title: Detection of granulocyte-reactive antibodies: a comparison of different methods.
abstract: OBJECTIVE
  Granulocyte-reactive antibodies can cause autoimmune and neonatal immune neutropenias as well as transfusion-related acute lung injury. The classical antibody-detection methods granulocyte aggregation test (GAT), granulocyte immunofluorescence test (GIFT) and monoclonal antibody-specific immobilization of granulocyte antigens (MAIGA) are time-consuming and technically challenging. In recent years, flow cytometric white blood cell immunofluorescence test (Flow-WIFT) and the microbeads assay LabScreen® Multi have emerged and are still subject of evaluation. These serological tests were compared on a screening and specification level.
  
  
  METHODS
  For screening, the combination of GAT/GIFT was compared to Flow-WIFT testing 333 samples. Positive samples were further analysed with MAIGA and LabScreen® Multi.
  
  
  RESULTS
  Granulocyte aggregation test/GIFT detected 77 positive samples, Flow-WIFT found 108 granulocyte-reactive samples. Six Samples were only positive in GAT/GIFT, and 37 samples were only positive in Flow-WIFT (κ = 0.682). Antibody specification with MAIGA and the microbeads assay confirmed granulocyte-reactivity in 83 cases with 70 matching results (κ = 0.742). However, out of six detected human neutrophil antigen (HNA) reactivities only two specificities matched in both assays.
  
  
  CONCLUSIONS
  Flow-WIFT may be a valuable addition to GIFT for granulocyte-reactive antibody screening. MAIGA remains the most reliable laboratory method for antibody specification.
authors.affiliation: Department of Blood Group Serology and Transfusion Medicine, Medical University of Vienna, Vienna, Austria.
authors.forename: M W
authors.initials: MW
authors.lastname: Heinzl
authors.forename: M
authors.initials: M
authors.lastname: Schönbacher
authors.forename: E-M
authors.initials: EM
authors.lastname: Dauber
authors.forename: S
authors.initials: S
authors.lastname: Panzer
authors.forename: W R
authors.initials: WR
authors.lastname: Mayr
authors.forename: G F
authors.initials: GF
authors.lastname: Körmöczi
mesh_terms: D000372:Agglutination Tests / Q000379:methods*; D000911:Antibodies, Monoclonal / Q000276:immunology*; D000918:Antibody Specificity; D006098:Granulocytes / Q000276:immunology*; D006801:Humans
chemical_list: D000911:Antibodies, Monoclonal
keywords: flow cytometry; granulocyte immunology; granulocyte-reactive antibodies; human neutrophil antigens; microbeads assay