title: Identification of anti-HPA-1a allo-antibodies using IgG platelet antibody detection and crossmatch system assay with Galileo Echo.
abstract: Fetal/neonatal allo-immune thrombocytopenia is the most frequent and the most dangerous clinical condition involving anti-human platelet antigens (HPA)-1a allo-antibodies. Anti-HPA-1a allo-immunization requires rapid and accurate diagnosis to determine appropriate treatment. The Capture-P Ready-Screen assay (C-PRS) is a new qualitative immunoassay to detect IgG anti-human leukocyte antigen (HLA) and anti-HPA allo-antibodies. The aim of this study is to assess the identification of anti-HPA-1a allo-antibodies using the C-PRS assay, associated with HLA class I stripping reagents, on the automated benchtop analyzer Galileo Echo. Forty-nine sera were analyzed: without anti-HLA class I or anti-HPA allo-antibodies, with anti-HLA class I allo-antibodies, with anti-HPA-1a allo-antibodies, among which with anti-HLA class I allo-antibodies. None of the samples without allo-antibodies were reactive. Only anti-HLA antibodies, detected by cytotoxicity-dependent complement and not by Luminex, remained positive before and after stripping reagents. Of the 13 samples, anti-HPA-1a allo-antibodies that were correctly identified before and after incubation with HLA assassin reagent were 70% and 85%, respectively. Anti-glycoprotein auto-antibodies and anti-HLA allo-antibodies do not interfere with the detection of anti-HPA-1a antibodies. This preliminary study indicates that further improvement of the test will be helpful in developing a clinically useful assay in the future.
authors.affiliation: CNRS, EFS, ADES UMR 7268, Aix Marseille Université , Marseille , France .
authors.forename: Julie
authors.initials: J
authors.lastname: Di Cristofaro
authors.forename: Coralie
authors.initials: C
authors.lastname: Frassati
authors.forename: Rolande
authors.initials: R
authors.lastname: Montagnie
authors.forename: Agnes
authors.initials: A
authors.lastname: Basire
authors.forename: Yves
authors.initials: Y
authors.lastname: Merieux
authors.forename: Christophe
authors.initials: C
authors.lastname: Picard
mesh_terms: D016824:Antigens, Human Platelet / Q000276:immunology*; D001323:Autoantibodies / Q000097:blood / Q000276:immunology; D001792:Blood Platelets / Q000276:immunology*; D002097:C-Reactive Protein; D006680:HLA Antigens / Q000276:immunology; D006801:Humans; D007118:Immunoassay / Q000295:instrumentation* / Q000379:methods*; D007074:Immunoglobulin G / Q000097:blood / Q000276:immunology*; D039661:Integrin beta3; D007518:Isoantibodies / Q000097:blood / Q000276:immunology*; D011933:Reagent Kits, Diagnostic; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D016824:Antigens, Human Platelet; D001323:Autoantibodies; D006680:HLA Antigens; C061248:ITGB3 protein, human; D007074:Immunoglobulin G; D039661:Integrin beta3; D007518:Isoantibodies; D011933:Reagent Kits, Diagnostic; D002097:C-Reactive Protein
keywords: Allo-antibodies; capture-P ready-screen; fetal/neonatal allo-immune thrombocytopenia; galileo Echo; human leukocyte antigen; human platelet antigens