title: Platelet alloimmunization after long-term red cell transfusion in transfusion-dependent thalassemia patients.
abstract: BACKGROUND
  The platelet (PLT) alloimminization status after long-term red cell (RBC) transfusion in thalassemia patients was investigated, including antibodies against HLA antigens and PLT-specific glycoprotein antigens.
  
  
  METHODS
  Blood samples from a total of 60 thalassemia patients who routinely received washed RBCs were tested for the presence of HLA antibodies and PLT-specific glycoprotein antibodies with a commercial enzyme immunoassay kit. All patients were rescreened at a follow-up period of 12 to 15 months.
  
  
  RESULTS
  At the first year of study, 19 (31%) patients had HLA antibodies, 13 (22%) had HLA antibodies and PLT-specific antibodies, and 1 (2%) had PLT-specific antibodies. One patient showed weak reactive PLT autoantibody. The follow-up study showed that 7 patients developed HLA antibodies, whereas 1 patient lost HLA antibody activity. Nine patients developed new PLT-specific antibodies, yet 12 patients lost at least one of their PLT-specific antibodies.
  
  
  CONCLUSIONS
  Long-term RBC transfusions can induce PLT alloimmunization, both to HLA antigens and to PLT-specific antigens. The residual PLTs and white blood cells in RBC components could be the sources of immunization. In our thalassemia patients, HLA antibodies likely sustain longer than PLT-specific antibodies.
authors.affiliation: Department of Laboratory Medicine, College of Medicine, National Taiwan University, Taipei, Taiwan.
authors.forename: Shyh-Chyi
authors.initials: SC
authors.lastname: Lo
authors.forename: Jhy-Sheng
authors.initials: JS
authors.lastname: Chang
authors.forename: Susannah Whay-Sue
authors.initials: SW
authors.lastname: Lin
authors.forename: Dong-Tsamn
authors.initials: DT
authors.lastname: Lin
mesh_terms: D000293:Adolescent; D000328:Adult; D000918:Antibody Specificity; D016824:Antigens, Human Platelet / Q000276:immunology; D001323:Autoantibodies / Q000097:blood / Q000276:immunology; D001792:Blood Platelets / Q000276:immunology*; D001803:Blood Transfusion; D002648:Child; D002675:Child, Preschool; D005260:Female; D005500:Follow-Up Studies; D006680:HLA Antigens / Q000276:immunology; D006801:Humans; D007518:Isoantibodies / Q000097:blood / Q000276:immunology*; D008297:Male; D017086:beta-Thalassemia / Q000276:immunology* / Q000628:therapy*
chemical_list: D016824:Antigens, Human Platelet; D001323:Autoantibodies; D006680:HLA Antigens; D007518:Isoantibodies