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Results for “Marginal zone B cells”

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PubMed2001

Novel genomic imbalances in B-cell splenic marginal zone lymphomas revealed by comparative genomic hybridization and cytogenetics.

Splenic marginal zone lymphoma (SMZL) has recently been recognized in the World Health Organization classification of hematological diseases as distinct type of non-Hodgkin's lymphoma. In contrast to the well-established chromosomal changes associated with other B-cell non-Hodgkin's lymphoma, few genetic alterations have been found associated with SMZL. The aim of our study was to analyze by comparative genomic hybridization (CGH) the chromosomal imbalances in 29 patients with SMZL and to correlate these findings with clinical and biological characteristics and patient outcome. In 21 cases, cytogenetic studies were simultaneously performed. Most of the patients (83%) displayed genomic imbalances. A total of 111 DNA copy number changes were detected with a median of four abnormalities per case (range, 1 to 12). Gains (n = 92) were more frequent than losses (n = 16), while three high-level amplifications (3q26-q29, 5p11-p15, and 17q22-q25) were observed. The most frequent gains involved 3q (31%), 5q (28%), 12q and 20q (24% each), 9q (21%), and 4q (17%). Losses were observed in 7q (14%) and 17p (10%). SMZL patients with genetic losses had a shorter survival than the remaining SMZL patients (P < 0.05). In summary, chromosomal imbalances in regions 3q, 4q, 5q, 7q, 9q, 12q, and 20q have been detected by CGH in SMZL. Patients with SMZL displaying genetic losses by CGH had a short survival.

Adult↗
PubMed1998

Detection of CD5 antigen on B cell lymphomas in fixed, paraffin embedded tissues using signal amplification by catalyzed reporter deposition.

CD5 surface antigen is expressed on some categories of B cell lymphomas. The detection of CD5 coexpression on malignant B cell infiltrates, particularly in small biopsy specimens, is useful in distinguishing between small lymphocytic lymphoma, mantle cell lymphoma, low grade marginal zone B cell lymphoma, and follicular small cleaved cell lymphoma. However, conflicting results have been reported with regard to the detection of CD5 antigen expression on B cell non-Hodgkin's lymphomas (B-NHLs) in fixed, paraffin embedded tissues using routine immunohistochemical (IHC) staining techniques. We used catalyzed reporter deposition (CARD) as a strategy to amplify the IHC signal and consequently increase the sensitivity of antigen detection. CARD improved detection of CD5 antigen without sacrificing specificity of the test. In our study, virtually all malignant B-NHLs with CD5 antigen expression showed strong immunoreactivity for a commercially available anti-CD5 monoclonal antibody using CARD, whereas the majority of the same lymphomas did not label for CD5 using routine IHC without CARD amplification. The concordance between CD5 antigen detection by immunophenotyping of fresh or frozen tissues and immunostaining with CARD amplification on paraffin fixed tissue sections was 100%. It appears that this method can be applied in the diagnostic evaluation of B-NHLs or in other situations that a weak antigen signal is present.

Biotin↗
PubMed2000

Primary splenic B-cell lymphoma (marginal zone lymphoma). Clinicopathological evaluation of 10 cases.

SMZL has been included in the REAL classification of lymphoid neoplasms (1994) as an entity. It affects middle aged adults presenting with splenomegaly, mild lymphocytosis and in 40% of cases with the presence of monoclonal paraprotein. Our material includes 10 patients (6 women + 4 men). In all patients bone marrow biopsy was the initial material for histopathological examination. With characteristic intertrabecular nodular interstitial infiltrates of CD20+ small lymphocytes and corresponding clinical data (splenomegaly, lymphocytosis in peripheral blood and sporadic elevation of IgM levels) it was very suggestive of SMZL diagnosis. Splenectomy was the treatment of choice. The spleen showed micronodular white foci in all cases. Morphologically the pattern of white pulp involvement was observed with lymphoma infiltrates as well as small foci in the red pulp. The white pulp showed follicles surrounded by a wide marginal zone, resembling reactive splenic follicles. A corona-like rim consisted of medium size cells with abundant clear cytoplasm, resembling monocytoid B cells, often with plasmacytoid differentiation, or centrocyte-like cells. Smaller aggregates of these cells were present in the red pulp. Lymphoma cells were CD20+, bcl-2 and IgM+. In all cases monoclonal kappa light chains were found. Although SMZL is a disseminated lymphoma at diagnosis, its course is indolent and splenectomy is the treatment of choice. Clinical and histopathological differential diagnoses include hairy cell leukemia and secondary involvement of the spleen by infiltrates of nodal B-cell lymphomas.

Aged↗
PubMed1997

Lymphomas in patients with Sjogren's syndrome are marginal zone B-cell neoplasms, arise in diverse extranodal and nodal sites, and are not associated with viruses.

The occurrence of non-Hodgkin's lymphoma (NHL) is the most serious complication of Sjogren's syndrome (SS). We performed a study of 16 NHLs occurring in patients with an underlying SS. These lymphomas arose not only in salivary glands (7 cases) but also in other mucosal extranodal sites (the stomach [4 cases], the lung [3 cases], the skin [3 cases], the buccal mucosa [1 case], the thymus [1 case]) and in nodal sites (8 cases). Low-grade marginal zone lymphomas (MZL) were diagnosed in 12 of the 16 patients, 9 of mucosa-associated lymphoid tissues (MALT) type in mucosal sites and 3 exclusively nodal. The 4 other patients presented with a high-grade B-cell lymphoma that was probably a histological transformation of an underlying low-grade MZL at least in 3 of the cases involving skin, stomach, and parotid, respectively. A t(14;18) translocation was detected in 1 of 8 lymphomas tested. We detected serum anti-p53 antibodies in 2 of the 14 studied patients. p53 protein was detected in 1 of 11 lymphomas tested. LMP protein and Eber RNAs of Epstein-Barr virus (EBV) were not detected in the 16 NHL biopsies. Using polymerase chain reaction, EBV was never detected except in 1 of 4 parotid lymphomas. No human T-lymphotropic virus 1 or human herpes virus 8 DNAs were detected in NHL biopsies. None of the patients had hepatitis C virus infection found using serological methods. Chemotherapy was usually efficient. In conclusion, lymphomas occurring in patients with an underlying SS are in most cases MZL. These lymphomas are not associated with viruses known to be present in other types of lymphomas. Some of the translocations or mutations of oncogenes or antioncogenes described in other lymphomas are detected in SS-associated lymphomas.

Adolescent↗
PubMed1976

T- and B-areas in immune reactions. Volume changes in T and B cell compartments of the rat spleen following intravenous administration of a thymus-dependent (SRBC) and a thymus-independent (paratyphoid vaccin-endotoxin) antigen. A histometric study.

In the white pulp of rat spleens cell numbers were studied in the different compartments following intravenous administration of comparable doses of paratyphoid vaccine (PTV, thymus-independent) and sheep red blood cells (SRBC, thymus-dependent). In the periarteriolar lymphatic sheaths (PALS) both cell concentration and volume were measured. For the follicles and the marginal zone only volume was recorded in the first 5 days following antigen administration. Additionally, histologic observations were made. In the thymus-dependent area PTV caused oedema 12-24 hours after administration. Following SRBC administration an increase in lymphocyte numbers occurred until the second day, probably representing an influx of T cells from the recirculating pool. Both antigens gave rise to a plasmacellular reaction in the peripheral PALS (2nd-4th day). In the bone marrow-dependent areas a massive shift of medium-sized lymphocytes from the marginal zone to the follicles took place in the first 24 hours following PTV administration. These cells subsequently transformed into blasts. After SRBC (6 and 12 hours) only a few marginal zone lymphocytes seemed to migrate into the follicles. It is aruged that the endotoxin present in PTV is responsible for the fact that, following administration of the antigen, all marginal zone (B) cells responded. Endotoxin stimulation might provide a model for the fate of marginal zone cells stimulated by other agents, such as antigen (stimulating antigen binding B cells) or antigen-antibody complexes (stimulating Fc-receptor B cells).

Animals↗
PubMed1985

Marginal zone macrophages identified by a monoclonal antibody: characterization of immuno- and enzyme-histochemical properties and functional capacities.

In the present study, the non-lymphoid cell of the marginal zone is described: the marginal zone macrophage, identified by a monoclonal antibody, ERTR9. The characteristics of these cells were investigated by use of a two-step immunoperoxidase method (on light and ultrastructural level) in combination with enzyme-cytochemical techniques and functional tests. The marginal zone macrophage appears to be a large cell with close contacts between its cell processes and surrounding marginal zone B cells, and with a well-developed phagocytic capacity. These ERTR9-positive macrophages are capable of selective uptake and retention of i.v. injected FITC-Ficoll and are negative for Ia antigen as well as for the macrophage-related F4/80 antigen. By these characteristics, they constitute a subpopulation of non-lymphoid cells of spleen unique for the marginal zone.

Animals↗
PubMed2006

Confounding B-cell defences: lessons from a staphylococcal superantigen.

Studies of microbial superantigens that target large clonal sets of B cells through conserved antigen-receptor-variable-region sites are providing new insights into the mechanisms of B-cell activation-induced cell death. These investigations have shown differences between the clonal regulation of follicular B cells (B2 cells) and the innate-like marginal-zone B cells and B1 cells, and have also shown how B-cell superantigens can affect specialized host defences against infection. Agents designed to emulate the properties of B-cell superantigens might also provide new approaches for the treatment of B-cell-mediated autoimmune and neoplastic diseases.

Animals↗
PubMed2001

The follicular versus marginal zone B lymphocyte cell fate decision is regulated by Aiolos, Btk, and CD21.

Most splenic B cells in mice that lack Aiolos are mature IgD(hi)IgM(lo) follicular lymphocytes, suggesting that maturation signals delivered via the BCR are enhanced in the absence of Aiolos. The enhanced maturation of follicular B cells is accompanied by the absence of MZ B lymphocytes and the downregulation of CD21 expression in follicular B cells, all of which depend on the generation of signals via Btk, which is in epistasis to Aiolos. The inverse relationship between the strength of BCR signaling and MZ B cell development is supported by an examination of MZ B cells in CD21 null mice. These data support the view that antigens (in contrast to "tonic" signals) drive the development of naive B cells.

Agammaglobulinaemia Tyrosine Kinase↗
PubMed2004

Triple association between hepatitis C virus infection, systemic autoimmune diseases, and B cell lymphoma.

OBJECTIVE: To analyze the clinical characteristics of patients from a Department of Autoimmune Diseases presenting chronic hepatitis C virus (HCV) infection, systemic autoimmune disease, and B cell lymphoma. METHODS: We analyzed the records of 100 consecutive patients with systemic autoimmune diseases and associated HCV infection seen in our department between 1994 and 2000. We retrospectively investigated the development of B cell malignancies after the diagnosis of HCV related autoimmune disease. RESULTS: Six patients with HCV related systemic autoimmune disease presented B cell non-Hodgkin's lymphoma (NHL). These patients fulfilled the diagnostic criteria for Sjögren's syndrome (n = 4) and polyarteritis nodosa (PAN; n = 2). Four patients were female and 2 male, with a mean age at lymphoma diagnosis of 62 years (range 45-78). The main immunologic markers were hypocomplementemia in all patients and cryoglobulinemia in 5 (83%). Primary extranodal localization of lymphoma was observed in 3 (50%) patients: prostate (n = 1), liver and ovary (n = 1), and ocular annexa (n = 1). Clinically, NHL was classified as indolent lymphoma in 3 patients and aggressive lymphoma in 3. NHL histologic types were diffuse large cell lymphoma (n = 4), extranodal marginal zone B cell lymphoma (n = 1), MALT lymphoma (n = 1), and lymphoplasmacytic lymphoma (n = 1). CONCLUSION: We describe 6 patients with a triple association of HCV infection, systemic autoimmune disease, and NHL. Characteristics of these patients included a high prevalence of cryoglobulinemia (that clearly contributes to fulfillment of diagnostic criteria for PAN) and an elevated frequency of primary extranodal involvement. We recommend careful evaluation of patients with B cell NHL to detect silent autoimmune or chronic viral diseases. This triple association reinforces the suspected links between autoimmunity, infection, and cancer.

Adult↗
PubMed2006

New insights into the cell biology of the marginal zone of the spleen.

In the marginal zone of the spleen the bloodstream passes through an open system of reticular cells and fibers in which various myeloid and lymphoid cells are located. Macrophages in this region are well equipped to recognize pathogens and filter the blood by virtue of unique combinations of pattern recognition receptors. They interact with a specific set of B cells that can be found only in the marginal zone and that are able to react rapidly to bacterial antigens in particular. This combination of strategically located cells is an important factor in our defense against blood-borne pathogens. New data on the development of the marginal zone itself and the marginal zone B cells are reviewed and discussed in light of the function of the spleen in host defense.

Animals↗