title: A and B antigen levels acquired by group O donor-derived erythrocytes following ABO-non-identical transfusion or minor ABO-incompatible haematopoietic stem cell transplantation.
abstract: OBJECTIVE
  ABO-incompatible haematopoietic stem cell transplantation (HSCT) presents a challenge to blood component transfusion. The aim of this study was to investigate the weak blood group A or B antigen expression by donor-derived group O red blood cells (RBC) observed following transfusion or minor ABO-incompatible HSCT. In addition, in vitro experiments were performed to elucidate possible mechanisms underlying this phenomenon.
  
  
  METHODS
  A sensitive flow cytometry assay for the semi-quantification of RBC A/B antigen levels was used to assess patient samples and evaluate in vitro experiments.
  
  
  RESULTS
  Analysis of blood samples from patients, originally typed as A, B and AB but recently transplanted or transfused with cells from group O donors, revealed the A antigen expression on donor-derived RBC, ranging from very low levels in non-secretor individuals to almost subgroup Ax-like profiles in group A secretors. The B antigen expression was less readily detectable. In vitro experiments, in which group O donor RBC were incubated with (i) group A/B secretor/non-secretor donor plasma or (ii) group A/B donor RBC in the absence of plasma, supported the proposed adsorption of A/B antigen-bearing glycolipids from secretor plasma but also indicated a secretor-independent mechanism for A/B antigen acquisition as well as direct cell-to-cell transfer of ABO antigens.
  
  
  CONCLUSIONS
  The in vivo conversion of donor-derived blood group O RBC to ABO subgroup-like RBC after transfusion or minor ABO-incompatible HSCT raises the question of appropriate component selection. Based on these data, AB plasma should be transfused following ABO-incompatible HSCT.
authors.affiliation: Clinical Immunology and Transfusion Medicine, Division of Laboratory Medicine, Office of Medical Services, Lund University, Lund, Sweden.|Division of Hematology and Transfusion Medicine, Department of Laboratory Medicine, Lund University, Lund, Sweden.
authors.forename: A K
authors.identifier: http://orcid.org/0000-0002-2503-7016
authors.initials: AK
authors.lastname: Hult
authors.affiliation: Clinical Immunology and Transfusion Medicine, Division of Laboratory Medicine, Office of Medical Services, Lund University, Lund, Sweden.
authors.forename: J H
authors.initials: JH
authors.lastname: Dykes
authors.affiliation: Clinical Immunology and Transfusion Medicine, Division of Laboratory Medicine, Office of Medical Services, Lund University, Lund, Sweden.|Division of Hematology and Transfusion Medicine, Department of Laboratory Medicine, Lund University, Lund, Sweden.
authors.forename: J R
authors.identifier: http://orcid.org/0000-0003-2940-2604
authors.initials: JR
authors.lastname: Storry
authors.affiliation: Clinical Immunology and Transfusion Medicine, Division of Laboratory Medicine, Office of Medical Services, Lund University, Lund, Sweden.|Division of Hematology and Transfusion Medicine, Department of Laboratory Medicine, Lund University, Lund, Sweden.
authors.forename: M L
authors.identifier: http://orcid.org/0000-0003-1647-9610
authors.initials: ML
authors.lastname: Olsson
mesh_terms: D000017:ABO Blood-Group System / Q000096:biosynthesis*; D064591:Allografts; D004912:Erythrocytes / Q000378:metabolism*; D005260:Female; D005434:Flow Cytometry; D005786:Gene Expression Regulation; D018380:Hematopoietic Stem Cell Transplantation; D006801:Humans; D008297:Male; D014019:Tissue Donors
chemical_list: D000017:ABO Blood-Group System
keywords: ABO blood group antigen; flow cytometry; glycosphingolipids; haematopoietic stem cell transplantation; red blood cell