title: Frequency and characterization of platelet-specific antibodies in patients who received multiple platelet transfusions.
abstract: OBJECTIVE
  Multiple platelet transfusions may induce alloimmunization. Platelet alloimmunization involves human leukocyte antigen (HLA) antibodies and platelet-specific antibodies, which recognize platelet glycoproteins. No data are available about the frequency and characteristics of platelet-specific antibodies in patients who have received multiple platelet transfusions in Taiwan.
  
  
  METHODS
  From June through December 1998, blood samples from 103 patients who had received multiple platelet transfusions were submitted to our laboratory for examination of platelet antibodies. The samples were first screened for HLA antibodies or platelet-specific antibodies using a solid phase method. Positive sera were further tested using an enzyme-linked immunosorbent assay (ELISA) to identify the specificities of the alloantibodies.
  
  
  RESULTS
  Forty of the 103 patients who had received multiple platelet transfusions were positive for platelet-reactive antibodies. Further study using ELISA showed that 22 patients had both HLA and platelet-specific antibodies, 12 patients had HLA antibodies alone, and five patients produced platelet-specific antibodies in the absence of HLA antibodies. Most platelet-specific antibodies were found among patients who had HLA antibodies: 81% of platelet-specific antibodies were found in HLA-immunized patients. The most frequently involved platelet glycoprotein antigens were Ia/IIa and IIb/IIIa.
  
  
  CONCLUSIONS
  HLA antibodies were the most frequently found platelet-reactive antibodies in Taiwanese patients who had received multiple transfusions, although platelet-specific antibodies were also common. The frequency of platelet-specific antibodies was not as low as previously reported.
authors.affiliation: Department of Laboratory Medicine, National Taiwan University Hospital, 7 Chung-Shan South Road, Taipei, Taiwan.
authors.forename: S C
authors.initials: SC
authors.lastname: Lo
authors.forename: D T
authors.initials: DT
authors.lastname: Lin
authors.forename: S W
authors.initials: SW
authors.lastname: Lin
authors.forename: J S
authors.initials: JS
authors.lastname: Chang
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000918:Antibody Specificity; D001792:Blood Platelets / Q000276:immunology*; D002648:Child; D002675:Child, Preschool; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006680:HLA Antigens / Q000276:immunology; D006801:Humans; D007223:Infant; D007518:Isoantibodies / Q000097:blood*; D008297:Male; D008875:Middle Aged; D010980:Platelet Membrane Glycoproteins / Q000276:immunology; D017713:Platelet Transfusion
chemical_list: D006680:HLA Antigens; D007518:Isoantibodies; D010980:Platelet Membrane Glycoproteins