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CD20 Antigen (cd20 + antigen)
Selected AbstractsPerformance of calibration standards for antigen quantitation with flow cytometry in chronic lymphocytic leukemiaCYTOMETRY, Issue 6 2007Eva D. Rossmann Abstract Background: The fluorescence intensities of CD3, CD4 on T cells and CD20, CD22 molecules on B cells were quantitatively measured on lymphocytes from chronic lymphocytic leukemia (CLL) patients and healthy donors. Methods: The performance of three different types of microbeads was compared, i.e. Quantum molecules of equivalent soluble fluorochrome (Q-MESF), Quantum simply cellular (QSC), and QuantiBRITEÔ (QB). As all PE-conjugates had a F/P ratio of 1:1, the MESF units represented also the antibody binding capacity (ABC). Results: The ABCs of CD4 and CD20 antigens estimated with QSC (ABCQSC) were higher than those assigned with QB (ABCQB) with an average difference 49%. Higher numbers of antigenic sites were obtained with Q-MESF than with QSC for CD20 antigen. On the contrary, CD4 antigenic sites numbers estimated with QSC were higher than those estimated with Q-MESF. ABC values estimated with Quantum MESF PE (ABCQ-MESF) were ,15% higher than ABCQSC, whereas ABCQ-MESF was ,49% higher than ABCQB. Statistically significant correlations were found between the values obtained using various standards. The present study is the first to report down-regulation of CD3 antigen on T cells from patients with CLL. Conclusions: This study emphasizes the relevance of quantitative measurement of fluorescence intensity by flow cytometry as a standardized approach to measure and interpret the expression of some CLL markers and reduce variability of results obtained at different sites in multi-center clinical studies. © 2007 Clinical Cytometry Society [source] Large B-cell lymphoma of the legINTERNATIONAL JOURNAL OF DERMATOLOGY, Issue 10 2001Elsa Vasquez-del-Mercado MD A 74-year-old Mexican man presented with an 18-month history of multiple, violaceous, coalescing, firm, tender nodules with an ulcer in the anterior aspect of the right leg (Fig. 1) and slightly infiltrated, ill-defined erythematous plaques affecting the left leg and both forearms. He had not received any treatment for his condition. Past medical history was relevant for noninsulin-dependent diabetes mellitus and hypertension without formal treatment and a history of heavy alcohol intake in his youth. A biopsy specimen of both plaque-type lesions of the forearm and tumorous lesions of the leg showed a diffuse, nonepidermotropic mononuclear infiltrate throughout the dermis and extending to the subcutis. The infiltrate was composed of pleomorphic, atypical, large mononuclear cells (Fig. 2). Immunostaining with CD20 was positive for the atypical cells while CD3 was positive for normal appearing lymphocytes, characterized as reactive T cells. Additional laboratory and image studies ruled out extracutaneous involvement. The diagnosis of primary cutaneous large B cell lymphoma of the leg (LBCLL) was made. The patient was initiated on radiotherapy localized to the right leg with a very good initial response, nevertheless resolution was not achieved and the plaques in the rest of the limbs remained unchanged. Thus, the patient started chemotherapy with CHOP (Cyclophosphamide, Vincristine, Doxorubicin, Prednisone). He has currently finished his fourth cycle with this chemotherapy regimen. The tumorous lesions involuted leaving only residual hyperpigmentation (Fig. 3) and the plaques in the rest of the limbs disappeared, the area of the ulcer diminished considerably. There is still no evidence of extracutaneous involvement. Figure 1. Nodules and ulcer in the anterior aspect of the right leg Figure 2. Atypical lymphocytes, with large, pleomorphic nuclei and multiple nucleoles. Positivity for CD20 antigen was demonstrated by immunohistochemical analysis (hematoxylin and eosin; X 600) Figure 3. Residual hyperpigmentation and granulation tissue after chemotherapy [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] Rituximab in the adjuvant treatment of pemphigus vulgaris: a prospective open-label pilot study in five patientsBRITISH JOURNAL OF DERMATOLOGY, Issue 5 2007M.S.Y. Goh Summary Background, Rituximab is a monoclonal antibody directed against the CD20 antigen expressed on B lymphocytes. There are reports of its efficacy in the treatment of autoimmune diseases, including pemphigus. Objectives, Prospectively to evaluate the efficacy of rituximab as adjuvant treatment for pemphigus vulgaris (PV). Methods, Patients with PV were treated with intravenous rituximab (375 mg m,2) weekly for 4 weeks in this prospective open-label pilot study. Other concurrent immunosuppression was continued. Results, Of five patients, one achieved complete remission and was able to cease all medication, while two achieved clearance of clinical lesions but continued on systemic therapy. Two patients had progressive disease. Time to response was 2,8 months, with a 13- to 18-month response duration. Response was associated with reduction in serum antiepithelial antibodies. Two patients had significant infectious complications (one developed community-acquired pneumonia associated with delayed-onset neutropenia and the other developed cytomegalovirus infection). Conclusions, Rituximab has shown efficacy in the treatment of PV. Patients on multiple immunosuppressives should be closely monitored for infectious complications. [source] Remarkable remission of a follicular lymphoma treated with rituximab and polychemotherapy (CHOP)CLINICAL & EXPERIMENTAL DERMATOLOGY, Issue 1 2003T. Schmook Summary We describe a 50-year-old female patient who developed extensive lymphomatous infiltrates on her forehead, scalp and face within a few months. Histology and immunohistochemistry of skin tumours revealed a CD20 positive follicular B-cell lymphoma. Subsequently, extracutaneous manifestations were detected by computed tomography scans and bone marrow biopsy. The patient suffered from a primary nodular malignant lymphoma with extraordinary cutaneous infiltration of the head. Therefore, combination treatment with a monoclonal antibody against the CD20 antigen, rituximab, and polychemotherapy (CHOP scheme) was administered every 3 weeks. After the second course of treatment a complete regression of cutaneous infiltrates was noticed. Follow-up biopsies on the forehead showed no evidence of CD20 positive lymphoma cells, now. Despite mild leucocytopaenia therapy was well tolerated. [source] Performance of calibration standards for antigen quantitation with flow cytometry in chronic lymphocytic leukemiaCYTOMETRY, Issue 6 2007Eva D. Rossmann Abstract Background: The fluorescence intensities of CD3, CD4 on T cells and CD20, CD22 molecules on B cells were quantitatively measured on lymphocytes from chronic lymphocytic leukemia (CLL) patients and healthy donors. Methods: The performance of three different types of microbeads was compared, i.e. Quantum molecules of equivalent soluble fluorochrome (Q-MESF), Quantum simply cellular (QSC), and QuantiBRITEÔ (QB). As all PE-conjugates had a F/P ratio of 1:1, the MESF units represented also the antibody binding capacity (ABC). Results: The ABCs of CD4 and CD20 antigens estimated with QSC (ABCQSC) were higher than those assigned with QB (ABCQB) with an average difference 49%. Higher numbers of antigenic sites were obtained with Q-MESF than with QSC for CD20 antigen. On the contrary, CD4 antigenic sites numbers estimated with QSC were higher than those estimated with Q-MESF. ABC values estimated with Quantum MESF PE (ABCQ-MESF) were ,15% higher than ABCQSC, whereas ABCQ-MESF was ,49% higher than ABCQB. Statistically significant correlations were found between the values obtained using various standards. The present study is the first to report down-regulation of CD3 antigen on T cells from patients with CLL. Conclusions: This study emphasizes the relevance of quantitative measurement of fluorescence intensity by flow cytometry as a standardized approach to measure and interpret the expression of some CLL markers and reduce variability of results obtained at different sites in multi-center clinical studies. © 2007 Clinical Cytometry Society [source] | ||||||||||