Circulating platelet-derived microparticles in XXXX . Association with increased @entity556 generation and procoagulant state.

@entity1 @entity556 @entity4404 @entity1252 @entity2786 @entity715
The risk for @entity715 is significantly increased in @entity1252 ( @entity1252 ), affecting both venous and arterial vessels. Activated platelets are known to participate in @entity715 formation and growth. A general feature of activated cells is the shedding of microparticles (MP) which support coagulation by exposure of negatively charged phospholipids and possibly tissue factor (TF). In this work we characterized circulating MP in @entity1 with @entity1252 and their relationship with a procoagulant state. Thirty @entity1 with @entity1252 (aged 15-72 years, mean age 38 years) and 20 healthy controls (aged 22-54 years, mean age 34 years) were studied; @entity1 fulfilled 4 revised criteria for @entity1252 . The number and cellular source of circulating MP were determined by flow cytometry using double labeling with specific monoclonal antibodies and @entity4404 . @entity556 generation was measured as the endogenous @entity556 potential (ETP) without the addition of exogenous phospholipids and TF; under these conditions the generation of @entity556 depended directly on the number of MP present in plasma. @entity556 anti- @entity556 (TAT) and plasmin-antiplasmin ( @entity2786 ) complexes were measured by ELISA. Compared to the controls, circulating MP were significantly elevated in the @entity1 group (1218 +/- 136 vs 653 +/- 74 x 10(3)/ml plasma, p: 0.0007). In both groups, most of these MP were of platelet origin (927 +/- 131 vs 517 +/- 72 x 10(3)/ml plasma, p:0.009 ). ETP was higher among @entity1 as compared to the controls (804 +/- 64 vs 631 +/- 37 nM @entity556 , p: 0.025). Plasma levels ofTAT in @entity1 and controls were 3.4 +/- 0.8 and 1.4 +/- 0.5 microg/L, respectively (p:0.04), and of @entity2786 complexes were 62.5 +/- 14 and 24.05 +/- 2.5 microg/ml, respectively (p: 0.014). The number of platelet-derived MP correlated significantly with @entity556 generation (r: 0.42; p: 0.038) and TAT levels (r: 0.40; p: 0.035). We did not find an association of circulating MP with disease activity nor with the presence of antiphospholipid antibodies. The increased number of circulating platelet-derived microparticles and their association with high ETP and activation of the coagulation system suggest that these microparticles play an important role in the pathogenesis of the prothrombotic state in @entity1252 @entity1 .
