The effect of antibiotic therapy on recovery of intracellular bacteria from bronchoalveolar lavage in suspected ventilator-associated nosocomial pneumonia

Several recent reports have suggested that nodular lymphocyte predominance Hodgkin's disease (NLPHD) may be distinct from other forms of Hodgkin's disease and may be more closely related to B-cell non-Hodgkin's lymphoma. This is primarily based on immunophenotypic studies that have shown that the L & H cells in NLPHD demonstrate a B-cell phenotype. In 1989, Poppema reported that the T cells in NLPHD differ from T cells in other forms of Hodgkin's disease in that they demonstrate reactivity for Leu 7 (CD57). In this study we tested the hypothesis that Leu 7 (CD57) reactivity of small lymphocytes in NLPHD is an immunophenotypic feature that distinguishes NLPHD from nodular sclerosing Hodgkin's disease and from certain B-cell lymphomas that may histologically simulate NLPHD, namely T-cell-rich B-cell lymphoma and follicular lymphoma. Using an image analysis method, we found Leu 7 (CD57) reactivity in an average of 18.9% of the small lymphocytes in the nodules of NLPHD compared with 3.9% in nodular sclerosing Hodgkin's disease, 4.3% in T-cell-rich B-cell lymphoma, and 2.1% in follicular lymphoma. Moreover, Leu 7 (CD57)-reactive small lymphocytes often showed a distinctive pattern in NLPHD, forming a ring of cells around the large L & H cells. While scattered Leu 7 (CD57)-reactive lymphocytes were found in the other disorders, the percentage of reactive cells and the pattern of reactivity were significantly different in NLPHD. These results suggest that Leu 7 (CD57) reactivity may be used as an additional immunophenotypic criterion in distinguishing NLPHD from nodular sclerosing Hodgkin's disease, T-cell-rich B-cell lymphoma, and follicular lymphoma. The clinical and biological significance of Leu 7 (CD57) reactivity of small lymphocytes in NLPHD merits further investigation.     

Nodular lymphocyte predominance Hodgkin's disease featuring blood atypical polyclonal B-cell lymphocytosis

The nodular lymphocyte predominance form of Hodgkin's disease (NLPHD) is considered as a B cell derived lymphoproliferative disease. A patient with NLPHD presented with an absolute increase in blood B cells with cytological features of mantle zone cells; these B cells were polyclonal, did not exhibit bcl-2 gene rearrangement, and some of them displayed non-clonal chromosomal aberrations. EB virus genome was not detected by Southern analysis. Thus, this study, taking advantage of the presence of an unusual population of blood atypical B cells, confirms data obtained on lymph nodes where, however, malignant cells may be scarce, indicating that NLPHD is a polyclonal B cell lympho-proliferative disease of mantle zone origin.     

The B7/BB1 antigen is expressed by Reed-Sternberg cells of Hodgkin's disease and contributes to the stimulating capacity of Hodgkin's disease-derived cell lines

The B7/BB1 molecule has recently been found to be expressed on professional antigen-presenting cells and to be the natural ligand for CD28 and CTLA-4 on T cells. On binding of B7/BB1, CD28 transduces a signal that synergizes with triggering of the T-cell antigen receptor, resulting in enhanced cytokine secretion. In view of the data supporting an antigen-presenting function of Reed-Sternberg cells, we evaluated the expression of B7/BB1 in lymph nodes affected by Hodgkin's disease. B7/BB1 was found to be strongly expressed by the Reed-Sternberg cells in all 47 cases of Hodgkin's disease studied. Moreover, Reed-Sternberg cells were frequently surrounded by CD28-expressing T cells. Evidence for a functional role of B7/BB1 on Reed-Sternberg cells was obtained by our findings that T-cell proliferation and interleukin-2 (IL-2) production in the primary allogenic mixed lymphocyte reaction (MLR), using the B7/BB1-expressing Hodgkin's disease-derived cell lines L428 and KM-H2 as stimulators, could be partially blocked by adding anti-B7 monoclonal antibody. B7/BB1 expression was also evaluated in a group of non-Hodgkin's lymphomas (n = 46). Whereas B7/BB1 was not expressed by the neoplastic cells of most non-Hodgkin's lymphomas, including T-cell-rich B-cell lymphoma (n = 11), it was present on the neoplastic cells of anaplastic large-cell lymphoma (Ki-1 lymphoma) (n = 5) and follicular lymphoma (n = 4). Our data provide further evidence for an accessory cell function of Reed-Sternberg cells. The accessory cell function of Reed-Sternberg cells might lead to pronounced T-cell activation in vivo, which might contribute to the Hodgkin's syndrome. In addition, our study indicates that B7/BB1 may be a useful marker for differentiating Hodgkin's disease from morphologically similar conditions such as T-cell-rich B-cell lymphoma.     

The antigen-presenting cell function of Reed-Sternberg cells

Reed-Sternberg cells, the neoplastic cells of Hodgkin's disease, express all membrane molecules required to function as antigen-presenting cells (APCs), such as major histocompatibility complex (MHC) class II antigens and the recently characterized B7 proteins, which are of critical importance for APC to adequately stimulate CD4+ T cells. As APC do, Reed-Sternberg cells also express the adhesion molecules ICAM-1 (CD54) and LFA-3 (CD58), via which T cells are able to adhere to the cell. MHC antigens, B7 proteins as well as the adhesion molecules are expressed by Reed-Sternberg cells in virtually all cases of Hodgkin's disease, irrespective of the subtype. In vitro studies have shown that Hodgkin's disease-derived cell lines are potent stimulators of mixed lymphocyte cultures and that the MHC antigens, B7 proteins and the adhesion molecules, expressed by Hodgkin's disease-derived cell lines, are essential for such a function. Taken together, these data strongly suggest that Reed-Sternberg cells function as APC in vivo, and that the APC function of the cell is a major common denominator of Hodgkin's disease. The APC function of Reed-Sternberg cells does not support the hypothesis that they derive from dendritic cells, since activated B and T cells may also exert an APC function. Analysis of the antigens that are potentially expressed by Reed-Sternberg cells may greatly advance our knowledge on the pathogenesis of Hodgkin's disease and may allow the development of immunotherapy as an alternative treatment method.     

Characterization of Reed-Sternberg cells with granulocyte specific monoclonal antibody

Monoclonal antibody Leu M1 represents a highly specific marker to locate granulocyte antigen in Reed-Sternberg cells in Hodgkin's disease. Except the L&H variants of reed-sternberg cells in lymphocyte predominance variety in which antigens are probably sialylated. All the cases of non-Hodgkin's lymphoma were negative with this marker, because of absence of antigen. Therefore this specific marker characterizes granulocyte origin of reed-sternberg cells.     

Pathological findings in human autoimmune lymphoproliferative syndrome

The defects in lymphocyte apoptosis that underlie the autoimmune lymphoproliferative syndrome (ALPS) are usually attributable to inherited mutations of the CD95 (Fas) gene. In this report, we present the histopathological and immunophenotypic features seen in the lymph nodes (n = 16), peripheral blood (n = 10), bone marrow (n = 2), spleen (n = 3), and liver (n = 2) from 10 patients with ALPS. Lymph nodes showed marked paracortical hyperplasia. Interfollicular areas were expanded and populated by T cell receptor-alphabeta CD3+ CD4-CD8- (double-negative, DN) T cells that were negative for CD45RO. CD45RA+ T cells were increased in all cases studied. The paracortical infiltrate was a result of both reduced apoptosis and increased proliferation, as measured by in situ detection of DNA fragmentation and staining with MIB-1, respectively. The paracortical proliferation may be extensive enough to suggest a diagnosis of malignant lymphoma. Many of the paracortical lymphocytes expressed markers associated with cytotoxicity, such as perforin, TIA-1, and CD57. CD25 was negative. In addition, most lymph nodes exhibited florid follicular hyperplasia, often with focal progressive transformation of germinal centers; in some cases, follicular involution was seen. A polyclonal plasmacytosis also was present. The spleens were markedly enlarged, more than 10 times normal size. There was expansion of both white pulp and red pulp, with increased DN T cells. DN T cells also were observed in liver biopsies exhibiting portal triaditis. In the peripheral blood, the T cells showed increased expression of HLA-DR and CD57 but not CD25. CD45RA+ T cells were increased in the four cases studied. Polyclonal B cell lymphocytosis with expansion of CD5+ B cells was a characteristic finding. Taken together, the histopathological and immunophenotypic findings, particularly in lymph nodes and peripheral blood, are sufficiently distinctive to suggest a diagnosis of ALPS. Of note, two affected family members of one proband developed lymphoma (T-cell-rich B-cell lymphoma and nodular lymphocyte predominance Hodgkin's disease, respectively).     

Malignant histiocytic lymphoma with large lacunar cells

A case of lymph node biopsy with a peculiar histological aspect is described. The clinical data suggest a malignant lymphoid disease. The histological picture is that of a malignant histiocytosis but, among the majority of small histiocytes, there are some large cells like the large lacunar cells from Hodgkin's disease. These large cells (and some small cells) contain the CD 30 antigen of Reed-Sternberg cells. It is discussed whether the appropriate diagnosis is Hodgkin's disease, malignant histiocytosis, or non-Hodgkin's malignant lymphoma. Our diagnosis is Hodgkin's disease, the nodular sclerosing form.     

Relation of follicular dendritic reticulum cells to Reed-Sternberg cells of Hodgkin's disease with emphasis on the expression of CD21 antigen

Based on observations of 66 cases, in which tissues were specially processed to optimize the simultaneous preservation of cell membrane antigens and morphology, we provide evidence in favor of a relationship between follicular dendritic reticulum cells (FDRC) and Reed-Sternberg (RS) cells of Hodgkin's disease (HD) other than the lymphocyte predominance subtype. RS cells were intimately related to the FDRC network (75% of cases), and the expression of CD21 antigen was frequent (41% of cases). Exclusive expression of CD21 antigen was found in 11 cases of HD, while the expression of other B-cell-associated markers (CD19, CD20, CD22) was both variable and inconsistent. The expression of T-cell antigens (CD3, CD4, CD8) was rare. Null phenotype of RS cells was observed in 27 of 66 cases (41%). Epstein-Barr virus (EBV) nucleic acids were found in 34 of 66 (51.5%) cases. Double labeling techniques showed the presence of EBV-positive RS cells within the FDRC network. A non-B-cell origin of RS cells was supported by the differential expression of EBV latent antigens in HD (latent membrane protein+, EB nuclear antigen 2-), which is unusual in EBV-driven lymphoblastoid cell lines and EBV-positive B-cell lymphomas. FDRC and RS cells are known to share morphological traits (binucleated cells), and both cell types possess Fc receptor for IgG. The hypothesis is further backed by the findings of CD15 antigen expression by occasional RS-like dysplastic FDRC in Castleman's disease (five cases), which is characterized by hyperplasia of FDRC. Whether FDRC might be the only cells involved in the conversion to RS cells by the loss or gain of antigens remains to be determined.     

Nodular lymphocyte predominance Hodgkin's disease: a monoclonal or polyclonal B-cell disorder?

Nodular lymphocyte predominance Hodgkin's disease (NLPHD) is characterized by the presence of atypical putatively neoplastic cells (L & H cells) with a B-cell phenotype. A proportion of patients with NLPHD develop a simultaneous or subsequent large cell B lymphoma (LCL) that is thought to evolve directly from the L & H cells of NLPHD. However, the clonal nature of L & H cells remains controversial, and the relationship between NLPHD and complicating LCL has not been fully established. In an attempt to determine the clonality of L & H cells and to clarify the link between NLPHD and complicating LCL, we used polymerase chain reaction (PCR) to analyze 33 cases of NLPHD, including 15 cases with simultaneous or subsequent LCL, for clonal immunoglobulin (lg) heavy chain variable region (VH) gene rearrangements. PCR amplifications with consensus primers covering framework 2 or framework 3 to joining region were performed on paraffin-embedded tissue sections and, in 12 cases, on microdissection-enriched L & H cells. No clonal Ig rearrangements were detected. In eight of the 15 LCL, monoclonal IgVH regions were amplified, four of which were cloned and sequenced. Clone specific primers were designed based on the unique N region sequences. These allowed detection of LCL clones at a sensitivity up to 1,000 times greater than the consensus primers, as determined by dilution assays. However, no LCL clones were detected in the preceding NLPHD, including microdissection-enriched L & H cells. Our results suggest that populations of L & H cells do not carry monoclonal Ig rearrangements and provide no evidence for a clonal link between NLPHD and complicating LCL.     

Early intrinsic deflection--a marker for successful radiofrequency ablation of overt accessory pathways

Striking morphological similarities exist between T-cell-rich B-cell lymphoma and lymphocyte-predominant Hodgkin's disease (Hodgkin's paragranuloma), making the distinction between them extremely difficult. Immunohistochemistry provides a means of overcoming this difficulty. Immunostaining with UCHL1, L26, MB1, and 4KB5 was performed on five T-cell-rich B-cell lymphomas and 11 Hodgkin's paragranulomas (7/11 nodular, 4/11 diffuse). L26 stained the tumour cells not only of T-cell-rich B-cell lymphomas, but also of L+H Hodgkin's disease. In contrast, MB1 as well as 4KB5 identified all of the neoplastic cells in 3/5 T-cell-rich B-cell lymphomas, but did not react with the L+H cells in 8/11 Hodgkin's paragranulomas. Some overlap of staining patterns became apparent in the remaining cases, with 2/5 T-cell-rich B-cell lymphomas showing the MB1+/4KB5+ phenotype in a tumor cell subset only. Similarly, in 3/11 Hodgkin's paragranulomas, some MB1/4KB5-positive L+H cells occurred in addition to MB1/4KB5-negative L+H cells. These cases, nevertheless, could be distinguished from one another by the numbers of MB1/4KB5-positive background lymphocytes, which were scanty or absent in T-cell-rich B-cell lymphomas and more numerous in Hodgkin's paragranulomas.     

Deficient major histocompatibility complex class II antigen presentation in a subset of Hodgkin's disease tumor cells

Hodgkin's disease is a common malignancy of the lymphoid system. Although the scarce Hodgkin and Reed-Sternberg (HRS) tumor cells in involved tissue synthesize major histocompatibility complex (MHC) class II and costimulatory molecules such as CD40 or CD86, it is unclear whether these tumor cells are operational antigen-presenting cells (APC). We developed an immunofluorescence-based assay to determine the number of MHC class II molecules present on the surface of single living HRS cells. We found that in fresh Hodgkin's disease lymph node biopsies, a subset of HRS cells express a substantial number of surface MHC class II molecules that are occupied by MHC class II-associated invariant chain peptides (CLIP), indicating deficient loading of MHC class II molecules with antigenic peptides. Cultured Hodgkin's disease-derived (HD) cell lines, however, were found to express few MHC class II molecules carrying CLIP peptides on the cell surface and were shown to generate sodium dodecyl sulphate (SDS)-stable MHC class II alphabeta dimers. In addition to showing deficient MHC class II antigen presentation in a subset of HRS cells, our results show that the widely used HD-cell lines are not ideal in vitro models for the disease. The disruption of MHC class II-restricted antigen presentation in HRS cells could represent a key mechanism by which these tumor cells escape immune surveillance.     

Relationships between lymphography and the histologic nodal and splenic types in Hodgkin''s disease. Considerations on clinical evolution

Trying to establish the eventual interrelations of the initial histologic nodal type and the splenic one, the general lymphographic picture, the histologic nodal type and spleen involvement, lymphographic and histologic examinations were carried out in 151 patients with Hodgkin's disease. Lympographies were performed in 139 cases, and splenectomy (followed by splenic, hepatic and abdominal lymph node biopsies) in 32. Lymphocyte depletion was found in 72.7% of the patients with lymph node obstruction diagnosed lymphographically. Splenic involvement was more frequent in cases with pathologic lymphographic picture and histologic aspects of lymphocyte predominance or nodular sclerosis. In patients with initial nodal histologic types of nodular sclerosis or lymphocyte depletion, the splenic histopathologic types were the same, but they got more severe in cases with lymphocyte predominance or mixed cellularity. Splenic biopsy might be unconclusive after protracted cytostatic treatment or splenic X-ray therapy. In the authors' opinion, early routine splenectomy is rather more advisable than differentiated splenectomy.     

Hodgkin's disease in American Negroes. Histologic classification of the disease in 143 untreated patients, and age distribution

The Rye histologic classification of Hodgkin's disease has been applied to 143 previously untreated cases of Hodgkin's disease in Negro patients seen in four hospitals in Washington, D.C.,during a 16-year period (1959-1974). The frequencies and age distributions of histologic subtypes were compared with those in American and two African series. Those histologic subtypes associated with poor prognoses (mixed-cellularity and lymphocytic depletion) predominated in American Negroes and in Negroes from Ibadan, Nigeria, and Kampala, Uganda. In an American series from Connecticut (approximately 98% Caucasian) the histologic subtypes lymphocytic predominance and nodular sclerosis were preponderant. There were statistically significantly less of the nodular sclerosis subtype (P less than 0.005), and more of the mixed-cellularity subtype in American Negroes compared with the Connecticut series (P less than 0.001). In contrast to findings in predominantly Caucasian populations, there was a predilection of the nodular sclerosis subtype for males in American and in African Negroes. This study showed that Hodgkin's disease in American Negroes epidemiologically corresponds to the so-called "intermediate pattern" of the disease.     

The mummified Hodgkin cell: cell death in Hodgkin's disease

This study attempts to define more clearly the morphology and ultrastructure of mummified Hodgkin cells, to determine their incidence in the different histological subtypes of Hodgkin's disease (HD), and to correlate these data with the expression of p53, bcl-2, mdm2, and p21/WAF1. Forty-five cases of primary HD were examined at light and electron microscopic level. DNA strand breaks were detected by the in situ end-labelling (ISEL) and the TdT-mediated dUTP-digoxigenin nick end-labelling (TUNEL) technique. Mummified Hodgkin cells display morphological features that differ from those of classical apoptosis. In contrast to apoptotic cells, mummified Hodgkin and Reed-Sternberg (HRS) cells do not react in the ISEL or TUNEL procedures and maintain the expression of antigens such as CD30 and CD15. The morphology of mummified tissue cells could be simulated by CD95-mediated induction of apoptosis in the Hodgkin cell line HDLM2 if internucleosomal DNA fragmentation was inhibited by zinc ions. The highest incidence of mummified cells was found in the nodular sclerosis and mixed cellularity subtypes, whereas the lowest frequency was observed in nodular paragranuloma. The frequency was independent of p53, bcl-2, p21, and mdm2 expression. p21 and mdm2 immunoreactivity of HRS cells was correlated with p53 status. HRS cells in nodular paragranuloma were virtually negative for p21/WAF1 or bcl-2. Classical apoptotic cells reacting in the TUNEL and ISEL procedures are found in all subtypes of HD and are derived from the non-neoplastic cellular background. In conclusion, mummified Hodgkin cells display features of apoptosis lacking the internucleosomal DNA fragmentation. The pattern of the p53-transactivated genes mdm2 and p21/WAF1 suggests that inactivating mutations of p53 are rare in HD.     

Classical Hodgkin and Reed-Sternberg cells demonstrate a non-clonal immature B lymphoid lineage: evidence from a single cell assay and in situ hybridization

Hodgkin and Reed-Sternberg (H & RS) cells are generally considered to be the neoplastic cells of Hodgkin's disease (HD), however such cells are only found in a minority of the lesions. Recently in a few studies on HD, the clonality of H & RS cells was examined, using a single-cell polymerase chain reaction (PCR) examination. To clarify the lineage and clonality of H & RS cells, we performed single cell PCR and in situ hybridization (ISH), and nine cases of classical HD were thus studied. By ISH, the immunoglobulin J chain, and the kappa and lambda light chain were rarely expressed in the H & RS cells, however, no T-cell markers could be detected. The expression of the recombination activating genes (RAG-1, 2) could be determined in the H & RS cells. We isolated CD30+ H & RS cells, CD3 + T cells and CD20 + B cells from suspended materials using a mechanical sorter. We performed single cell PCR in a sorted individual cell, to amplify the complementarity determining region of the Ig heavy chain (IgH) gene and T-cell receptor gamma chain (TCR gamma) gene. In all cases, TCR gamma could be frequently amplified in the T cells, but was only rarely amplified in the H & RS and B cells. In contrast, the IgH was frequently amplified in the H & RS and B cells, but not in the T cells. In addition, the PCR production of the H & RS cells all showed different lengths. The results therefore support the polyclonal nature and immature B lymphoid cell origin of H & RS cells.     

CD40/CD40 ligand interactions in normal, reactive and malignant lympho-hematopoietic tissues

CD40 is a 48 Kd integral membrane protein expressed by cells of B cells, origin, dentritic cells, monocytes, epithelial cells, endothelial cells and tumor cells including carcinomas, B cell lymphomas/leukemias and Hodgkin and Reed-Sternberg (HRS) cells of Hodgkin's disease (HD). CD40 has been clustered as a member of the nerve growth factor (NGF)/tumor necrosis factor (TNF) receptor superfamily with the corresponding counterstructure, the CD40 ligand (L) being mainly expressed by activated CD4+ T cells, but also some activated CD8+ T cells, basophils, eosinophils, mast cells and stromal cells. CD40L shares significant amino acid homology with TNF particularly in its extracellular domain ("TNF homology region") and is therefore viewed as a member of the TNF ligand superfamily. Binding of CD40L+ T cells to CD40+ B cells is thought to play a major role in T cell-dependent B cell activation, B cell proliferation, Ig isotype switching, memory B cell formation and rescue of B cells from apoptotic death in germinal centers. Mutations of the CD40L gene have been associated with the X-linked hyper-IgM immunodeficiency syndrome, pointing to the critical role of the CD40/CD40L interaction in the T cell-B cell interplay. Accordingly, expression of CD40 by human lympho-hematopoietic tumors has been shown in most of the B cell neoplasias, H-RS cells and HD and some carcinomas. In contrast, CD40L+ tumor cells are almost invariably restricted to CD4+/CD8- T cell lymphomas. Overall, functional CD40/CD40L interactions appear to be critical for cellular activation signals during immune responses and neoplastic tumor cell growth. The understanding of the biology of CD40L has improved our diagnostic and therapeutic repertoire in the management of several human diseases, including CD40+ tumors.