title: New crossmatch technique eliminates interference by humanized and chimeric monoclonal antibodies.
abstract: Humanized and chimeric antilymphocyte antibodies (Ab) are used to prevent and treat rejection and for treatment of human disease. Rituximab (RIT, anti-CD20), daclizumab (DAC; anti-CD25), alemtuzumab (ALE; anti-CD52), or infliximab (IFX) may interfere with Ab detection methods such as complement-dependent cytotoxicity (CDC) and flow cytometric crossmatch (FCXM). These agents are recognized as anti-human Ab or fix complement and are not differentiated from anti-allo-Ab. A new enzyme-linked immunosorbent assay crossmatch (XM) utilizing class I and II HLA antigens from donor cells called Transplant Monitoring System (TMS; GTI, Waukesha, Wisc) potentially precludes interference by eliminating non-major histocompatability complex antigens. To test this, normal sera (nonsensitized volunteers) were supplemented with 0.1 or 10 microg/mL of RIT, DAC, IFX or ALE, and were tested using three methods: the TMS T-cell CDCXM with antihuman globulin (AHG); and B-cell CDCXM without AHG; and FCXM with mean channel shifts of 45 and 150 indicating positive T-cell and B-cell crossmatch, respectively. No reactivity occurred with normal sera using any crossmatch technique. At 0.1 and 10 microg/mL, RIT interfered with CDC B-cell, but not T-cell crossmatch. RIT at 10, but not 0.1 microg/mL interfered with B-cell FCXM. No interference occurred with RIT in T-cell FCXM or TMS. ALE interfered with B-cell and T-cell CDC and FCXM but neither class I nor II TMS. DAC did not interfere with CDC or FCXM at 0.1 microg/mL, but gave false positive B-cell FCXM and CDCXM with some samples. No interference by DAC occurred using TMS. TMS may be useful to differentiate de novo donor-specific Ab after treatment with humanized or chimeric Ab.
authors.affiliation: Department of Surgery, Indiana University, Indianapolis, Indiana 46202, USA. bbook@iupui.edu
authors.forename: B K
authors.initials: BK
authors.lastname: Book
authors.forename: A
authors.initials: A
authors.lastname: Agarwal
authors.forename: A B
authors.initials: AB
authors.lastname: Milgrom
authors.forename: C M
authors.initials: CM
authors.lastname: Bearden
authors.forename: R A
authors.initials: RA
authors.lastname: Sidner
authors.forename: N G
authors.initials: NG
authors.lastname: Higgins
authors.forename: M D
authors.initials: MD
authors.lastname: Pescovitz
mesh_terms: D000074323:Alemtuzumab; D000911:Antibodies, Monoclonal / Q000097:blood* / Q000494:pharmacology; D061067:Antibodies, Monoclonal, Humanized; D058846:Antibodies, Monoclonal, Murine-Derived; D000912:Antibodies, Neoplasm / Q000494:pharmacology; D001803:Blood Transfusion; D002678:Chimera; D000077561:Daclizumab; D004797:Enzyme-Linked Immunosorbent Assay; D006650:Histocompatibility Testing / Q000379:methods*; D006801:Humans; D007074:Immunoglobulin G / Q000494:pharmacology; D000069285:Infliximab; D008297:Male; D012016:Reference Values; D000069283:Rituximab; D018183:Transplantation Chimera; D019172:Transplantation Conditioning
chemical_list: D000911:Antibodies, Monoclonal; D061067:Antibodies, Monoclonal, Humanized; D058846:Antibodies, Monoclonal, Murine-Derived; D000912:Antibodies, Neoplasm; D007074:Immunoglobulin G; D000074323:Alemtuzumab; D000069283:Rituximab; D000069285:Infliximab; D000077561:Daclizumab