectious etiology and pathogenesis of the disease, characterizes the relationships between various specific pathogens and CTCL, and discusses some of the difficulties in establishing a causal link between infectious agents and CTCL carcinogenesis. Researchers have evaluated CTCL specimens for evidence of infection with a variety of agents, including human T-lymphotropic virus, Epstein-Barr virus, human herpesvirus-8, and Staphylococcus aureus, although other pathogens also have been detected in CTCL. Although there is significant evidence implicating one or more infectious agents in CTCL, studies to date have not linked definitively any pathogen to disease development, and various studies have yielded conflicting results.

CD8+ T lymphocytes reactive against Epstein-Barr virus antigens in skin lesions of a patient with Sézary syndrome

Several studies have investigated the possible involvement of viral agents, and among them herpes viruses, in the development of cutaneous T-cell lymphoma. The aim of our study was to determine whether T cells specific to Epstein-Barr virus (EBV) antigens were detectable among tumor-infiltrating lymphocytes infiltrating cutaneous lesions of a patient with Sézary syndrome. To analyze responses to EBV, we used a transient SV-40 origin-defective transformed simian cells transfection assay that permits an estimation of CD8 T-cell responses against a large number of HLA/viral protein combinations. This technique allowed the detection of EBV-specific T lymphocytes mainly directed against epitopes generated during the lytic cycle in the cutaneous lesions. This is, to our knowledge, the first description of the presence of EBV-specific T lymphocytes among tumor-infiltrating lymphocytes infiltrating the lesional skin of a patient with Sézary syndrome.

[Prevalence of Epstein-Barr virus in non-Hodgkin's lymphomas in central region of Tunisia]

The purpose of this study was to evaluate the prevalence of EBV in non-Hodgkin's lymphomas occuring in non-immunocopromised patients in Tunisia through a series of 126 cases. EBV was investigated by EBER oligonucleotide in situ hybridization (ISH) and LMP1-immunohistochemistry. Serological study of EBV has been performed before therapy in 28 patients. EBV was detected in tumor cells by ISH in 28/126 (22.2%) cases. Variable proportions of tumor cells were positive. LMP1 was identified in only 8 cases. EBV was more frequently observed in T-cell lymphomas (9/24 patients; 37.5%) than in B-cell lymphomas (19/102 patients; 18.6%) (p=0.04). There was a strong relationship between EBV and small intestine lymphomas (6/8 patients; 75%) and T/NK nasal type lymphomas (3/3 patients; 100%). EBV serological reactivation was noted in 7/13 patients in clinical stages III/IV and in only 1/10 patients in stages I/II (p=0.03). In conclusion, the prevalence of EBV in Tunisian non-Hodgkin's lymphomas is low but variable depending on the histological type and anatomical location with a predilection for small intestine and nasal lymphomas.

Prevalence of mycosis fungoides and its association with EBV and HTLV-1 in Pakistanian patients

Mycosis fungoides (MF) is an indolent T cell lymphoma that is distinguished from other lymphomas by its initial appearance on the skin. The histologic diagnosis of MF may be difficult because there is significant overlap in the histologic features of neoplastic T-cell infiltrates and inflammatory dermatoses. This T-cell neoplasm commonly occurs in a mixed, reactive background and can show only a subtle degree of cytologic atypia, rendering histologic diagnosis difficult. In this study MF constituted 0.86% of all non-Hodgkin s lymphoma (NHL) both T and B, as compared to the Western studies which have reported 0.5% prevalence for MF of all NHL. Polymerase chain reaction (PCR) technique was used to assess T-cell clonality in paraffin-embedded skin biopsies clinically and pathologically suspicious for early MF. Out of the 14 cases diagnosed as MF, amplifiable DNA was isolated from 6 cases, which were further studied for T-cell receptor (TcR) beta, gamma, and delta chain gene rearrangements. Clonal product was seen in 4 out of 6 cases for beta, gamma, and delta TcR chain genes. Association for Epstein Barr virus (EBV) was observed in 3 out of 6 cases (50%) of MF. Although these 3 cases were positive for EBV by PCR, but were negative by in-situ hybridization (ISH). No heterogeneity was noted in these 3 cases of MF for BamHI E, K, N, and Z regions of EBV. All six cases were negative for HTLV-1 (tax region) by PCR. It was concluded that the prevalence of MF in Pakistani population is comparable to the Western data, and that EBV association to MF cases was higher than in Western studies.

Infrequent Fas mutations but no Bax or p53 mutations in early mycosis fungoides: a possible mechanism for the accumulation of malignant T lymphocytes in the skin

Mycosis fungoides (MF) is the most frequent manifestation of cutaneous T cell lymphoma but its cause and pathophysiology remain unclear. Because progression of lesions is characteristically slow, we hypothesized that mycosis fungoides originates from an accumulation of lymphocytes due to defective apoptosis of skin homing T lymphocytes. In this study, we investigate possible alterations of three molecules regulating apoptosis, i.e., Fas antigen, Bax, and p53, at the genomic level in skin lesions from 44 patients with MF, as Fas mediates one of two major pathways for apoptosis of activated T cells. Fas mutations were found in six patients using a polymerase chain reaction and single-strand conformational polymorphism method followed by cloning and sequencing of abnormal polymerase chain reaction products. The mutations predict for defective transmission of the death signal in three cases. Immunohistochemistry demonstrated the lack of Fas protein expression on dermal lymphocytes in one case with Fas gene mutation predicting for a truncated death domain, whereas Fas protein was expressed by dermal lymphocytes in the other investigated cases. By contrast, no mutations of Bax or p53 were found, whereas immunohistochemistry demonstrated increased p53 expression in the nucleus of basal keratinocytes above the neoplastic infiltrate in some MF cases. These results support the hypothesis that Fas defects may play a role in the pathogenesis of MF.

Comparison of primary and secondary cutaneous CD56+ NK/T cell lymphomas

CD56+ NK/T cell lymphoma (NKTL) frequently involves skin and subcutaneous tissue. The characteristics of primary cutaneous nasal-type CD56+ NKTLs and secondary cutaneous involvement of nasal CD56+ NKTLs have not been clearly separated. This retrospective study analyzed 15 cases of NKTL (10 primary CD56+ NKTLs and 5 secondary CD56+ NKTLs) for their clinicopathologic and immunophenotypic characteristics using CD3, CD4, CD20, CD45RO, CD56, TIA-1, CD30, and Ki-67 antigens. In situ hybridization for Epstein-Barr virus RNA (EBERISH) and PCR for T cell receptor (TCR) gamma gene rearrangement were also performed. Clinically, NKTL-P was seen with equal frequency among male (five cases) and female (five cases) patients and presented with subcutaneous nodules without epidermal changes (nine cases), whereas all cases of NKTL-S occurred in male patients and presented with nodules or plaques with distinct epidermal changes (five cases). Microscopically, initial NKTL-P lesions had the panniculitic patterns of small to medium-sized cells (nine cases). NKTL-S lesions were extensive in both subcutis and dermis, with larger and more pleomorphic tumor cells (four cases) that also showed signs epidermotropism (five cases). In initial biopsies of CD56+ NKTL-P, a minority of tumor cells showed signals for EBERISH and in biopsies of CD56+ NKTL-S, virtually every tumor cell showed signals. While all five patients with secondary CD56+ NKTL died of disease with widespread systemic involvement within 16 months after onset of skin lesions, 7 out of the 10 primary CD56+ NKTL patients survived more than 20 months after onset of skin lesions, with slow progression and episodic recurrences. The primary and secondary cutaneous CD56+ NKTLs showed considerable clinicopathologic differences, suggesting differences in pathogenesis.

Examination of mycosis fungoides for the presence of Epstein-Barr virus and human herpesvirus-6 by polymerase chain reaction

BACKGROUND

The aetiology of cutaneous T-cell lymphoma (CTCL) remains unknown despite numerous investigations. In recent years, retroviruses and human herpesviruses have been implicated to play a causal part in CTCL.

OBJECTIVE

The aim of this study was to elucidate the possible aetiopathogenetic role of human herpesviruses (HHV) in mycosis fungoides (MF).

METHODS

Polymerase chain reaction was used to study formalin-fixed, paraffin-embedded lesional skin biopsies from 92 subjects with MF to evidence possible presence of Epstein-Barr virus (EBV) and HHV-6.

RESULTS

Biopsy specimens from nine subjects (9.8%) evidenced EBV DNA, whereas all except one of the subjects (1.1%) lacked HHV-6 DNA.

CONCLUSIONS

Although these findings do not support a primary aetiological role for EBV and HHV-6 in classical CTCL, the possibility remains that both viruses, particularly EBV, may act as potential cofactors in the development of CTCL.

Expression of Epstein-Barr virus in cutaneous T-cell lymphoma including mycosis fungoides

Cutaneous T-Cell lymphoma (CTCL) is a non-Hodgkin's lymphoma of unknown pathogenesis. Mycosis fungoides (MF) is a clinically determined subset of CTCL with intensive infiltration of lymphoma cells into the epidermis. To determine whether Epstein-Barr virus (EBV) is associated with these lymphoma cells, we performed mRNA in situ hybridization in 5 cases of CTCL and 7 cases of MF using an RNA probe transcribed from BamHI W fragment of EBV genome. These transcripts were detected in the majority of lymphoma cells in all cases examined. We also detected intensive hybridization signals on epidermal squamous cells contiguous to strong infiltration with lymphoma cells into the subcutaneous connective tissue. Similarly, positive signals were detected using the probes transcribed from the sequences of EBV-encoded small nonpolyadenylated RNAs-1 (EBER1) and EBV-determined nuclear antigen-2 (EBNA2). The EBNA2 latent membrane protein-1 (LMP1) and BZLF1 product (ZEBRA) were also detected by immunofluorescence staining using monoclonal antibodies. Further in the same experiment, we detected immunofluorescence of epidermal cells. EBV DNA was detected in all cases tested by DNA in situ hybridization. Moreover, we also identified the signals on epidermal cells via this technique. Polymerase chain reaction revealed amplified EBV DNA for most cases tested. Double staining with immunohistochemistry and RNA in situ hybridization showed that T-cell marker-positive cells, but not EBV-carrying B-cells, exhibited signals for the EB viral RNA. These findings suggest that EBV is involved in the neoplastic transformation of CTCL and MF.

Decreased expression of Fas (APO-1/CD95) on peripheral blood CD4+ T lymphocytes in cutaneous T-cell lymphomas

BACKGROUND

The usually protracted and indolent course of cutaneous T-cell lymphoma (CTCL) is consistent with an accumulation of lymphocytes rather than being a true proliferative disorder, perhaps as the result of defective lymphocyte apoptosis. Fas (CD95) is the main signalling membrane molecule involved in postactivation T-lymphocyte apoptosis.

OBJECTIVES

To evaluate expression of Fas on circulating CD4+ lymphocytes in patients with CTCL.

METHODS

Fas expression on peripheral blood CD4+ T cells in 16 patients with mycosis fungoides (patch and infiltrated plaque stages) and in four patients with Sézary syndrome was compared with that in 25 matched patients with lymphocyte-mediated cutaneous benign inflammatory disorders and in 15 subjects without inflammatory cutaneous diseases.

RESULTS

Fas expression on peripheral CD4+ lymphocytes was significantly lower in patients with CTCL compared with subjects with benign inflammatory cutaneous disorders and with healthy donors.

CONCLUSIONS

This pattern supports the hypothesis that a defect in T-cell apoptosis may play a part in the pathophysiology of CTCL, perhaps through abnormalities of the Fas/Fas ligand system. Alternatively, this decrease could be the result of the presence of the soluble Fas ligand molecule in the sera of patients with CTCL.

A Novel Epstein-Barr Virus-Like Virus, HVMNE, in aMacaca Nemestrina With Mycosis Fungoides

Epstein-Barr virus (EBV) infection of humans has been associated with the development of lymphoid malignancies mainly of B-cell lineage, although occasionally T-cell lymphomas have been reported. We describe here the characterization of a novel EBV-like virus (HVMNE) isolated from a simian T-cell lymphotropic virus type I/II (STLV-I/II) seronegative pigtailed macaque (Macaca nemestrina) with a cutaneous T-cell lymphoma. Immunohistochemistry studies on the skin lesions demonstrated that the infiltrating cells were of the CD3+/CD8+ phenotype. Two primary transformed CD8+ T-cell lines were obtained from cultures of peripheral blood mononuclear cells (PBMC) and skin, and, with time, both cell lines became interleukin-2–independent and acquired the constitutive activation of STAT proteins. Polymerase chain reaction analysis of the DNA from the cell lines and tissues from the lymphomatous animal demonstrated the presence of a 536-bp DNA fragment that was 90% identical to EBV polymerase gene sequences, whereas the same DNA was consistently negative for STLV-I/II sequences. Electron microscopy performed on both cell lines, after sodium butyrate treatment, showed the presence of a herpes-like virus that was designated HVMNE according to the existing nomenclature. In situ hybridization studies using EBV Epstein-Barr viral-encoded RNA probes showed viral RNA expression in both CD8+ T-cell lines as well as in the infiltrating CD8+ T cells of skin-tissue biopsies. Phylogenetic analysis of a 465-bp fragment from the polymerase gene of HVMNE placed this virus within theLymphocryptovirus genus and demonstrated that HVMNEis a distinct virus, clearly related to human EBV and other EBV-like herpesviruses found in nonhuman primates.

A Novel Epstein-Barr Virus-Like Virus, HVMNE, in aMacaca Nemestrina With Mycosis Fungoides

Epstein-Barr virus (EBV) infection of humans has been associated with the development of lymphoid malignancies mainly of B-cell lineage, although occasionally T-cell lymphomas have been reported. We describe here the characterization of a novel EBV-like virus (HVMNE) isolated from a simian T-cell lymphotropic virus type I/II (STLV-I/II) seronegative pigtailed macaque (Macaca nemestrina) with a cutaneous T-cell lymphoma. Immunohistochemistry studies on the skin lesions demonstrated that the infiltrating cells were of the CD3+/CD8+ phenotype. Two primary transformed CD8+ T-cell lines were obtained from cultures of peripheral blood mononuclear cells (PBMC) and skin, and, with time, both cell lines became interleukin-2–independent and acquired the constitutive activation of STAT proteins. Polymerase chain reaction analysis of the DNA from the cell lines and tissues from the lymphomatous animal demonstrated the presence of a 536-bp DNA fragment that was 90% identical to EBV polymerase gene sequences, whereas the same DNA was consistently negative for STLV-I/II sequences. Electron microscopy performed on both cell lines, after sodium butyrate treatment, showed the presence of a herpes-like virus that was designated HVMNE according to the existing nomenclature. In situ hybridization studies using EBV Epstein-Barr viral-encoded RNA probes showed viral RNA expression in both CD8+ T-cell lines as well as in the infiltrating CD8+ T cells of skin-tissue biopsies. Phylogenetic analysis of a 465-bp fragment from the polymerase gene of HVMNE placed this virus within theLymphocryptovirus genus and demonstrated that HVMNEis a distinct virus, clearly related to human EBV and other EBV-like herpesviruses found in nonhuman primates.