title: RBC alloimmunization and double alloantibodies in thalassemic patients.
abstract: OBJECTIVE
  Alloimmunization is a common consequence of chronic blood transfusion. Double alloantibody production may complicate the condition of such patients especially for finding matched blood. In this study, we evaluated the frequency of alloantibodies in thalassemic patients with previous history of transfusion reactions.
  
  
  METHODS
  This study was performed on 441 multiply transfused thalassemia patients Antibody screening test was carried out using three cell-panel by gel method. Positive patients were followed up for antibody identification using 11-cell panel. Direct combs' test was performed to detect auto antibodies.
  
  
  RESULTS
  In a total of 441 cases (362 thalassemia major and 79 intermedia), 234 were males (53.1%) and 207 females (46.9%); mean age 22 years, range 3-61 years. Alloimmunization was detected in 50(11.3%) patients, including 37(74%) patients with one alloantibody, 8(16%) with two antibodies, 4(8%) patients with unknown antibodies and one patient (2%) with autoantibody. The most common alloantibodies were anti-Rh antibodies (-E/e/C/c/Cw) (26%), anti-K (28%), anti-D (16%), and anti-Colton (4%). Double antibodies were detected in eight out of 50 patients, including: Anti-D+anti-C (8%), anti-D+anti-E (2%), anti-Kell+anti-D (2%), and anti-Kell+KPa (2%). A significant association was observed between the transfusion reaction history and the alloantibody detection results (p < 0.05).
  
  
  CONCLUSIONS
  Antibody production against RBC antigens makes hard condition in regular blood transfusion. Double antibodies production may more complicate this situation. Thus, it is advisable to phenotype patients and matches the red cells in multiply transfused thalassemia patients.
authors.forename: Azita
authors.initials: A
authors.lastname: Azarkeivan
authors.forename: Mohammad Hossein
authors.initials: MH
authors.lastname: Ahmadi
authors.forename: Sima
authors.initials: S
authors.lastname: Zolfaghari
authors.forename: Mojgan
authors.initials: M
authors.lastname: Shaiegan
authors.forename: Shirin
authors.initials: S
authors.lastname: Ferdowsi
authors.forename: Negar
authors.initials: N
authors.lastname: Rezaei
authors.forename: Parvin
authors.initials: P
authors.lastname: Lotfi
mesh_terms: D000293:Adolescent; D000328:Adult; D001803:Blood Transfusion; D002648:Child; D002675:Child, Preschool; D004912:Erythrocytes / Q000276:immunology*; D005260:Female; D006801:Humans; D007518:Isoantibodies / Q000032:analysis / Q000097:blood / Q000276:immunology*; D008297:Male; D008875:Middle Aged; D013789:Thalassemia / Q000097:blood / Q000276:immunology* / Q000628:therapy*; D065227:Transfusion Reaction; D055815:Young Adult
chemical_list: D007518:Isoantibodies
keywords: Alloantibody; Antibody screening; Double antibody; Thalassemia; Transfusion reaction