Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0079731 (B-cell lymphoma)
 16,671 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

It is often difficult to differentiate extranodal marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue (MALT lymphoma) from non-neoplastic inflammatory conditions. Demonstration of clonal lymphoid proliferation by molecular procedures is important for accurate diagnosis. We examined the clonal population of B-cell lymphomas in nine cases of thyroid and two cases of salivary gland B-cell lymphoma using semi-nested polymerase chain reaction (PCR)-based assay for IgH gene arrangement and reverse transcription (RT)-PCR single-strand conformation polymorphism (SSCP) for the detection of IgL gene rearrangement. Clonality was evident in nine out of 11 cases of B-cell lymphomas examined by PCR, and in six of eight cases by RT-PCR SSCP. In addition, analysis of VH families was performed in eight cases. Although VH3 family was frequently used, each case demonstrated the VH4, VH5 or VH6 family. It is possible that the normal counterpart of thyroid or salivary gland lymphoma might be different from peripheral blood B lymphocytes, which usually use VH3 family. Our results indicate that although no clonality was noted in one case by both PCR and SSCP, these molecular methods are useful as supplementary diagnostic tests for both thyroid and salivary gland lymphomas.
 ...
PMID:Rearrangement of immunoglobulin heavy and light chains and VH family in thyroid and salivary gland lymphomas. 1258 43

Patients with diffuse large B-cell lymphoma (DLBCL) rarely show relapse after 4 years of complete remission (CR). In this study, we addressed the following questions: (1) Does late-relapsing DLBCL represent clonally related disease or a second malignancy; and (2) is there a characteristic biologic background? In 10 of 13 DLBCL patients with relapse after 4 to 17 years, a clonal relationship was established based on identical IgH-sequences and/or identical bcl2-IgH translocation. Most (77%) showed features of germinal center (GC) cells, as defined by expression of CD10, bcl-2, and bcl-6 protein and ongoing immunoglobulin heavy chain variable region (VH) hypermutation. A GC phenotype was seen in 8 (20%) of 38 control patients matched for age, stage, and (extra)nodal localization with relapse within 2.5 years (P =.005). In conclusion, we have found evidence that late-relapsing DLBCL represents truly clonally related disease episodes in most cases and that this clinical behavior may be related to the biologic features of GC cells.
 ...
PMID:Very late relapse in diffuse large B-cell lymphoma represents clonally related disease and is marked by germinal center cell features. 1264 52

Translocations and somatic mutations are common genetic alterations of the BCL-6 gene on chromosome 3q27 in B-cell lymphoma, with implications for lymphomagenesis. The 2 events may have linked origins and can influence juxtaposed loci. To evaluate this further, we compared mutations occurring within the major mutation cluster region of the translocated and untranslocated BCL-6 alleles in 7 t(3;14)(q27;14q32) lymphomas. In 6 of 7 cases, the translocated allele revealed significantly higher mutations (mean, 5.8 x 10-2 bp-1) than did the untranslocated allele (mean, 5.3 x 10-3 bp-1; P <.01). The increase mapped to der(14q32), which retains the BCL-6 promoter and is transcriptionally active, as revealed by fusion transcripts and ongoing somatic mutations, absent in the der(3q27) region. These results indicate that enhanced mutational activity at the translocated allele may be a consequence of loss of cis regulatory elements or gain of IgH enhancer elements. Junctional sequences indicate translocation origins from earlier BCL-6 mutations and switch recombinase events.
 ...
PMID:Intronic BCL-6 mutations are preferentially targeted to the translocated allele in t(3;14)(q27;q32) non-Hodgkin B-cell lymphoma. 1277 68

The great majority of primary central nervous system lymphoma (PCNSL) is known to be of B-lineage, with T-cell PCNSL (T-PCNSL) accounting for <5%. We report an unusually high incidence of T-cell lymphoma among the PCNSLs originated in a large general-care hospital in the metropolitan Seoul area. PCNSLs (n = 42) accrued from April 1995 through June 2001 were reviewed for histologic and clinical features, and immunohistochemical staining was done for CD3, CD20, CD4, CD8, Bcl-6, and CD10. Clonal rearrangements of the TCR-gamma and IgH genes were studied with semi-nested PCR in all seven cases of T-PCNSL and seven of 35 B-cell PCNSL (B-PCNSL). Formalin-fixed, paraffin-embedded specimens were used in all these studies. By immunohistochemical staining and molecular studies, seven cases (16.7%) were diagnosed as T-PCNSL, each displaying clonal rearrangement of the TCR-gamma gene, and 35 (83.3%) as B-PCNSL. Radiologically, T-PCNSL was significantly correlated with the superficial and subcortical lobar location (p <0.001), solitary mass formation (p = 0.001), presence of rim enhancement (p <0.001), and peritumoral edema (p = 0.029). Involvement of cerebrospinal fluid was observed only in B-PCNSL (n = 17) but not in T-PCNSL (p = 0.010). Histologically, T-PCNSL was characterized by a population of mixed predominantly small- and occasionally medium-sized cells (p <0.001), which were loosely scattered without forming a solid mass (p = 0.024), and perivascular infiltration was frequent (p = 0.007), in contrast to predominantly large cells of B-PCNSL, i.e., diffuse large B-cell lymphoma (DLBCL), in which the cells tended to aggregate to form monomorphous sheets (p = 0.024). In T-PCNSL, staining for CD8 was positive in five, including one with coexpression of CD4, and two were negative for CD4 and CD8. Of 24 DLBCLs tested, the pattern of Bcl-6+ tumor cells was diffusely dense, similar to that of the germinal center in nine cases (37.5%), with coexpression of CD10 in three of the nine cases. T-PCNSL accounted for 16.7% of the PCNSLs; thus, in Korea it may not be as rare as previously known. The T-PCNSL presented with certain clinical and pathologic features that were distinct from B-PCNSL and displayed preponderance of CD8 expression. DLBCL of the germinal center B-cell derivation defined by bcl-6 expression comprised 37.5% of DLBCL of the brain.
 ...
PMID:Primary central nervous system lymphoma in Korea: comparison of B- and T-cell lymphomas. 1282 84

Rituximab is a monoclonal antibody against the CD20 molecule which is used to treat B-cell lymphomas. In 60% of low-grade B lymphomas in which rituximab was effective at first, there was no clinical response in a second treatment and a few cases of follicular lymphomas (FL) with transformation to diffuse large B-cell lymphoma (DLBCL) have been reported. We describe a new case and hypothesize about the mechanisms of transformation: a 52-year-old man, in follow-up during 8 years for FL, who after rituximab treatment and complete remission of FL showed progressive disease involving the liver and duodenal mucosa. Immunohistochemical and molecular studies were performed on paraffin-embedded tissue samples of lymph nodes, the small intestine, and liver tumors. After rituximab treatment, biopsies of a liver lesion and the small bowel both showed CD20-negative large B-cell lymphoma. Molecular study of the initial and relapse specimens shows a CDR2 IgH rearrangement with the same height and t14;18 (MBR). The rapid relapse with the same rearrangement of IgH seems to support the interpretation that the change of grade of lymphoma and loss of CD20 expression occurred before rituximab treatment. The existence of a varying proportion of a CD20-negative cell population in every B-cell lymphoma which does not respond to rituximab should therefore be considered. The reduction of CD20 expression could be a resistance mechanism to rituximab retreatment in DLBCL as a consequence of the progression of low-grade B-cell non-Hodgkin's lymphoma (B-NHL). It is necessary to perform new biopsies to evaluate CD20 expression in relapse or the progression of B-cell lymphoma after rituximab treatment.
 ...
PMID:CD20-negative DLBCL transformation after rituximab treatment in follicular lymphoma: a new case report and review of the literature. 1289 84

Lymphocytoma cutis (LC) is considered as the stereotypical example of the cutaneous B-cell pseudolymphomas. It can be induced by various antigenic stimuli including arthropod bites, vaccination, and drugs among others. In endemic regions, Borrelia burgdorferi is the principal causative agent for LC. We studied retrospectively 108 biopsies from 106 patients (male : female, 48 : 58; mean age, 44.6; median, 51.5; range, 3-81) with B. burgdorferi-associated LC retrieved from the files of the Department of Dermatology of the University of Graz (Austria). Only cases with a B. burgdorferi etiology (typical locations, positivity of serologic and/or polymerase chain reaction (PCR) tests, clinical history) were included in the study. Lesions were located on the nipple (63 cases), earlobe (18 cases), genital region (9 cases), and trunk or extremities (16 cases). PCR analysis of B. burgdorferi DNA was positive in 54 of 80 cases tested (67.5%). In 47 cases, we could retrieve data on serologic examination for B. burgdorferi antibodies performed at the time of diagnosis of LC. Positivity was found in 45 patients (IgG+/IgM+, 5 cases; IgG+/IgM-, 37 cases; IgG-/IgM+, 3 cases; IgG-/IgM-, 2 cases). Histology revealed dense lymphoid infiltrates with prominent germinal centers (GCs) in all cases. Atypical morphologic and/or immunophenotypic features of the GCs were commonly observed. In 5 cases, due to confluence of large follicles, the histopathologic pattern simulated that of a large B-cell lymphoma. PCR analysis of the IgH gene rearrangement performed in 33 cases showed a polyclonal pattern in 31 cases and a monoclonal band in 2. In summary, B. burgdorferi-associated LC can present with misleading histopathologic, immunophenotypic, and molecular features, and integration of all data is necessary for a correct diagnosis.
 ...
PMID:Borrelia burgdorferi-associated lymphocytoma cutis: clinicopathologic, immunophenotypic, and molecular study of 106 cases. 1498 75

Mantle cell lymphoma is non-Hodgkin's B-cell lymphoma characterized by the t(11;14)(q13;q32) translocation. Peripheral blood involvement of mantle cell lymphoma is usually associated with a poor prognosis and therefore, its identification is clinically important. In this study, we performed cyclin D1/IgH-probe fusion fluorescence in situ hybridization analysis on 223 peripheral blood samples: 185 from 125 mantle cell lymphoma patients, and 38 normal controls. The cutoff values for the test were established using normal controls. Flow cytometry on peripheral blood and corresponding bone marrow samples was used to evaluate this test. In all, 26% of the 185 peripheral blood samples and 27% of the 161 corresponding bone marrow samples were flow cytometry positive for mantle cell lymphoma. The mean numbers of single and- double-fusion signals and the mean number of CD5/CD19-positive cells, absolute blood lymphocyte count, and white blood cell count were significantly higher in peripheral blood and corresponding bone marrow samples with mantle cell lymphoma-positive flow cytometry. Double-fusion signals were more specific than single-fusion ones. Fluorescence in situ hybridization was far more likely to be positive for mantle cell lymphoma when the peripheral blood and the corresponding bone marrow samples had positive flow cytometry results or morphology (P<0.01). Our study indicates that cyclin D1/IgH-fusion fluorescence in situ hybridization analysis could be used to determine the presence and character of circulating mantle cell lymphoma cells in peripheral blood, thus enhancing our ability to evaluate leukemic mantle cell lymphoma and minimum residual disease.
 ...
PMID:Evaluation of peripheral blood involvement of mantle cell lymphoma by fluorescence in situ hybridization in comparison with immunophenotypic and morphologic findings. 1500 94

We have recently developed a novel Immunoglobulin heavy chain gene rearrangement (IgH-R) assay that combines polymerase chain reaction (PCR) amplification and analysis in the same closed capillary tube using the LightCycler System. IgH-R can be identified by DNA melting curve analysis within 40 minutes after DNA preparation and amplification. To test the clinical utility of this new IgH-R assay for rapidly diagnosing cutaneous B-cell lymphomas, we prospectively analyzed 44 formalin-fixed, paraffin-embedded tissues suspected of B-cell malignant lymphoma: skin (n = 31), lymph node (n = 7), stomach (n = 3), spleen (n = 1), colon (n = 1), and soft tissue (n = 1). We detected IgH-R in 12 DNA samples, including 8 skin biopsies, with the following diagnoses: B-cell chronic lymphocytic leukemia (n = 4), extranodal marginal zone B-cell lymphoma (n = 4), diffuse large B-cell lymphoma (n = 2), Burkitt lymphoma (n = 1), and precursor B-lymphoblastic lymphoma (n = 1). DNA melting curve analysis, compared with polyacrylamide gel electrophoresis, achieved a sensitivity equal to 92.3% and a specificity equal to 100%. There was a single false negative result because DNA melting curve analysis could not detect less than 10.0% clonal B-cells. We conclude that this new, rapid PCR assay for detecting IgH-R based on DNA melting curve analysis can be clinically useful for confirming the initial diagnosis of B-cell malignant lymphoma.
 ...
PMID:Rapid diagnosis of clonal immunoglobulin heavy chain gene rearrangements in cutaneous B-cell lymphomas using the LightCycler-Polymerase Chain Reaction with DNA melting curve analysis. 1536 70

A number of genetic abnormalities have been detected in multiple myeloma (MM) using cytogenetic techniques. The prominent abnormalities are deletions of 13q and translocations affecting the IgH locus on 14q32. The recurrence of chromosomal abnormalities in MM suggests a specific role for them concerning its pathogenesis. We performed comparative genomic hybridization (CGH) on samples from 53 patients with MM and 4 with monoclonal gammopathies of undetermined significance. In 31 cases (54%), normal ratio profiles were found, whereas 26 cases (46%) had aberrant profiles. The most common aberrations were gains of 9p (n = 14), 11 (n = 9), and 21q (n = 5) and loss of 22 (n = 7). In earlier reports on cytogenetics of lymphomas, gains of 9p are described as characteristic of primary mediastinal B-cell lymphoma, but the consensus region is smaller than in the present study (9p23pter vs 9p13pter). Therefore, we suggest a stronger genetic affinity between MM and primary mediastinal B-cell lymphoma than MM and other B-cell lymphomas. To support this suggestion, more molecular cytogenetic techniques and expression analyses have to be performed.
 ...
PMID:Frequent gains of the short arm of chromosome 9 in multiple myeloma with normal G-banded karyotype detected by comparative genomic hybridization. 1553 80

The most frequently recurring translocations in mucosa-associated lymphoid tissue (MALT) B-cell non-Hodgkin lymphoma, t(11;18)(q21;q21) and t(14;18)(q32; q21), lead to formation of an API2-MALT1 fusion or IgH-mediated MALT1 overexpression. Various approaches have implicated these proteins in nuclear factor kappaB (NF-kappa B) signaling, but this has not been shown experimentally in human B cells. Immunohistochemistry showed that MALT1 is predominantly expressed in normal and malignant germinal center B cells, corresponding to the differentiation stage of MALT lymphoma. We expressed MALT1 and apoptosis inhibitor-2 API2/MALT1 in human B-cell lymphoma BJAB cells and found both transgenes in membrane lipid rafts along with endogenous MALT1 and 2 binding partners involved in NF-kappa B signaling, B-cell lymphoma 10 (BCL10) and CARMA1 (caspase recruitment domain [CARD]-containing membrane-associated guanylate kinase [MAGUK] 1). API2-MALT1 and exogenous MALT1 increased constitutive NF-kappa B activity and enhanced I kappa B kinase (IKK) activation induced by CD40 stimulation. Both transgenes protected BJAB cells from FAS (CD95)-induced death, consistent with increases in NF-kappa B cytoprotective target gene expression, and increased their proliferation rate. Expression of a dominant-negative I kappa B alpha mutant showed that these survival and proliferative advantages are dependent on elevated constitutive NF-kappa B activity. Our findings support a model in which NF-kappa B signaling, once activated in a CD40-dependent immune response, is maintained and enhanced through deregulation of MALT1 or formation of an API2-MALT1 fusion.
 ...
PMID:MALT1 and the API2-MALT1 fusion act between CD40 and IKK and confer NF-kappa B-dependent proliferative advantage and resistance against FAS-induced cell death in B cells. 1559 10


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>