1. Monitoring of the Complement System Status in Patients With B-Cell Malignancies Treated With Rituximab.
- Author
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Felberg A, Taszner M, Urban A, Majeranowski A, Jaskuła K, Jurkiewicz A, Stasiłojć G, Blom AM, Zaucha JM, and Okrój M
- Subjects
- Antibodies, Monoclonal, Humanized pharmacology, Antibodies, Monoclonal, Murine-Derived pharmacology, Antigens, CD20 immunology, Antineoplastic Combined Chemotherapy Protocols pharmacology, Cell Line, Tumor, Complement Activation drug effects, Complement Activation immunology, Humans, Lymphoma, Non-Hodgkin drug therapy, Lymphoma, Non-Hodgkin immunology, B-Lymphocytes drug effects, B-Lymphocytes immunology, Complement System Proteins immunology, Leukemia, Lymphocytic, Chronic, B-Cell drug therapy, Leukemia, Lymphocytic, Chronic, B-Cell immunology, Rituximab pharmacology
- Abstract
Rituximab is a pioneering anti-CD20 monoclonal antibody that became the first-line drug used in immunotherapy of B-cell malignancies over the last twenty years. Rituximab activates the complement system in vitro , but there is an ongoing debate on the exact role of this effector mechanism in therapeutic effect. Results of both in vitro and in vivo studies are model-dependent and preclude clear clinical conclusions. Additional confounding factors like complement inhibition by tumor cells, loss of target antigen and complement depletion due to excessively applied immunotherapeutics, intrapersonal variability in the concentration of main complement components and differences in tumor burden all suggest that a personalized approach is the best strategy for optimization of rituximab dosage and therapeutic schedule. Herein we critically review the existing knowledge in support of such concept and present original data on markers of complement activation, complement consumption, and rituximab accumulation in plasma of patients with chronic lymphocytic leukemia (CLL) and non-Hodgkin's lymphomas (NHL). The increase of markers such as C4d and terminal complement complex (TCC) suggest the strongest complement activation after the first administration of rituximab, but not indicative of clinical outcome in patients receiving rituximab in combination with chemotherapy. Both ELISA and complement-dependent cytotoxicity (CDC) functional assay showed that a substantial number of patients accumulate rituximab to the extent that consecutive infusions do not improve the cytotoxic capacity of their sera. Our data suggest that individual assessment of CDC activity and rituximab concentration in plasma may support clinicians' decisions on further drug infusions, or instead prescribing a therapy with anti-CD20 antibodies like obinutuzumab that more efficiently activate effector mechanisms other than complement., (Copyright © 2020 Felberg, Taszner, Urban, Majeranowski, Jaskuła, Jurkiewicz, Stasiłojć, Blom, Zaucha and Okrój.)
- Published
- 2020
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