title: Platelet antibody analysis by three different tests.
abstract: BACKGROUND
  Platelet-reactive antibodies lead to thrombocytopenia and bleeding disorders, and diverse assays are used for their detection. In this retrospective analysis, the applicability of three different test systems was compared and antibody specificities were assessed.
  
  
  METHODS
  Sera of 1,234 patients were tested with an enzyme-linked immunosorbent assay (ELISA; Lifecodes PAKPLUS(®) or PAK 12(®), Gen-Probe) and a solid-phase assay (Capture-P Ready Screen(®), Immucor Inc.). In cases of suspected anti-HLA class I antibodies, a specific lymphocytotoxicity test (LCT, Bio-Rad(®)) was performed.
  
  
  RESULTS
  Platelet antibodies were detected in 366 of 1,234 samples (29.7%). In 70.3% concordant negative but only in 8.4% concordant positive results were obtained with both the methods; 185 of 1,053 in the solid-phase assay negative samples were positive in the ELISA (15.0%). In samples positive in both methods, most antibodies reacted against HLA class I antigens. Glycoprotein (GP) specific platelet antibodies, mainly against GPIIb/IIIa and GPIa/IIa, were more frequently detectable in the ELISA than in the solid-phase assay, whereas weakly positive results have to be interpreted cautiously.
  
  
  CONCLUSIONS
  ELISA, solid-phase assay, and LCT showed highly divergent results. Due to several limitations, the additional analysis by the "monoclonal antibody-specific immobilization of platelet antigen" (MAIPA)-assay is highly recommended.
authors.affiliation: Department of Blood Group Serology and Transfusion Medicine, Medical University of Graz, Graz, Austria.
authors.forename: Nazanin
authors.initials: N
authors.lastname: Sareban
authors.affiliation: Department of Blood Group Serology and Transfusion Medicine, Medical University of Graz, Graz, Austria.
authors.forename: Susanne
authors.initials: S
authors.lastname: Macher
authors.affiliation: Department of Blood Group Serology and Transfusion Medicine, Medical University of Graz, Graz, Austria.
authors.forename: Camilla
authors.initials: C
authors.lastname: Drexler
authors.affiliation: Department of Blood Group Serology and Transfusion Medicine, Medical University of Graz, Graz, Austria.
authors.forename: Ursula
authors.initials: U
authors.lastname: Posch
authors.affiliation: Department of Blood Group Serology and Transfusion Medicine, Medical University of Graz, Graz, Austria.
authors.forename: Gerhard
authors.initials: G
authors.lastname: Lanzer
authors.affiliation: Department of Blood Group Serology and Transfusion Medicine, Medical University of Graz, Graz, Austria.|Department of Blood Group Serology and Transfusion Medicine, Paracelsus Medical University Hospital, Salzburg, Austria.|Spinal Cord Injury & Tissue Regeneration Center Salzburg (SCI-TReCS), Paracelsus Medical University (PMU), Salzburg, Austria.
authors.forename: Katharina
authors.initials: K
authors.lastname: Schallmoser
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016824:Antigens, Human Platelet / Q000276:immunology*; D001323:Autoantibodies / Q000032:analysis* / Q000097:blood; D016009:Chi-Square Distribution; D002648:Child; D002675:Child, Preschool; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006402:Hematologic Diseases / Q000097:blood* / Q000175:diagnosis*; D015395:Histocompatibility Antigens Class I / Q000276:immunology; D006801:Humans; D007223:Infant; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D055815:Young Adult
chemical_list: D016824:Antigens, Human Platelet; D001323:Autoantibodies; D015395:Histocompatibility Antigens Class I
keywords: platelet antibody; thrombocytopenia