Platelet flow cytometry: An evolving platform for clinical hematology.

Flow cytometry has transformed platelet biology and diagnostics through high-resolution, single-cell analysis of surface markers, activation states, and intracellular signaling. This review traces its evolution from early applications in glycoprotein profiling and immune thrombocytopenia to clinical roles in HIT, VITT, and FNAIT. Advances in spectral cytometry, phosphoflow, and fluorescent barcoding have increased analytical depth and supported development of whole blood-compatible platelet function assays. Flow cytometry now enables characterization of platelet subpopulations, assessment of complement deposition, and functional evaluation across immune and thrombotic disorders. These capabilities support applications in diagnostics, bleeding and cardiovascular risk assessment, drug-induced thrombocytopenia, and platelet product quality control. As these technologies mature, flow cytometry is expanding its role in clinical workflows and may enable more biologically informed and individualized approaches in precision hematology.