title: Red cell alloimmunisation in regularly transfused beta thalassemia patients in Pakistan.
abstract: BACKGROUND
  In Pakistan routine blood group typing of thalassemia patients identifies ABO and Rh(D) antigens only. Therefore, other antigen incompatibilities between blood donor and blood recipient may cause alloimmunisation.
  
  
  OBJECTIVE
  The aim of this study was to estimate the frequency of alloimmunisation and to evaluate the risk factors associated with its development in beta (β)-thalassemia patients receiving regular blood transfusions.
  
  
  METHODS
  In total 162 β thalassemia patients were included in this study. An extended red cell antigen panel was performed to detect antibodies. Patients received red cell concentrates, which were matched for ABO and Rh(D) antigens. Clinical and laboratory data were collected and analysed to estimate the frequency of alloantibodies and the factors influencing immunisation in patients on regular blood transfusion.
  
  
  RESULTS
  The median age of patients was 6·7 (range: 0·5-25) years. A total of 14 (8·6%) patients developed alloantibodies against red cell antigens. The most frequently occurring alloantibodies was anti-E (2·5%), anti-K (1·8%), anti-e (1·2%) and anti-D (0·6%). Five (3·1%) patients developed more than one red blood cell (RBC) alloantibody. Age at first transfusion in alloimmunised patients was 1·22 ± 0·87 years. The frequency of blood transfusion in alloimmunised patients was 23 ± 8·81 days and in those without alloimmunisation was 31·8 ± 16 days (p = 0·02). Logistic regression analysis showed no independent risk factor associated with alloimmunisation.
  
  
  CONCLUSIONS
  The frequency of transfusion was increased in patients who developed alloantibodies. Typing patients and donors to match for Rh and Kell antigens would prevent more than 90% of RBC alloantibodies and reduce the frequency of transfusion in thalassemia patients.
authors: Department of Blood Transfusion, National Institute of Blood Disease and Bone Marrow Transplantation (NIBD), Karachi, Pakistan.
authors: U
authors: U
authors: Zaidi
authors: Department of Blood Transfusion, National Institute of Blood Disease and Bone Marrow Transplantation (NIBD), Karachi, Pakistan.
authors: M
authors: M
authors: Borhany
authors: Department of Blood Transfusion, National Institute of Blood Disease and Bone Marrow Transplantation (NIBD), Karachi, Pakistan.
authors: S
authors: S
authors: Ansari
authors: Department of Blood Transfusion, National Institute of Blood Disease and Bone Marrow Transplantation (NIBD), Karachi, Pakistan.
authors: S
authors: S
authors: Parveen
authors: Department of Blood Transfusion, National Institute of Blood Disease and Bone Marrow Transplantation (NIBD), Karachi, Pakistan.
authors: S
authors: S
authors: Boota
authors: Department of Blood Transfusion, National Institute of Blood Disease and Bone Marrow Transplantation (NIBD), Karachi, Pakistan.
authors: I
authors: I
authors: Shamim
authors: Department of Blood Transfusion, National Institute of Blood Disease and Bone Marrow Transplantation (NIBD), Karachi, Pakistan.
authors: D
authors: D
authors: Zahid
authors: Department of Blood Transfusion, National Institute of Blood Disease and Bone Marrow Transplantation (NIBD), Karachi, Pakistan.
authors: T
authors: T
authors: Shamsi
mesh_terms: D000293:Adolescent; D001789:Blood Group Antigens / Q000276:immunology; D001787:Blood Group Incompatibility / Q000453:epidemiology* / Q000209:etiology; D001788:Blood Grouping and Crossmatching / Q000379:methods; D002648:Child; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D004912:Erythrocytes / Q000276:immunology*; D006801:Humans; D007223:Infant; D007518:Isoantibodies / Q000097:blood; D007626:Kell Blood-Group System / Q000276:immunology; D010154:Pakistan; D012204:Rh-Hr Blood-Group System / Q000276:immunology; D013156:Splenectomy; D065227:Transfusion Reaction; D055815:Young Adult; D017086:beta-Thalassemia / Q000276:immunology / Q000601:surgery / Q000628:therapy*
chemical_list: D001789:Blood Group Antigens; D007518:Isoantibodies; D007626:Kell Blood-Group System; D012204:Rh-Hr Blood-Group System
keywords: alloimmunisation; beta thalassemia; blood group antigens; blood transfusion; red cells antibody