Seregina E., Nikulina O., Tsvetaeva N.,Balandina A.,Ataullakhanov F.

XXIVth Congress of the International Society on Thrombosis and Hemostasis (ISTH). 2013. Amsterdam, Netherlands.

Eculizumab is approved to reduce the intensity of intravascular hemolysis and thrombotic risk in patients with paroxysmal nocturnal hemoglobinuria (PNH)[1].

The aim of this study was to investigate the coagulation state in PNH patients under eculizumab treatment.

Three patients with PNH in state of permanent hemolysis, requiring constant red cell transfusions, were enrolled in this study. Eculizumab administration was 1 time per week; the tests were performed one day before and one day after administration for 4 weeks. Further eculizumab administrations last for 2 months, the tests were performed in the day of administration before the infusion. Thrombodynamics (a new method based on a spatial fibrin clot growth registration), thromboelastography (TEG), activated partial thromboplastin time (aPTT), prothrombin index (PI), D-dimer assay, the concentration of lactate dehydrogenase (LDH), and the concentration of hemoglobin (Hb) were performed. In thrombodynamics assay the initial clot growth velocity (Vi) was determined.

TEG parameters, aPTT and PI were in normal or in hypocoagulation area before treatment. Vi was increased (58±7um/min with normal range 36-56 um/min, p <0,001). Enlarged D-dimer levels in 2 patients (0.8mg/l, 2.1mg/l with normal range 0-0.5 mg/l) confirmed the well-known tendency to hypercoagulability during haemolytic crises. D-dimers were in norm for 1 patient (0,3mg/l). Coagulation tests data wasn’t significantly (p>0,5) changed the day after eculizumab administration: Vi was 60±8 um/min, the parameters of the TEG, aPTT, PI were in normal or in hypocoagulation area. D-dimers remained in norm in 1 patient under eculizumab treatment. Other 2 patients had the decrease of D-dimer level with some incidents of D-dimer’s increase during the treatment. LDH level progressively decreased and Hb level increased in all patients indicating the reduction of hemolysis. Physical health was improved. During further eculizumab administrations for 2 months all tests data was not significantly (p>0,5) changed.

Eculizumab administrations did not reduce hypercoagulability in PNH patients, they are still need the prescription of anticoagulant therapy. Thrombodynamics was sensitive to the state associated with the increased risk of thrombotic events in PNH patients.