title: Isotype-specific detection of ABO blood group antibodies using a novel flow cytometric method.
abstract: Several methods to detect anti-A/B antibodies based on haemagglutination and haemolysis have been described. These methods measure predominantly anti-A/B immunoglobulin (Ig)M, whereas anti-A/B IgG and IgG subclasses are less well examined. We established a flow cytometry method (ABO-fluorescence-activated cell sorting; ABO-FACS) to quantify binding of anti-A/B IgM, IgG and IgG subclasses to human A or B red blood cells. Anti-A/B IgM were present in the majority of 120 blood donors, as expected from blood group typing. The sensitivity and specificity of anti-A/B IgM to predict the blood group was 93% and 96% respectively. Anti-A/B IgG was found in 34/38 blood group O samples (89%). Anti-B IgG in blood group A or anti-A IgG in blood group B was present in 4/28 (14%) and 1/28 (4%) samples, respectively, and absent in 26 AB sera. IgG2 was the predominant IgG subclass. The correlation of anti-A/B IgM and IgG in the ABO-FACS with haemagglutination titres was 0.870 and 0.783, respectively (n = 240; P < 0.001) whereas the comparison of ABO-FACS with ABO-enzyme-linked immunosorbent assay was less significant. In conclusion, ABO-FACS is a valid method to quantify anti-A/B IgM, IgG and IgG subclasses. It opens the possibility of isotype-specific monitoring of anti-A/B antibodies levels after ABO-incompatible solid organ and stem cell transplantation.
authors.affiliation: Laboratory for Transplantation Immunology, Department of Internal Medicine, University Hospital Zürich, Zürich, Switzerland.
authors.forename: G
authors.initials: G
authors.lastname: Stussi
authors.forename: K
authors.initials: K
authors.lastname: Huggel
authors.forename: H U
authors.initials: HU
authors.lastname: Lutz
authors.forename: U
authors.initials: U
authors.lastname: Schanz
authors.forename: R
authors.initials: R
authors.lastname: Rieben
authors.forename: J D
authors.initials: JD
authors.lastname: Seebach
mesh_terms: D000017:ABO Blood-Group System; D000328:Adult; D000368:Aged; D001782:Blood Donors; D001788:Blood Grouping and Crossmatching / Q000379:methods*; D003429:Cross Reactions; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D005260:Female; D005434:Flow Cytometry / Q000379:methods; D006386:Hemagglutination Tests; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood; D007132:Immunoglobulin Isotypes / Q000097:blood*; D007075:Immunoglobulin M / Q000097:blood; D007518:Isoantibodies / Q000097:blood*; D008297:Male; D008875:Middle Aged
chemical_list: D000017:ABO Blood-Group System; D007074:Immunoglobulin G; D007132:Immunoglobulin Isotypes; D007075:Immunoglobulin M; D007518:Isoantibodies