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B-cell Lymphoproliferative Disorders (b-cell + lymphoproliferative_disorders)
Selected AbstractsHigh sensitivity of chemiluminescent methodology for detection of clonal CDR3 sequences in patients with acute lymphoblastic leukemiaHEMATOLOGICAL ONCOLOGY, Issue 2 2004E. Leal Abstract Detection of minimal residual disease (MRD) in patients with B-cell acute lymphoblastic leukemia (B-ALL) has been achieved using several radioactive labelling methodologies; however, limited information exists about the use of chemiluminescent labelling. Although many malignant disorders are related to cytogenetic alterations, there is not a consistent chromosomal translocation that could serve as a tumour marker for the monitoring of MRD. ALL are derived from B-lymphocytes in 80% of cases. In the early stages of their maturation, the immunoglobulin heavy chain genes (IgH) undergo rearrangements among their V, D, and J segments, giving rise to the Complementary Determining Regions (CDR). Among these, CDR3 is considered unique for each lymphocyte and used as a tumour-specific marker in B-ALL patients. In this study, the CDR3 was labelled with digoxigenin and used as a patient-specific probe to test its sensitivity for further detection of MRD. Fourteen pretreatment samples of bone marrow (BM) or peripheral blood (PB) from B-ALL patients were included. Tumour-specific probes were designed from each clonal product by elimination of the consensus sequences. Ten digoxigenin-labelled probes were hybridized with a mixture of their respective clonal DNA and the polyclonal product from a normal healthy donor, in serial dilutions from 1:1 up to 1:107. A sensitivity range of 1:103,1:106 was obtained, with an average of 1:105. Crossed tests performed in four patients, showed right probe specificity in all cases. We propose that the design of allele-specific probes with chemiluminescent labelling, represents a reliable, sure and sensitive alternative methodology for MRD detection in patients with B-cell lymphoproliferative disorders. Copyright © 2004 John Wiley & Sons, Ltd. [source] Quantitation of cytological parameters of malignant lymphocytes using computerized image analysisINTERNATIONAL JOURNAL OF LABORATORY HEMATOLOGY, Issue 4 2008S. A. HAMID JAHANMEHR Summary Computerized image analysis may add to morphological evaluation by turning qualitative data into quantitative values. In this study, image analysis program was used to quantitate cytological parameters of lymphocytes in B-cell lymphoproliferative disorders. Chronic lymphocytic leukemia (CLL), mantle cell lymphoma (MCL) and B-cell prolymphocytic leukemia (B-PLL) were selected to represent typically small, medium, and large-sized lymphocytes, respectively. Image analysis was performed to determine the morphological parameters. A set of measurements was generated for quantitation of total cell area, cell diameter, cytoplasm area, nuclear area, nuclear/cell ratio, and nuclear density. The quantitated parameters substantiated morphological characteristics of the tumor cells. Comparative assessments demonstrated that CLL, MCL, and PLL can be differentiated by the quantitative descriptors. The results from image analysis may assist in defining morphological criteria and in developing quantitative cell morphology. [source] Age-related EBV-associated B-cell lymphoproliferative disorders: Diagnostic approach to a newly recognized clinicopathological entityPATHOLOGY INTERNATIONAL, Issue 12 2009Yoshie Shimoyama EBV is prevalent among healthy individuals, and is implicated in numerous reactive and neoplastic processes in the immune system. The authors originally identified a series of senile or age-related EBV-associated B-cell lymphoproliferative disorders (LPD) bearing a resemblance to immunodeficiency-associated ones, which may be associated with immune senescence in the elderly and which are now incorporated into the 2008 World Health Organization lymphoma classification as EBV-positive diffuse large B-cell lymphoma (DLBCL) of the elderly. This newly described disease is pathologically characterized by a proliferation of atypical large B cells including Reed,Sternberg-like cells with reactive components, which pose a diagnostic problem for pathologists. Clinically, this disease may present with lymphadenopathy, and is often extranodal, frequently involving the skin, gastrointestinal tract, or lung. Onset is usually after the age of 50; the median patient age is 70,79 years, and incidence continues to increase with age, providing additional support to the nosological term of EBV+ DLBCL of the elderly. These patients have a worse prognosis than those with EBV-negative DLBCL or EBV+ classical Hodgkin lymphoma (CHL). The aim of the present review was to summarize the clinicopathological profile of age-related EBV+ LPD and EBV+ Hodgkin lymphoma to facilitate diagnostic approach. [source] Rituximab for the treatment of post-bone marrow transplantation refractory hemolytic anemia in a child with Omenn's syndromePEDIATRIC TRANSPLANTATION, Issue 5 2007Briuglia Silvana Abstract:, Omenn's syndrome is a rare severe combined immunodeficiency that kills affected subjects before the end of the first year of life unless patients are treated with bone marrow transplantation (BMT). Unfortunately, post-BMT patients may develop autoimmune diseases, such as autoimmune hemolytic anemia (AIHA), which sometimes fails to respond to standard therapies. Rituximab is a chimeric, human, immunoglobulin G1/k monoclonal antibody specific for the CD20 antigen expressed on the surface of B lymphocytes. Rituximab is currently only labeled for treatment of B-cell lymphoproliferative disorders, such as B-cell non-Hodgkin's lymphoma and follicular lymphoma; however, it is also employed in the treatment of a variety of disorders mediated by auto-antibodies, such as AIHA and transplant-related autoimmune disorders. Herein, we describe the case of a 23-month-old male child with Omenn's syndrome, who had undergone BMT and was successfully treated with rituximab (375 mg/m2 intravenously, weekly for three times) for refractory post-BMT hemolytic anemia. Our findings evidence that rituximab should be considered for treatment of post-BMT AIHA refractory to traditional therapy also in children with primary immunodeficiencies; furthermore, rituximab might represent a means to obtain remissions without the toxic effects associated with corticosteroid and immunosuppressive agents. [source] CD5-Negative, CD10-Negative small B-cell leukemia: Variant of chronic lymphocytic leukemia or a distinct entity?,AMERICAN JOURNAL OF HEMATOLOGY, Issue 4 2002Salwa S. Sheikh Abstract CD5- and CD10-negative chronic lymphocytic leukemias are quite uncommon as compared to the CD5-positive CLL. We reviewed 250 sequential cases of peripheral blood lymphocytosis to characterize cases of small B-cell lymphoproliferative disorders, submitted with a clinical diagnosis of chronic lymphocytic leukemia exhibiting a non-classic immunophenotypic profile. Six cases of CD5-, CD10-negative chronic lymphocytic leukemias and no tissue involvement were identified that revealed high-density surface-membrane immunoglobulin and CD20 expression, with variable expression of CD11c, CD23, and CD25. Most had a profound leukocytosis (mean WBC 180 × 109/L) with proliferation of mature-appearing lymphocytes. Subsequent bone marrow biopsies showed diffuse infiltration by neoplastic cells in all evaluated patients. The clinical course appeared indolent, with follow-up revealing three patients alive (survival time 38,68 months), while two died of unrelated causes and one was lost to follow-up soon after diagnosis. These cases may represent somewhat unusual chronic lymphoproliferative disorders, with morphologic features and immunophenotypic profile not readily classifiable, but which are certainly atypical for classic chronic lymphocytic leukemia. Some of these features are reminiscent of those seen in marginal-zone lymphoma. However, it is most unusual for this known to be tissue-based disease to present primarily as leukemia rather than lymphoma. Am. J. Hematol. 71:306,310, 2002. © 2002 Wiley-Liss, Inc. [source] Bcl-2, Bcl-6 and CD10 expression in cutaneous B-cell lymphoma: further support for a follicle centre cell origin and differential diagnostic significanceBRITISH JOURNAL OF DERMATOLOGY, Issue 6 2003J.J. Hoefnagel Summary Background Primary cutaneous follicle centre cell lymphomas (PCFCCLs) are the most common type of cutaneous B-cell lymphoma. There is ongoing discussion on the origin of the neoplastic B cells in these PCFCCLs, and consequently on their relation to the groups of primary cutaneous marginal zone B-cell lymphomas (PCMZLs) and nodal follicular lymphomas. Objectives To define better the neoplastic B cells in PCFCCLs, and to find out if differences in the expression of the antiapoptopic protein Bcl-2, and Bcl-6 and CD10, molecules which are normally expressed by the neoplastic B cells in nodal follicular lymphomas, might have diagnostic or prognostic significance in cutaneous B-cell lymphoproliferative disorders. Methods Pretreatment biopsies of well-defined groups of PCFCCL (n = 24), PCMZL (n = 14), primary cutaneous large B-cell lymphoma of the leg (PCLBCL-leg; n = 19), secondary cutaneous follicular lymphoma (n = 3) and cutaneous pseudo-B-cell lymphoma (n = 6) were investigated by immunohistochemistry for expression of Bcl-2, Bcl-6 and CD10. Results The PCFCCLs consistently expressed Bcl-6, whereas CD10 and Bcl-2 were expressed in only one and two of 24 cases, respectively. In contrast, PCMZLs were always negative for Bcl-6 and CD10, but were Bcl-2 positive, whereas skin and lymph node localizations of secondary cutaneous follicular lymphomas consistently expressed all of Bcl-2, Bcl-6 and CD10. Reactive follicle centre cells in pseudo-B-cell lymphomas expressed Bcl-6 (six of six cases) and CD10 (five of six cases), but not Bcl-2. PCLBCL-leg was Bcl-6 positive and CD10 negative in all cases, irrespective of clinical outcome, and strongly expressed Bcl-2 protein in all but two cases. Conclusions The results of the present study provide further support for the follicle centre cell origin of both PCFCCL and PCLBCL-leg, and indicate that staining for Bcl-2, Bcl-6 and CD10 can serve as an important adjunct in the differential diagnosis of cutaneous B-cell lymphoproliferative disorders. [source] Rituxan (anti-CD20 antibody)-induced translocation of CD20 into lipid rafts is crucial for calcium influx and apoptosisCLINICAL & EXPERIMENTAL IMMUNOLOGY, Issue 3 2005E. Janas Summary Rituxan, a chimeric anti-CD20 antibody, is the first antibody approved for immunotherapy in non-Hodgkin's B-cell lymphoma and other B-cell lymphoproliferative disorders. Additionally, efficacy of Rituxan treatment has been reported in nonmalignant autoimmune diseases such as rheumatoid arthritis. Crosslinking of CD20 molecules by Rituxan induces therapeutic B-cell depletion. CD20 is a B-lymphocyte specific integral membrane protein, proposed to function as a store-operated calcium channel, which is activated upon receptor-stimulated calcium depletion of intracellular stores. Crosslinking of CD20 by antibodies has been reported to induce a redistribution of CD20 molecules to specialized microdomains at the plasma membrane known as lipid rafts. Here, we report that in the absence of Rituxan, CD20 exhibits a low affinity to lipid rafts. However, binding of Rituxan significantly increases the affinity of CD20 for lipid rafts resulting in its redistribution to a fraction resistant to Triton X-100 solubilization. Furthermore, we demonstrate that disturbing the raft integrity by cholesterol extraction results in dissociation of CD20 from a Triton X-100 resistant fraction followed by complete inhibition of Rituxan-induced calcium entry and apoptosis. The integrity of lipid rafts seems to play a crucial role for CD20-induced caspase activation. These data show, for the first time, that Rituxan-induced translocation of CD20 to lipid rafts is important for increased intracellular Ca2+ levels and downstream apoptotic signalling. [source] | ||||||||||