VEGF-A, sVEGFR-1, and sVEGFR-2 in BCR-ABL negative myeloproliferative neoplasms.

BACKGROUND AND OBJECTIVE: Data from the literature indicate the relationship between the bone marrow microvessel density and the blood parameters of angiogenesis. The aim of this study was to evaluate selected parameters of angiogenesis (VEGF-A, sVEGFR-1, and sVEGFR-2) and their correlations with white blood cells, platelets, and red blood cells. MATERIALS AND METHODS: The study included 72 patients (mean age, 61.84 years) with myeloproliferative neoplasms (MPNs): essential thrombocythemia (ET) (n=46), polycythemia vera (PV) (n=19), and primary myelofibrosis (PMF) (n=7). Serum VEGF-A, sVEGFR-1, and sVEGFR-2 were determined using the ELISA assay. RESULTS: We observed a significantly higher level of VEGF-A and reduced concentrations of sVEGFR-1 and sVEGFR-2 in the whole group of patients with MPNs as compared to controls. Detailed analysis confirmed significantly higher level of VEGF-A and lower concentration of sVEGFR-2 in each subgroups of MPNs patients. However, sVEGFR-1 concentrations were significantly lower only in PV and ET patients. CONCLUSIONS: The study showed an increased level of VEGF-A, which may indicate the intensity of neoangiogenesis in the bone marrow. Decreased sVEGFR-1 and sVEGFR-2 in the blood of patients with MPNs may reflect consumption of these soluble receptors.

Overweight and obesity versus concentrations of VEGF-A, sVEGFR-1, and sVEGFR-2 in plasma of patients with lower limb chronic ischemia.

OBJECTIVE: Being overweight or obese comprises a significant risk factor for atherosclerosis. Fat tissue also generates factors stimulating angiogenesis, the process by which new blood vessels form. The purpose of this paper is to assess concentrations of the vascular endothelial growth factor A (VEGF-A) and its soluble type-1 and type-2 receptors (sVEGFR-1 and sVEGFR-2) in plasma of patients with peripheral arterial disease (PAD) depending on the level of nutrition according to body mass index (BMI). METHODS: The study group included patients suffering from symptomatic PAD (n=46) in Fontaine classes IIa-IV without any history of neoplastic disease and who have a normal BMI (n=15), are overweight (n=21) or are obese (n=10). The control group (n=30) consisted of healthy non-smoking volunteers who were neither overweight nor obese. Venous blood plasma samples were collected from both groups at rest in the morning to determine plasma concentrations of VEGF-A, sVEGFR-1, and sVEGFR-2 using the enzyme-linked immunosorbent assay (ELISA) method. RESULTS: The group of patients with PAD co-existent with being overweight or obese tended to have higher mean concentration levels of VEGF-A and sVEGFR-2 when compared with patients suffering from PAD with normal BMI. A statistically significant positive correlation was obtained between BMI and average plasma concentrations of sVEGFR-2 (R=0.37, P=0.0103). However, no significant correlation was noticed between BMI and VEGF-A or sVEGFR-1 concentrations. CONCLUSIONS: A positive correlation determined between the level of antiangiogenic factor and BMI value may be indicative of the linearly growing prevalence of some antiangiogenic factors in patients with metabolic disorders, which may be one of numerous factors contributing to incomplete efficiency of collateral circulation development in patients with PAD.

Extrinsic blood coagulation pathway and risk factors for thrombotic events in patients with essential thrombocythemia.

INTRODUCTION    The clinical course of essential thrombocythemia (ET) is varied, and some patients do not exhibit any clinical signs of the disease at the time of diagnosis. The most frequent complications that occur during the course of ET are hemostasis abnormalities manifesting as hemorrhagic or thrombotic events. The mechanism of thrombotic events in patients with ET is complex and not fully understood. OBJECTIVES    The aim of the study was to evaluate the concentration and activity of tissue factor (TF) and tissue factor pathway inhibitor (TFPI), depending on the most important risk factors of thrombotic complications (age >60 years, history of thrombotic episodes, presence or absence of the JAK2 V617F mutation, and increased leukocyte count). PATIENTS AND METHODS    The study group included 113 patients with diagnosed ET, and the control group, 30 healthy volunteers matched for age and sex. The concentration and activity of TF and TFPI were measured using enzyme-linked immunosorbent assays. RESULTS    Patients with ET had a significantly higher activity and concentration of TF and increased activity of TFPI, as compared with controls. The analysis of the studied parameters in relation to risk factors revealed that patients with ET with a history of thrombotic events had a significantly higher concentration of TF, and patients with the JAK2 V617F mutation had a lower TFPI activity, as compared with patients without the mutation. CONCLUSIONS    Our study showed that in patients with ET who have a history of thrombosis or the JAK2 V617F mutation, the enhanced risk of thrombosis may result from an increased TF concentration or decreased TFPI activity.

Activation of the tissue factor-dependent extrinsic pathway and its relation to JAK2 V617F mutation status in patients with essential thrombocythemia.

Thrombotic complications may occur in 7.6-29.4% of patients with essential thrombocythemia. According to the cellular theory, tissue factor (TF) activating extrinsic blood coagulation pathway is essential for the activation of blood clotting. The aim of the study was to evaluate the activation of the TF-dependent extrinsic pathway in patients with essential thrombocythemia, depending on the presence or absence of the Janus kinase 2 (JAK2) V617F mutation. The study included 74 newly diagnosed patients (F/M: 47/27; mean age 61 years) with essential thrombocythemia (Tefferi and Vardiman, Leukemia 2008; 22(1):14-22). Patients were diagnosed in the Department of Clinical Hematology and Hematological Malignancies University Hospital No. 2, Bydgoszcz, Poland. The control group consisted of 30 healthy volunteers (F/M: 17/13; mean age 49 years). The concentration and activity of TF and TF pathway inhibitor (TFPI) were measured using ELISA method. In patients with essential thrombocythemia, we observed a higher concentration of TF [median (Me) = 686.90 vs 164.28 pg/ml] and over 10-fold higher activity of TF (Me = 46.05 vs 4.01 pmol/l) when compared with the control group. We also reported significantly higher activity of TFPI compared with the control group (Me = 1.93 vs 1.78 U/ml). Moreover, a concentration of TFPI was significantly lower in patients with essential thrombocythemia with JAK2 V617F mutation as compared with patients without the mutation (Me = 1.90 vs 2.16 U/ml; P = 0.039639). Increased TF activity and concentration is responsible for higher procoagulant potential in patients with essential thrombocythemia. Reduced activity of TFPI in patients with essential thrombocythemia with JAK2 V617F mutation indicates an increased prothrombotic risk in this group of patients.

Morphine delays and attenuates ticagrelor exposure and action in patients with myocardial infarction: the randomized, double-blind, placebo-controlled IMPRESSION trial.

AIMS: The currently available data indicate a drug-drug interaction between morphine and oral P2Y12 receptor inhibitors, when administered together. The aim of this trial was to assess the influence of infused morphine on pharmacokinetics and pharmacodynamics of ticagrelor and its active metabolite (AR-C124910XX) in patients with acute myocardial infarction. METHODS AND RESULTS: In a single-centre, randomized, double-blind trial, patients were assigned in a 1:1 ratio to receive intravenously either morphine (5 mg) or placebo, followed by a 180 mg loading dose of ticagrelor. Pharmacokinetics was determined with liquid chromatography tandem mass spectrometry and ticagrelor antiplatelet effects were measured with up to three different platelet function tests: vasodilator-stimulated phosphoprotein phosphorylation assay, multiple electrode aggregometry and VerifyNow. The pharmacokinetic and pharmacodynamic assessment was performed in 70 patients (35 in each study group). Morphine lowered the total exposure to ticagrelor and its active metabolite by 36% (AUC(0-12): 6307 vs. 9791 ng h/mL; P = 0.003), and 37% (AUC(0-12): 1503 vs. 2388 ng h/mL; P = 0.008), respectively, with a concomitant delay in maximal plasma concentration of ticagrelor (4 vs. 2 h; P = 0.004). Multiple regression analysis showed that lower AUC(0-12) values for ticagrelor were independently associated with the administration of morphine (P = 0.004) and the presence of ST-segment elevation myocardial infarction (P = 0.014). All three methods of platelet reactivity assessment showed a stronger antiplatelet effect in the placebo group and a greater prevalence of high platelet reactivity in patients receiving morphine. CONCLUSIONS: Morphine delays and attenuates ticagrelor exposure and action in patients with myocardial infarction. ClinicalTrials.gov Identifier: NCT02217878.

Impact of type 2 diabetes on the plasma levels of vascular endothelial growth factor and its soluble receptors type 1 and type 2 in patients with peripheral arterial disease.

OBJECTIVE: Type 2 diabetes coexistent with lower extremity artery disease (peripheral arterial disease (PAD)) can be observed in numerous patients. The mechanism compensating for ischemia and contributing to healing is angiogenesis-the process of forming new blood vessels. The purpose of this study was to assess the likely impact of type 2 diabetes on the plasma levels of proangiogenic factor (vascular endothelial growth factor A (VEGF-A)) and angiogenesis inhibitors (soluble VEGF receptors type 1 and type 2 (sVEGFR-1 and sVEGFR-2)) in patients with PAD. METHODS: Among 46 patients with PAD under pharmacological therapy (non-invasive), we identified, based on medical history, a subgroup with coexistent type 2 diabetes (PAD-DM2+, n=15) and without diabetes (PAD-DM2-, n=31). The control group consisted of 30 healthy subjects. Plasma levels of VEGF-A, sVEGFR-1, and sVEGFR-2 were measured using the enzyme-linked immunosorbent assay (ELISA) method. RESULTS: The subgroups of PAD-DM2+ and PAD-DM2- revealed significantly higher concentrations of VEGF-A (P=0.000 007 and P=0.000 000 1, respectively) and significantly lower sVEGFR-2 levels (P=0.02 and P=0.000 01, respectively), when compared with the control group. Patients with PAD and coexistent diabetes tended to have a lower level of VEGF-A and higher levels of sVEGFR-1 and sVEGFR-2 comparable with non-diabetic patients. CONCLUSIONS: The coexistence of type 2 diabetes and PAD is demonstrated by a tendency to a lower plasma level of proangiogenic factor (VEGF-A) and higher levels of angiogenesis inhibitors (sVEGFR-1 and sVEGFR-2) at the same time. Regardless of the coexistence of type 2 diabetes, hypoxia appears to be a crucial factor stimulating the processes of angiogenesis in PAD patients comparable with healthy individuals, whereas hyperglycemia may have a negative impact on angiogenesis in lower limbs.

CRP, but not TNF-α or IL-6, decreases after weight loss in patients with morbid obesity exposed to intensive weight reduction and balneological treatment.

OBJECTIVE: The aim of this study was to evaluate the concentrations of C-reactive protein (CRP), tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), and the degree of homeostasis model assessment-insulin resistance (HOMA-IR) in patients with morbid obesity exposed to a three-week low-calorie diet and balneotherapy. METHODS: The study included 33 patients (25 females and 8 males; mean age 46 years) with body mass index (BMI) values of >40 kg/m(2). Evaluations of CRP, IL-6, TNF-α, lipid profile, HOMA-IR, and fasting glucose were carried out before (baseline data) and three weeks after the treatment. The control group consisted of 20 healthy volunteers (15 females and 5 males) with a mean age of 39 years and BMI values of ≤24.9 kg/m(2). RESULTS: In the blood of patients with morbid obesity we found significantly elevated levels of CRP, TNF-α, triglycerides, HOMA-IR and fasting glucose, but a decreased level of high density lipoprotein (HDL)-cholesterol, compared with the healthy individuals. The treatment resulted in about a 9.4% reduction in body weight from 122.5 to 111.0 kg and a significant decrease in the concentration of CRP, but no change in TNF-α or IL-6. HOMA-IR was significantly reduced. CONCLUSIONS: The decrease in CRP level without changes in TNF-α or IL-6 concentrations after the low-calorie diet and balneological treatment, suggests that an essential amount of adipose tissue must be removed before proper adipocyte function is restored. The decrease in HOMA-IR indicates an improvement in insulin sensitivity, which is beneficial in obese patients.

The number of circulating endothelial progenitor cells in healthy individuals--effect of some anthropometric and environmental factors (a pilot study).

PURPOSE: The aim of the study was the evaluation of the number of circulating endothelial progenitor cells (CEPCs) in healthy people and the assessment of the variability of quantitative of CEPCs after 6 weeks. MATERIAL AND METHODS: The study involved 48 healthy individuals; the group consisted of 24 men and 24 women; the mean age of 34. The criterion for the patients' eligibility for the study was the absence of diabetes, thrombosis and cardiovascular diseases such as atherosclerosis, hypertension, and heart failure. Neither did the respondents take any medication that could clearly affect the value of the results. In the whole blood samples the number of circulating endothelial progenitor cells was determined using flow cytometry. During the analysis the fluorescence of 100,000 cells was measured. CEPCs were identified with immunophenotype CD45-, CD31+, CD34+, CD133+. RESULTS: In the study, the median of the number of circulating endothelial progenitor cells in the whole group was 0.41/µL. There was also recorded an increased number of CEPCs after 6 weeks, as compared to the baseline; the difference was significant. There were no differences in the number of CEPCs between the women and the men. There was found no effect on the number of CEPCs factors such as: smoking, physical activity and alcohol consumption. CONCLUSIONS: The study showed that in healthy individuals the gender had no essential effect on the number of endothelial progenitor cells. Based on the demographic and lifestyle data acquired, it is difficult to explain the increase number of CEPCs after 6 weeks.

Prasugrel overcomes high on-clopidogrel platelet reactivity in the acute phase of acute coronary syndrome and maintains its antiplatelet potency at 30-day follow-up.

BACKGROUND: The aim of this study was to assess antiplatelet effect of prasugrel in acute coronary syndrome (ACS) patients with high on-treatment platelet reactivity (HTPR) on clopidogrel, undergoing percutaneous coronary intervention (PCI). METHODS: A prospective, platelet reactivity-guided, parallel-group, open-label study including 71 patients pretreated with clopidogrel 600 mg and assigned either to prasugrel (30 mg loading dose, 10 mg maintenance dose; n = 46) or clopidogrel (150 mg maintenance dose for 6 days and thereafter 75 mg maintenance dose; n = 25) regimen, based on vasodilator-stimulated phosphoprotein (VASP)-assessed platelet reactivity index (PRI; > 50% vs. ≤ 50%) measured next morning post-PCI. RESULTS: Median PRI value after switch to prasugrel sharply declined at 24 h (70.0 [61.3-75.6] vs. 11.9 [6.8-25.7]%; p < 0.000001) and slightly but significantly rose between 24 h and 30 days (27.9 [15.5-46.8]%; p < 0.0006). In contrast, median PRI values in the clopidogrel group were similar at baseline and at 24 h (25.1 [13.7-40.2] vs. 22.0 [18.4-36.8]%; p = NS) and then modestly rose at 30 days (30.3 [20.4-45.7]%; p < 0.03). The prevalence of HTPR decreased in the prasugrel group between baseline and 24 h measurements (100.0 vs. 4.3%; p < 0.0001). Rates of patients with HTPR at 24 h and 30 days were similar in both groups, so were the tendencies in patterns of platelet inhibition evaluated with multiple electrode aggregometry as compared with the VASP assay. CONCLUSIONS: Our study indicates that prasugrel overcomes HTPR on clopidogrel in the acute phase of interventionally treated ACS and maintains its antiplatelet potency in 30-day follow-up. Potential clinical benefits of personalized antiplatelet prasugrel-based therapy warrant further investigation in clinical ACS trials.

Selected parameters of hemostasis in patients with myeloproliferative neoplasms.

Hemostatic disorders are a major clinical problem in patients with myeloproliferative neoplasms (MPNs) and they are the second most common cause of death in MPN patients, after infections. The aim of this study was to assess the fibrinolytic potential of the blood of patients with MPNs. The study involved 112 patients with MPNs diagnosed at the Hematology Clinic Dr J. Biziel University Hospital No. 2 in Bydgoszcz, Poland. The study group included 63 patients with essential thrombocythemia, 29 with polycythemia vera, 11 with chronic myelogenous leukemia (CML) and nine with primary myelofibrosis. The control group consisted of 25 healthy volunteers who were age and sex-matched. The following parameters were determined: concentration of tissue plasminogen activator antigen (t-PA:Ag), plasminogen activator inhibitor type 1 antigen concentration (PAI-1:Ag), D-dimer, thrombin-antithrombin complexes, fibrinogen, activated partial thromboplastin time and international normalized ratio. The study showed significantly increased t-PA:Ag, PAI-1:Ag and D-dimer levels in patients with MPNs. Moreover, we found increased concentrations of thrombin-antithrombin complexes and fibrinogen, as well as elevated platelet counts. Detailed analysis revealed that t-PA:Ag concentration was elevated in patients with essential thrombocythemia, CML and polycythemia vera. Concentration of PAI-1:Ag was increased in patients with essential thrombocythemia and polycythemia vera; D-dimer was significantly higher in essential thrombocythemia, polycythemia vera, CML and primary myelofibrosis patients. Increased concentrations of t-PA:Ag and D-dimer indicate secondary activation of the fibrinolytic system in patients with MPNs. Elevated levels of PAI-1 in MPN patients may result from its increased production by elevated number of activated platelets and vascular endothelial damage. PAI-1 by having an inhibitory effect on fibrinolysis manifests its procoagulant activity.

Endothelial progenitor cells in diabetic foot syndrome.

In the late 20th century endothelial progenitor cells (EPCs) were discovered and identified as cells capable of differentiating into endothelial cells. Antigens characteristic of endothelial cells and hematopoietic cells are located on their surface. EPCs can proliferate, adhere, migrate and have the specific ability to form vascular structure, and they have a wide range of roles: They participate in maintaining hemostasis, and play an important part in the processes of vasculogenesis and angiogenesis. They are sources of angiogenic factors, especially vascular endothelial growth factor (VEGF). EPCs exist in bone marrow, from which they are recruited into circulation in response to specific stimuli. Tissue ischemia is thought to be the strongest inductor of EPC mobilization. Local ischemia accompanies many pathological states, including diabetic foot syndrome (DFS). Impaired angiogenesis--in which EPCs participate--is typical of DFS. An analysis of the available literature indicates that in diabetic patients the number of EPCs declines and their functioning is impaired. Endothelial progenitor cells are crucial to vasculogenesis and angiogenesis during ischemic neovascularization. The pathomechanisms underlying impaired angiogenesis in patients with DFS is complicated, but the discovery of EPCs has shed new light on the pathogenesis of many diseases, including diabetes foot syndrome.