Résumé
Thrombotic phenomenon has an important role in the vasooclusive manifestations of sickle cell disease [SCD] that dominate its clinical spectrum. For evaluation of thrombotic activities in SCD patients, the markers of thrombin generation: thrombin anti-thrombin complex [TAT] and prothrombin fragment 1, 2 [F 1, 2], enhanced fibrinolysis markers: plasmin anti- plasmin complex [PAP] and D-dimer and platelet activation markers: platelet factor 4 [PF4] and B - thromboglobulin [BTG] were measured in 35 patients with SCD [25 during steady state and 10 during crisis], compared to 12 normal controls. The measurements were performed by enzyme-linked immunosorbent assays. The thrombotic markers [TAT and F 1, 2], fibrinolytic markers [PAP and D-dimer] and platelet activation markers [PF4 and BTG] were significantly increased in SCD patients during steady state. During vasooclusive crisis, there were marked increase in TAT, D- dimer, BTG and PF4 while there was no significant increase in the levels of PAP and F 1, 2. Also, there was significantly positive correlation among thrombin generation markers, platelet activation markers and fibrinolysis markers in SCD patients during steady state. During episodes there was significant positive correlation among markers of thrombin generation, fibrinolysis and platelet activation except PAP and F 1, 2 markers as compared with asymptomatic intervals. We concluded that, during pain episodes, there was enhanced platelet procoagulant activity, elevated fibrinolytic activity and thrombin generation. These changes may predict the frequency of pain. These findings suggested that increased their levels may increase the risk of thrombosis in these patients and establish a relationship between the laboratory determination of these parameters and clinical pain episodes in patients with SCD. The findings of platelet activation, fibrinolytic activity and thrombin generation in asymptomatic patients indicate ongoing subclinical thrombogeinc activity in patients with SCD