[A new look at platelets and microparticles, including their role in haemostatic disorders and progression of neoplastic disease].

Platelets (PLT) are the smallest yet highly reactive components of the circulatory system. Microvesicles (platelet-derived microvesicles - PMV), also known as microparticles or microplatelets (platelet-derived microparticles - PMP), are released from platelets upon stimulation by thrombin, collagen or others platelet agonists. Both PLT and PMP play a role in haemostasis and mediate signal transmission between cells, especially cancer cells, thus modulating their functions. Moreover, these two platelet populations participate in transcellular exchange of information, affect immune responses and angiogenesis, which may facilitate tumour growth and development of distant metastases. Their role in tumour progression has been recognized, but the mechanism of their action remains still unclear. Assessment of PMP as a diagnostic and prognostic marker in various disorders is currently a subject of intense investigation.