Detection and identification of platelet antibodies and antigens in the clinical laboratory

As a result of the unique functional properties of platelets, more-robust methods were required for detection of antibodies raised against them. Immunofluorescence detection by flow cytometry, solid-phase red cell adherence, and antigen capture ELISAs are some of the current tests that have been developed to meet the challenges of platelet antibody detection and identification and antigen phenotyping. Recently developed protein liquid bead arrays are becoming the next-generation platelet antibody tests. Fueled by development of PCR and determination of the molecular basis of the Pl^A1 human platelet antigen (HPA), serologic platelet typing has now been replaced by genotyping of DNA. Allele-specific PCR, melting curve analysis, and 5′-nuclease assays are now evolving into more high-throughput molecular tests. Laboratory testing for the diagnosis of immune platelet disorders has advanced considerably from its humble beginnings. Immunohematology2009;25:125–135.