title: Comparison of conventional tube test with diamed gel microcolumn assay for anti-D titration.
abstract: Anti-D titration is the first step in the evaluation of the RhD-sensitized patient. Traditionally, anti-D titration has been performed by tube agglutination. Gel microcolumn assay is a method that has gained widespread usage throughout the world, mainly for ABO/Rh typing, unexpected antibody screening and direct antiglobulin tests. As gel assay has become widely used as a routine method to detect red blood cell alloantibodies, a critical anti-D titer needs to be established. Seventy-nine known blood samples with anti-D (titers 1-32) were titrated simultaneously by the conventional tube test and the gel microcolumn assay. Red blood cells (R0r phenotype) were used, with a final concentration of 3% for tube and 0.8% for gel. Serial twofold dilutions (2-2.048) were prepared for each technique, followed by reading in antiglobulin phase. Anti-D titration in the gel microcolumn assay showed significantly higher titers (mean 3.4-fold) than the conventional tube test in all samples studied. Based on these data, it was not possible to determine a critical titer for anti-D titration by the gel microcolumn assay.
authors.affiliation: Hematology Department, University of São Paulo Medical School and Immunohematology Department, Fundação Pró-Sangue/Hemocentro de São Paulo, São Paulo, Brazil.
authors.forename: M C Z
authors.initials: MC
authors.lastname: Novaretti
authors.forename: E
authors.initials: E
authors.lastname: Jens
authors.forename: T
authors.initials: T
authors.lastname: Pagliarini
authors.forename: S L
authors.initials: SL
authors.lastname: Bonifácio
authors.forename: P E
authors.initials: PE
authors.lastname: Dorlhiac-Llacer
authors.forename: D A F
authors.initials: DA
authors.lastname: Chamone
mesh_terms: D001788:Blood Grouping and Crossmatching / Q000379:methods*; D015941:Complement Hemolytic Activity Assay; D006386:Hemagglutination Tests / Q000379:methods*; D006801:Humans; D007518:Isoantibodies / Q000097:blood*; D012204:Rh-Hr Blood-Group System / Q000032:analysis / Q000276:immunology; D018029:Rho(D) Immune Globulin; D017186:Titrimetry
chemical_list: D007518:Isoantibodies; C061961:RHO(D) antibody; D012204:Rh-Hr Blood-Group System; D018029:Rho(D) Immune Globulin; C026410:Rho(D) antigen