title: High risk of transfusion-induced alloimmunization of patients with inflammatory bowel disease.
abstract: BACKGROUND
  Anemia is highly prevalent in inflammatory bowel disease patients, and red blood cell transfusion is often indicated already at reproductive age. Both transfusion and pregnancy may induce red cell alloantibodies, potentially complicating further transfusions and pregnancies. As recent evidence suggests that inflammation may promote red cell antibody induction, the alloimmunization risk of these patients after allogenic erythrocyte exposure was investigated.
  
  
  METHODS
  Red cell alloantibody status and clinical data were analyzed in 193 inflammatory bowel disease patients with a history of transfusion or pregnancy, and compared with transfused controls with noninflammatory diseases (n=357).
  
  
  RESULTS
  In transfused patients with inflammatory bowel disease, a 2.5-fold-increased red cell antibody prevalence was found (10/119, 8.4%), compared with transfused sex-matched controls with noninflammatory diseases (12/357, 3.4%; P=.023). Patients with inflammatory bowel disease had fewer transfusions (mean 3.0 vs 4.2, P=.003) but higher C-reactive protein levels during transfusion than controls (mean 8.4 vs 5.4 mg/dL, P <.001). The red cell antibodies of inflammatory bowel disease patients were clinically significant, directed against different Rh, Kell, Duffy, or Lutheran blood group antigens, and associated with higher number of transfusions (odds ratio 1.57; 95% confidence interval, 1.03-2.39). Conversely, immunomodulatory therapy during transfusion showed negative association (odds ratio 0.12; 95% confidence interval, 0.02-0.61). Only 1.4% of inflammatory bowel disease patients with pregnancy alone had antibodies.
  
  
  CONCLUSIONS
  Patients with inflammatory bowel disease exhibited a very high risk of transfusion-induced red cell alloimmunization, possibly potentiated by inflammation. Aside from a restrictive transfusion strategy, the implementation of prophylactic blood group phenotype matching of red cell concentrates (not only for ABO and RhD but also RhCcEe, Kell, Kidd, Duffy) could prevent antibody induction and associated complications in these patients.
authors.affiliation: Department of Internal Medicine III, Division of Gastroenterology and Hepatology, Vienna General Hospital, Medical University of Vienna, Austria.
authors.forename: Pavol
authors.initials: P
authors.lastname: Papay
authors.forename: Klaus
authors.initials: K
authors.lastname: Hackner
authors.forename: Harald
authors.initials: H
authors.lastname: Vogelsang
authors.forename: Gottfried
authors.initials: G
authors.lastname: Novacek
authors.forename: Christian
authors.initials: C
authors.lastname: Primas
authors.forename: Walter
authors.initials: W
authors.lastname: Reinisch
authors.forename: Alexander
authors.initials: A
authors.lastname: Eser
authors.forename: Andrea
authors.initials: A
authors.lastname: Mikulits
authors.forename: Wolfgang R
authors.initials: WR
authors.lastname: Mayr
authors.forename: Günther F
authors.initials: GF
authors.lastname: Körmöczi
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001787:Blood Group Incompatibility / Q000209:etiology*; D016022:Case-Control Studies; D002648:Child; D004912:Erythrocytes / Q000276:immunology*; D005260:Female; D006801:Humans; D015212:Inflammatory Bowel Diseases / Q000150:complications / Q000276:immunology*; D008297:Male; D008875:Middle Aged; D065227:Transfusion Reaction; D055815:Young Adult