Nasal natural killer/T-cell lymphoma and its association with type "i"/XhoI loss strain Epstein-Barr virus in Chile

What Effect Does Epstein-Barr Virus Have on Extranodal Natural Killer/T-Cell Lymphoma Prognosis? A Review of 153 Reported Cases

The primary aim of this review is to identify the relationship between Epstein-Barr virus (EBV) and prognosis in extranodal natural killer/T-cell lymphoma (ENKTL). Additionally, a literature review of ENKTL was carried out. The investigators designed and implemented a 21-year literature review using the online databases PubMed and Google Scholar. The total number of cases analyzed was 153 (64 case reports; one comparative study; one systematic review). Information related to ENKTL from July 1999 to February 2021 was included in the study. Study variables included: patient demographics, tumor classification, screening modalities, tumor characteristics, symptomatology, treatment, and prognosis. The average age at diagnosis was 50.9 years (range: 4-90 years). Patients of Asian ethnicity were most commonly affected, and there was a 1.6:1 male to female ratio. ENKTL was most frequently detected in the head and neck region, and 53.1% of cases metastasized. Of all head and neck cases, the nose was the most affected location. Immunohistochemistry positivity included: EBV (32.0%), CD2 (96.6%), CD3ϵ (81.7%), CD43 (91.7%), CD56 (86.4%), Granzyme (97.1%), Perforin (90.9%), TIA-1 (97.8%), p53 (33.3%). The most frequently employed single treatment modality was chemotherapy alone, and 34.2% of patients expired within five years of diagnosis. The average follow-up period was 16.51 months (range: 0.25-66 months). EBV was significantly associated with metastatic ENKTL (χ² = 4.36; CV = 3.84; p = 0.037). We found no association between EBV and ENKTL prognosis (χ² = 17.2; CV = 21.0; p = 0.14).

EBV and the Pathogenesis of NK/T Cell Lymphoma

Epstein-Barr virus (EBV) is a ubiquitous gamma herpes virus with tropism for B cells. EBV is linked to the pathogenesis of B cell, T cell and NK cell lymphoproliferations, with extranodal NK/T cell lymphoma, nasal type (ENKTCL) being the prototype of an EBV-driven lymphoma. ENKTCL is an aggressive neoplasm, particularly widespread in East Asia and the native population of Latin America, which suggests a strong genetic predisposition. The link between ENKTCL and different populations has been partially explored. EBV genome sequencing analysis recognized two types of strains and identified variants of the latent membrane protein 1 (LMP1), which revealed different oncogenic potential. In general, most ENKTCL patients carry EBV type A with LMP1 wild type, although the LMP1 variant with a 30 base pair deletion is also common, especially in the EBV type B, where it is necessary for oncogenic transformation. Contemporary high-throughput mutational analyses have discovered recurrent gene mutations leading to activation of the JAK-STAT pathway, and mutations in other genes such as BCOR, DDX3X and TP53. The genomic landscape in ENKTCL highlights mechanisms of lymphomagenesis, such as immune response evasion, secondary to alterations in signaling pathways or epigenetics that directly or indirectly interfere with oncogenes or tumor suppressor genes. This overview discusses the most important findings of EBV pathogenesis and genetics in ENKTCL.

EBV miR-BARTs and human lncRNAs: Shifting the balance in competing endogenous RNA networks in EBV-associated gastric cancer

Non-coding RNAs (ncRNAs) contribute to the regulation of gene expression. By acting as competing endogenous RNA (ceRNA), long non-coding RNAs (lncRNAs) hijack microRNAs (miRNAs) and inhibit their ability to bind their coding targets. Viral miRNAs can compete with and target the same transcripts as human miRNAs, shifting the balance in networks associated with multiple cellular processes and diseases. Epstein-Barr virus (EBV) is an example of how a subset of viral coding RNA and non-coding RNAs can cause deregulation of human transcripts and contribute to the development of EBV-associated malignancies. EBV non-coding transforming genes include lncRNAs (i.e circular RNAs), and small ncRNAs (i.e. miRNAs). Among the latter, most ongoing research has focused on miR-BARTs whereas target many genes associated with apoptosis and epithelial-mesenchymal transition, in EBV-associated gastric cancer (GC). In this review, we propose to include the interactions between EBV ncRNAs human transcripts in the hypothesis known as "competitive viral and host RNAs". These interactions may shift the balance in biological pathways such as apoptosis and epithelial-mesenchymal transition in EBV-associated gastric cancer.

Lymphotropic Viruses EBV, KSHV and HTLV in Latin America: Epidemiology and Associated Malignancies. A Literature-Based Study by the RIAL-CYTED

The Epstein-Barr virus (EBV), Kaposi sarcoma herpesvirus (KSHV) and human T-lymphotropic virus (HTLV-1) are lymphomagenic viruses with region-specific induced morbidity. The RIAL-CYTED aims to increase the knowledge of lymphoma in Latin America (LA), and, as such, we systematically analyzed the literature to better understand our risk for virus-induced lymphoma. We observed that high endemicity regions for certain lymphomas, e.g., Mexico and Peru, have a high incidence of EBV-positive lymphomas of T/NK cell origin. Peru also carries the highest frequency of EBV-positive classical Hodgkin lymphoma (HL) and EBV-positive diffuse large B cell lymphoma, not otherwise specified (NOS), than any other LA country. Adult T cell lymphoma is endemic to the North of Brazil and Chile. While only few cases of KSHV-positive lymphomas were found, in spite of the close correlation of Kaposi sarcoma and the prevalence of pathogenic types of KSHV. Both EBV-associated HL and Burkitt lymphoma mainly affect young children, unlike in developed countries, in which adolescents and young adults are the most affected, correlating with an early EBV seroconversion for LA population despite of lack of infectious mononucleosis symptoms. High endemicity of KSHV and HTLV infection was observed among Amerindian populations, with differences between Amazonian and Andean populations.

Extranodal NK/T-cell lymphoma, nasal type without evidence of EBV infection

Extranodal natural killer/T cell lymphoma-nasal type (EN-NK/T-NT) is extremely rare in Western countries; however, it is the most common subtype of peripheral T cell lymphoma in China. Despite this, there are a limited number of clinicopathological research studies on Epstein-Barr virus (EBV)-negative EN-NK/T-NTs. EBV-negative EN-NK/T-NT is a rare disease type, which has not been fully investigated. If other diagnostic criteria are met, such as the lesions being located predominantly in the upper aerodigestive tract, the presence of angiocentricity or angioinvasion, necrosis and expression of NK/T-cell phenotype, EN-NK/T-NT may be diagnosed, even if EBV is negative. In the present study, 99 cases of EN-NK/T-NTs were analyzed retrospectively, among which seven cases were EBV-negative EN-NK/T-NTs and selected for further investigation. In addition, the present study reviewed previously published research into EN-NK/T-NT, highlighting that EBV-negative EN-NK/T-NT is rare and that its geographical distribution is mainly in countries in Asia, Central America and South America. Patients with EBV-negative EN-NK/T-NT were all of Chinese ethnicity, with a median age of 32 years and primarily female. Furthermore, these patients shared similar clinicopathological characteristics (such as the tumor occurring mainly in the upper aerodigestive tract, the presence of vascular destruction, necrosis and cytotoxic phenotypes) to patients with EBV-positive EN-NK/T-NT. Immunohistochemistry and molecular analysis results indicated that tumor cells were primarily of NK or cytotoxic T origin; however, EBV-encoded small RNAs were not detected in any of these cases. Among the immunochemistry markers, T-bet was statistical significantly different between EBV-positive and -negative cases. Fluorescence in situ hybridization was also performed in two EBV-negative cases, including one case with a co-deletion of 6q21 and PR/SET domain 1 genes. There was only available follow-up data in 3/5 patients who survived for 37–113 months (median, 40 months). As EN-NK/T-NT can be diagnosed, even when EBV is negative, awareness of this subtype may prevent misdiagnosis or delayed diagnosis.

Genome-Wide Analysis of Epstein-Barr Virus Isolated from Extranodal NK/T-Cell Lymphoma, Nasal Type

BACKGROUND

Extranodal natural killer (NK) cell/T-cell lymphoma (NKTCL), a rare type of non-Hodgkin's lymphoma, has strongly been associated with Epstein-Barr virus (EBV) infection. However, there are no EBV genomes isolated from NKTCL, and the roles the variations of EBV strains play in the pathogenesis of NKTCL are still unclear.

MATERIALS AND METHODS

In this study, whole EBV genomes from eight primary NKTCL biopsy specimens were obtained using next-generation sequencing, designated NKTCL-EBV1 to NKTCL-EBV8.

RESULTS

Compared with the six mostly referenced EBV strains, NKTCL-EBVs closely resemble the GD1 strain but still harbor 2,072 variations, including 1,938 substitutions, 58 insertions, and 76 deletions. The majority of nonsynonymous mutations were located in latent and tegument genes. Moreover, the results from phylogenetic analysis of whole NKTCL genomes and specific genes demonstrated that all the NKTCL-EBVs were related to Asian EBV strains. Based on the amino acid changes in certain residues of latent membrane protein 1 (LMP1) and EBV-determined nuclear antigen 1 (EBNA1), all the NKTCL-EBVs were sorted to China 1 and V-val subtype, respectively. Furthermore, changes in CD4+ and CD8+ T-cell epitopes of EBNA1 and LMP1 may affect the efficacy for a cytotoxic T lymphocyte (CTL)-based therapy.

CONCLUSION

This is the first large study to our knowledge to obtain EBV genomes isolated from NKTCL and show the diversity of EBV genomes in a whole genome level by phylogenetic analysis.

IMPLICATIONS FOR PRACTICE

In this study, the full-length sequence of Epstein-Barr virus (EBV) isolated from eight patients with nasal natural killer/T-cell lymphoma (NKTCL) was determined and further compared with the sequences previously reported isolated from other malignancies. Phylogenetic analysis showed that NKTCL-EBV strains are close to other Asian subtypes instead of non-Asian ones, leading to the conclusion that EBV infections are more likely affected by different geographic regions rather than particular EBV-associated malignancies. Therefore, these data have implications for the development of effective prophylactic and therapeutic vaccine approaches targeting the personalized or geographic-specific EBV antigens in these aggressive diseases.

Epstein-Barr virus-negative extranodal "true" natural killer-cell lymphoma harbouring a KDM6A mutation

Extranodal natural killer (NK)/T-cell lymphoma, nasal type (ENKTL) is an extranodal aggressive T or NK-cell lymphoma that is characteristically associated with Epstein-Barr virus (EBV) infection and cytotoxic tissue-destructive features. Although ENKTL is described as a distinct entity according to the 2008 WHO classification, a considerable complexity is associated with the differential diagnosis of other T-cell lymphomas with respect to tumour cell origins, locations, and the presence of EBV infection, as well as molecular and cytogenetic abnormalities. Here, we report a rare case of EBV-negative ENKTL, where the absence of EBV in the true NK-lineage cells was confirmed by extensive phenotypic and genotypic analyses. Furthermore, using the next-generation sequencing approach, we identified mutations in the tumour suppressor genes KDM6A and TP53. The clinicopathological characteristics were almost similar to those of EBV-positive ENKTL, except for the absence of EBV and histologically apparent angioinvasiveness. This is the first reported ENKTL case with mutations in the KDM6A gene. KDM6A is one of the histone-modifying genes that are mutated in many human diseases including haematological cancers. Epigenetic regulation of gene expression has recently been demonstrated in ENKTL, and a similar pathway is thought to play an oncogenic role in EBV-negative ENKTL. Our report shows the extent of comprehensive examination required before making a definitive diagnosis for NK- and T-cell neoplasms and broadens the therapeutic options for potential targets.

Epstein-Barr virus strains and variations: Geographic or disease-specific variants?

The Epstein-Barr Virus (EBV) is associated with the development of several diseases, including infectious mononucleosis (IM), Burkitt's Lymphoma (BL), Nasopharyngeal Carcinoma, and other neoplasias. The publication of EBV genome 1984 led to several studies regarding the identification of different viral strains. Currently, EBV is divided into EBV type 1 (B95-8 strain) and EBV type 2 (AG876 strain), also known as type A and type B, which have been distinguished based upon genetic differences in the Epstein-Barr nuclear antigens (EBNAs) sequence. Several other EBV strains have been described in the past 10 years considering variations on EBV genome, and many have attempted to clarify if these variations are ethnic or geographically correlated, or if they are disease related. Indeed, there is an increasing interest to describe possible specific disease associations, with emphasis on different malignancies. These studies aim to clarify if these variations are ethnic or geographically correlated, or if they are disease related, thus being important to characterize the epidemiologic genetic distribution of EBV strains on our population. Here, we review the current knowledge on the different EBV strains and variants and its association with different diseases. J. Med. Virol. 89:373-387, 2017. © 2016 Wiley Periodicals, Inc.

Predictors of survival of natural killer/T-cell lymphoma, nasal type, in a non-Asian population: a single cancer centre experience

Background

Natural killer/T-cell lymphoma (NKTCL), part of T-cell and NK-cell neoplasms in the World Health Organisation (WHO) classification, is an aggressive lymphoma with poor prognosis more predominantly seen in Asian and South American countries. This study evaluates the factors associated with survival among patients with newly diagnosed NKTCL in Peru.

Methods

Information was abstracted from medical records (MR) for all NKTCL patients >13 years of age at the Instituto Nacional de Enfermedades Neoplasicas (INEN) between 2002 and 2011. The estimate of the survival curves was performed by the Kaplan-Meier method, and the difference was computed by the log-rank test.

Results

Around 226 MR were reviewed, 153 met the selection criteria, the median age was 40 years (14–84). The median progression-free survival (PFS) was 20 months, five year PFS was 42.6%, univariable analysis (UA) showed statistical significance (p < 0.05) for male sex, non-nasal primary site, advanced clinical stages, B symptoms, poor performance status, regional nodal involvement (RNI). In the multivariate analysis the only poor prognostic factors was primary non-nasal (Hazard ratio (HR) = 2.40, 95% confidence interval (CI) = 1.43– 4.02, P = 0.01). The median overall survival (OS) was 49 months, five year OS was 48.9%, UA showed statistical significance for non-nasal primary site, advanced clinical stages, B symptoms, lactate dehydrogenase (LDH) > normal, RNI and local tumour invasion. In the multivariate analysis, primary non-nasal was the only poor prognostic factor with HR = 2.57, 95% CI = 1.37–4.83, P = 0.03.

Conclusions

In Peru, OS of NKTCL is similar to other countries. This result suggests that non-nasal NKTCL is the only poor prognostic factor of OS and PFS.

Pitfalls and major issues in the histologic diagnosis of peripheral T-cell lymphomas: results of the central review of 573 cases from the T-Cell Project, an international, cooperative study

Peripheral T-cell lymphomas (PTCLs) comprise a heterogeneous group of neoplasms that are derived from post-thymic lymphoid cells at different stages of differentiation with different morphological patterns, phenotypes and clinical presentations. PTCLs are highly diverse, reflecting the diverse cells from which they can originate and are currently sub-classified using World Health Organization (WHO) 2008 criteria. In 2006 the International T-Cell Lymphoma Project launched the T-Cell Project, building on the retrospective study previously carried on by the network, with the aim to prospectively collect accurate data to improve knowledge on this group of lymphomas. Based on previously published reports from International Study Groups it emerged that rendering a correct classification of PTCLs is quite difficult because the relatively low prevalence of these diseases results in a lack of confidence by most pathologists. This is the reason why the T-Cell Project requested the availability of diagnostic material from the initial biopsy of each patient registered in the study in order to have the initial diagnosis centrally reviewed by expert hematopathologists. In the present report the results of the review process performed on 573 cases are presented. Overall, an incorrect diagnosis was centrally recorded in 13.1% cases, including 8.5% cases centrally reclassified with a subtype eligible for the project and 4.6% cases misclassified and found to be disorders other than T-cell lymphomas; 2.1% cases were centrally classified as T-Cell disorders not included in the study population. Thus, the T-Cell Project confirmed the difficulties in providing an accurate classification when a diagnosis of PTCLs is suspected, singled out the major pitfalls that can bias a correct histologic categorization and confirmed that a centralized expert review with the application of adequate diagnostic algorithms is mandatory when dealing with these tumours. Copyright © 2016 John Wiley & Sons, Ltd.

Genotypic analysis and latent membrane protein 1 expression of Epstein-Barr virus in extranodal NK/T-cell lymphoma from Northern Chinese patients

As the most common NK/T-cell lymphoma in Asian countries, extranodal NK/T-cell lymphoma, nasal type (ENKTL), has unique clinical features and a strong association with Epstein-Barr virus (EBV). In order to gain a preliminary understanding of the relationship between ENKTL and EBV, we performed genotypic analysis of EBV and investigated LMP1 expression in extranodal NK/T-cell lymphoma. Our study shows that ENKTL is an EBV-associated malignancy and that A, C and F are the predominant EBV genotypes in northern China. LMP1 expression is stronger in extranasal sites than nasal sites, and the expression level is strongly correlated to ENKTL and may play an important role in the development of ENKTL.

Increased expression of Trop2 correlates with poor survival in extranodal NK/T cell lymphoma, nasal type

Human trophoblastic cell surface antigen 2 (Trop2) has been suggested to play an important role in the development of solid tumors. However, the expression of Trop2 in extranodal NK/T cell lymphoma, nasal type (ENKTL) and the relationship with the clinical characteristics of this disease remain poorly understood. In this study, one-step quantitative PCR reverse transcription-polymerase chain reaction and immunohistochemical staining with tissue sections were employed to evaluate the expression of Trop2 in ENKTL. Furthermore, the relationship between Trop2 expression and prognosis of ENKTL was investigated. Expression of Trop2 mRNA and protein was significantly higher in ENKTL tissue than in corresponding non-lymphomatous tissue (p = 0.04 and p < 0.001, respectively). Expression of Trop2 protein in ENKTL was associated with lymph node involvement and poor overall survival (p = 0.045 and p = 0.018, respectively). Kaplan-Meier analysis and the logrank test indicated that lymph node involvement (p = 0.0481), single therapy strategy (p = 0.0037), and high expression of Trop2 (p = 0.0042) are significantly correlated with poor prognosis of ENKTL patients. The data suggest that Trop2 expression reflects a more malignant phenotype and may serve as an unfavorable prognostic factor for ENKTL.

Extranodal natural killer/T-cell lymphoma, nasal type: 'midline lethal granuloma.' A case report

Extranodal natural killer/T cell lymphoma, nasal type, is a non-Hodgkin lymphoma, most commonly affecting the nasal cavity, paranasal sinuses and nasopharynx. Clinically it is characterised by destruction of facial tissues, commencing in the midline. In most cases it arises from malignant transformation of natural killer cells (NK); sometimes from malignant transformation of cytotoxic T cells.Extranodal NK/T cell lymphoma, nasal type, is rare, but even more rare in black persons. The purpose of this article is to report a severe case of extranodal NK/T cell lymphoma, nasal type, in an elderly black male.

Aberrant antigenic expression in extranodal NK/T-cell lymphoma: a multi-parameter study from Thailand

Background

Extranodal NK/T-cell lymphoma, nasal type (ENKTL) is not common worldwide, but it is the most common T- and NK-cell lymphomas in many Asian countries. Immunophenotypic profiles were studied based on limited series. The authors, therefore, studied on ENKTL according to characterize immunophenotypic profiles as well as the distribution of EBV subtype and LMP-1 gene deletion.

Methods

By using tissue microarray (TMA), immunohistochemical study and EBV encoded RNA (EBER) in situ hybridization were performed. T-cell receptor (TCR) gene rearrangement, EBV subtyping, and LMP-1 gene deletion were studied on the available cases.

Results

There were 22 cases eligible for TMA. ENKTL were positive for CD3 (91%), CD5 (9%), CD7 (32%), CD4 (14%), CD56 (82%), TIA-1 (100%), granzyme B (95%), perforin (86%), CD45 (83%), CD30 (75%), Oct2 (25%), and IRF4/MUM1 (33%). None of them was positive for βF1, CD8, or CD57. TCR gene rearrangement was negative in all 18 tested cases. EBV was subtype A in all 15 tested cases, with 87% deleted LMP-1 gene. Cases lacking perforin expression demonstrated a significantly poorer survival outcome (p = 0.008).

Conclusions

The present study demonstrated TIA-1 and EBER as the two most sensitive markers. There were a few CD3 and/or CD56 negative cases noted. Interestingly, losses of CD45 and/or CD7 were not uncommon while Oct2 and IRF4/MUM1 could be positive in a subset of cases. Based on the present study in conjunction with the literature review, determination of PCR-based TCR gene rearrangement analysis might not be a useful technique for making diagnosis of ENKTL.

Primary NK/T cell lymphoma nasal type of the stomach with skin involvement: a case report

Since nasal NK/T cell lymphoma and NK/T cell lymphoma nasal type are rare diseases, gastric involvement has seldom been seen. We report a unique case of a patient with a primary NK/T cell lymphoma nasal type of the stomach with skin involvement. The patient had no history of malignant diseases and was diagnosed with hematemesis and intense bleeding from his gastric primary site. Shortly after this event, exanthemic skin lesions appeared with concordant histology to the primary site. Despite chemotherapy, the patient died one month after the first symptomatic appearance of disease.