Evaluation of a new microbeads assay for granulocyte antibody detection. Issue 1 (23rd October 2016) - Schulz, Undine
Abstract : BACKGROUND: To reduce the risk of transfusion‐associated acute lung injury (TRALI), a high number of plasma donors were tested for human leukocyte antigen (HLA) and human neutrophil antigen (HNA) antibodies. For HNA antibody detection, the gold standard is a combination of the granulocyte immunofluorescence test (GIFT) and the granulocyte agglutination test (GAT). However, these tests are not suitable for a high‐throughput of samples. STUDY DESIGN AND METHODS: To evaluate the new generation of the LABScreen MULTI assay (One Lambda, Inc.), which has special new beads for all the known HNA specificities, including HNA‐3a, 97 sera samples containing well‐defined HNA antibodies were used. For background testing, we used 91 samples from plasma donors previously identified by GAT, GIFT, and the monoclonal antibody‐specific immobilization of granulocyte antigens (MAIGA) assay. RESULTS: Compared with previous tests, the new LABScreen MULTI assay was highly specific for the HNA‐1a, HNA‐1b, HNA‐2, and HNA‐3a antibody specificities required to prevent TRALI. Ninety‐eight percent of the HNA‐1a, HNA‐1b, and HNA‐2 antibodies could be detected as true positive; and 90% of the HNA‐3a antibodies were recognized correctly as positive. False‐positive reactions were identified in 5.5% of samples that previously tested negative. CONCLUSION: The detection of HNA‐3a antibody specificities could be integrated into the new LABScreen MULTI assay; however, we detected only 90%. In addition, we detected further HNA antibodies, such as HNA‐1c, HNA‐1d, and some HNA‐3b and HNA‐4a antibodies. The new generation of LABScreen MULTI is a great step toward feasible high‐throughput testing for HNA antibodies. Nevertheless, GIFT and GAT remain the gold‐standard methods for the differentiation of rare and currently unknown HNA specificities.