Procoagulant microparticles are increased in patients with Behçet's disease but do not define a specific subset of clinical manifestations.

Microparticles (MP) are considered a key component in the haemostatic response. Beyond their in vitro procoagulant properties, a number of pieces of evidence points to procoagulant MP as efficient effectors in the haemostatic response and as pathogenic markers of thrombotic disorders and vascular damage. The aim of the present study was to analyze the procoagulant activity of MP and its correlation with clinical manifestations focusing on vascular involvement in patients with Behçet's disease (BD). We analyzed 55 BD patients in inactive phase of the disease (26 men; mean age, 35 ± 15 years) of which 19 had previously suffered from thrombosis (deep venous thrombosis in 17 and ischemic stroke in 2), and 73 healthy controls matched for age and sex. Procoagulant MP were assessed by a functional assay. BD patients showed higher procoagulant MP values than controls (22.89 ± 15.74 nM versus 14.47 ± 7.34 nM; p < 0.0001). Conversely, we did not find differences in the levels of procoagulant MP according to the gender of patients (22.22 ± 16.23 nM for men versus 21.46 ± 16.47 for women; p = 0.846) or to previous and current treatments. Moreover, the plasmatic concentration of MP does not define any clinical phenotype and it was not related to the time of evolution of the disease. Although inactive BD patients had high values of procoagulant MP, they did not differentiate between BD patients with or without thrombosis.