thromboplastin and Precursor-Cell-Lymphoblastic-Leukemia-Lymphoma

Thromboembolism is one of the most common complications during induction therapy of pediatric acute lymphoblastic leukemia (ALL). Procoagulant microparticles in the circulation may cause thromboembolic events. The aim of our study was to determine the levels of apoptotic, platelet-derived, endothelial-derived, and tissue factor-positive microparticles of children with ALL at diagnosis and during induction therapy.. Sixteen precursor B-cell ALL cases and 30 healthy children between 1 and 18 years of age were included. Microparticle levels were analyzed from peripheral blood samples at initial diagnosis, on days 12 and 13 (before and after the first L-asparaginase administration), and on day 33 of ALL-BFM 2000 treatment protocol. Microparticle levels were analyzed by using flow cytometry.. At initial diagnosis, platelet, endothelial-derived, and tissue factor-positive microparticle levels were significantly high in children with ALL. They increased significantly after prednisone and L-asparaginase administration. Apoptotic microparticle levels were not elevated at diagnosis, but remained high during all induction therapy period. None of the patients had evidence of thromboembolism during induction therapy.. Our study demonstrated that children with ALL have increased levels of apoptotic, platelet-derived, endothelial-derived, and tissue factor-positive microprticles during induction therapy. Further studies are needed in larger groups of patients in order to evaluate the risk of elevated microprticles for development of thromboembolism during induction therapy period in children with ALL.

Topics: Adolescent; Apoptosis; Asparaginase; Blood Platelets; Cell-Derived Microparticles; Child; Child, Preschool; Endothelial Cells; Female; Humans; Infant; Male; Precursor Cell Lymphoblastic Leukemia-Lymphoma; Prednisone; Remission Induction; Thromboembolism; Thromboplastin

Thromboembolic events are frequent and serious complications of acute lymphoblastic leukaemia treatment. The importance of chemotherapy in the pathogenesis of this increased risk is enhanced by the fact that thrombosis rarely occurs at diagnosis. Our study aims at investigating the effect of chemotherapy on pro-coagulant activity (PCA), phosphatidylserine (PS) exposure, tissue factor (TF) activity and derived extracellular vesicles (EV) of Jurkat cells. Jurkat cells were treated with two commonly used chemotherapeutics: Vincristine (VCR) or Daunorubicin (DNR), at relevant concentrations. PCA of cells and derived EV were evaluated using Thrombin generation Assay (TGA). Cells or EV were incubated with annexin V or anti TF antibodies to assess the respective contribution of TF and PS. PS exposure on cells was analysed by flow cytometry. Derived EV were evaluated in fluorescence microscopy and flow cytometry. Untreated Jurkat cells and EV support thrombin generation. Thrombin generation was abolished when PS activity was inhibited by annexin V. VCR treatment resulted in a time dependent increase of thrombin generation. After VCR exposure, TF activity increased as well as PS exposure increased on the cell surface. The increase in TF activity was abolished by annexin V indicating that PS was required. A spontaneous release of EV from Jurkat cells was observed and VCR treatment increased the number of generated EV. Our results indicate that VCR increased the PCA of Jurkat cells predominantly through PS exposure and increased EV generation. Lymphoid blasts derived EV could be biomarkers to determine high thrombotic risk ALL patients.

Topics: Annexin A5; Antineoplastic Agents, Phytogenic; Blood Coagulation; Extracellular Vesicles; Flow Cytometry; Humans; Jurkat Cells; Phosphatidylserines; Precursor Cell Lymphoblastic Leukemia-Lymphoma; Thromboplastin; Vincristine

The use of L-asparaginase (L-ASP) in paediatric patients with acute lymphoblastic leukaemia (ALL) is associated with thrombotic complications. We evaluated the activities of tissue factor (TFa), thrombomodulin (TMa) and procoagulant phospholipids (PPL) in 26 consecutive children with ALL (25 B-ALL and one T-ALL) treated by the French Acute Lymphoblastic Leukemia group (FRALLE)-2000 protocol. Samples were obtained at diagnosis, after glucocorticoid (GC) therapy, during the induction phase with L-ASP, vincristine (VCR) and adriamycin (ADR), during the re-induction and within the week after treatment. Plasma levels of TFa, TMa and PPL increased gradually and significantly during the different phases of the treatment, with higher levels observed during the induction period, and decreased after treatment discontinuation. In vitro studies showed that the different drugs used for ALL treatment could induce a weak expression of TF and procoagulant activity (PCA) on normal and leukaemia blood cells, while a marked effect was observed on endothelial cells. In conclusion, these data indicate that, in addition to the well-identified increased in coagulation factors and inhibitor deficiencies, the injury of the endothelium could lead to the release of TF and PPL and could contribute to the hypercoagulability of children treated for ALL.

Topics: Adolescent; Antineoplastic Combined Chemotherapy Protocols; Blood Coagulation Factors; Cells, Cultured; Child; Child, Preschool; Endothelium, Vascular; Female; Humans; Male; Phospholipids; Precursor Cell Lymphoblastic Leukemia-Lymphoma; Thrombomodulin; Thromboplastin

Heparanase is an endo-β-D-glucuronidase dominantly involved in tumor metastasis and angiogenesis. Recently, we demonstrated that heparanase is involved in the regulation of the hemostatic system. Our hypothesis was that heparanase is directly involved in activation of the coagulation cascade.. Activated factor X and thrombin were studied using chromogenic assays, immunoblotting and thromboelastography. Heparanase levels were measured by enzyme-linked immunosorbent assay. A potential direct interaction between tissue factor and heparanase was studied by co-immunoprecipitation and far-western assays.. Interestingly, addition of heparanase to tissue factor and activated factor VII resulted in a 3- to 4-fold increase in activation of the coagulation cascade as shown by increased activated factor X and thrombin production. Culture medium of human embryonic kidney 293 cells over-expressing heparanase and its derivatives increased activated factor X levels in a non-enzymatic manner. When heparanase was added to pooled normal plasma, a 7- to 8-fold increase in activated factor X level was observed. Subsequently, we searched for clinical data supporting this newly identified role of heparanase. Plasma samples from 35 patients with acute leukemia at presentation and 20 healthy donors were studied for heparanase and activated factor X levels. A strong positive correlation was found between plasma heparanase and activated factor X levels (r=0.735, P=0.001). Unfractionated heparin and an inhibitor of activated factor X abolished the effect of heparanase, while tissue factor pathway inhibitor and tissue factor pathway inhibitor-2 only attenuated the procoagulant effect. Using co-immunoprecipitation and far-western analyses it was shown that heparanase interacts directly with tissue factor.. Overall, our results support the notion that heparanase is a potential modulator of blood hemostasis, and suggest a novel mechanism by which heparanase increases the generation of activated factor X in the presence of tissue factor and activated factor VII.

Topics: Adolescent; Adult; Aged; Anticoagulants; Blood Coagulation; Factor VIIa; Factor Xa; Female; Glucuronidase; Glycoproteins; HEK293 Cells; Heparin; Humans; Leukemia, Myeloid, Acute; Male; Middle Aged; Precursor Cell Lymphoblastic Leukemia-Lymphoma; Serine Proteinase Inhibitors; Thromboplastin

To detect plasma concentrations of vascular endothelial cell growth factor (VEGF) and tissue factor (TF) in children with acute lymphoblastic leukemia (ALL) and explore their clinical significance in ALL.. Thirty-three children with newly diagnosed ALL, including 18 cases of low risk, 7 cases of moderate risk and 8 cases of high risk, were enrolled in this study. Twenty-five patients received a complete remission and 8 cases were in non-remission after conventional remission induction chemotherapy. Plasma concentrations of VEGF and TF in the patients were detected using ELISA before and after treatment. Sixteen healthy children served as normal control group.. Plasma concentrations of VEGF and TF in ALL patients before treatment were significantly higher than those in normal controls (P < 0.01). Plasma concentrations of VEGF and TF in the non-remission group before treatment were significantly higher than those in the remission group (P < 0.05) and the control group (P < 0.01). After treatment the plasma concentrations of VEGF and TF in the non-remission group were not significantly reduced and higher than those in the remission and the control groups (P < 0.01). There were significant differences in plasma concentrations of VEGF and TF among the low-risk, moderate-risk and high-risk groups before and after treatment (P < 0.05). Plasma concentrations of VEGF and TF in the high risk group were not significantly reduced after treatment and higher than those in the control group (P < 0.01). A linear correlation was noted between plasma VEGF and TF concentrations in ALL patients before treatment (r=0.50, P < 0.01).. VEGF and TF play an important role in the development of ALL and may be useful to the evaluation of the severity and the outcome in ALL.

Topics: Adolescent; Child; Child, Preschool; Female; Humans; Infant; Male; Precursor Cell Lymphoblastic Leukemia-Lymphoma; Thromboplastin; Vascular Endothelial Growth Factor A

Over-expression of tissue factor (TF) and activation of the coagulation system are common in cancer patients. Heparanase is an endo-beta-D-glucuronidase that cleaves heparan sulfate chains on cell surfaces and in the extracellular matrix, activity that closely correlates with cell invasion, angiogenesis and tumor metastasis. The study was undertaken to investigate the involvement of heparanase in TF expression.. Tumor-derived cell lines were transfected with heparanase cDNA and TF expression was examined. The effect of exogenous addition of active and inactive heparanase on TF expression and activity was studied in tumor cell lines and primary human umbilical vein endothelial cells. TF expression was also explored in heparanase over-expressing transgenic (Tg) mice. Blast cells were collected from acute leukemia patients and TF and heparanase expression levels were analyzed.. Over-expression of heparanase in tumor-derived cell lines resulted in a 2-fold increase in TF expression levels, and a similar trend was observed in heparanase Tg mice in vivo. Likewise, exogenous addition of heparanase to endothelial or tumor-derived cells resulted in enhanced TF expression and activity. Interestingly, TF expression was also induced in response to enzymatically inactive heparanase, suggesting that this effect was independent of heparanase enzymatic activity. The regulatory effect of heparanase on TF expression involved activation of the p38 signaling pathway. A positive correlation between TF expression levels and heparanase activity was found in blasts collected from 22 acute leukemia patients.. Our results indicate that in addition to its well-known function as an enzyme paving a way for invading cells, heparanase also participates in the regulation of TF gene expression and its related coagulation pathways.

Topics: Blood Coagulation; Cell Line, Tumor; Endothelial Cells; Gene Expression Regulation, Leukemic; Heparin Lyase; Humans; Leukemia, Myeloid, Acute; Neoplasm Invasiveness; Precursor Cell Lymphoblastic Leukemia-Lymphoma; Thromboplastin

To investigate the changes of plasma tissue factor(TF) and tissue factor pathway inhibitor(TFPI) activities in the patients with acute leukemia.. TF and TFPI activities were measured by using chromogenic assays.. Plasma TF activity in the patients with acute leukemia was higher and TFPI activity was lower than those in normal(P < 0.01). In 7 patients who underwent the first chemotherapy, the plasma TF activity was decreased after chemotherapy(P < 0.01), while TFPI activity increased(P < 0.05).. The unbalance between plasma TF and TFPI activities contributes to the coagulant disorders in acute leukemia.

Topics: Adolescent; Adult; Aged; Blood Coagulation; Female; Humans; Leukemia, Myeloid, Acute; Lipoproteins; Male; Middle Aged; Precursor Cell Lymphoblastic Leukemia-Lymphoma; Thromboplastin

Tissue factor activity of intact cell and cell lysate, and the presence of tissue factor antigen on cell surface, were examined in leukemic cells from patients with acute myelogenous leukemia (AML, M1-M5) or acute lymphoblastic leukemia (ALL-L1), and in mononuclear cells from normal donors. Leukemic cells from AML or ALL had significantly more tissue factor activity not only on intact cells but also in cell lysate than mononuclear cells from normal donors (p < 0.001). Tissue factor activities of the intact leukemic cells and lysate from AML patients with DIC were significantly higher than those without DIC (p < 0.001). The relationship between the percent of positive cells for tissue factor and the presence of DIC at the time of diagnosis of acute leukemia was observed. The patients with DIC showed the higher percentage of tissue factor-positive cells than those without (p < 0.01). The development of DIC following chemotherapy was recognized in 2 out of 7 AML-MI patients and 2 out of 4 ALL-L1 patients who had relatively high tissue factor activities of cell lysate. The release of tissue factor from cytoplasm induced by chemotherapy would be another mechanism for the development of DIC. The report suggests the possibility of the prediction for DIC by the flowcytometric assay of tissue factor antigen.

Topics: Antigens, Surface; Disseminated Intravascular Coagulation; Flow Cytometry; Humans; Leukemia; Leukemia, Myeloid, Acute; Precursor Cell Lymphoblastic Leukemia-Lymphoma; Thromboplastin