title: Impact of azacitidine on red blood cell alloimmunisation in myelodysplastic syndrome.
abstract: BACKGROUND
  The incidence of alloimmunisation in myelodysplastic syndromes (MDS) during the era of supportive treatment ranges from 9 to 56%. However, it is unknown if the widespread use of hypomethylating agents has changed the risk of immunisation. The aim of this study is to evaluate the impact of azacitidine (AZA) therapy on red blood cell (RBC) alloimmunisation in transfused patients with MDS, myelodysplastic syndromes/myeloproliferative syndromes (MDS/MPS) and secondary acute myeloid leukaemia (AML).
  
  
  METHODS
  We have analysed retrospectively all patients with MDS, MDS/MPS and secondary AML from MDS, who received their first transfusion in our hospital between January 1995 and December 2014. We have assessed the impact of age, sex, RBC and platelets units transfused, and AZA treatment on developing alloantibodies.
  
  
  RESULTS
  In our study, the number of RBC units transfused increased the risk of developing alloantibodies. However aging and the treatment with AZA were associated with a lower rate of alloimmunisation.
  
  
  CONCLUSIONS
  Patients with MDS, MDS/MPS and secondary AML who received treatment with AZA developed RBC antibodies at a lower rate than control group. We suggest that aging and immunosuppression due to AZA therapy could develop an immunological tolerance with a weak response to allotransfusions.
authors.affiliation: Service of Haematology, "Hospital General Universitario de Valencia", Valencia, Spain.
authors.forename: Sebastián
authors.initials: S
authors.lastname: Ortiz
authors.affiliation: Service of Haematology, "Hospital General Universitario de Valencia", Valencia, Spain.
authors.forename: Maria T
authors.initials: MT
authors.lastname: Orero
authors.affiliation: Service of Haematology, "Hospital General Universitario de Valencia", Valencia, Spain.
authors.forename: Karla
authors.initials: K
authors.lastname: Javier
authors.affiliation: Service of Haematology, "Hospital General Universitario de Valencia", Valencia, Spain.
authors.forename: Carolina
authors.initials: C
authors.lastname: Villegas
authors.affiliation: Service of Haematology, "Hospital General Universitario de Valencia", Valencia, Spain.
authors.forename: Irene
authors.initials: I
authors.lastname: Luna
authors.affiliation: Service of Haematology, "Hospital General Universitario de Valencia", Valencia, Spain.
authors.forename: Pedro
authors.initials: P
authors.lastname: Pérez
authors.affiliation: Service of Haematology, "Hospital General Universitario de Valencia", Valencia, Spain.
authors.forename: Mónica
authors.initials: M
authors.lastname: Roig
authors.affiliation: Service of Haematology, "Hospital General Universitario de Valencia", Valencia, Spain.
authors.forename: María
authors.initials: M
authors.lastname: López
authors.affiliation: Service of Haematology, "Hospital General Universitario de Valencia", Valencia, Spain.
authors.forename: Sofía
authors.initials: S
authors.lastname: Costa
authors.affiliation: Service of Haematology, "Hospital General Universitario de Valencia", Valencia, Spain.
authors.forename: Félix
authors.initials: F
authors.lastname: Carbonell
authors.affiliation: Service of Haematology, "Hospital General Universitario de Valencia", Valencia, Spain.
authors.forename: Rosa
authors.initials: R
authors.lastname: Collado
authors.affiliation: Service of Haematology, "Hospital General Universitario de Valencia", Valencia, Spain.
authors.forename: David
authors.initials: D
authors.lastname: Ivars
authors.affiliation: Service of Haematology, "Hospital General Universitario de Valencia", Valencia, Spain.
authors.forename: Mariano
authors.initials: M
authors.lastname: Linares
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001323:Autoantibodies / Q000276:immunology*; D001374:Azacitidine / Q000008:administration & dosage / Q000009:adverse effects*; D017707:Erythrocyte Transfusion / Q000009:adverse effects*; D004912:Erythrocytes / Q000276:immunology* / Q000473:pathology; D005260:Female; D006801:Humans; D007114:Immunization; D008297:Male; D008875:Middle Aged; D009190:Myelodysplastic Syndromes / Q000276:immunology / Q000473:pathology / Q000628:therapy; D065227:Transfusion Reaction / Q000139:chemically induced / Q000276:immunology* / Q000473:pathology
chemical_list: D001323:Autoantibodies; D001374:Azacitidine