title: Anti-AnWj causing acute hemolytic transfusion reactions in a patient with aplastic anemia.
abstract: BACKGROUND
  AnWj is a high-prevalence red blood cell (RBC) antigen in the ISBT 901 series. Only nine reports of anti-AnWj have been published since it was first documented in 1972; two of these cases involved transfusion reactions. We present a case of a patient with aplastic anemia who developed anti-AnWj with clinically significant hemolysis after transfusion of AnWj-positive RBCs.
  
  
  METHODS
  A 56-year-old woman with aplastic anemia developed a pan-reactive antibody with clinically significant hemolysis after transfusion of RBCs. Investigations included antibody identification by serologic methods at the national immunohematology reference laboratory and the in vitro monocyte-monolayer assay (MMA) to predict clinical significance.
  
  
  RESULTS
  The antibody was identified as having specificity for the AnWj antigen. The posttransfusion MMA indicated that the antibody had complement-fixing capability highly likely to cause clinically significant acute hemolytic transfusion reactions. The patient required long-term transfusion support with AnWj-negative RBCs and Lu(a-b-) RBCs of the In(Lu) type which have reduced AnWj expression. Cross-Canada and international collaboration was required to obtain rare units for transfusion.
  
  
  CONCLUSIONS
  A case of acute hemolytic transfusion reaction caused by anti-AnWj is reported in a patient with aplastic anemia requiring allogeneic stem cell transplantation. This is the second documented case of anti-AnWj to cause a hemolytic transfusion reaction. The case demonstrates the complexity of managing patients with rare antibodies and the importance of international collaboration in the management of these difficult cases.
authors.affiliation: University of Ottawa, Ottawa, Ontario, Canada.
authors.forename: Zhaodong
authors.initials: Z
authors.lastname: Xu
authors.forename: Lisa
authors.initials: L
authors.lastname: Duffett
authors.forename: Melanie
authors.initials: M
authors.lastname: Tokessy
authors.forename: Jacqueline
authors.initials: J
authors.lastname: Cote
authors.forename: Mindy
authors.initials: M
authors.lastname: Goldman
authors.forename: Elianna
authors.initials: E
authors.lastname: Saidenberg
mesh_terms: D000741:Anemia, Aplastic / Q000097:blood / Q000276:immunology / Q000628:therapy*; D001789:Blood Group Antigens / Q000276:immunology*; D001787:Blood Group Incompatibility / Q000097:blood / Q000209:etiology / Q000276:immunology / Q000628:therapy*; D017707:Erythrocyte Transfusion; D004912:Erythrocytes / Q000276:immunology*; D005260:Female; D006461:Hemolysis / Q000276:immunology*; D006801:Humans; D007518:Isoantibodies / Q000097:blood / Q000276:immunology*; D008875:Middle Aged
chemical_list: D001789:Blood Group Antigens; D007518:Isoantibodies