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Development of a recombinant anti‐Vel immunoglobulin M to identify Vel‐negative donors
Author(s) -
van der Rijst Marea V.E.,
LissenbergThunnissen Suzanne N.,
Ligthart Peter C.,
Visser Remco,
Jongerius John M.,
Voorn Lesley,
Veldhuisen Barbera,
Vidarsson Gestur,
van den Akker Emile,
van der Schoot C. Ellen
Publication year - 2019
Publication title -
transfusion
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.045
H-Index - 132
eISSN - 1537-2995
pISSN - 0041-1132
DOI - 10.1111/trf.15147
Subject(s) - antibody , recombinant dna , antigen , agglutination (biology) , medicine , immunology , titer , biology , gene , biochemistry
BACKGROUND Alloimmunization against the high‐frequency Vel blood group antigen may result in transfusion reactions or hemolytic disease of fetus and newborn. Patients with anti‐Vel alloantibodies require Vel‐negative blood but Vel‐negative individuals are rare (1:4000). Identification of Vel‐negative donors ensures availability of Vel‐negative blood; however, accurate Vel blood group typing is difficult due to variable Vel antigen expression and limited availability of anti‐Vel typing sera. We report the production of a recombinant anti‐Vel that also identifies weak Vel expression. STUDY DESIGN AND METHODS A recombinant anti‐Vel monoclonal antibody was produced by cloning the variable regions from an anti‐Vel–specific B cell isolated from an alloimmunized patient into a vector harboring the constant regions of immunoglobulin (Ig)G1‐kappa or IgM‐kappa. Antibody Vel specificity was tested by reactivity to SMIM1‐transfected HEK293T cells and by testing various red blood cells (RBCs) of donors with normal, weak, or no Vel expression. High‐throughput donor screening applicability was tested using an automated blood group analyzer. RESULTS A Vel‐specific IgM class antibody was produced. The antibody was able to distinguish between Vel‐negative and very weak Vel antigen–expressing RBCs by direct agglutination and in high‐throughput settings using a fully automated blood group analyzer and performed better than currently used human anti‐Vel sera. High‐throughput screening of 13,288 blood donations identified three new Vel‐negative donors. CONCLUSION We generated a directly agglutinating recombinant anti‐Vel IgM, M3F5S‐IgM, functional in manual, automated agglutination assays and flow cytometry settings. This IgM anti‐Vel will improve diagnostics by facilitating the identification of Vel‐negative blood donors.