title: Transfusion-related alloimmunization in children: epidemiology and effects of chemotherapy.
abstract: OBJECTIVE
  Alloimmunization rates following red blood cell (RBC) transfusion in paediatric oncology are not known. This study aimed to: (1) describe frequency and specificity of alloantibodies in paediatric oncology patients after RBC transfusions; (2) determine the effect of chemotherapy on alloimmunization rate.
  
  
  METHODS
  Retrospective cohort study of paediatric patients at a tertiary care hospital is evaluated by two groups: control group, paediatric patients without cancer; study group, paediatric oncology patients who received chemotherapy. Alloimmunization was defined as clinically significant IgG alloantibody formation against RBC antigens.
  
  
  RESULTS
  A total of 1273 children were evaluated including 324 in study group, 909 controls, and 40 haemoglobinopathy patients. Overall, frequency of alloimmunization was 1·5%: 0·3% (95% CI: 0, 1·90) in study group; 1·3% (95% CI: 0·73, 2·32) in control group and 15% in haemoglobinopathies. The association between chemotherapy and alloimmunization was not significant; P value = 0·20 Fisher's exact test, OR 0·23 (95% CI: 0·03, 1·79).
  
  
  CONCLUSIONS
  This is the first study exploring RBC alloimmunization in paediatric patients by diagnosis. Alloimmunization frequency was low. It was not possible to determine an association between chemotherapy and alloimmunization due to the low event rate.
authors.affiliation: Department of Pediatrics, Faculty of Health Sciences, McMaster University, Hamilton, ON, Canada. ziad.solh@medportal.ca.|Department of Pathology and Molecular Medicine, Faculty of Health Sciences, McMaster University, Hamilton, ON, Canada. ziad.solh@medportal.ca.|Centre for Innovation, Canadian Blood Services, Hamilton, ON, Canada. ziad.solh@medportal.ca.
authors.forename: Z
authors.initials: Z
authors.lastname: Solh
authors.affiliation: Department of Pediatrics, Faculty of Health Sciences, McMaster University, Hamilton, ON, Canada.
authors.forename: U
authors.initials: U
authors.lastname: Athale
authors.affiliation: Department of Medicine, Faculty of Health Sciences, McMaster University, Hamilton, ON, Canada.
authors.forename: D M
authors.initials: DM
authors.lastname: Arnold
authors.affiliation: Department of Statistics and Actuarial Science, University of Waterloo, Waterloo, ON, Canada.
authors.forename: R J
authors.initials: RJ
authors.lastname: Cook
authors.affiliation: Department of Pathology and Molecular Medicine, Faculty of Health Sciences, McMaster University, Hamilton, ON, Canada.
authors.forename: R
authors.initials: R
authors.lastname: Foley
authors.affiliation: Department of Medicine, Faculty of Health Sciences, McMaster University, Hamilton, ON, Canada.|Centre for Innovation, Canadian Blood Services, Hamilton, ON, Canada.
authors.forename: N M
authors.initials: NM
authors.lastname: Heddle
mesh_terms: D000293:Adolescent; D000970:Antineoplastic Agents / Q000627:therapeutic use; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D017707:Erythrocyte Transfusion / Q000009:adverse effects*; D004912:Erythrocytes / Q000276:immunology*; D005260:Female; D018380:Hematopoietic Stem Cell Transplantation; D006453:Hemoglobinopathies / Q000628:therapy; D006801:Humans; D006967:Hypersensitivity / Q000209:etiology*; D007223:Infant; D007518:Isoantibodies / Q000097:blood; D008297:Male; D009369:Neoplasms / Q000188:drug therapy; D012189:Retrospective Studies; D062606:Tertiary Care Centers
chemical_list: D000970:Antineoplastic Agents; D007518:Isoantibodies
keywords: alloimmunization; chemotherapy; paediatric transfusion; red cell alloantibodies