title: Complement receptor 1 inhibitors for prevention of immune-mediated red cell destruction: potential use in transfusion therapy.
abstract: Activation of complement cascade via the antibody-mediated classical pathway can initiate red blood cell (RBC) destruction, causing transfusion reactions and hemolytic anemia. In the present study, we have assessed the ability of a human recombinant soluble form of complement receptor 1 (sCR1) to inhibit complement-mediated RBC destruction in vitro and in vivo. Using an in vitro alloimmune incompatibility model, sCR1 inhibited complement activation and prevented hemolysis. Following transfusion of human group O RBCs into mice lacking detectable pre-existing antibodies against the transfused RBCs, systemic coadministration of 10 mg/kg sCR1, a dose well tolerated in human subjects for prevention of tissue injury, completely inhibited the in vivo clearance of the transfused RBCs and surface C3 deposition in the first hour after transfusion, correlating with the half-life of sCR1 in the circulation. Treatment with sCR1 increased the survival of transfused human group A RBCs in the circulation of mice with pre-existing anti-A for 2 hours after transfusion by 50%, reduced intravascular hemolysis, and lowered the levels of complement deposition (C3 and C4), but not immunoglobulin G (IgG) or IgM, on the transfused cells by 100-fold. We further identified potential functional domains in CR1 that can act to limit complement-mediated RBC destruction in vitro and in vivo. Collectively, our data highlight a potential use of CR1-based inhibitors for prevention of complement-dependent immune hemolysis.
authors.affiliation: Complement Biology Research Program, New York Blood Center, New York 10021, USA. kyazdanbakhsh@nybloodcenter.org
authors.forename: Karina
authors.initials: K
authors.lastname: Yazdanbakhsh
authors.forename: Stanley
authors.initials: S
authors.lastname: Kang
authors.forename: Daniel
authors.initials: D
authors.lastname: Tamasauskas
authors.forename: Dorothy
authors.initials: D
authors.lastname: Sung
authors.forename: Andromachi
authors.initials: A
authors.lastname: Scaradavou
mesh_terms: D000017:ABO Blood-Group System; D000743:Anemia, Hemolytic / Q000276:immunology / Q000517:prevention & control*; D000818:Animals; D001787:Blood Group Incompatibility / Q000188:drug therapy*; D001803:Blood Transfusion; D003169:Complement Inactivator Proteins / Q000627:therapeutic use*; D003165:Complement System Proteins / Q000032:analysis / Q000276:immunology; D006461:Hemolysis / Q000276:immunology*; D006801:Humans; D051379:Mice; D008810:Mice, Inbred C57BL; D011951:Receptors, Complement / Q000737:chemistry / Q000235:genetics / Q000627:therapeutic use*; D011994:Recombinant Proteins / Q000627:therapeutic use; D012091:Repetitive Sequences, Nucleic Acid; D012995:Solubility
chemical_list: D000017:ABO Blood-Group System; D003169:Complement Inactivator Proteins; D011951:Receptors, Complement; D011994:Recombinant Proteins; D003165:Complement System Proteins