Granulocyte antibody screening: evaluation of a bead‐based assay in comparison with classical methods

BACKGROUND: Granulocyte antibodies have been implicated in allo‐ and autoimmune neutropenia and in transfusion reactions. STUDY DESIGN AND METHODS: Fifty‐one sera from suspected alloimmune neutropenia or transfusion‐related acute lung injury (TRALI) and 40 sera from suspected autoimmune neutropenia were tested for granulocyte antibodies using LABScreen MULTI (One Lambda, Inc.), compared with classical tests (flow cytometry [FC] and granulocyte agglutination [GAT] followed by monoclonal antibody–specific immobilization of granulocyte antigens [MAIGA]). RESULTS: In alloimmune situations, 48 sera were concordant (94%), two sera positive for HNA with LABScreen MULTI were negative by FC/GAT and/or MAIGA, and one serum sample negative for HNA with LABScreen MULTI was positive by classical tests. In autoimmune neutropenia, 30 sera were concordant (75%), four sera positive for HNA with LABScreen MULTI were negative by FC/GAT and/or MAIGA, and six sera negative for HNA with LABScreen MULTI were positive by FC/GAT and/or MAIGA. For detection of autoantibodies, the LABScreen MULTI was less concordant. However, with the exception of one case, the discrepancies were observed in sera that did not show a clear specificity. CONCLUSIONS: LABScreen MULTI correlated well with our classical methods for HNA‐1 and HNA‐2a antibody screening. It can be used for screening blood donors or patients suspected of TRALI, but GAT is still needed for HNA‐3a antibody screening.