Cluster designation (CD) 20 antigen is expressed on most B-cell lymphomas and serves as a therapeutic target for rituximab. A small minority of aggressive B-cell lymphomas, predominantly plasmablastic variants, do not express CD 20. We systematically reviewed all cases of aggressive B-cell lymphomas diagnosed at our institution over a period of 13 years. Of the 232 cases, 7 did not express CD 20. Five of these were plasmablastic lymphomas while two were unclassifiable B-cell lymphomas. While most of the plasmablastic lymphomas responded to chemotherapy, patients with unclassifiable lymphomas were primarily refractory or relapsed soon after chemotherapy.
The distribution of subpopulations of lymphocytes in lymph nodes and tumors from cattle with enzootic bovine leukosis (EBL) was examined by immunohistochemistry using a panel of monclonal antibodies against leukocyte differentiation molecules of EBL. The lesions in lymph nodes could be divided into three types based on the extent of infiltration and proliferation of neoplastic cells with provirus and differential expression of leukocyte differentiation molecules. The number of B-B2+, sIgM+ cells was reduced in frequency in follicles during the neoplastic cell proliferation. CD4- and CD8-positive α/β T cells and γ/δ T cells positive for WC1 (workshop cluster designation) were also reduced in frequency in areas infiltrated with neoplastic cells. Almost all neoplastic cells were B-B2- and IgM-positive. However, there were a few B-B2- and/or IgM-negative cells or cells stained faintly in all cases. WC1+ cells were not observed in tumor tissues. However, CD4+ and CD8+ cells were observed throughout tumor tissues, suggesting a role for these cells in tumor immunity.
Changing Faces of Obstructive Sleep Apnea: Treatment Effects by Cluster Designation in the Icelandic Sleep Apnea Cohort