Increased Levels of Circulating Microparticles Are Associated with Increased Procoagulant Activity in Patients with Cutaneous Malignant Melanoma

Microparticles (MPs) are known to be increased in various malignancies and are involved in tumor invasion, angiogenesis, coagulation, and metastasis. We investigated the plasma levels of annexin-V MPs (AV+MPs), platelet-derived MPs (PMPs), and endothelial-derived MPs (EMPs) in patients with melanoma (n=129) and in healthy controls (n=49). A functional coagulation test STA Procoag-PPL measuring the clotting time was performed on samples containing MPs to evaluate their procoagulant potential. The plasma levels of PMPs, EMPs, and AV+MPs were significantly higher, and the clotting time-PPL was significantly lower in melanoma patients than in healthy controls. The plasma levels of PMPs, EMPs, and AV+MPs were higher in stage IV than in the other stages of melanoma, but with no significant difference. In addition, we observed an inverse correlation between PMPs, AV+MPs, and clotting times. Our data suggest that MPs are involved in the progression of melanoma and may be associated to melanoma-associated thrombogenesis.