Summary

An increased or disturbed activation and aggregation of plateletsplays a major role in the pathophysiology of thrombosis and haemostasisand is related to cardiovascular disease processes. In addition toqualitative disturbances of platelet function, changes in thrombopoiesisor an increased elimination of platelets, (e. g., in autoimmune thrombocytopenia),are also of major clinical relevance. Flow cytometry isincreasingly used for the specific characterisation of phenotypic alterationsof platelets which are related to cellular activation, haemostaticfunction and to maturation of precursor cells. These new techniquesalso allow the study of the in vitro response of platelets to stimuli andthe modification thereof under platelet-targeted therapy as well as thecharacterisation of platelet-specific antibodies. In this protocol, specificflow cytometric techniques for platelet analysis are recommendedbased on a description of the current state of flow cytometric methodology.These recommendations are an attempt to promote the use ofthese new techniques which are at present broadly evaluated fordiagnostic purposes. Furthermore, the definition of the still openquestions primarily related to the technical details of the method shouldhelp to promote the multi-center evaluation of procedures withthe goal to finally develop standardized operation procedures as thebasis of interlaboratory reproducibility when applied to diagnostictesting.