Rabbit Anti-Human CD5 monoclonal antibody, clone TQ20

Dogs with Diffuse Large B-Cell Lymphoma (DLBCL) benefit from the addition of active immunotherapy to traditional chemotherapy. We hypothesized that immune cells within neoplastic lymph nodes (LNs) may play a role in the tumor pathobiology and treatment response. The present study describes the composition and prognostic role of non-neoplastic lymphocytes in LNs of 59 dogs with treatment-naive DLBCL receiving chemo-immunotherapy. The percentage of small non-neoplastic cells and of CD5+, CD21+, CD4+ and CD8+ small cells was recorded via flow cytometry. CD4+/CD8+ and CD5+/large CD21+ cell ratios were calculated. The likelihood of progression significantly diminished with increasing percentage of small cells, CD5+ and CD8+ small cells, and CD5+/large CD21+ cell ratio, with decreasing CD4+/CD8+ ratio and in non-anemic dogs. Active immunotherapy is more effective in dogs with higher percentage of non-neoplastic lymphocytes at diagnosis. We lay the ground for future studies assessing the role of the immune system in the pathobiology of canine DLBCL.

Primary low-grade dural marginal zone lymphoma is an indolent low grade lymphoma occurring especially among middle-aged immunocompetent women, and is not associated to an infectious process, contrary to gastric or intestinal marginal zone lymphomas. Dural location is rare since only 105 cases have been reported so far. We report herein on two additional cases, a 72-year-old woman and a 36-year-old man whose lymphoma was revealed by partial seizures and headaches. Morphological analysis of surgical specimens displayed a tumoral proliferation made of small lymphocytes arranged in sheets or in nodules with CD20, CD79a and BCL2-immunopositivity, but CD5 and CD10 negativity. Molecular analysis using a panel of 34 genes involved in lymphomagenesis disclosed a deletion of SOCS1 and TNFAIP3 genes, implicated in the JAK/STAT and NFKB pathways respectively in the first patient that could explain unfavourable prognosis despite complementary radiotherapy. No anomaly was identified in the second patient who is alive with no recurrence or progression seven years after the diagnosis. Currently, there are no standardized treatment schedules, but the vast majority of patients are treated by surgery, then radiotherapy followed by adjuvant chemotherapy using methotrexate atone or in combination with rituximab. Literature review indicates that five-year survival has been estimated at 96.7%, suggesting a better prognosis compared to other locations. (C) 2019 Elsevier Masson SAS. All rights reserved.