The Epstein-Barr virus and nasopharyngeal carcinoma

Epstein Barr virus in Argentine pediatric Hodgkin's disease

Since Hodgkin's disease (HD) is an heterogeneous condition with diverse histological and epidemiological subgroups, it seemed worthwhile to investigate the Argentine pediatric pattern. Moreover, the presence of Epstein Barr virus (EBV) infection occurs at different ages depending on the development status of the country. Thus, it was interesting to assess the relation between EBV and HD in the Argentine pediatric population. The age distribution profile of our pediatric HD patients showed a peak in early childhood which declined towards adolescence, closely resembling EBV infection pattern. Male:female ratio of the studied population was 3.2:1 and the histological subtype distribution disclosed that mixed cellularity HD (MCHD) was the most common, an epidemiological profile shared with other developing countries. Fifty percent of assessed HD cases were associated with EBV, showing a significantly higher prevalence in the 3-6 years-old group, indicating a non-random distribution. EBV was also present in most of MCHD cases and in some nodular lymphocyte predominance HD (nLPHD) but entirely absent in nodular sclerosis HD (NSHD). Both EBV subtypes, namely EBV-1 and EBV-2, were detected in studied HD cases. EBV-HD association in the Argentine pediatric population reveals typical epidemiological features indicating EBV as the aetiologic agent or, alternatively as a cofactor in a considerable percentage of such HD cases.

Epstein-Barr virus (EBV) latent membrane protein (LMP) in tumor cells of Hodgkin's disease in pediatric patients

Twenty-nine out of 31 consecutive pediatric patients with Hodgkin's disease treated at our hospital from 1988 to 1992 were studied. The selection criterion was the availability of sufficient formalin-fixed, paraffin-embedded tissue for analysis. Patient age ranged from 3 to 15 years with a median age of 7 years. Lymph node biopsies were examined for the presence of Epstein-Barr virus (EBV)-encoded latent membrane protein (LMP) in malignant cells by peroxidase immunolabeling. LMP positivity was present in 10/15 (67%) of mixed cellularity, 1/6 (17%) of lymphocyte predominance, 0/7 (0%) of nodular sclerosis, and 1/1 (100%) of lymphocyte depletion. Positive cases by age range were: 10/12 (83%) for 3-6 years and 2/17 (11%) for 7-15 years. The association between EBV and Hodgkin's disease in children appeared to be more frequent in patients with mixed cellularity and those in the 3-6 age range, through examples of EBV-positive tumors were found in other histologic subtypes, stages and ages. Findings indicate that Hodgkin's disease in children is at least as strongly linked to EBV as in adults. Furthermore, we suggest that the EBV is associated with a subgroup of patients which can be defined on the basis of the age at diagnosis.

Detection of EBV DNA in post-nasal space biopsy tissue from asymptomatic EBV-seropositive individuals

The association between EBV and nasopharyngeal carcinoma (NPC) has been well documented although the precise role of the virus in the genesis of the tumour is not understood. We undertook this study to examine the prevalence of EBV infection in nasopharyngeal tissue obtained from 33 healthy individuals not considered to be at risk of developing NPC. Using polymerase chain amplification (PCR) and in situ hybridization we have identified EBV DNA in 70% (23/33) of the tissues examined. Our data demonstrate that EBV is present at the site of tumour development in the low-risk population and by inference that the virus is also present before the onset of disease in the high-risk group. This survey supports the concept of NPC pathogenesis as a multifactorial process.

Detection of occult nasopharyngeal primary tumours by means of in situ hybridization

Detection of nasopharyngeal carcinoma primaries in patients presenting with neck node metastases may sometimes demand considerable efforts. By using the 'in situ hybridization' technique, we manage to identify the Epstein-Barr virus in neck metastases secondary to nasopharyngeal carcinomas. We propose that such identification in neck node metastases where the primary lesion is unknown indicates a nasopharyngeal primary.

Expression of the Epstein-Barr virus genome in a nasopharyngeal carcinoma epithelial tumor cell line

An epithelial tumor cell line was recently established from a biopsy specimen of a nasopharyngeal carcinoma (NPC), and designated HONE-I. Uncloned (parental) HONE-I and HONE-I clone (C)-40 cells were found to contain latent Epstein-Barr virus (EBV). Expression of the latent EBV genome in HONE-I C-40 cells has been examined. It was possible to detect a small percentage of cells spontaneously synthesizing EBV early antigen (EA) and virus capsid antigen (VCA) by immunofluorescence (IF). In addition, the EBV nuclear antigens (EBNA-I and EBNA-2), as well as the EBV latent membrane protein (LMP) were detected in the HONE-I cells. Attempts were made to induce the latent EBV genome in these cells with iododeoxyuridine (IUdR). We observed a significant increase in the number of EA/VCA-positive cells, an increase in EBV DNA, the synthesis of virus particles, and the rescue of infectious virus after treatment of HONE-I C-40 cells with IUdR. The HONE-I C-40 cells should facilitate studies of the expression and regulation of the EBV genome in NPC epithelial tumor cells, which have not previously been available.