title: In vitro evaluation of the efficacy and biocompatibility of new, synthetic ABO immunoabsorbents.
abstract: Synthetic ABO immunoabsorbents (known as Synsorbs) were in use for several years to specifically eliminate ABO antibodies from the patient's circulation before ABO-incompatible organ or bone marrow transplantation. Because Synsorbs are no longer available, we have developed new ABO immunoabsorbents. These substances, termed BioSorbents A and B, respectively, consist of synthetic A or B trisaccharides covalently coupled to macroporous glass beads via polyacrylamide. Here we report the evaluation of BioSorbents in regard to efficacy, specificity, and biocompatibility. Using a closed-circuit in vitro system, representing a 1:10-1:20 scale as compared with the immunoabsorption procedure with an adult patient, blood group O plasma was run through columns filled with ethylene oxide-sterilized BioSorbent. Hemagglutination was reduced by 4 titer steps after absorption, and anti-A and/or anti-B IgM/G/A, as measured by ABO ELISA, dropped by 85% or more, while no nonspecific absorption of immunoglobulins occurred. No significant changes could be observed for complement (C3, C4, and total hemolytic complement of the classical pathway) or for coagulation parameters (fibrinogen, prothrombin time, activated partial thromboplastin time). As monitored by immunoblotting, neither factor XII nor high molecular weight kininogen was cleaved. In addition, a monocyte phagocytosis inhibition test provided evidence that no significant aggregation of IgG had occurred during absorption. We conclude that BioSorbents A and B are efficient, specific, and biocompatible with human plasma.
authors.affiliation: Central Hematology Laboratory, University of Bern, Switzerland.
authors.forename: R
authors.initials: R
authors.lastname: Rieben
authors.forename: E Y
authors.initials: EY
authors.lastname: Korchagina
authors.forename: E
authors.initials: E
authors.lastname: von Allmen
authors.forename: J K
authors.initials: JK
authors.lastname: Hovinga
authors.forename: B
authors.initials: B
authors.lastname: Lammle
authors.forename: T W
authors.initials: TW
authors.lastname: Jungi
authors.forename: N V
authors.initials: NV
authors.lastname: Bovin
authors.forename: U E
authors.initials: UE
authors.lastname: Nydegger
mesh_terms: D000017:ABO Blood-Group System / Q000276:immunology*; D000328:Adult; D001672:Biocompatible Materials / Q000494:pharmacology*; D003165:Complement System Proteins / Q000032:analysis; D005174:Factor XII / Q000378:metabolism; D006801:Humans; D007074:Immunoglobulin G / Q000032:analysis; D007075:Immunoglobulin M / Q000032:analysis; D007164:Immunosorbents / Q000494:pharmacology*; D010587:Phagocytosis
chemical_list: D000017:ABO Blood-Group System; D001672:Biocompatible Materials; D007074:Immunoglobulin G; D007075:Immunoglobulin M; D007164:Immunosorbents; D005174:Factor XII; D003165:Complement System Proteins