title: Complement activation plays a key role in antibody-induced infusion toxicity in monkeys and rats.
abstract: Infusion reactions are a major side effect of the administration of therapeutic Abs and are the result of a complex immune reaction. In this study, we report that substitutions of Fc amino acids in the anti-HLA-DR Ab HD8 reduce its ability to induce infusion reactions in rats and monkeys. We first showed that i.v. administration of IgG1- and IgG2-subclass HD8 Abs induces severe infusion reactions in monkeys. These Abs express strong complement-dependent cytotoxicity (CDC), and in vivo depletion of complement in rats by pretreatment with cobra venom factor abrogated the lethal infusion reactions generated by HD8-IgG1. Thus, the infusion reactions appear to be largely driven by the complement system. To reduce the CDC function of HD8-IgG1, its Fc region was modified by two amino acid substitutions at Pro(331)Ser and Lys(322)Ala. The modified Ab was incapable of expressing CDC in vitro and did not induce severe infusion reactions in rats and monkeys, even at extremely high doses. The modified Ab retained its Ab-dependent cellular cytotoxicity function as well as its antitumor activity in a tumor-bearing mouse model. In summary, complement appears to drive infusion reactions, and modifications that eliminate the CDC activity of an Ab also reduce its ability to induce infusion reactions.
authors.affiliation: Discovery Research Laboratories, Kirin Pharma, Miyahara 3, Takasaki, Gunma, Japan. ttawara@kirin.co.jp
authors.forename: Tomonori
authors.initials: T
authors.lastname: Tawara
authors.forename: Kazumasa
authors.initials: K
authors.lastname: Hasegawa
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Sugiura
authors.forename: Katsuhiko
authors.initials: K
authors.lastname: Harada
authors.forename: Toru
authors.initials: T
authors.lastname: Miura
authors.forename: Sunao
authors.initials: S
authors.lastname: Hayashi
authors.forename: Tomoyuki
authors.initials: T
authors.lastname: Tahara
authors.forename: Masaharu
authors.initials: M
authors.lastname: Ishikawa
authors.forename: Hideaki
authors.initials: H
authors.lastname: Yoshida
authors.forename: Kinya
authors.initials: K
authors.lastname: Kubo
authors.forename: Isao
authors.initials: I
authors.lastname: Ishida
authors.forename: Shiro
authors.initials: S
authors.lastname: Kataoka
mesh_terms: D000818:Animals; D020296:Animals, Congenic; D000920:Antibody-Dependent Cell Cytotoxicity / Q000276:immunology*; D000970:Antineoplastic Agents / Q000008:administration & dosage / Q000627:therapeutic use; D016466:CHO Cells; D002460:Cell Line; D045744:Cell Line, Tumor; D003167:Complement Activation / Q000276:immunology*; D003165:Complement System Proteins / Q000633:toxicity; D006224:Cricetinae; D003412:Cricetulus; D006684:HLA-DR Antigens / Q000276:immunology / Q000378:metabolism; D006801:Humans; D007141:Immunoglobulin Fc Fragments / Q000008:administration & dosage / Q000235:genetics / Q000378:metabolism; D007262:Infusions, Intravenous / Q000009:adverse effects; D007518:Isoantibodies / Q000008:administration & dosage / Q000627:therapeutic use / Q000633:toxicity*; D008223:Lymphoma / Q000276:immunology / Q000401:mortality / Q000628:therapy; D008252:Macaca fascicularis; D008297:Male; D051379:Mice; D016513:Mice, SCID; D051381:Rats; D014183:Transplantation, Heterologous
chemical_list: D000970:Antineoplastic Agents; D006684:HLA-DR Antigens; D007141:Immunoglobulin Fc Fragments; D007518:Isoantibodies; D003165:Complement System Proteins