Epstein-Barr virus genomes in Hodgkin's disease and non-Hodgkin's lymphomas

Detection of Epstein-Barr virus and human T-cell lymphotropic virus type 1 in malignant nodal lymphoma, studied in Okinawa, a subtropical area in Japan

Formalin-fixed paraffin-embedded lymph node samples were collected from 100 cases of malignant nodal lymphoma documented in Okinawa in the period from 1973 through 1998. According to the new World Health Organization classification, 12 cases were Hodgkin's lymphoma (HL). Eighty-eight cases of non-Hodgkin's lymphoma (NHL) included 54 cases of T-cell type and 34 cases of B-cell type. Using polymerase chain reaction (PCR), Epstein-Barr virus (EBV) was detected in 11 cases (91.7%) of HL and in 57 cases (64.8%) of NHL, and human T-cell lymphotropic virus type 1 (HTLV-1) was detected in 23 cases (26.1%) of NHL. Clonal integration of HTLV-1 was detected in 10 (43.5%) of 23 HTLV-1 PCR-positive cases by the inverse PCR technique. The EBV-infected cells were detected by EBER-1 in situ hybridization in 11 (91.7%) of 12 HL cases and in 64 (72.7%) of 88 NHL cases. Irrespective of phenotype and tissue type of the malignant lymphoma, the rate of EBV-positive infection in Okinawa was higher than that in any other districts reported in Japan. This characteristic high rate of EBV-positive infection in Okinawa can be ascribed to various factors, such as racial and geographical differences.

LMP1-induced downregulation of CD99 molecules in Hodgkin and Reed-Sternberg cells

Hodgkin's and Reed-Sternberg (H-RS) cells are morphological hallmarks of Hodgkin's disease (HD). So far, several characteristics frequently seen in H-RS cells from different origins have been described, such as the high expression of Epstein-Barr virus latent membrane protein 1 (LMP1), the elevation of NF-kappaB activity, and the aberrant expression of molecules such as CD15, CD30, and CD99. Despite extensive studies on the nature of H-RS cells, the molecular mechanism by which H-RS cells are generated remained elusive. Recently, the forced down-regulation of CD99 was reported to induce typical H-RS phenotypes in vitro in a B cell line. Furthermore, it was revealed that LMP1 markedly reduces the CD99 expression at the transcriptional level. Since the presence of LMP1 is known to be associated with the H-RS cell formation, the data provide a possibility of linkage between LMP1 and HD via CD99, thus suggesting that, at least in part, the loss of CD99 may play a critical role in the pathogenic sequence to the formation of H-RS cells in HD. In this review, the role of CD99 in the generation of H-RS cells and its molecular mechanism will be suggested.

Epstein-Barr virus association in classical Hodgkin's disease provides survival advantage to patients and correlates with higher expression of proliferation markers in Reed-Sternberg cells

BACKGROUND

Most Epstein-Barr virus (EBV) associated lymphoproliferative disorders have high proliferation indices. However, classical Hodgkin's disease (cHD) is heterogeneous, with respect to proliferation index of the Reed-Sternberg cell (RS cell), and EBV association. Hence, we investigated whether cHD with and without EBV-association differ with respect to the proliferation index of the RS cells. Further we investigated whether this would have a bearing on patients survival.

PATIENTS AND METHODS

We investigated 110 cases of cHD for: a) EBV association by immunohistochemical demonstration of EBV-latent membrane protein-1 and EBV encoded nuclear RNA 1 by mRNA in situ hybridisation; b) Proliferating cell nuclear antigen (PCNA) expression in the RS cells.

RESULTS

EBV association was noted in 86 of 110 cases (78%). Higher PCNA expression (P = 0.004) and younger age (P = 0.001) correlated independently with EBV association. The 10 year relapse free survival (RFS) of EBV+ and EBV- patients were 60% and 44%, respectively (P = 0.03). The 10 year overall survival (OS) of EBV+ and EBV- patients were 85% and 64%, respectively (P = 0.03). EBV association maintained its significant impact on RFS and OS within Cox proportional hazard model.

CONCLUSIONS

Our study suggests that EBV is likely to confer a higher PCNA expression and also contribute towards maintaining the RS cells of cHD in cell cycle. Hence, RS cells in EBV associated cHD would be more responsive to chemotherapy and radiotherapy associated DNA damage. Thus, EBV-association provides survival advantage to cHD patients treated with standard chemotherapy and radiotherapy protocols.

Non-Hodgkin's lymphoma presenting with adrenal insufficiency and hypothyroidism: an autopsy case report

A 55-year-old male presented with an initial manifestation of primary adrenal insufficiency, hypothyroidism. Computed tomography scans showed enlarged bilateral adrenal glands and thyroid. A pathological diagnosis of diffuse large cell, B cell lymphoma was made by a needle biopsy of the adrenal gland. He was treated with combination chemotherapy and adrenal and thyroid hormone replacement. The lymphoma subsequently involved the central nervous system. He died of pneumonia 8 months after the presentation of the first symptom. The postmortem examination demonstrated a complete regression of lymphoma in the bilateral adrenal glands and thyroid. This is an extremely rare case of coexistent lymphoma of the adrenal glands and the thyroid presenting with adrenal failure and hypothyroidism.

Reappraisal of the relationship between immunoglobulin heavy chain gene rearrangement and Epstein-Barr virus infection in Reed-Sternberg cells of Hodgkin's disease

We investigated 44 cases of Hodgkin's disease for Epstein-Barr virus genome with EBER-1 in situ hybridization. Twenty of 44 (45.5%) were positive for EBV. Simultaneously, immunoglobulin gene rearrangements were assessed in 32 of these 44 cases with PCR on DNA extracted from Reed-Sternberg cell (RS-cell) -rich areas microdissected from paraffin sections. Clonally rearranged immunoglobulin (IgH) gene was observed in 15 cases (46.9%). EBV-negative cases showed more frequent IgH rearrangement than EBV-positive cases (10 and 5 cases, respectively). In 9 cases, the RS cells were CD20-positive immunohistochemically and these were all EBV negative and the IgH gene was rearranged in all except one. These findings may suggest that EBV infection has occurred before the immunoglobulin gene rearrangement or that EBV infection has influenced the rearrangement of the immunoglobulin gene. The results may also hint towards the obscure B-cell nature of the RS cells.

Epstein-Barr virus (EBV)-induced CD30+ natural killer cell-type malignancy resembling malignant histiocytosis: malignant transformation in chronic active EBV infection associating hypogammaglobulinemia

A 27-year-old male suffered from Epstein-Barr virus (EBV)-related liver dysfunction with persistent hypogammaglobulinemia. IgG titers to EBV antigens were significantly high, while other hepatitis markers were negative. Liver biopsy disclosed active intralobular inflammation. Two years later, he manifested persistent fever, leukopenia, effusions and hypoproteinemia, and his general condition worsened progressively. The peripheral blood small lymphocytes predominantly expressed natural killer (NK)-like phenotypes (CD2+, CD7+, CD16+, CD56+). Hepatosplenomegaly and marked elevation of serum lactic dehydrogenase were observed. He died of respiratory failure at the age of 29. At autopsy, the liver (2190 g), spleen (860 g), small bowel and mesenteric lymph nodes showed massive infiltration of large atypical lymphoid cells in close association with hemophagocytic histiocytes. Involvement was mildly noted also in the bone marrow, lungs, gall-bladder and kidneys. The atypical cells belonged to CD30+ activated NK-type cells expressing CD2, cytoplasmic CD3 epsilon, CD7, CD45RO, CD56, HLA-DR and HLA-DQ. T cell receptors (TCR), surface CD3, CD4, CD5 and CD8 were not expressed. Epstein-Barr virus-related small nuclear RNA (EBER1) and Epstein-Barr virus-associated nuclear antigen 1 were detected in the nuclei of a significant number of atypical cells, while EBV-related latent membrane protein-1 was negative. EBER1 was also identified in the nuclei of non-neoplastic small lymphocytes at both biopsy and autopsy. Monoclonal integration of the EBV genome into the lymphoma cells was shown by Southern blot analysis. Clonal rearrangement of TCR was undetectable. Roles of chronic active EBV infection in the development of NK cell-type malignancy resembling malignant histiocytosis are discussed.