title: Delayed hemolytic transfusion reaction in children with sickle cell disease.
abstract: BACKGROUND
  Transfusion is a cornerstone of the management of sickle cell disease but carries a high risk of hemolytic transfusion reaction, probably because of differences in erythrocyte antigens between blood donors of European descent and patients of African descent. Patients may experience hemolytic transfusion reactions that are delayed by from a few days to two weeks and manifest as acute hemolysis (hemoglobinuria, jaundice, and pallor), symptoms suggesting severe vaso-occlusive crisis (pain, fever, and acute chest syndrome), and profound anemia, often with reticulocytopenia. This case-series study aims to describe the main characteristics of this syndrome, to discuss its pathophysiology, and to propose a management strategy.
  
  
  METHODS
  We identified 8 pediatric cases of delayed hemolytic transfusion reactions between 2006 and 2009 in the database of the Necker Hospital, France. All patients had received cross-matched red cell units compatible in the ABO, RH, and KEL systems. We reviewed the medical charts in the computerized blood transfusion databases. All patients were admitted to the intensive care unit. We progressively adopted the following strategy: intravenous immunoglobulins, and darbopoietin alpha when the reticulocyte count was below 150×10(9)/L, without further blood transfusion during the acute episode unless absolutely necessary.
  
  
  RESULTS
  The median time between the transfusion and the diagnosis of delayed hemolytic transfusion reaction was six days. All patients had severe bone pain; all but one had a high-grade fever. Five patients had hemoglobin levels less than than 4 g/dL and 3 had reticulocytopenia. In 5 patients, no new antibody was found; one patient had weakly reactive antibodies. Only 2 patients had new allo-antibodies possibly responsible for the delayed hemolytic reaction.
  
  
  CONCLUSIONS
  The initial symptoms of delayed hemolytic transfusion reaction were complex and mimicked other complications of sickle cell disease. In most of our cases, no new antibody was identified, which underlines the complexity of the pathophysiology of this syndrome.
authors.affiliation: Service de Pédiatrie Générale, Hopital Necker-Enfants Malades, Centre de Référence de la Drépanocytose, Université Paris Descartes, 149 rue de Sevres, 75015, Paris, France. mariane.demontal@nck.aphp.fr
authors.forename: Mariane
authors.initials: M
authors.lastname: de Montalembert
authors.forename: Marie-Dominique
authors.initials: MD
authors.lastname: Dumont
authors.forename: Claire
authors.initials: C
authors.lastname: Heilbronner
authors.forename: Valentine
authors.initials: V
authors.lastname: Brousse
authors.forename: Oussama
authors.initials: O
authors.lastname: Charrara
authors.forename: Béatrice
authors.initials: B
authors.lastname: Pellegrino
authors.forename: Christophe
authors.initials: C
authors.lastname: Piguet
authors.forename: Valérie
authors.initials: V
authors.lastname: Soussan
authors.forename: France
authors.initials: F
authors.lastname: Noizat-Pirenne
mesh_terms: D000293:Adolescent; D000755:Anemia, Sickle Cell / Q000097:blood / Q000150:complications* / Q000276:immunology / Q000628:therapy*; D002648:Child; D002675:Child, Preschool; D005260:Female; D006461:Hemolysis / Q000276:immunology*; D006801:Humans; D016756:Immunoglobulins, Intravenous; D007518:Isoantibodies / Q000097:blood / Q000276:immunology; D008297:Male; D012204:Rh-Hr Blood-Group System / Q000276:immunology; D065227:Transfusion Reaction; D016896:Treatment Outcome
chemical_list: D016756:Immunoglobulins, Intravenous; D007518:Isoantibodies; D012204:Rh-Hr Blood-Group System