Tissue-type plasminogen activator and plasminogen activator inhibitor type 1 in patients with symptomatic lower extremity artery disease.

BACKGROUND: Lower extremity artery disease (LEAD) involves progressive arterial narrowing manifested by intermittent claudication (IC). LEAD entails endothelial dysfunction and fibrinolytic disorders. In the current study, we analyze the selected parameters of the fibrinolytic system in the blood of patients with symptomatic LEAD depending on clinical parameters. METHODS: The test group was comprised of 80 patients with diagnosis of LEAD based on Ankle-Brachial Index (ABI) test (27 female/53 male) with an average age of 63.5±9 years. The control group included 30 healthy, non-smoking volunteers (10 female/20 male), with the median age of 56±6 years. The research material - venous blood - was sampled to determine the concentrations of tissue-type plasminogen activator (t-PA Ag), plasminogen activator inhibitor type 1 (PAI-1 Ag), D-dimer, fibrinogen, and platelet count (PLT). RESULTS: We found elevated concentrations of t-PA Ag, PAI-1 Ag, D-dimer, and fibrinogen in the plasma of subjects with symptomatic LEAD. Various stages of the Fontaine classification demonstrated a gradual, statistically significant increase in the concentrations of fibrinogen and PLT count as the disease progressed. More so, in the subgroup of LEAD patients aged ≥65 years, we observed significantly higher levels of D-dimer than in the group of younger subjects. In addition to that, the LEAD group demonstrated negative correlations of IC distance, fibrinogen concentrations, and PLT count, negative correlations of ABI at rest and concentrations of D-dimer and PLT count, as well as positive correlations between age and D-dimer levels. CONCLUSIONS: High t-PA Ag concentrations in LEAD patients suggest damage to the endothelium which comprises the main source of this factor. With high PAI-1 Ag levels, inactive fibrinolytic t-PA-PAI-1 complexes are formed. Increasing fibrinogen concentrations at the subsequent stages in accordance with the Fontaine classification, indicate increasing inflammation. Moreover, heightened values of D-dimer reflect an increased secondary fibrinolysis activation as patients get older and impaired extremity vascularization, manifested by the decreasing ABI, progresses.

VASCULAR-1 and VASCULAR-2 as a New Potential Angiogenesis and Endothelial Dysfunction Markers in Peripheral Arterial Disease.

The quotient of concentrations concerning the key proangiogenic factor, that is, the vascular endothelial growth factor (VEGF-A) and the angiogenesis inhibitor, namely, its soluble receptors (sVEGFR-1 or sVEGFR-2), seems to reflect increased hypoxia and intensity of compensation angiogenesis. Therefore, it can be an ischemic and endothelial dysfunction marker reflected in intermittent claudication (IC) or critical limb ischemia (CLI) in patients with symptomatic peripheral arterial disease (PAD). The main objective of this study was to evaluate the levels of VEGF-A/sVEGFR-1 and VEGF-A/sVEGFR-2-presented using a novelty acronym VASCULAR-1 and VASCULAR-2-in patients with IC and CLI, as well as displayed in 4 classes of severity of PAD. VASCULAR-1 and VASCULAR-2 were calculated using the plasma of venous blood sampled from 80 patients with IC (n = 65) and CLI (n = 15) and the control group (n = 30). Patients with CLI were reported to have a slightly higher index of VASCULAR-1 and double VASCULAR-2 levels as compared to patients with IC (P = nonsignificant), and these markers were significantly higher than controls (P < .01 and P < .01, respectively). VASCULAR-2 levels were observed to have an increasing tendency in the subsequent degrees of PAD severity according to the Fontaine classification (P = .02). In view of the need to consider the role of the proangiogenic and antiangiogenic factor in the assessment of the so-called "angiogenic potential," VASCULAR-1 ratio and VASCULAR-2 ratio may be a new useful biomarker of limb ischemia in patients with IC and CLI. However, this requires further studies and evidence on a very large group of patients with PAD.

Type 2 Diabetes and Cardiovascular Factors Contrasted with Fibrinolysis Disorders in the Blood of Patients with Peripheral Arterial Disease.

Background and objectives: Both in the pathogenesis of type 2 diabetes (DM 2) and Peripheral Arterial Disease (PAD), a vital role is played by endothelial dysfunction. Metabolic disorders found in DM 2 (hyperglycemia, insulin resistance), endothelial dysfunction, and increased inflammation lead to intensified atherothrombosis. The fibrinolysis system comprises a natural compensatory mechanism in case of hypercoagulability. The aim of this study was to assess concentrations of selected fibrinolysis parameters in the blood of patients with symptomatic PAD, including in particular concurrent DM 2 and other cardiovascular factors. Materials and Methods: In the group of 80 patients with PAD (27 F/53 M) and 30 healthy volunteers (10 F/20 M), the following parameters were measured: Concentrations of fibrinogen, tissue-Plasminogen Activator (t-PA Ag), Plasminogen Activator Inhibitor-1 (PAI-1 Ag), D-dimer, and platelet (PLT) count. Results: In the blood of patients with PAD and concomitant DM 2 significantly higher concentrations of fibrinogen were found in comparison with patients with PAD and without diabetes (p = 0.044). No significant impact was observed in individuals with atherosclerotic complications (manifested by coronary artery disease, atherosclerosis of cerebral arteries) and selected cardiovascular risk factors (smoking, LDL and triglyceride concentrations, BP values) on the levels of t-PA, PAI-1, D-dimer, and PLT count. It was found that t-PA Ag and PAI-1 Ag values tended to rise along with a BMI increase in the subgroups of subjects (with normal body mass, overweight, and obesity), but no statistically significant differences were observed. However, two significant positive correlations were reported between t-PA Ag and BMI, as well as between PAI-1 Ag and BMI. Conclusions: Type 2 diabetes in peripheral arterial disease affects the concentration of fibrinogen causing its increase, which is connected with the inflammation and prothrombotic process in the course of both conditions. The concurrence of atherosclerosis of coronary or cerebral arteries, smoking, LDL and TG concentrations, and BP value do not have a significant impact on the levels of analyzed fibrinolysis parameters. A positive correlation between BMI and t-PA Ag and PAI-1 Ag concentrations needs to be supported in further studies on a larger number of overweight and obese patients.

Coexistence of proangiogenic potential and increased MMP-9, TIMP-1, and TIMP-2 levels in the plasma of patients with critical limb ischemia.

The objective of this study was to assess the angiogenic potential expressed as a quotient of vascular endothelial growth factor A (VEGF-A), as an indicator of proangiogenic activity, and the circulating receptors (soluble VEGF receptor protein R1 (sVEGFR-1) and sVEGFR-2), as indicators of the effect of angiogenic inhibition, depending on the concentrations of matrix metalloproteinase 2 (MMP-2) and MMP-9 and their tissue inhibitor 1 (TIMP-1) and TIMP-2 in the plasma of patients with lower extremity artery disease (LEAD). These blood parameters in patients with intermittent claudication (IC) and critical limb ischemia (CLI) were compared for select clinical and biochemical features. Stimulation of angiogenesis in the plasma of individuals with LEAD was evident as indicated by the significant increase in VEGF-A concentration along with reduced inhibition depending on circulating receptors sVEGFR-1 and sVEGFR-2. Critical ischemia was associated with higher VEGF-A, MMP-9, TIMP-1, and TIMP-2 concentrations than in the case of IC.

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.