title: A Memory B Cell Crossmatch Assay for Quantification of Donor-Specific Memory B Cells in the Peripheral Blood of HLA-Immunized Individuals.
abstract: Humoral responses against mismatched donor HLA are routinely measured as serum HLA antibodies, which are mainly produced by bone marrow-residing plasma cells. Individuals with a history of alloimmunization but lacking serum antibodies may harbor circulating dormant memory B cells, which may rapidly become plasma cells on antigen reencounter. Currently available methods to detect HLA-specific memory B cells are scarce and insufficient in quantifying the complete donor-specific memory B cell response due to their dependence on synthetic HLA molecules. We present a highly sensitive and specific tool for quantifying donor-specific memory B cells in peripheral blood of individuals using cell lysates covering the complete HLA class I and class II repertoire of an individual. Using this enzyme-linked immunospot (ELISpot) assay, we found a median frequency of 31 HLA class I and 89 HLA class II-specific memory B cells per million IgG-producing cells directed at paternal HLA in peripheral blood samples from women (n = 22) with a history of pregnancy, using cell lysates from spouses. The donor-specific memory B cell ELISpot can be used in HLA diagnostic laboratories as a cross-match assay to quantify donor-specific memory B cells in patients with a history of sensitizing events.
authors.affiliation: Department of Immunohaematology and Blood Transfusion, Leiden University Medical Center, Leiden, the Netherlands.
authors.forename: G E
authors.initials: GE
authors.lastname: Karahan
authors.affiliation: Department of Immunohaematology and Blood Transfusion, Leiden University Medical Center, Leiden, the Netherlands.
authors.forename: Y J H
authors.initials: YJH
authors.lastname: de Vaal
authors.affiliation: Department of Immunohaematology and Blood Transfusion, Leiden University Medical Center, Leiden, the Netherlands.
authors.forename: J
authors.initials: J
authors.lastname: Krop
authors.affiliation: Department of Immunohaematology and Blood Transfusion, Leiden University Medical Center, Leiden, the Netherlands.
authors.forename: C
authors.initials: C
authors.lastname: Wehmeier
authors.affiliation: Department of Immunohaematology and Blood Transfusion, Leiden University Medical Center, Leiden, the Netherlands.
authors.forename: D L
authors.initials: DL
authors.lastname: Roelen
authors.affiliation: Department of Immunohaematology and Blood Transfusion, Leiden University Medical Center, Leiden, the Netherlands.
authors.forename: F H J
authors.initials: FHJ
authors.lastname: Claas
authors.affiliation: Department of Immunohaematology and Blood Transfusion, Leiden University Medical Center, Leiden, the Netherlands.
authors.forename: S
authors.initials: S
authors.lastname: Heidt
mesh_terms: D001323:Autoantibodies / Q000276:immunology; D001402:B-Lymphocytes / Q000276:immunology*; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006680:HLA Antigens / Q000276:immunology*; D006650:Histocompatibility Testing; D006801:Humans; D007156:Immunologic Memory; D011247:Pregnancy
chemical_list: D001323:Autoantibodies; D006680:HLA Antigens
keywords: alloantibody; basic (laboratory) research/science; clinical research/practice; histocompatibility; immunobiology; major histocompatibility complex (MHC); organ transplantation in general