title: Implications for urgent transfusion of uncrossmatched blood in the emergency department: The prevalence of clinically significant red cell antibodies within different patient groups.
abstract: OBJECTIVE
  To define the prevalence of alloantibodies as a factor of age and underlying clinical disease, with particular relevance to the prediction of the safety of uncrossmatched blood in different demographic groups.
  
  
  METHODS
  A retrospective review was conducted of all immunohaematological studies on blood samples submitted to the blood bank of a tertiary referral hospital between January 1998 and December 1999.
  
  
  RESULTS
  A total of 27 968 antibody screens in 15 966 patients were analysed. When only clinically significant antibodies were considered, the total alloimmunization prevalence was 1.9% and the prevalence of antibodies capable of causing an immediate transfusion reaction was 0.6%. The prevalence of antibodies capable of causing an immediate transfusion reaction was 0.1% in the under 30 years of age group. Clinically significant antibodies were found in 5.1% in the haematology and oncology unit patients. The risk rises with age and female sex.
  
  
  CONCLUSIONS
  We conclude that uncrossmatched blood is associated with low risk in patients < 30 years of age. The knowledge that patients have not been exposed to previous transfusion or pregnancy will reduce the risk even further.
authors.affiliation: Haematology Department, Liverpool Hospital, South Western Area Pathology Service, University of New South Wales, New South Wales, Australia. Jsobel.Saverimuttu@swsahs.nsw.gov.au
authors.forename: Josobel
authors.initials: J
authors.lastname: Saverimuttu
authors.forename: Tony
authors.initials: T
authors.lastname: Greenfield
authors.forename: Irene
authors.initials: I
authors.lastname: Rotenko
authors.forename: John
authors.initials: J
authors.lastname: Crozier
authors.forename: Bin
authors.initials: B
authors.lastname: Jalaludin
authors.forename: Michael
authors.initials: M
authors.lastname: Harvey
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D001323:Autoantibodies / Q000097:blood* / Q000276:immunology; D001788:Blood Grouping and Crossmatching / Q000009:adverse effects; D001803:Blood Transfusion; D004632:Emergency Medical Services; D004912:Erythrocytes / Q000276:immunology*; D005260:Female; D006801:Humans; D007518:Isoantibodies / Q000097:blood*; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D012307:Risk Factors
chemical_list: D001323:Autoantibodies; D007518:Isoantibodies