Detection of Epstein-Barr viral genomes in lymph nodes of Hodgkin's disease patients

Safety of allogeneic Epstein-Barr virus (EBV)-specific cytotoxic T lymphocytes for patients with refractory EBV-related lymphoma

Epstein-Barr virus (EBV) causes lymphomas in immunocompromised individuals such as recipients of stem cell or organ transplants and patients with acquired immunodeficiency syndrome (AIDS). EBV has also been detected in the Reed-Sternberg cells of approximately 50% of all cases of Hodgkin's disease (HD). The purpose of this study was to examine the safety, and the clinical and immunological effects of infusing allogeneic EBV-specific cytotoxic T lymphocytes (CTL) for patients with refractory EBV-positive malignancies. In this pilot study, we have treated four patients with EBV-related lymphoma using allogeneic EBV-specific CTL. Two patients received EBV-specific CTL derived from partially human leucocyte antigen (HLA)-matched donors and the other two from HLA-matched siblings. No complications were observed as a result of the CTL infusions and all patients showed increased levels of EBV-specific CTL precursors (CTLp) post infusion. Of the two organ transplant patients, one had refractory disease and has sustained a complete remission following the T-cell infusions. The second has also been disease free since T-cell infusions, although the efficacy cannot be definitively attributed to CTL therapy because this patient received local radiation therapy prior to immunotherapy. A patient with AIDS-related, EBV-positive lymphoma had disease progression following CTL infusions. One HD patient received HLA 4/6 matched T cells from an unrelated donor and showed a decrease in the size of affected lymph nodes and resolution of B-symptoms post infusion. In conclusion, adoptive immunotherapy with allogeneic EBV-specific CTL is safe and may have efficacy in patients with high-risk or refractory EBV-related tumours.

Effect of Epstein-Barr Virus Infection on Response to Chemotherapy and Survival in Hodgkin’s Disease

We have analyzed paraffin sections from 190 patients with histologically confirmed Hodgkin’s disease (HD) for the presence of Epstein-Barr virus (EBV) using in situ hybridization to detect the EBV-encoded Epstein-Barr virus early RNAs (EBERs) and immunohistochemistry to identify latent membrane protein-1 (LMP1) expression. EBV was present in the tumor cells in 51 HD cases (27%) and was mainly confined to the mixed cellularity and nodular sclerosis subtypes. There was no difference between EBV-positive and EBV-negative HD patients with regard to age, clinical stage, presentation, and the number of alternating chemotherapy cycles of ChIVPP and PABIOE received. The complete remission rate after study chemotherapy was 80% in EBV-positive patients versus 69% in EBV-negative patients (P = .05). The 2-year failure-free survival rate was significantly better for EBV-positive patients when compared with the EBV-negative HD group (P = .02). Although 2-year and 5-year overall survival rates were better for EBV-positive HD patients, the differences were not statistically significant (P = .18 andP = .40, respectively). In conclusion, the results confirm the favorable prognostic value of EBV in the tumor cells of HD patients and suggest important differences in response to chemotherapy between EBV-positive and EBV-negative patients.

Effect of Epstein-Barr Virus Infection on Response to Chemotherapy and Survival in Hodgkin’s Disease

We have analyzed paraffin sections from 190 patients with histologically confirmed Hodgkin’s disease (HD) for the presence of Epstein-Barr virus (EBV) using in situ hybridization to detect the EBV-encoded Epstein-Barr virus early RNAs (EBERs) and immunohistochemistry to identify latent membrane protein-1 (LMP1) expression. EBV was present in the tumor cells in 51 HD cases (27%) and was mainly confined to the mixed cellularity and nodular sclerosis subtypes. There was no difference between EBV-positive and EBV-negative HD patients with regard to age, clinical stage, presentation, and the number of alternating chemotherapy cycles of ChIVPP and PABIOE received. The complete remission rate after study chemotherapy was 80% in EBV-positive patients versus 69% in EBV-negative patients (P = .05). The 2-year failure-free survival rate was significantly better for EBV-positive patients when compared with the EBV-negative HD group (P = .02). Although 2-year and 5-year overall survival rates were better for EBV-positive HD patients, the differences were not statistically significant (P = .18 andP = .40, respectively). In conclusion, the results confirm the favorable prognostic value of EBV in the tumor cells of HD patients and suggest important differences in response to chemotherapy between EBV-positive and EBV-negative patients.

Detection of Epstein-Barr virus (EBV) DNA and antigens in oral mucosa of renal transplant patients without clinical evidence of oral hairy leukoplakia (OHL)

The use of the polymerase chain reaction (PCR) to detect the presence of Epstein-Barr virus (EBV) DNA in oral mucosa in the absence of specific lesions gives rise to the problem of identifying the real viral replication sites. To verify whether the detection of EBV is due to salivary contamination or its true replicative capacity in oral mucosa, saliva samples and exfoliated cells from four different oral mucosa sites were taken from 40 renal transplant patients and 20 normal subjects for examination by PCR using two pairs of primers specific for the BamHI-L and BamHI-K genomic regions. EBV-specific sequences were detected in one or more of the oral mucosa samples from 29 transplant patients (72.5%) and six healthy controls (30%), and in the saliva samples of 16 transplant patients (40%) and three healthy controls (15%). A total of 89 oral mucosa smears from 29 transplant patients, and 13 from healthy subjects, were EBV-positive. The positive samples were also investigated by means of in situ hybridization in order to confirm the intracellular presence of the viral genome, and by means of immunofluorescence testing with monoclonal antibodies to assess the possible expression of viral antigens. Hybridization with the EBV-specific probe was observed in 40/ 89 and 2/13 samples, respectively. Latent antigens (with or without lytic antigens) were detected in only 23 of the 40 samples (collected from eight different transplant patients) that were positive by in situ hybridization. Our data show that EBV is more frequently present in the oral mucosa of immunodeficient patients (where it can efficiently replicate) than in normal subjects.

Evaluation of Epstein-Barr virus antibody patterns and detection of viral markers in the biopsies of patients with Hodgkin's disease

We assessed the relationship of Epstein-Barr virus (EBV) serology to the presence or absence of EBV genome in 39 cases of Hodgkin's disease (HD). Biopsies from patients included in 2 previous published studies, 1 involving patients from the United States (eastern Massachusetts) and 1 from Denmark, were evaluated for EBV (EBER-1) and latent membrane protein (LMP-1). The presence of EBV in Reed-Sternberg cells in the biopsies correlated with the histologic subtype of HD (mixed cellularity and lymphocyte depletion) but not with IgG antibody titers against the viral capsid antigen (VCA). These data suggest that, unlike Burkitt's lymphoma, the IgG antibody against VCA is not predictive of the presence or absence of EBV in Reed-Sternberg cells in HD. The predictive value of other antibodies should be evaluated.

Incidence of Epstein-Barr virus bcl-2 expression and chromosomal translocation t(14;18) in large cell lymphoma associated with paragranuloma (lymphocyte-predominant Hodgkin's disease)

Seven cases of large cell lymphoma (LCL) developing simultaneously or secondarily to lymphocyte-predominant Hodgkin's disease (nodular paragranuloma [NP]) were investigated for the presence of Epstein-Barr virus genomic material and the chromosomal translocation t(14;18) involving the major breakpoint region of the bcl-2 gene using the polymerase chain reaction on paraffin-embedded material. The translocation t(14;18) and Epstein-Barr virus could not be demonstrated in any case. The expression of the bcl-2 oncogene product was investigated using immunohistochemistry. Only in one case were the lymphocytic and histiocytic cells positively stained with the bcl-2 antibody, whereas the associated LCL demonstrated a completely negative immunoreaction. In another case the LCL had a positive immunoreaction with this antibody and the corresponding lymphocytic and histiocytic cells were completely negative. We conclude that Epstein-Barr virus infection is rare or absent in NP and in the LCLs associated with NP. The chromosomal translocation t(14;18) does not seem to be a factor in the transformation of NP into LCL.

Detection of Epstein-Barr virus DNA in Hodgkin- and Reed-Sternberg-cells by single cell PCR

The Epstein-Barr virus (EBV) can be detected in the majority of lymph nodes involved by Hodgkin's lymphoma using the highly sensitive polymerase chain reaction (PCR). However, the rate of EBV-DNA detection by in-situ hybridisation, which allows allocation of EBV to a defined cell population, i.e. the neoplastic H&RS-cells, is lower. In an attempt to combine the advantages of the high sensitivity of the PCR and the possibility of cellular allocation by in-situ hybridisation, we established a single-cell PCR of Hodgkin- and Reed-Sternberg (H&RS)-cells isolated by micromanipulation from biopsy tissues. We amplified EBV sequences from the BamW-region by single-cell PCR. Using this method we were able to detect EBV-DNA in the H&RS-cells from 4 of 6 patients. In EBV positive cases all H&RS-cells of a given patient were positive, proving the high sensitivity and reproducibility of the method. Other cells in the biopsy tissue involved by EBV-positive H&RS-cells were shown to be negative. This indicates that EBV may have a role in the pathogenesis of many but not all cases of Hodgkin's disease.

Is Hodgkin's disease an infectious disease?

Several lines of evidence question the concept of Hodgkin's disease (HD) starting as a true malignant disorder of the lymphatic system: (i) In early stages HD exerts pronounced clinical and biological features of an atypic immune response. (ii) Despite extensive investigations, the Hodgkin/Reed-Sternberg (H/RS) cells have not been unequivocally determined as the definite malignant cell population in HD. (iii) The epidemiological pattern of HD strongly resembles that of an infectious disease. (iv) About 50% of HD cases can be linked to infection with Epstein-Barr virus. Hodgkin's disease in early stages might thus be understood as the unsuccessful attempt of the organism to eliminate a cell expressing a putative (cellular or viral) target antigen. A stepwise transformation of this antigen-carrying cell, possibly triggered by an inherent genetic instability, might then lead to outgrowth of a malignant cell clone in late stages of the disease.

Antibodies to human herpes virus-6 and clinical course in patients with Hodgkin's disease

Serial serum samples from 37 patients with Hodgkin's disease (HD) and 39 healthy controls were studied for antibodies to human herpes virus-6 (HHV-6) using ELISA and indirect immunofluorescent antibody (IFA) tests and to the Epstein-Barr virus (EBV) using a radio-complement fixation assay. Antibodies to HHV-6 in the pre-treatment sera from the HD patients were not significantly different from those of controls, but significant changes in titers related to clinical course were noted among the HD patients. HHV-6 IFA titers increased significantly in the course of follow-up in patients who relapsed and decreased significantly over time in patients who did not. These serologic studies support tissue-based investigations indicating that EBV plays a greater etiologic role in HD than HHV-6, although HHV-6 serology may be of prognostic value or may assist in identifying individuals with immunologic abnormalities. The identification of diverse HHV-6 antibody patterns using different assays may reflect the presence of a number of antibodies with varying implications, similar to those identified for EBV.

Hodgkin's disease

The epidemiological features of Hodgkin's disease (HD) suggest that it is a heterogeneous condition which may have different aetiologies in different age groups. The risk factors for the development of HD in young adults suggest that delayed exposure to a common infectious agent may be involved in this age group. Seroepidemiological studies have shown that HD patients have elevated antibody titres to Epstein-Barr virus (EBV) and the elevated titres have been shown to precede the diagnosis of HD. Recent molecular studies provide support for the idea that EBV is involved in the pathogenesis of HD. EBV genomes are consistently found in a proportion of tumour biopsies, the EBV-infected cells are clonal and the EBV genomes have been localized to Reed-Sternberg cells. Furthermore, EBV latent gene products are expressed by the Reed-Sternberg cells. The majority of HD samples from patients aged greater than 50 years and less than 15 years are EBV positive, whereas the minority (less than 15%) of samples from young adults contain detectable EBV DNA. The results suggest that EBV plays a role in HD in children and older adults but that other agents, possibly other viruses, are involved in young adults.

Detection of Epstein-Barr virus genomes in Hodgkin's disease: relation to age

An investigation as to whether any particular subgroup of patients with Hodgkin's disease was particularly likely to be Epstein-Barr virus (EBV) genome positive was made on samples from 95 patients. These were grouped according to age and Hodgkin's disease subtype, and analysed using Southern blot analysis. Most samples from children or adults aged 50 years or over contained detectable EBV genomes; samples from young adults were only rarely positive. The differences in EBV positivity by age were highly significant, but there was no significant association between EBV and histological subtype after allowing for the effect of age. The results support the hypothesis that Hodgkin's disease in different age groups may have different aetiologies, and suggest that EBV does have a pathogenetic role in Hodgkin's disease in children and older age groups.

Epstein-Barr viral DNA in Hodgkin's disease: amplification and detection using the polymerase chain reaction

The presence of Epstein-Barr virus (EBV) DNA in biopsy tissues from patients with Hodgkin's disease (HD) was investigated by the polymerase chain reaction (PCR) using primers specific to a sequence within the EBV Bam H1W region. EBV genome was detected in 33 of 57 (58 per cent) cases of HD. Viral DNA was, however, also demonstrated in nine of 24 non-Hodgkin's lymphomas, in three of nine non-neoplastic lymph nodes and in seven of 12 normal peripheral blood samples used as controls. In all cases, the band obtained following PCR was verified using Southern blotting and hybridization with highly specific Bam H1W probes. The results suggest that the technique is sufficiently sensitive to detect EBV in persistent latent infection in B-lymphocytes. Distinction between virus present as a possible aetiological agent of malignancy or as a latent infection is not possible when PCR is used under these conditions. The possible role of EBV as an aetiological agent of HD remains unresolved.

Amplification of nucleic acids by polymerase chain reaction (PCR) and other methods and their applications

The in vitro replication of DNA, principally using the polymerase chain reaction (PCR), permits the amplification of defined sequences of DNA. By exponentially amplifying a target sequence, PCR significantly enhances the probability of detecting target gene sequences in complex mixtures of DNA. It also facilitates the cloning and sequencing of genes. Amplification of DNA by PCR and other newly developed methods has been applied in many areas of biological research, including molecular biology, biotechnology, and medicine, permitting studies that were not possible before. Nucleic acid amplification has added a new and revolutionary dimension to molecular biology. This review examines PCR and other in vitro nucleic acid amplification methodologies--examining the critical parameters and variations and their widespread applications--giving the strengths and limitations of these methodologies.

Detection of Epstein-Barr virus by polymerase chain reaction

The polymerase chain reaction (PCR) was used to study DNA extracted from the blood of 25 transplant patients, 5 patients with infectious mononucleosis, and 13 healthy subjects and autopsy or biopsy tissue from 29 patients with lymphoproliferative disorders. Primers were directed to conserved regions of the Epstein-Barr virus (EBV) genome encoding capsid protein gp220 and Epstein-Barr nuclear antigen 1. Specific EBV amplification was found in the blood of 11 of 25 transplant patients and all patients with infectious mononucleosis. All patients with lymphoproliferative disorders occurring in the presence of immunosuppression (eight organ transplant patients and two patients with acquired immunodeficiency syndrome) had biopsies positive for EBV by PCR. Only 1 of 19 samples from lymphomas or leukemias unrelated to immunosuppression contained EBV. PCR confirmed the very close association of EBV and lymphoproliferative disorders occurring in the presence of immunosuppression. The significance of detecting EBV sequences in the blood of transplant patients, particularly in relationship to lymphoproliferation, requires further study.