title: Determination of platelet-bound glycoprotein-specific autoantibodies by flow cytometric immunobead assay in primary immune thrombocytopenia.
abstract: OBJECTIVE
  Primary immune thrombocytopenia (ITP) is an autoimmune disorder characterized by premature platelet destruction induced by autoantibodies directed against platelet glycoproteins (GPs). Despite being a clinically important disorder, ITP lacks a feasible diagnostic assay for routine clinical use. This study was meant to evaluate a newly developed flow cytometric immunobead assay for determination of platelet-bound GP-specific autoantibodies in comparison with indirect monoclonal antibody-specific immobilization of platelet antigen (MAIPA) in the diagnosis of ITP.
  
  
  METHODS
  Platelet-bound and plasma GPIIb/IIIa and GPIb/IX autoantibodies were determined by flow cytometric immunobead assay and indirect modified MAIPA, respectively. The average fluorescence level for platelet-bound, GP-specific autoantibodies was given as a ratio to three normal controls tested simultaneously.
  
  
  RESULTS
  The median value of platelet-bound GPIIb/IIIa and GPIb/IX autoantibodies in ITP group were 3.09 (range 0.78, 30.2) and 3.09 (range 0.72, 19.2), respectively, which were significantly higher than non-ITP group [1.01 (0.67, 5.59) and 1.01 (0.79, 5.56), respectively, P<0.001] and normal controls [1.02 (0.72, 1.76) and 1.03 (0.79, 1.73), respectively, P<0.001]. The receiver-operating characteristics curve analysis showed an area under the curve of 0.895 for GPIIb/IIIa autoantibody and 0.859 for GPIb/IX autoantibody, respectively. Combined detection of GPIIb/IIIa or GPIb/IX autoantibodies by flow cytometric immunobead assay showed a sensitivity of 82.11% for ITP diagnosis.
  
  
  CONCLUSIONS
  This study demonstrated that determination of platelet-bound, GP-specific autoantibodies by flow cytometric immunobead assay was a convenient, sensitive, and specific test for the differential diagnosis of thrombocytopenic patients.
authors.affiliation: Department of Hematology, Qilu Hospital, Shandong University, Jinan, China.
authors.forename: Xin-Guang
authors.initials: XG
authors.lastname: Liu
authors.forename: Jin-Lin
authors.initials: JL
authors.lastname: Li
authors.forename: Ping
authors.initials: P
authors.lastname: Qin
authors.forename: Juan
authors.initials: J
authors.lastname: Ren
authors.forename: Shi-Hui
authors.initials: SH
authors.lastname: Ma
authors.forename: Lin
authors.initials: L
authors.lastname: Sun
authors.forename: Yan
authors.initials: Y
authors.lastname: Shi
authors.forename: Xue-Bin
authors.initials: XB
authors.lastname: Ji
authors.forename: Yuan-Yuan
authors.initials: YY
authors.lastname: Zhu
authors.forename: Dao-Xin
authors.initials: DX
authors.lastname: Ma
authors.forename: Cheng-Shan
authors.initials: CS
authors.lastname: Guo
authors.forename: Xin
authors.initials: X
authors.lastname: Du
authors.forename: Ming
authors.initials: M
authors.lastname: Hou
authors.forename: Jun
authors.initials: J
authors.lastname: Peng
mesh_terms: D000293:Adolescent; D000328:Adult; D000918:Antibody Specificity; D016824:Antigens, Human Platelet / Q000097:blood; D001323:Autoantibodies / Q000097:blood*; D001792:Blood Platelets / Q000276:immunology*; D016022:Case-Control Studies; D005260:Female; D005434:Flow Cytometry / Q000379:methods; D006801:Humans; D007118:Immunoassay / Q000379:methods*; D008297:Male; D008875:Middle Aged; D010980:Platelet Membrane Glycoproteins / Q000276:immunology; D016553:Purpura, Thrombocytopenic, Idiopathic / Q000097:blood* / Q000175:diagnosis / Q000276:immunology*; D055815:Young Adult
chemical_list: D016824:Antigens, Human Platelet; D001323:Autoantibodies; D010980:Platelet Membrane Glycoproteins