Andrew S. Krajewski

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

An investigation as to whether any particular subgroup of patients with Hodgkins 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 Hodgkins 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 Hodgkins disease in different age groups may have different aetiologies, and suggest that EBV does have a pathogenetic role in Hodgkins disease in children and older age groups.

The ins and outs of EBV infection

Epstein-Barr virus (EBV) infects almost the entire adult population of the world. The success of this virus appears to be based on its ability to infect the B cell, rather than any other cell type. We review EBV B-cell tropism, and discuss the mechanisms by which the virus may gain access to, and egress from, B cells in the normal host.

Primary cutaneous follicular lymphoma: a clinicopathologic and molecular study of 16 cases in support of a distinct entity

Primary cutaneous B-cell lymphomas displaying a prominent follicular growth pattern are rare and remain poorly defined, particularly in terms of the frequency of detection of t(14;18) and whether or not, as a group, they represent an entity distinct from follicular lymphoma arising in lymph nodes. The morphologic, immunophenotypic, and clinical features of 16 cases of primary cutaneous follicular lymphoma, identified during a review of all PCBCL in the Scotland and Newcastle Lymphoma Group database, were studied and the number of cases harboring t(14;18) assessed by polymerase chain reaction using primers to the major breakpoint cluster region. Comparisons were made with stage I follicular lymphoma arising in lymph nodes and follicular lymphoma secondarily involving the skin. All cases of primary cutaneous follicular lymphoma had undergone thorough staging, including physical examination and CT scans of chest and abdomen, with 15 of 16 cases also having bone marrow aspiration and/or trephine performed. The morphology and immunophenotype of the lesions were similar to that expected in lymph nodes. All cases displayed a follicular architecture complete with follicular dendritic cell networks and comprised an admixture of CD10 and/or bcl-6-positive neoplastic centrocytes and centroblasts with 13 of 16 cases also expressing bcl-2 protein. None harbored t(14;18), a significantly different finding compared with cases of stage I nodal follicular lymphoma (p <0.001) and secondary cutaneous follicular lymphoma (p <0.039). Relapses occurred in five of 15 patients with a median time to first relapse of 20 months (range 1–73 months; mean 27.2 months). These were multiple in two patients and involved extracutaneous sites in two patients. The propensity for relapse was similar to that in a comparative cohort of stage I nodal follicular lymphoma, but the group of primary cutaneous follicular lymphoma were significantly more likely to attain complete remission; all cases of primary cutaneous follicular lymphoma were in complete remission when last seen compared with 49 of 87 patients with stage I nodal follicular lymphoma (p <0.005). No lymphoma-related deaths were encountered in 15 cases with a mean follow-up >60 months (range 5–119 months). These results support the concept of a subtype of follicular lymphoma lacking t(14;18) involving the major breakpoint cluster region, and with a propensity to arise in the skin. Despite a high relapse rate patients with primary cutaneous follicular lymphoma are more likely to achieve complete remission and may ultimately have a more favorable long-term prognosis than those with equivalent nodal disease.

Primary cutaneous diffuse large B-cell lymphoma: prognostic significance of clinicopathological subtypes

Classification and subdivision of primary cutaneous diffuse large B-cell lymphoma (PCDLBCL) are a matter of ongoing debate. In this study we assessed the morphologic, immunophenotypic, and clinical features of 30 cases of PCDLBCL identified during a review of all primary cutaneous B-cell lymphomas in the Scotland and Newcastle Lymphoma Group database. We also determined the number of cases harboring t(14;18) using a polymerase chain reaction and primers to the major breakpoint cluster region. The effect on prognosis of a variety of clinical and pathologic factors was assessed for the group of 30 PCDLBCL and the 5-year disease-specific survival (DSS) of this cohort compared with that of 195 cases of stage I diffuse large B-cell lymphoma arising primarily in lymph nodes, also identified from within the Scotland and Newcastle Lymphoma Group database. Location on the leg was the only independent prognostic factor for determining outcome in PCDLBCL (67% 5-year DSS compared with 100% for the upper body; P = 0.0047). The presence of multiple lesions, involvement of more than one body site, and expression or not of CD10, bcl-2, bcl-6, and CD10 and bcl-6, had no effect on survival. Compared with cases arising above the waist, those on the leg were more often female, were of an older age, and had a significantly higher incidence of bcl-2 expression (P = 0.002) as well as the aforementioned poorer prognosis. They also showed more frequent co-expression of CD10 and bcl-6, supporting a follicle center cell origin for some, but this difference was not statistically significant. Although there was no significant difference in the 5-year DSS between the group of PCDLBCL and the cases of stage I nodal diffuse large B-cell lymphoma (88% 5-year DSS vs. 78%; P = 0.06), the latter were generally treated with more aggressive therapy. Moreover, a significant difference in 5-year DSS was seen when the nodal DLBCLs were compared with PCDLBCLs arising above the waist (78% vs. 100% respectively; P = 0.0135). These results support the current EORTC approach of subdividing PCLBCL on the basis of site to produce prognostically relevant groupings.

The Scotland and Newcastle epidemiological study of Hodgkin’s disease: impact of histopathological review and EBV status on incidence estimates

Aims: The epidemiological and pathological features of Hodgkin lymphoma (HL) are complex. The Epstein-Barr virus (EBV) is consistently associated with a proportion of cases, and these cases are thought to represent a distinct aetiological subgroup of HL. The aim of the present analysis was to determine the age and sex specific incidence of EBV associated and non-associated HL, analysed separately, using data derived from a population based study–the Scotland and Newcastle epidemiological study of Hodgkin’s disease (SNEHD). This study also provided a unique opportunity to evaluate accuracy in the current diagnosis and classification of HL. Methods: SNEHD analysed consecutive cases of HL diagnosed in the study area between 1993 and 1997. Diagnostic biopsy material was retrieved, EBV status of tumours was determined, and histological review was performed. Results: In total, 622 cases were eligible for the study, and EBV studies and histopathological review were performed on biopsy material from 537 and 549 cases, respectively. Accuracy in the overall diagnosis of HL and classification of nodular sclerosis HL was good, but diagnosis of HL in the elderly and classification of other subtypes was less reliable. One third of classic HL cases were EBV associated, and age specific incidence curves for EBV associated and non-associated cases were distinct. Conclusions: Comparison of age specific incidence curves for EBV associated and non-associated HL supports the hypothesis that these are two distinct aetiological entities. Accuracy in the diagnosis of HL is generally good, but certain subgroups of cases continue to present diagnostic difficulties.

Epstein-Barr virus infection in colorectal neoplasms associated with inflammatory bowel disease: detection of the virus in lymphomas but not in adenocarcinomas

Epstein–Barr virus (EBV) is associated with several lymphoid and epithelial human malignancies. The latter include gastric adenocarcinomas, while sporadic colorectal adenocarcinomas (CRCs) have been reported to be EBV‐negative. Recently, increased numbers of EBV‐infected B lymphocytes have been detected in intestinal mucosal samples affected by ulcerative colitis (UC) and, to a lesser extent, Crohns disease (CD). Both CRC and colorectal non‐Hodgkins lymphoma (NHL) are recognized complications of inflammatory bowel disease (IBD), but it is unclear to what extent EBV contributes to the development of these neoplasms. Seventeen cases of IBD‐associated CRC and nine cases of IBD‐associated colorectal NHL were therefore studied for the presence of EBV by in situ hybridization. EBV‐positive cases were further studied for the expression of the EBV‐encoded nuclear antigen (EBNA) 2 and the latent membrane protein (LMP) 1 of EBV by immunohistochemistry. Four out of seven cases of colorectal NHL associated with UC were shown to be EBV‐positive. In addition, two of two colorectal NHLs developing in patients with CD were EBV‐positive. Of the EBV‐positive lymphomas, three displayed a pattern of EBV latent gene expression consistent with type I latency (EBNA2−/LMP1−), two a type II pattern (EBNA2−/LMP1+), and one a type III pattern (EBNA2+/LMP1+). These findings suggest that EBV infection is involved in the pathogenesis of a proportion of colorectal NHLs developing in IBD. Iatrogenic immunosuppression may contribute to the development of these lymphomas. By contrast, all 17 IBD‐associated CRCs were EBV‐negative, including a case of CRC occurring synchronously with an EBV‐positive NHL. In conjunction with previous reports on sporadic CRCs, this suggests that EBV is not involved in the pathogenesis of CRC. Copyright

THE IMMUNOLOGICAL ARCHITECTURE OF B-LYMPHOCYTE AGGREGATES IN CRYPTOGENIC FIBROSING ALVEOLITIS

Cryptogenic fibrosing alveolitis (CFA) is believed to have a pathogenesis mediated by the cellular arm of the immune system. Previous studies have, however, indicated the presence of B‐lymphocyte aggregates, as well as evidence of local immunoglobulin production and increased levels of B‐cell growth factors. It has recently been shown that CFA is associated with the production of circulating IgG autoantibodies to antigen(s) associated with alveolar lining cells. This prompted an examination of the immunological architecture of the B‐lymphocyte aggregates, in order to assess whether they might provide histological confirmation of a local humoral immune response in these patients. Thirty‐eight consecutive open lung biopsy specimens were examined from patients with CFA and aggregates of B lymphocytes were identified in 37/38. In only five cases were germinal centres seen. The morphological appearances of the aggregates were reminiscent of those observed in mucosal associated lymphoid tissue (MALT). Using immunohistochemistry, despite the low frequency of true germinal centre formation, the B‐lymphocyte aggregates were shown to contain the cellular micro‐environment necessary for a humoral immune response. In addition, there was evidence of lymphocyte proliferation and activation within these aggregates. These results provide evidence of a local humoral immune response associated with B‐lymphocyte aggregates in the lungs of patients with CFA.

Immunophenotype analysis of malignant histiocytosis of the intestine.

Five cases of malignant histiocytosis of the intestine and one case of true histiocytic lymphoma were studied using immunohistological techniques. In paraffin sections tumour cells in all cases were shown to contain alpha-1-antitrypsin and to express the leucocyte common antigen. Four of the five cases of malignant histiocytosis of the intestine and the case of histiocytic lymphoma expressed the epithelial membrane antigen. Cryostat sections in four cases of malignant histiocytosis of the intestine showed that most tumour cells reacted with anti-T cell monoclonal antibodies. Only a minority expressed a typical monocyte macrophage phenotype.

The expression of the EBV latent membrane protein (LMP‐1) is independent of CD23 and bcl‐2 in Reed‐Sternberg cells in Hodgkin's disease

A series of 33 cases of Hodgkins disease was investigated for the presence of the EBV encoded latent gene product LMP‐1 and of CD23 using immunohistochemical techniques. The expression of bcl‐2 was examined in a subset of cases. LMP‐1 was detected in the Reed‐Sternberg cells in 15 cases. Although LMP‐1 is known to upregulate CD23 and bcl‐2, there was no correlation between the expression of LMP‐1 and the detection of CD23 and bcl‐2 in Reed‐Sternberg cells.

Increased CD45RO expression on T lymphocytes in mediastinal lymph node and pulmonary lesions of patients with pulmonary sarcoidosis

Sarcoidosis is characterized by a cell‐mediated response mediated by the activation of CD4′ T lymphocytes in an environment lacking adequate numbers of regulatory CD8 T lymphocytes. Immunohistological studies on frozen tissues have shown that sarcoid lesions have activated CD4 heiper/inducer T lymphocytes at the centre of granulomata, whereas lymphocytes at the periphery are mainly CD8 suppressor/cytotoxic cells. In this study we investigated the immunohistological distribution of CD45 isoforms of T cells in 29 paraffin‐embedded sarcoid lesions in mediastinal and open lung biopsies. Ten of these were assessed quantitatively, with single‐staining of serial sections demonstrating a predominance of CD45RO memory T lymphocytes in granulomata and intergranulomalous areas. Ratios of CD45RO;CD45RA T lymphocytes (or the ratio oi memory to naive T cells) were 420:1 for granulomata and 17‐9:l for intergranulomatous areas of sarcoid lesions counted. This finding is compatible with the hypothesis that nearly all the lymphocytes present in sarcoid lesions have been previously activated, and selectively home to sarcoid lesions.