Original article

Blood Transfusion - 4 2022 (July-August)

ABO antibody titres: a multisite comparative study of equivalency and reproducibility for automated solid-phase and haemagglutination titration, and manual dilution with gel column agglutination technology


Key words: ABO automated titrations, isotype (IgM,IgG), titre range, ABO antibody
Publication Date: 2022-01-22


Background - ABO antibody titres are important in many clinical decisions; however, much variability is observed in titre results. For reliable and reproducible titre results, automated ABO titration methods have been developed. In this 10-site study, we evaluated the equivalency of the automated ABO titration assays on the Galileo NEO, a fully automated blood bank analyzer (Immucor, Inc.) to manual titration with gel Column Agglutination Technology (CAT), as well as the reproducibility of both methods.
Materials and methods - Ten different locations participated in this study. The equivalency study included 70 random samples at each site. The reproducibility study tested the same blinded 30-sample panel at each study site. Anti-A and anti-B IgM and IgG antibody titres were tested with both the automated and manual methods; additionally, dithiothreitol (DTT) treatment was used to inactivate IgM antibodies in the manual CAT method.
Results - The equivalency between CAT manual method and Galileo NEO automated titres at each site ranged from 38 to 88%; equivalency for each isotype was 66.2% for IgM, 60.6% for IgG, and 88.5% for DTT-treated IgG. The reproducibility study evaluated the titre variation of each sample obtained from the 10 sites. The average titre ranges (in doubling dilutions) for the automated and manual methods, respectively, were 2.15±1.0 and 4.03±1.8 for IgM, and 1.53±0.7 and 4.10±1.9 for IgG; for the manual DTT-treated IgG, the average titre range was 3.45±1.8 doubling dilutions.
Discussion - The results demonstrated that the Galileo NEO automated and manual CAT ABO titres are not equivalent. However, the study also demonstrated that titre reproducibility is enhanced with the Galileo NEO automated ABO titration assays relative to the manual CAT ABO titration method.  Therefore, to improve management of patients receiving care across multiple institutions, our study supports the use of automated ABO titration.



Dana Schneider - Immucor Inc., Norcross, GA, United States of America

Mariangela Vicarioto - Department of Transfusion Medicine, University Hospital of Padua, Padua, Italy

Serelina Coluzzi - Blood Transfusion Service and Haematology, Umberto I Hospital, Rome, Italy

Antonella Matteocci - Transfusion Medicine Unit, San Camillo Forlanini Hospital, Rome, Italy

Nicoletta Revelli - Department of Transfusion Medicine and Haematology and Lombardy Regional Rare Blood Bank, IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy

Barbara Foglieni - Department of Transfusion Medicine and Haematology ASST Lecco, Lecco, Italy

Patrizia Artusi - Department of Transfusion Medicine, Azienda Ospedaliera Universitaria Policlinico, Modena, Italy

Donatella Londero - Department of Transfusion Medicine, Azienda Sanitaria Universitaria Friuli Centrale, Udine, Italy

Anna Quaglietta - Department of Haematolgy and Oncology, Center of Transfusion Medicine, Pescara General Hospital, Pescara, Italy

Giancarla Barrotta - Department of Transfusion Medicine, Giovanni Paolo II Hospital, Ragusa, Italy

Domenico Visceglie - Blood Transfusion Service, Di Venere Hospital Bari, Italy

Giuseppina Portararo - Department of Transfusion Medicine, University Hospital, Parma, Italy

Jonella Gilsdorf - Immucor Inc., Norcross, GA, United States of America

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