HLA-B27 typing by use of flow cytofluorometry

We describe the use of flow cytofluorometry to type lymphocytes for HLA-B27 antigens. We modified the cytotoxicity test of Terasaki and McClelland [Nature (London) 1964;204:998] for use with a flow cytofluorometer. In a second assay we used a commercially available monoclonal anti-HLA-B27 antibody and indirect immunofluorescence staining of cell surfaces. Although this antibody cross reacts with B7 and Bw22 antigens, the results for HLA-B27 and the cross-reacting antigens can be separated. Comparison of our results with those by a HLA-typing laboratory for 100 patients showed total agreement of the assigned typings.