Report on the sixth international society of blood transfusion platelet serology workshop

Background: The Sixth International Society of Blood Transfusion Platelet Serology Workshop continued studies to identify methods to detect platelet-specific antigens and antibodies. Study Design and Methods: The study was designed to meet three goals. The first was the establishment of antigen-typed platelet panels and determination of the correlation between serologic and DNA typing of platelet-specific antigens. The second goal was the determination of the proficiency of detecting platelet-specific antibodies by laboratory and by technique. The third goal was the identification of any platelet-specific antibodies present in uncharacterized (unknown) antisera. Results: For platelet-antigen typing, concordance between serologic testing and DNA techniques was 93 percent for oligonucleotide typing and 92 percent for allele-specific restriction site analysis. Agreement between these two was 98 percent. Individual laboratories correctly identified the antibodies contained in coded sera 79 +/- 17 percent of the time. The expected results were obtained from the modified antigen-capture enzyme-linked immunosorbent assay in 75 +/- 46 percent of instances, from the monoclonal antibody-specific immobilization of platelet antigens assay in 72 +/- 24 percent of instances, from the mixed passive hemagglutination assay in 71 +/- 13 percent, from radioimmunoprecipitation procedures in 67 +/- 47 percent, and from Western blot 34 +/- 40 percent, Seven (54%) of 13 antisera of unknown specificity were determined to contain clearly identifiable platelet-specific alloantibodies. Conclusion: Concordant results were achieved by using either serologic or DNA techniques to identify platelet-specific antigens. Except for the significantly lower results found with Western blotting, all other platelet-specific antibody assays were comparable. Established serologic laboratories can identify and characterize platelet-specific antibodies.