Analysis of African Burkitt's and high-grade B cell non-Burkitt's lymphoma for Epstein-Barr virus genomes using in situ hybridization

Worldwide Prevalence of Epstein-Barr Virus in Patients with Burkitt Lymphoma: A Systematic Review and Meta-Analysis

Burkitt lymphoma (BL) is a form of B-cell malignancy that progresses aggressively and is most often seen in children. While Epstein-Barr virus (EBV) is a double-stranded DNA virus that has been linked to a variety of cancers, it can transform B lymphocytes into immortalized cells, as shown in BL. Therefore, the estimated prevalence of EBV in a population may assist in the prediction of whether this population has a high risk of increased BL cases. This systematic review and meta-analysis aimed to estimate the prevalence of Epstein-Barr virus in patients with Burkitt lymphoma. Using the appropriate keywords, four electronic databases were searched. The quality of the included studies was assessed using the Joanna Briggs Institute's critical appraisal tool. The results were reported as percentages with a 95% confidence interval using a random-effects model (CI). PROSPERO was used to register the protocol (CRD42022372293), and 135 studies were included. The prevalence of Epstein-Barr virus in patients with Burkitt lymphoma was 57.5% (95% CI: 51.5 to 63.4, n = 4837). The sensitivity analyses demonstrated consistent results, and 65.2% of studies were of high quality. Egger's test revealed that there was a significant publication bias. EBV was found in a significantly high proportion of BL patients (more than 50% of BL patients). This study recommends EBV testing as an alternative for predictions and the assessment of the clinical disease status of BL.

EPSTEIN -BARR VIRUS ASSOCIATION WITH MALIGNANT LYMPHOMA SUBGROUPS IN ZARIA, NIGERIA

Epstein-Barr virus (EBV) is said to infect more than 90% of humans worldwide with latent infection for life. A recognized carcinogen, EBV is linked to malignant lymphoma (ML) subtypes of Burkitt's lymphoma (BL), plasmablastic lymphoma, diffuse large cell lymphoma (DLBCL) and Hodgkin's lymphoma (HL). We report the association of EBV with ML in a segment of our patient population. Paraffin blocks from the archives of ABUTH, Zaria were used to construct tissue microarray sections stained using 30 monoclonal antibodies for common Non-Hodgkin's lymphoma/ Hodgkin's lymphoma antigen and chromogenic in situ hybridization (CISH) for EBV-encoded RNA were done. Fewer associations of ML with EBV were found than reported from elsewhere in Africa.

Oral manifestations of sexually transmitted diseases

Sexually transmitted diseases frequently affect the mucous membranes producing characteristic and potentially diagnostic lesions on the oral mucosa. This article reviews the classic route of transmission and the corresponding clinical presentation of several of the sexually transmitted viruses, including herpes virus types I and II, Epstein Barr virus, cytomegalovirus, human papilloma virus, molluscum contagiosum, as well as the human immunodeficiency virus. Bacterial infections such as syphilis, gonorrhea, as well as the fungus candida are reviewed under the umbrella of STDs with potential oral involvement encountered in the sexually active patient.

Early Stage of Epstein-Barr Virus Lytic Infection Leading to the “Starry Sky” Pattern Formation in Endemic Burkitt Lymphoma

Context.—Burkitt lymphoma (BL) is histologically characterized by a “starry sky” appearance, representing scattered macrophages that have phagocytosed cell debris among proliferating lymphoma cells. As is well known, almost all the neoplastic cells of endemic BL are infected with Epstein-Barr virus (EBV). Previous studies have indicated that most of the EBV in B cells is latent, and few virus particles enter the lytic cycle.

Objective.—To examine the histologic relationship between EBV infection stages and the formation of the starry sky pattern in African endemic BL tissues.

Design.—Tissue samples from 44 patients with African endemic BL were examined with immunohistochemistry and in situ hybridization. We used EBV-encoded small RNA (EBER) as a marker of latent infection, and BamHI H left frame 1 (BHLF1) and BamHI Z EBV replication activator (ZEBRA) as lytic cycle markers.

Results.—In all cases, signals for EBER were found in most neoplastic lymphocytes, and in 73% of cases, signals for BHLF1 and/or ZEBRA were recognized in the lymphoma cells within and around the lacunae in starry sky figures. The mean number of lacunae per unit area in cases positive for lytic cycle markers was significantly higher than that in negative cases (P < .001).

Conclusions.—Our findings suggest that EBV-infected lymphoma cells in the lytic cycle, which eventually lapse into cell death, are phagocytosed prior to their rupture by macrophages that have migrated into the parenchyma. We emphasize that transition of EBV-infected lymphoma cells to the lytic cycle is one of the histomorphogenetic factors influencing the formation of starry sky pattern in endemic BL.

Viral diseases of the oral mucosa

A wide variety of both DNA and RNA viruses affect the oral cavity. When considered in conjunction with cutaneous features, careful examination of the oral mucosa and oropharynx aids the clinician in making a diagnosis. Examination of the oral cavity should be incorporated as a regular component of the dermatologic examination because diagnostic clues are readily available to assist in the evaluation of infectious processes.

Analysis of single EBER-positive and negative tumour cells in EBV-harbouring B-cell non-Hodgkin lymphomas

In situ hybridization for Epstein-Barr virus (EBV) encoded small nuclear RNAs (EBERs) is the method of choice for the detection of EBV infection at the single cell level. With the application of this technique it was shown that non-Hodgkin's lymphomas of B-cell type may be associated with an EBV infection of tumour cells. Interestingly, in many EBV-positive cases, only a proportion of the tumour cell population has been found to be EBER-positive. To clarify whether EBV is absent or whether EBER gene expression is downregulated in EBER-negative tumour cells, single EBER-positive and negative tumour cells were isolated from paraffin sections from four B-cell non-Hodgkin's lymphoma cases with partial EBER expression in the neoplastic cells. These single cells were then screened for the presence of EBV DNA by a nested single cell PCR. EBV DNA was undetectable in all but one of the 86 EBER-negative cells, whereas in the EBER-positive cells EBV-specific DNA amplificates could be generated following single cell PCR. This finding prompts the conclusion that the inability to detect EBERs in a proportion of tumour cells is not due to a down-regulation of gene expression but to a real absence of EBV from these cells. This partial absence of EBV is thought to be caused by a loss of the EBV episomes during cell division, rather than by infection of only a proportion of the tumour cells.

Absence of Epstein-Barr virus encoded RNA and latent membrane protein (LMP1) in salivary gland neoplasms

A series of 55 (42 benign and 13 malignant) salivary gland tumours were investigated by immunohistochemistry, to detect Epstein-Barr virus (EBV) latent membrane protein (LMP1) and by in situ hybridization for EBV-encoded RNA. Non-neoplastic gland from all the patients with tumours and 15 control glands were also examined. All cases, both neoplastic and non-neoplastic were negative for LMP1 and failed to show any positive signal by in situ hybridization for EBV RNA. One undifferentiated carcinoma from a European patient was included in the group. These results confirm previous reports of an ethnic association between EBV and undifferentiated carcinomas of the salivary gland. They do not support an aetiological role for EBV in other salivary gland tumours.

Association between Epstein-Barr virus and Burkitt's lymphoma in Taiwan

BACKGROUND

The association between Epstein-Barr virus (EBV) and Burkitt's lymphoma (BL) in Taiwan is not clear. In this study, the authors attempted to determine the frequency of the occurrence of EBV infection in patients with BL in Taiwan.

METHODS

A retrospective study was performed using a nonisotopic in situ hybridization technique to detect the presence of EBV-encoded small RNAs (EBERs) in paraffin embedded BL tissues. Tissues of other types of B-cell non-Hodgkin's lymphoma (NHL) were used as controls. Immunohistochemical staining was performed to examine the presence of an EBV-encoded protein, latent membrane protein (LMP), and p53 in specimens.

RESULTS

EBERs were detectable in 10 of 18 BL specimens. It was present in the cervical lymph nodes (LNs) in six of the seven cases of cervical tumors, in the maxillary region in one case, in one of two cases of axillary LNs, and in the abdominal tumors in two of the seven cases of intraabdominal disease. EBER positive cells were diffusely present in all tumors except in one abdominal BL, in which only a few EBER positive cells were scattered in a small part of the tumor. EBER positive cells were not detected in the case with BL in an inguinal LN and in the seven cases with intraabdominal tumors. Immunohistochemical studies showed that LMP and p53 were expressed in 3 and 4 of the 18 cases, respectively. In another 20 NHLs in peripheral LNs, EBERs were detectable in only 1 case of diffuse large cell histology with numerous reactive T cells in which only large tumor cells expressed EBERs and LMP. EBERs were not detected in any of the ten cases of extranodal NHL.

CONCLUSIONS

In Taiwan, EBV is frequently associated with BL occurring outside the abdomen but rarely with intraabdominal BL. The overall association between EBV and BL in Taiwan is intermediate compared with other regions of the world. These results support the theory that the frequency of EBV associated with BL is influenced by the endemicity of EBV and/or the socioeconomic status of a country.

Primary mediastinal large B-cell lymphoma. A clinicopathologic study of 141 cases compared with 916 nonmediastinal large B-cell lymphomas, a GELA ("Groupe d'Etude des Lymphomes de l'Adulte") study

Among non-Hodgkin's lymphomas, primary mediastinal large B-cell lymphoma (PMLCL) has been considered a separate entity that has specific clinical and histological aspects and a poor prognosis. In this study, we reexamined the clinicopathologic features and the response to current treatment of 141 PMLCL and compare them with 916 nonmediastinal large B-cell lymphomas (NMLCL) recorded in the same period and treated with similar combined chemotherapy. The clinical features of PMLCL at diagnosis were largely homogeneous and distinct from NMLCL, with a predilection for young women (59% with a mean age of 37 years versus 42% with a mean age of 54 years), bulky tumor (77% versus 7%, p < 10(4)), high serum lactic dehydrogenase (LDH) level 76% versus 51%, p < 10(4)), and frequent intrathoracic extension to adjacent organs such as pleura, pericardium, and lung. By contrast, extrathoracic or hematologic dissemination was uncommon (2% of bone marrow involvement versus 17%). All patients had diffuse large B-cell nonimmunoblastic, nonanaplastic lymphomas. Histological analysis of the 141 PMLCL evaluated two common patterns: the presence of large cells with clear cytoplasm (found in 38% of cases) and the presence of fibrosis (marked in 25% of cases). The presence of clear cells or intense fibrosis did not constitute prognostic indicators. Immunologic and molecular analysis assessed the profile of bcl-2 expression and the presence of Epstein-Barr virus (EBV) in PMLCL: 30% expressed a high level of bcl-2 protein; EBER RNAs were detected by in situ hybridization in only two of the 41 cases tested. Monotypic light chain restriction could be demonstrated in seven of the 41 PMLCL tested on fixed-section. Treated with polychemotherapy regimens without radiotherapy, 79% of PMLCL patients achieved a complete remission compared with 68% in the NMLCL patient group (p = 0.01). Overall, 3-year survival rates were estimated at 66 and 61%, respectively (p = 0.05), and disease-free survival rates were not significantly different (61 versus 64%). Stratified analysis on the International Prognostic Index (based on age, tumor stage, serum LDH level, and performance status) showed no difference in the overall and disease-free survivals between the two lymphoma groups. In conclusion, PMLCL can be combined with other diffuse large B-cell lymphomas on morphologic grounds; it is not associated with EBV. It responds favorably to treatment and should be managed like other high-grade lymphomas of equivalent histology. However, the uncommon clinical presentation makes it a distinct entity.

B lymphocytes with latent EBV infection appearing in long-term bone marrow cultures (HLTBMCs) from haematological patients induce lysis of stromal microenvironment

Human long-term bone marrow cultures (HLTBMCs) are a valuable in vitro model for studying the role of the haemopoietic microenvironment. Here we report the spontaneous appearance of EBV-positive B cells in 6/40 HLTBMCs from patients with various haematological diseases after 3-5 months of culture. After subcultivation of these cells, a novel type of cell line could be characterized, which displayed surface markers and morphological features typical for EBV transformed B-cell lines. As the deproteinized and ultrafiltrated culture supernatants of these cell lines were found to contain an agent with stroma toxic properties, they were termed SSB lines (stroma-toxic-agent-secreting B-cell lines). This agent also exhibited a colony-inhibitory activity on in vitro myelopoiesis and erythropoiesis. These properties are typical for the two polyamines spermine and spermidine which were detected at elevated levels in the culture supernatants of SSB lines. The hypothesis that latent presence of EBV in bone marrow may induce an increased synthesis of spermine and spermidine, which are known to be associated with malignant haematological diseases and bone marrow aplasia, is discussed.

Correlation between cytopathological results and in situ hybridisation on needle aspiration biopsies of suspected African Burkitt's lymphomas

Burkitt's lymphoma (BL) is a very high-incidence malignancy in sub-Saharan Africa, where it targets mainly young children. This lymphoma is closely associated with Epstein-Barr virus (EBV). Diagnosis of BL relies on clinical presentation as well as histological results obtained from biopsies. In this report, 66 new patients from Malawi (one of the southernmost African countries with high-incidence BL), suspected on clinical grounds to present with BL, had fine needle aspiration biopsies taken, smeared on slides and used for May-Grünwald Giemsa staining. Duplicate slides were independently assessed for EBV presence and expression by DNA-DNA and/or RNA-RNA in situ hybridisation (ISH), using respectively the repetitive viral BamHIW DNA fragment in a biotinylated probe and the small EBV-encoded RNA EBER I in a digoxigenin-labelled riboprobe. There was very good correlation between the various techniques in the diagnosis of the lymphomas, showing 67% of clinically suspect cases to be BL. Our report, presenting data on BL in Malawi, illustrates the usefulness of a simple aspiration biopsy in the diagnosis of this malignancy by Giemsa staining and also in both types of ISH.

Detection of Epstein Barr virus in an hepatic leiomyomatous neoplasm in an adult human immunodeficiency virus 1-infected patient

We report the first case of a human immunodeficiency virus (HIV)-related primary hepatic leiomyoma in an adult patient. The diagnosis was made at autopsy and confirmed by immunohistochemistry. Epstein Barr virus (EBV) was identified in tumour cells by in situ hybridization. Review of the literature revealed 13 cases of visceral myogenic tumours occurring in acquired immunodeficiency syndrome children, and only 2 cases in adults. One was a spinal epidural leiomyoma, the other multiple smooth muscle tumours of the colon and adrenal gland. This is the first report of EBV in smooth muscle neoplastic cells in an HIV-infected adult patient.

Detection of Epstein-Barr virus small RNAs in routine paraffin sections using non-isotopic RNA/RNA in situ hybridization

The Epstein-Barr virus (EBV) is associated with an increasing range of reactive and neoplastic lesions. There is a need for a sensitive and specific method for detecting latent EBV in routine histological sections. We report the use of a highly sensitive paraffin section RNA/RNA in situ hybridization (ISH) technique using digoxigenin-labelled antisense riboprobes for demonstrating EBV encoded small RNAs (EBERs), EBV gene products that are transcribed in abundance during latent EBV infection. We applied EBER-ISH to 846 paraffin embedded specimens, including cases of reactive lymphoid hyperplasia (n = 28), infectious mononucleosis (16), Burkitt's lymphoma (44), immunodeficiency-associated lymphomas in transplant recipients (9) and AIDS patients (128), Hodgkin's disease (130), CD30 antigen positive lymphomas (106), peripheral T-cell lymphomas (104), sporadic B-cell non-Hodgkin's lymphomas (162), undifferentiated nasopharyngeal carcinoma (86), salivary gland lymphoepithelioma (11), and oral hairy leukoplakia (5). Strong, reproducible EBER staining was seen in EBV latently infected cells in archival surgical biopsy and autopsy specimens. EBER-ISH is specific, has a sensitivity comparable to that of the polymerase chain reaction, and is now the method of choice for the in situ detection of latent EBV infection.

Detection of Epstein-Barr virus genome in primary cutaneous T and B cell lymphomas and pseudolymphomas

The Epstein-Barr virus (EBV) genome has recently been identified in Hodgkin's disease (HD) and nodal non-Hodgkin's lymphomas (NHL). In order to elucidate the possible aetiopathogenetic role of EBV in benign and malignant lymphoproliferative disorders we investigated skin specimens from 24 patients with a primary cutaneous lymphoproliferative disorders (10 T-cell lymphomas 6 B-cell lymphomas and 8 pseudolymphomas) and from 22 normal individuals for the presence of EBV DNA using the polymerase chain reaction (PCR) technique and in situ hybridization (ISH) on formalin-fixed paraffin-embedded tissue sections. EBV DNA was identified by PCR in one of two cases of mycosis fungoides, in one of seven cases of pleomorphic T-cell lymphomas, in one case of centroblastic (CB) lymphoma of six B-cell lymphomas, and in three of eight pseudolymphomas. The EBV genome was also found in 2 of 22 specimens of normal skin. The small EBV-encoded nuclear RNAs, EBERs, were not detected in any PCR-positive sample by ISH. Based on our PCR and ISH findings, EBV does not seem to play a significant role in the development of cutaneous lymphomas.