title: Flow cytometric analyses of the subclasses of red cell IgG antibodies.
abstract: We report on flow cytometric IgG subclass determinations of red cell antibodies using polyclonal FITC-labeled antibodies. The limit of detection of this method was 1 ng anti-D per 1 x 10(7) red cells. The inter- and intra-assay coefficients of variance were 8.2 and 2.3%, respectively. In 8 newborns with a positive direct antiglobulin test (DAT) in the gel centrifugation test (GCT), due to ABO antibodies, IgG1 was detected in all and IgG2 additionally in 4 of these cases. In 5 severe cases of hemolytic disease of the newborn (HDN) due to anti-D, large amounts of IgG1 were found, and in 3 of these 5, IgG3 in combination with IgG1. In 8 mild or moderate HDN cases (4 anti-D, 2 anti-E, 1 anti-Fya, 1 anti-Jka), phototherapy sufficed, and IgG1 was the only antibody. In 7 adult patients with malignant lymphoma and a positive DAT (GCT), only small amounts of IgG1 red cell autoantibodies could be demonstrated by flow cytometry. In 5 further patients with malignant lymphoma, a positive DAT, and severe hemolytic anemia, large amounts of IgG1 autoantibodies were found and IgG3 was also present in 3 of these cases. Flow-cytometric determination of IgG subclasses may be a useful tool in immunohematology, since subclass determinations were possible in all of these cases. This method is suited for clinical routine and offers the possibility of sufficient standardization.
authors.affiliation: Abteilung Transfusionsmedizin, Klinikum der Universität, Göttingen, Deutschland.
authors.forename: R
authors.initials: R
authors.lastname: Lynen
authors.forename: R
authors.initials: R
authors.lastname: Neuhaus
authors.forename: D W
authors.initials: DW
authors.lastname: Schwarz
authors.forename: G
authors.initials: G
authors.lastname: Simson
authors.forename: J
authors.initials: J
authors.lastname: Riggert
authors.forename: W R
authors.initials: WR
authors.lastname: Mayr
authors.forename: M
authors.initials: M
authors.lastname: Köhler
mesh_terms: D000328:Adult; D000743:Anemia, Hemolytic / Q000097:blood / Q000175:diagnosis / Q000209:etiology / Q000276:immunology; D001323:Autoantibodies / Q000097:blood*; D001789:Blood Group Antigens / Q000276:immunology*; D003298:Coombs Test; D004899:Erythroblastosis, Fetal / Q000097:blood / Q000175:diagnosis / Q000276:immunology* / Q000628:therapy; D004912:Erythrocytes / Q000276:immunology*; D005078:Exchange Transfusion, Whole Blood; D005260:Female; D005313:Fetal Death / Q000209:etiology; D005434:Flow Cytometry; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood / Q000145:classification*; D007231:Infant, Newborn; D007518:Isoantibodies / Q000097:blood / Q000145:classification*; D008223:Lymphoma / Q000150:complications; D010789:Phototherapy; D011247:Pregnancy; D011248:Pregnancy Complications / Q000097:blood / Q000276:immunology; D012203:Rh Isoimmunization / Q000097:blood / Q000276:immunology; D012720:Severity of Illness Index
chemical_list: D001323:Autoantibodies; D001789:Blood Group Antigens; D007074:Immunoglobulin G; D007518:Isoantibodies