Different levels of CD52 antigen expression evaluated by quantitative fluorescence cytometry are detected on B‐lymphocytes, CD 34⁺ cells and tumor cells of patients with chronic B‐cell lymphoproliferative diseases

Analysis of the antibody repertoire of patients with mantle cell lymphoma directed against mantle cell lymphoma-associated antigens

“…In contrast, the expression pattern of CD52, which can function as a costimulatory molecule for the induction of CD4 + regulatory T cells [18], is more restricted: CD52 is expressed by B and T lymphocytes, natural killer cells, monocytes, macrophages, red blood cells, platelets, hematopoietic progenitor cells [15,16], and mast cells [19]. Among hematologic neoplasms, the expression of CD52 is heterogeneous [20], but MCL cells express CD52 consistently [20][21][22] rendering MCL a promising target for therapy with the monoclonal antibody alemtuzumab, a humanized monoclonal antibody against CD52, even though experience with the anti-CD52 antibody in MCL is limited [23,24]. Notably, the MCL patient with serum anti-CD52 antibodies in our study had never been treated with alemtuzumab, excluding the possibility that the immune response in her serum might have had its origin in an idiotypic anti-alemtuzumab immune response.…”

Immune Mechanisms Underlying the Beneficial Effects of Autologous Hematopoietic Stem Cell Transplantation in Multiple Sclerosis

“…One early report suggested that it is present on more than 95% of thymocytes [26]. Importantly, however, its expression on CD34 + HSCs is low [27]. Binding of alemtuzumab to CD52 leads to cytotoxicity through different mechanisms, including antibody-mediated cytolysis [28], complement-induced membrane attack complex [29], and apoptosis [30,31].…”

Residual Cancer Lymphocytes in Patients With Chronic Lymphocytic Leukemia After Therapy Show Increased Expression of Surface Antigen CD52 Detected Using Quantitative Fluorescence Cytometry

“…12 The function of CD52 in the immune system is not known, and its expression by CLL cells is lower than that in, for example, either mantle cell lymphoma or normal B-lymphocytes. 14 We assume that in addition to cell cycle arrest and direct apoptosis induction the effectiveness of the monoclonal antibodies on tumor cells occurs through effector mechanisms of the immune system, the necrosis-causing complement-dependent cytotoxicity (CDC) and antibody-dependent cellular cytotoxicity (ADCC). Although we know neither the complex working of these mechanisms in vivo nor their role in individual compartments, studies have been able to illustrate them separately in vitro.…”