Evaluation of a new flow cytometry crossmatch procedure for simultaneous detection of cytotoxicity and antibody binding

Abstract In this study we have evaluated an alternative 96‐well format flow cytometry based ( FCtox ) method which enable simultaneous detection of cytotoxicity and human leukocyte antigen ( HLA ) antibody binding. Comparable results were obtained in side‐by‐side comparisons with conventional complement‐dependent cytotoxicity ( CDC ) and flow cytometric crossmatch (FCXM) in terms of sensitivity and specificity. There was 91 and 93% agreement between results obtained by FCtox and CDC for T and B cells, respectively. In addition, comparable results were obtained with FCtox IgG and FCXM IgG for both T and B cells. Furthermore, compared with a recently developed and highly sensitive Luminex based C1q assay we obtained close to 90% method agreement with the FCtox assay. Our alternative cytotoxicity and IgG binding assay which exhibit low intra‐and inter‐assay variation will improve the workflow and speed up the pre‐transplant testing and also allow continuous monitoring of assay performance and proper quality assurance.