title: Red blood cell alloimmunization in transfusion-dependent Egyptian patients with thalassemia in a limited donor exposure program.
abstract: BACKGROUND
  Thalassemia is considered the most common hemoglobinopathy in Egypt and is one of its major health problems. Lifelong red blood cell (RBC) transfusion remains the main treatment for severe forms; however, RBC alloimmunization results as a complication of regular transfusions due to repeated exposure to foreign antigens. The objective was to compare the frequency of alloantibodies in a group of patients in a limited donor exposure program (LDEP) with those receiving RBCs from multiple donors in Egyptian transfusion-dependent patients with thalassemia.
  
  
  METHODS
  A total of 235 regularly transfused patients with thalassemia were studied, 36 of which were on LDEP. All patients were investigated for the presence of RBC autoantibodies and alloantibodies, followed by antibody identification for positive patients.
  
  
  RESULTS
  Forty-six (19.5%) patients developed RBC alloantibodies. The most common clinically significant alloantibodies were directed against antigens in the Kell and Rh systems. Development of alloantibodies was associated with older age, higher transfusion frequency, and splenectomy. A trend toward lower alloimmunization was elicited in the LDEP group, where 8.3% (3/36) patients were alloimmunized compared to 21.6% (43/199) in the non-LDEP one (p=0.057).
  
  
  CONCLUSIONS
  Examination of donor RBCs for presence of Kell and Rh(E) antigens before transfusion can help decrease RBC alloimmunization. Further larger studies are required to assess the frequency of alloantibody production in patients on LDEP.
authors: Department of Clinical Pathology, Ain Shams University, Cairo, Egypt.
authors: Azza S
authors: AS
authors: el-Danasoury
authors: Doaa G
authors: DG
authors: Eissa
authors: Reham M
authors: RM
authors: Abdo
authors: Mohsen S
authors: MS
authors: Elalfy
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D002675:Child, Preschool; D017707:Erythrocyte Transfusion / Q000009:adverse effects; D004912:Erythrocytes / Q000276:immunology*; D005260:Female; D006801:Humans; D007223:Infant; D007518:Isoantibodies / Q000276:immunology; D007626:Kell Blood-Group System / Q000276:immunology; D008297:Male; D012204:Rh-Hr Blood-Group System / Q000276:immunology; D013789:Thalassemia / Q000276:immunology* / Q000628:therapy*; D055815:Young Adult
chemical_list: D007518:Isoantibodies; D007626:Kell Blood-Group System; D012204:Rh-Hr Blood-Group System