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PO-26 Activated factor VII–Antithrombin complex (FVIIa-AT) in patients with acute promyelocytic leukemia (APL)
Abstracts / Thrombosis Research 120 Suppl. 2 (2007) S145–S178 Conclusions: Our study confirmed the presence of elevated FVIII in MM patients. FVIII levels seemed not to be risk factors for VTE. PO-25 Predictive value for VTE of hemostatic markers in patients with multiple myeloma receiving thalidomide A. Falanga *, M. Galli, L. Russo, D. Balducci, A. Vignoli, M. Marchetti, A. Rambaldi, T. Barbui. Department of Hematology, Ospedali Riuniti di Bergamo, Bergamo, Italy Introduction: Multiple Myeloma (MM) and other plasma cell dyscrasias are thrombogenic as a consequence of their multiple hemostatic effects. The oral drug thalidomide (Thal) has produced major therapeutic responses in patients with MM when used in combination with oral steroids and chemotherapy, but significantly increases the risk of venous thromboembolism (VTE). Aim of this study is to investigate whether the pre-Thal plasma levels of thrombotic markers may predict for therapy-associated thrombosis in MM patients. Methods: Blood samples were collected from 42 consecutive MM patients (18 F/24 M; age range: 44 81 years), 17 with newly diagnosed MM and 25 with relapsed MM, before starting 1st line (Thal + dexamethasone or MP) or 2nd line (Thal ± dexamethasone ± MP) therapies, respectively. At enrolment, patients were screened for VTE by doppler ultrasonography. All patients with newly diagnosed MM received thrombo-prophylaxis with the LMWH enoxaparin 4 mg/d (n = 16) or with Acenocumarol (n = 1). The group with relapsed MM did not receive thromboprophylaxis, except for six subjects who were on antithrombotic therapies for chronic cardiovascular diseases (4 LMWH and 2 ASA). Plasma levels of markers of hypercoagulation (TAT, F1+2, D-Dimer), endothelial (vWF:Ag, t-PA, PAI-1) and leukocyte (elastase) activation were measured by ELISA, before starting therapy for myeloma. Twenty-five healthy subjects acted as the control group. The statistical analysis was performed using Student’s t-test and Fisher’s exact test. Results: Eight of 42 patients (19%) developed VTE during therapy: 2/17 with newly diagnosed MM (11%) and 6/25 (24%) with relapsed MM. At baseline TAT, F1+2, and D-Dimer levels were significantly higher in patients compared to controls (P < 0.05). In addition vWF:Ag and t-PA were also significantly increased (P < 0.05), whereas PAI-1 and elastase levels were not stastically different from controls. Mean pre-Thal levels of TAT, F1+2, D-Dimer, t-PA and PAI-1 were significantly (P < 0.05) greater in the group of patients who developed VTE compared to the VTE-free group. The relative risk (RR) for VTE of laboratory markers was calculated. The statistical analysis showed a significant predictive value for preThal TAT levels 3 ng/ml (RR = 9.5; 95% CI: 8.98 23.66, P < 0.003), and pre-Thal F1+2 levels 0.25 nmol/l (RR = 6.6; 95% CI: 0.06 1.26, P < 0.02). Conclusion: The data suggest that pre-Thal plasma levels of TAT and F1+2 may be useful markers in predicting the thrombotic risk in patient with MM receiving Thal. However larger prospective studies are needed to definitely establish the clinical role of these markers. PO-26 Activated factor VII Antithrombin complex (FVIIa-AT) in patients with acute promyelocytic leukemia (APL)
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expression of procoagulant activities, including Tissue Factor (TF), by the promyelocytic blasts. All-trans retinoic acid (ATRA) has raised the complete remission rate to >90% of APL cases, together with a rapid resolution of the coagulopathy. Accordingly, ATRA reduces the TF expression by leukemic blasts and the levels of plasma hypercoagulable markers of APL patients. Aim: In this study, for the first time, in patients with APL receiving ATRA therapy, we evaluated the plasma levels of factor VIIa Antithrombin complexes (FVIIa-AT) which may reflect the degree of intravascular TF exposure. In parallel TFPI was measured as a direct TF inhibitor, and thrombin antithrombin complex (TAT) and D-dimer were evaluated as markers of thrombin and fibrin generation, respectively. Methods: Forty-nine consecutive patients with APL (F/M = 23/26; age range = 8 84 years) were enrolled at our Centre (from January 2000 to June 2007) in a prospective registry of major haemorrhage and thrombosis in APL patients receiving ATRA + Idarubicin (AIDA 2000, GIMEMA protocol). Blood samples were obtained from 21 of these patients at the following time intervals: 1. at baseline (before ATRA = D0), and on days 7 (D7), 15 (D15), and 25 (D25) after starting ATRA. Control samples were obtained from 25 healthy subjects. Results: Of the overall 49 patient group, 8 had early major haemorrhages (16%), including 3 (6.1%) fatal intracranial bleedings (1 before starting ATRA, and 2 after 1 and 3 days ATRA, respectively); 3 patients (6.1%) presented with thrombosis, including one fatal Budd-Chiari syndrome (2%), and two non-fatal events (4%). During the induction therapy period, two patients (4%) developed thrombosis at day 9 and 15, respectively. The study of plasma markers showed that at D0 the levels of FVIIa-AT were significantly higher in APL over the control group and remained persistently elevated. In particular, they became significantly reduced only at D25 of therapy (p < 0.05 vs baseline), when they reached the levels of the control group. Accordingly, TFPI was persistently elevated until D15. Differently, as shown by previous studies, TAT complex and D-dimer levels were significantly elevated at diagnosis and were rapidly reduced (D7 vs baseline, p < 0.05) and remained downregulated thereafter. Conclusions: This study confirms a significant rate of early deaths in APL due to thrombo-hemorrhagic complications in the ATRA era. The findings of elevated FVIIa-AT levels suggest that this complex likely reflects an increase in TF exposure by leukemic and/or normal vascular cells. The parallel decrease of hypercoagulation markers (i.e. TAT and D-dimer) with high TFPI levels, demonstrates that the clotting activation at the cellular site is efficiently controlled by means of indirect (i.e. AT) and direct (i.e. TFPI) inhibitors of FVIIa-TF. The study suggests that monitoring the levels of FVII-AT complex may be important for understanding the mechanisms of the coagulopathy of APL and might help to identify APL patients with persistent TF/FVIIa activation, who may carry an increased thrombotic risk.
Poster Session III: Platelets & coagulation proteases PO-27 Raised levels of CD39 in leucocytosis result in marked inhibition of ADP-induced platelet aggregation via rapid ADP hydrolysis
D. Balducci1 *, L. Russo1 , A. Vignoli1 , M. Marchetti1 , B. Woodhams2 , J. Morrissey3 , T. Barbui1 , A. Falanga1 . 1 Department of Haematology, Ospedali Riuniti di Bergamo, Bergamo, Italy, 2 Stago R&D, Genneviliers, France, 3 Department of Biochemistry, Univ. Illinois, Urbana, IL, USA
S. Heptinstall1 *, B. Myers2 , S.C. Fox1 , J.R. Glenn1 , A.J. Johnson1 , A.E. White1 . 1 Cardiovascular Medicine, University of Nottingham, 2 Haematology, Queens Medical Centre, Nottingham, UK
Background: The coagulation/bleeding syndrome typical of the onset of APL is a complex disorder, and is one cause of early death in this disease. Abnormalities of the laboratory coagulation tests, compatible with disseminated intravascular coagulation, are present in the majority of these patients. Among the mechanisms responsible for intravascular clotting activation in APL is the
Introduction: We recently observed markedly reduced platelet aggregation induced by ADP in blood from patients with leucocytosis which may explain the low incidence of thrombosis reported in chronic leukaemias. Aim: This study was to investigate the role of leucocyte CD39 (NTPDase) in the reduced aggregation response.
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expression of procoagulant activities, including Tissue Factor (TF), by the promyelocytic blasts. All-trans retinoic acid (ATRA) has raised the complete remission rate to >90% of APL cases, together with a rapid resolution of the coagulopathy. Accordingly, ATRA reduces the TF expression by leukemic blasts and the levels of plasma hypercoagulable markers of APL patients. Aim: In this study, for the first time, in patients with APL receiving ATRA therapy, we evaluated the plasma levels of factor VIIa Antithrombin complexes (FVIIa-AT) which may reflect the degree of intravascular TF exposure. In parallel TFPI was measured as a direct TF inhibitor, and thrombin antithrombin complex (TAT) and D-dimer were evaluated as markers of thrombin and fibrin generation, respectively. Methods: Forty-nine consecutive patients with APL (F/M = 23/26; age range = 8 84 years) were enrolled at our Centre (from January 2000 to June 2007) in a prospective registry of major haemorrhage and thrombosis in APL patients receiving ATRA + Idarubicin (AIDA 2000, GIMEMA protocol). Blood samples were obtained from 21 of these patients at the following time intervals: 1. at baseline (before ATRA = D0), and on days 7 (D7), 15 (D15), and 25 (D25) after starting ATRA. Control samples were obtained from 25 healthy subjects. Results: Of the overall 49 patient group, 8 had early major haemorrhages (16%), including 3 (6.1%) fatal intracranial bleedings (1 before starting ATRA, and 2 after 1 and 3 days ATRA, respectively); 3 patients (6.1%) presented with thrombosis, including one fatal Budd-Chiari syndrome (2%), and two non-fatal events (4%). During the induction therapy period, two patients (4%) developed thrombosis at day 9 and 15, respectively. The study of plasma markers showed that at D0 the levels of FVIIa-AT were significantly higher in APL over the control group and remained persistently elevated. In particular, they became significantly reduced only at D25 of therapy (p < 0.05 vs baseline), when they reached the levels of the control group. Accordingly, TFPI was persistently elevated until D15. Differently, as shown by previous studies, TAT complex and D-dimer levels were significantly elevated at diagnosis and were rapidly reduced (D7 vs baseline, p < 0.05) and remained downregulated thereafter. Conclusions: This study confirms a significant rate of early deaths in APL due to thrombo-hemorrhagic complications in the ATRA era. The findings of elevated FVIIa-AT levels suggest that this complex likely reflects an increase in TF exposure by leukemic and/or normal vascular cells. The parallel decrease of hypercoagulation markers (i.e. TAT and D-dimer) with high TFPI levels, demonstrates that the clotting activation at the cellular site is efficiently controlled by means of indirect (i.e. AT) and direct (i.e. TFPI) inhibitors of FVIIa-TF. The study suggests that monitoring the levels of FVII-AT complex may be important for understanding the mechanisms of the coagulopathy of APL and might help to identify APL patients with persistent TF/FVIIa activation, who may carry an increased thrombotic risk.
Poster Session III: Platelets & coagulation proteases PO-27 Raised levels of CD39 in leucocytosis result in marked inhibition of ADP-induced platelet aggregation via rapid ADP hydrolysis
D. Balducci1 *, L. Russo1 , A. Vignoli1 , M. Marchetti1 , B. Woodhams2 , J. Morrissey3 , T. Barbui1 , A. Falanga1 . 1 Department of Haematology, Ospedali Riuniti di Bergamo, Bergamo, Italy, 2 Stago R&D, Genneviliers, France, 3 Department of Biochemistry, Univ. Illinois, Urbana, IL, USA
S. Heptinstall1 *, B. Myers2 , S.C. Fox1 , J.R. Glenn1 , A.J. Johnson1 , A.E. White1 . 1 Cardiovascular Medicine, University of Nottingham, 2 Haematology, Queens Medical Centre, Nottingham, UK
Background: The coagulation/bleeding syndrome typical of the onset of APL is a complex disorder, and is one cause of early death in this disease. Abnormalities of the laboratory coagulation tests, compatible with disseminated intravascular coagulation, are present in the majority of these patients. Among the mechanisms responsible for intravascular clotting activation in APL is the
Introduction: We recently observed markedly reduced platelet aggregation induced by ADP in blood from patients with leucocytosis which may explain the low incidence of thrombosis reported in chronic leukaemias. Aim: This study was to investigate the role of leucocyte CD39 (NTPDase) in the reduced aggregation response.