Population pharmacokinetic-pharmacodynamic modeling of serum biomarkers as predictors of tumor dynamics following lenvatinib treatment in patients with radioiodine-refractory differentiated thyroid cancer (RR-DTC).

Lenvatinib is a receptor tyrosine kinase (RTK) inhibitor targeting vascular endothelial growth factor (VEGF) receptors 1-3, fibroblast growth factor (FGF) receptors 1-4, platelet-derived growth factor receptor-α (PDGFRα), KIT, and RET that have been implicated in pathogenic angiogenesis, tumor growth, and cancer. The primary objective of this work was to evaluate, by establishing quantitative relationships, whether lenvatinib exposure and longitudinal serum biomarker data (VEGF, Ang-2, Tie-2, and FGF-23) are predictors for change in longitudinal tumor size which was assessed based on data from 558 patients with radioiodine-refractory differentiated thyroid cancer (RR-DTC) receiving either lenvatinib or placebo treatment. Lenvatinib PK was best described by a 3-compartment model with simultaneous first- and zero-order absorption and linear elimination from the central compartment with significant covariates (body weight, albumin <30 g/dL, ALP>ULN, RR-DTC, RCC, HCC subjects, and concomitant CYP3A inhibitors). Except for body weight, none of the covariates have any clinically meaningful effect on exposure to lenvatinib. Longitudinal biomarker measurements over time were reasonably well defined by a PK/PD model with common EC50, Emax, and a slope for disease progression for all biomarkers. Longitudinal tumor measurements over time were reasonably well defined by a tumor growth inhibition Emax model, which in addition to lenvatinib exposure, included model-predicted relative changes from baseline over time for Tie-2 and Ang-2 as having significant association with tumor response. The developed PK/PD models pave the way for dose optimization and potential prediction of clinical response.

Mid trimester amniotic fluid soluble receptor tunica interna endothelial cell kinase-2 levels and risk for preeclampsia.

OBJECTIVES: The purpose of this study was to determine if elevated concentration of soluble receptor tunica interna endothelial cell kinase-2 (Tie-2) in the amniotic fluid represent a risk factor for the subsequent development of preeclampsia (PE). STUDY DESIGN: Amniotic fluid samples were collected as a part of routine clinical diagnostics from women referred to clinical care due to genetic indications. A total of 12 women with preeclampsia and 26 normotensive pregnant women were included in the study. Mean gestational age at amniocentesis was 17.92 weeks of pregnancy in preeclampsia and 17.88 in control group, respectively. Concentrations of sTie-2 in the amniotic fluid were determined by a standardized enzyme immunoassay. RESULTS: Median concentration of Tie-2 in the amniotic fluid of PE patients was lower (median 1.109 ng/ml) compared with normotensive pregnant women (median 1.433 ng/Ml) but the difference was not statistically significant (p = 0.2973). Concentration of sTie-2 in the amniotic fluid did not significantly correlate with maternal age, gestational age at amniocentesis or delivery, as well as weight or length at birth. A difference in the gestational age at delivery in PE patients (mean 37.7 weeks) and normotensive pregnant controls (mean 39.8 weeks) was statistically significant (p = 0.0003). Birth weight and length of children delivered by PE women (mean 2863.3 g and 48.3 cm) were significantly lower compared with normal pregnancies (mean 3591.2 g and 51.4 cm, p = 0.0002 and p = 0.006, respectively). CONCLUSION: Our results suggest that amniotic fluid concentrations of sTie-2 do not predict development of PE and that further studies on biomarkers as predictors of PE should include other angiogenic biological response modifiers.

Upregulated Tie2 expression in plasma: a potential non-invasive biomarker for the diagnosis of breast cancer.

Breast cancer is by far the most common malignancy found in women and causes a significant public health problem around the world. Early diagnosis of cancer plays an important role in successful treatment and survival of patients. This study aims to investigate the possibility of plasma Tie2 to be used as a biomarker for diagnosis of breast cancer. In total, 20 healthy volunteers and 33 breast cancer patients were considered for this study. The level of Tie2 in plasma was detected using the ELISA technique and immunohistochemistry was performed to measure the expression of Tie2 in normal and breast cancer tissues. Plasma concentrations of Tie2 were significantly higher among breast cancer patients compared to healthy subjects, and both mRNA and protein expression of Tie2 were higher in breast cancer tissue than in normal tissue. Plasma concentrations of Tie2 were positively correlated with the grade of breast cancer. Finally, in vitro knockdown of Tie2 expression in a breast adenocarcinoma cell line inhibited the proliferation of these cells. It is concluded from the results that Tie2 might be a useful plasma biomarker for the early detection of breast cancer and could be developed to be a target for novel drug discovery.

A panel of selected serum protein biomarkers for the detection of aggressive prostate cancer.

Background: Current PSA-based tests used to detect prostate cancer (PCa) lack sufficient specificity, leading to significant overdetection and overtreatment. Our previous studies showed that serum fucosylated PSA (Fuc-PSA) and soluble TEK receptor tyrosine kinase (Tie-2) had the ability to predict aggressive (AG) PCa. Additional biomarkers are needed to address this significant clinical problem. Methods: A comprehensive Pubmed search followed by multiplex immunoassays identified candidate biomarkers associated with AG PCa. Subsequently, multiplex and lectin-based immunoassays were applied to a case-control set of sera from subjects with AG PCa, low risk PCa, and non-PCa (biopsy negative). These candidate biomarkers were further evaluated for their ability as panels to complement the prostate health index (phi) in detecting AG PCa. Results: When combined through logistic regression, two panel of biomarkers achieved the best performance: 1) phi, Fuc-PSA, SDC1, and GDF-15 for the detection of AG from low risk PCa and 2) phi, Fuc-PSA, SDC1, and Tie-2 for the detection of AG from low risk PCa and non-PCa, with noticeable improvements in ROC analysis over phi alone (AUCs: 0.942 vs 0.872, and 0.934 vs 0.898, respectively). At a fixed sensitivity of 95%, the panels improved specificity with statistical significance in detecting AG from low risk PCa (76.0% vs 56%, p=0.029), and from low risk PCa and non-PCa (78.2% vs 65.5%, p=0.010). Conclusions: Multivariate panels of serum biomarkers identified in this study demonstrated clinically meaningful improvement over the performance of phi, and warrant further clinical validation, which may contribute to the management of PCa.

Association of Lymphangiogenic Factors With Pulmonary Arterial Hypertension in Systemic Sclerosis.

OBJECTIVE: Pulmonary arterial hypertension (PAH) is a major complication in systemic sclerosis (SSc), a disease marked by vascular and lymphatic vessel abnormalities. This study was undertaken to assess the role of the lymphangiogenic factors vascular endothelial growth factor C (VEGF-C) and angiopoietin 2 (Ang-2) and the soluble forms of their respective cognate receptors, soluble VEGF receptor 3 (sVEGFR-3) and soluble TIE-2, in patients with SSc, and to evaluate their predictive ability as markers for PAH development in SSc. METHODS: In this cohort study, we used multiplex bead assays to assess serum levels of lymphangiogenic factors in 2 well-characterized SSc cohorts: an unselected identification cohort of SSc patients from Oslo University Hospital (n = 371), and a PAH-enriched validation cohort of SSc patients from Zurich University Hospital and Oslo University Hospital (n = 149). As controls for the identification and validation cohorts, we obtained serum samples from 100 healthy individuals and 68 healthy individuals, respectively. Patients in whom SSc-related PAH was identified by right-sided heart catheterization (RHC) in both cohorts were studied in prediction analyses. PAH was defined according to the European Society of Cardiology/European Respiratory Society 2015 guidelines for the diagnosis and treatment of PAH. Associations of serum levels of lymphangiogenic factors with the risk of PAH development were assessed in logistic regression and Cox regression analyses. Associations in Cox regression analyses were expressed as the hazard ratio (HR) with 95% confidence interval (95% CI). RESULTS: In the identification cohort, SSc patients had lower mean serum levels of VEGF-C and higher mean serum levels of Ang-2 compared to healthy controls (for VEGF-C, mean ± SD 2.1 ± 0.5 ng/ml in patients versus 2.5 ± 0.4 ng/ml in controls; for Ang-2, mean ± SD 6.1 ± 7.6 ng/ml in patients versus 2.8 ± 1.8 ng/ml in controls; each P < 0.001); these same trends were observed in SSc patients with PAH compared to those without PAH. The association of serum VEGF-C levels with SSc-PAH was confirmed in the PAH-enriched RHC validation cohort. For prediction analyses, we assembled all 251 cases of SSc-PAH identified by RHC from the identification and validation cohorts. In multivariable Cox regression analyses adjusted for age and sex, the mean serum levels of VEGF-C and sVEGFR-3 were predictive of PAH development in patients with SSc (for VEGF-C, HR 0.53 [95% CI 0.29-0.97], P = 0.04; for sVEGFR-3, HR 1.21 [95% CI 1.01-1.45], P = 0.042). CONCLUSION: These findings support the notion that lymphangiogenesis is deregulated during PAH development in SSc, and indicate that VEGF-C could be a promising marker for early PAH detection in patients with SSc.

Angiopoietin-2 as a Prognostic Factor in Patients with Incurable Stage IV Colorectal Cancer.

PURPOSE: Angiopoietin (Ang), a ligand of the endothelium-specific receptor Tie-2 system, is associated with tumor growth and progression that depend on angiogenesis. The present study aimed to investigate the predictive potential of angiopoietin factors in incurable stage IV colorectal cancer (CRC) patients who have undergone primary tumor resection. METHODS: The study included 40 consecutive patients with incurable stage IV CRC who underwent primary tumor resection at our hospital between 2011 and 2015. Patients were divided into subgroups of low and high Ang-1, Ang-2, and Tie-2. Patient age and sex, tumor location, TNM stages, vascular invasion, chemotherapy, and overall survival were assessed. RESULTS: The cut-off values of Ang-1, Ang-2, and Tie-2 were 0.4, 1.8, and 15.0 ng/mL, respectively. Overall survival was significantly longer in the low Ang-2 group than in the high Ang-2 group. High Ang-2 levels were associated with age, N stage, and chemotherapy. Immunofluorescent staining of Ang-2 revealed that endothelial cells and cancer cells expressed Ang-2 in each case. CONCLUSIONS: Our findings suggest that the serum Ang-2 level is associated with disease progression and is an important predictor of mortality in incurable stage IV CRC patients. Thus, it may be a useful prognostic biomarker in these patients.

Effects of Negative Pressure Wound Therapy on Levels of Angiopoetin-2 and Other Selected Circulating Signaling Molecules in Patients with Diabetic Foot Ulcer.

BACKGROUND AND AIMS: Diabetic foot ulcers (DFUs) are linked to amputations and premature deaths. Negative pressure wound therapy (NPWT) has been used for DFUs. The mechanism of NPWT's action may be associated with its influence on circulating molecules. We assessed NPWT's effect on the plasma levels of angiopoietin-2 (Ang2), a key regulator of angiogenesis, and its microvesicular receptors (Tie2) as well as the microvesicles (MVs) themselves in DFU patients. MATERIALS AND METHODS: We included 69 patients with type 2 diabetes mellitus (T2DM) and neuropathic, noninfected DFUs-49 were treated with NPWT and 20 were treated with standard therapy (ST). Assigning patients to the NPWT group was not random but based on DFU characteristics, especially wound area. Ang2 was measured by ELISA in the entire group, while in a subgroup of 19 individuals on NPWT and 10 on ST, flow cytometry was used to measure Tie2+ and the corresponding isotype control (Iso+) and annexin V (AnnV+) as well as total MVs. Measurements were performed at the beginning and after 8 ± 1 days of therapy. RESULTS: Treatment groups were similar for basic characteristics but differed by their median DFU areas (10.3 (4.2-18.9) vs. 1.3 (0.9-3.4) cm2, p = 0.0001). At day 0, no difference was observed in Ang2 levels, total MVs, MV Tie+, and MV AnnV+ between the groups. Ang2 decreased after 8 days in the NPWT group, unlike in the ST group (3.54 (2.40-5.40) vs. 3.32 (2.33-4.61), p = 0.02, and 3.19 ± 1.11 vs. 3.19 ± 1.29 ng/mL, p = 0.98, respectively). No other parameters were identified that may have been influenced by the NPWT treatment. CONCLUSION: NPWT in T2DM patients with neuropathic, noninfected DFU seems to lead to reduction of the Ang2 level. Influencing the level of Ang2 may constitute one of NPWT-related mechanisms to accelerate wound healing.

The contribution of dietary and plasma folate and cobalamin to levels of angiopoietin-1, angiopoietin-2 and Tie-2 receptors depend on vascular endothelial growth factor status of primary breast cancer patients.

The aim of this study was to determine the association of dietary folate and cobalamin with plasma levels of Angiopoietins (ANG), vascular endothelial growth factor-C (VEGF-C) and tyrosine kinase receptor-2 (Tie-2) of primary breast cancer patients. Women (n = 177), aged 30 to 75 years diagnosed with breast cancer were recruited from an ongoing case series study. Dietary intake of nutrients was estimated by using a validated food frequency questionnaire. Enzyme-linked immunosorbent assay was applied to measure biomarkers. MCF-7 cell cultures were supplemented with folic acid (0-40 µM) for 24 h to measure cell viability and fold change of expression by the real-time reverse transcriptase-polymerase chain reaction. Structural equation modeling was applied to analyze the structural relationships between the measured variables of nutrients and Angiopoietins. Dietary intake of folate and cobalamin showed a significant inverse correlation with plasma ANG-1 and ANG-2 (P < 0.05), particularly in subjects with estrogen-receptor positive tumors or low plasma VEGF-C. Plasma folate was positively associated with the ratio of ANG-1/ANG-2 (P < 0.05). Residual intake levels of total cobalamin were inversely associated with plasma ANG-1 when plasma stratum of VEGF-C was high (P < 0.05). Structural equation modeling identified a significant inverse contribution of folate profiles on the latent variable of Angiopoietins (coefficient ß = -0.99, P < 0.05). Folic acid treatment resulted in dose-dependent down-regulations on ANGPT1 and ANGPT1/ANGPT2 ratio but VEGF and ANGPT2/VEGF were upregulated at folic acid >20 µM. Studying the contributing role of dietary folate to pro-angiogenic biomarkers in breast cancer patients can infer the preventive role of folate in the ANGs/VEGF-C-dependent cascade of tumor metastasis. By contrast, high concentrations of folic acid in vitro supported VEGF-C-dependent ANGPT2 overexpression might potentiate micro-lymphatic vessel development to support malignant cell dissemination.

Biomarkers associating endothelial Dysregulation in pediatric-onset systemic lupus erythematous.

BACKGROUND/PURPOSE: Endothelium is a key element in the regulation of vascular homeostasis and its alteration can lead to the development of vascular diseases. Systemic lupus erythematosus (SLE) is a systemic autoimmune disease with potential extensive vascular lesions, involving skin vessels, renal glomeruli, cardiovascular system, brain, lung alveoli, gastrointestinal tract vessels and more. We aimed to assess endothelial dysregulation related biomarkers in pediatric-onset SLE (pSLE) patient serum and elucidate its correlation with their clinical features, laboratory parameters, and the overall disease activity. METHODS: Disease activities were evaluated by SLE disease activity index (SLEDAI). Patient characteristics were obtained by retrospective chart review. Six biomarkers associated with endothelial dysregulation, including Angiopoietin-1 (Ang-1), Angiopoietin-2 (Ang-2), Tie2, Vascular endothelial growth factor (VEGF), thrombomodulin, and a disintegrin-like and metalloprotease with thrombospondin type 1 motif (ADAMTS13) were tested through enzyme-linked immunosorbent assay (ELISA) measurement. RESULTS: This study comprised 118 pSLE patients. Data from 40 age-matched healthy controls were also obtained. The mean diagnostic age was 13 ± 4.12 years-old and 90.7% are females. Serum levels of VEGF, Tie2, thrombomodulin were significantly higher while serum ADAMTS13 was lower in active pSLE patients when compared to those with inactive diseases (all p < 0.05). In organ specific association, serum thrombomodulin level was higher in pSLE patient with renal involvement, and serum ADAMTS13 levels was negatively associated with neurological involvement (p < 0.05). A cutoff of thrombomodulin at 3333.6 pg/ml best correlated renal involvement. (AUC = 0.752, p < 0.01). CONCLUSION: Endothelial dysregulation associating proteins seems to be potent biomarkers for pSLE activity as well as organ involvement in pSLE patients. These biomarkers may be beneficial in understanding of the vascular pathogenesis and disease monitoring.

Phase II trial of ponatinib in patients with bevacizumab-refractory glioblastoma.

BACKGROUND: Responses to bevacizumab in glioblastoma (GBM) are not durable. Plasma levels of basic fibroblast growth factor (bFGF) increase at the time of tumor progression. By targeting vascular endothelial growth factor receptor (VEGFR), platelet-derived growth factor receptor, Src, and FGF receptor pathways, ponatinib may potentially help to overcome some of the putative mechanisms of adaptive resistance. METHODS: We performed a phase II trial of ponatinib in patients with bevacizumab-refractory GBM and variants. Adult patients with Karnofsky performance score (KPS) ≥60, measurable disease, and normal organ and marrow function received 45 mg ponatinib daily. No limit on the number of prior therapies but only one prior bevacizumab-containing regimen was allowed. Primary endpoint was 3-month progression-free survival. Plasma biomarkers of angiogenesis and inflammation were evaluated before and after treatment. RESULTS: The study closed after the first stage. Fifteen patients enrolled: median age 61 [27-74]; median KPS 80 [70-90]; median number of prior relapses 2 [2-4]. Three-month progression-free survival rate was 0, median overall survival was 98 days [95% CI 56, 257], and median PFS was 28 days [95% CI 27, 30]. No responses were seen. The most common grade ≥3 adverse events included fatigue (n = 3), hypertension (2), and lipase elevation (2). Ponatinib treatment significantly increased plasma VEGF, soluble (s)VEGFR1, sVEGFR2, sTIE2, interferon gamma (IFNγ), tumor necrosis factor alpha (TNF-α), interleukin (IL)-6, IL-8, and IL-10 and decreased sVEGFR2. CONCLUSIONS: Ponatinib was associated with minimal activity in bevacizumab-refractory GBM patients. Circulating biomarker data confirmed pharmacodynamic changes and suggested that resistance to ponatinib may be related to an increase in inflammatory cytokines.

The relationship with clinical course and prognosis of serum endothelin-1, angiopoietin-2, and tie-2 levels in Crimean-Congo hemorrhagic fever

Background/aim: Crimean-Congo hemorrhagic fever (CCHF) is a serious illness characterized by fever and hemorrhage. Endothelin-1 (ET-1), angiopoietin-2 (Ang-2), and endothelial cell-specific receptor tyrosine kinase (Tie-2) are believed to be important markers of the pathogenesis, clinical course, and prognosis of the disease. The aim of this study was to determine ET-1, Ang-2, and Tie-2 levels in adults with CCHF and investigate the associations between these markers and pathogenesis and disease course. Materials and methods: Sixty CCHF patients were included in the study. The patients were classified according to disease severity criteria and Ang-2, Tie-2, and ET-1 levels were compared. Results: Mean serum ET-1 level was 36.62 ± 27.99 pg/mL in the patient group and 3.70 ± 4.71 pg/mL in the control group (P = 0.001). Mean serum Ang-2 levels were 2511.18 ± 1018.64 pg/mL in the patient group and 3570.76 ± 209.52 pg/mL in the control group (P = 0.001). Mean serum Tie-2 levels were 7.35 ± 7.75 ng/mL in the patient group and 0.67 ± 1.26 ng/mL in the control group (P = 0.001). Conclusion: Elevated ET-1 and Tie-2 levels were associated with more severe disease course, while Ang-2 level was negatively correlated with severity in adult CCHF patients. ET-1, Tie-2, and Ang-2 levels are important prognostic parameters in CCHF and may contribute significantly to treatment and follow-up.

Microcirculatory perfusion disturbances following cardiac surgery with cardiopulmonary bypass are associated with in vitro endothelial hyperpermeability and increased angiopoietin-2 levels.

BACKGROUND: Endothelial hyperpermeability following cardiopulmonary bypass (CPB) contributes to microcirculatory perfusion disturbances and postoperative complications after cardiac surgery. We investigated the postoperative course of renal and pulmonary endothelial barrier function and the association with microcirculatory perfusion and angiopoietin-2 levels in patients after CPB. METHODS: Clinical data, sublingual microcirculatory data, and plasma samples were collected from patients undergoing coronary artery bypass graft surgery with CPB (n = 17) before and at several time points up to 72 h after CPB. Renal and pulmonary microvascular endothelial cells were incubated with patient plasma, and in vitro endothelial barrier function was assessed using electric cell-substrate impedance sensing. Plasma levels of angiopoietin-1,-2, and soluble Tie2 were measured, and the association with in vitro endothelial barrier function and in vivo microcirculatory perfusion was determined. RESULTS: A plasma-induced reduction of renal and pulmonary endothelial barrier function was observed in all samples taken within the first three postoperative days (P < 0.001 for all time points vs. pre-CPB). Angiopoietin-2 and soluble Tie2 levels increased within 72 h after CPB (5.7 ± 4.4 vs. 1.7 ± 0.4 ng/ml, P < 0.0001; 16.3 ± 4.7 vs. 11.9 ± 1.9 ng/ml, P = 0.018, vs. pre-CPB), whereas angiopoietin-1 remained stable. Interestingly, reduced in vitro renal and pulmonary endothelial barrier moderately correlated with reduced in vivo microcirculatory perfusion after CPB (r = 0.47, P = 0.005; r = 0.79, P < 0.001). In addition, increased angiopoietin-2 levels moderately correlated with reduced in vitro renal and pulmonary endothelial barrier (r = - 0.46, P < 0.001; r = - 0.40, P = 0.005) and reduced in vivo microcirculatory perfusion (r = - 0.43, P = 0.01; r = - 0.41, P = 0.03). CONCLUSIONS: CPB is associated with an impairment of in vitro endothelial barrier function that continues in the first postoperative days and correlates with reduced postoperative microcirculatory perfusion and increased circulating angiopoietin-2 levels. These results suggest that angiopoietin-2 is a biomarker for postoperative endothelial hyperpermeability, which may contribute to delayed recovery of microcirculatory perfusion after CPB. TRIAL REGISTRATION: NTR4212 .

Dysregulation of circulating sTie2 and sHER2 in HIV-infected women with preeclampsia.

OBJECTIVE: This study assesses whether circulating sTie2 and sHER2 are altered in HIV-negative and HIV-positive pregnant normotensive and preeclamptic women. METHODS: Serum samples were obtained from 80 pregnant women, stratified into four groups, namely, HIV-negative normotensives (20); HIV-positive normotensives (20); HIV-negative preeclamptics (20); and HIV-positive preeclamptics (20). The concentration of sTie2 and sHER2 was analyzed by Bio-Plex multiplex immunoassay and generated from a standard curve. RESULTS: sTie2 differed significantly by pregnancy type (p = 0.0403) but not by HIV status (p = 0.5214). sHER2 did not show a significant difference between normotensive and preeclampsia (p = 0.3677) and by HIV status (p = 0.5249). CONCLUSION: Irrespective of HIV status, reduced concentrations of sTie2 were evident in preeclampsia (PE) reflecting a dysregulation of the angiogenic process. sHER2 was similar between pregnancy types, attributable to the oxidative stressed microenvironment which promotes dysregulation of the MAPK and P13K/Akt signaling. HIV status did not influence sTie2 and sHER2 expression, reflecting the immune reconstitution of highly active antiretroviral therapy. sTie2 and sHER2 were not influenced by PE comorbid with HIV infection.

Plasma Tie2 is a tumor vascular response biomarker for VEGF inhibitors in metastatic colorectal cancer.

Oncological use of anti-angiogenic VEGF inhibitors has been limited by the lack of informative biomarkers. Previously we reported circulating Tie2 as a vascular response biomarker for bevacizumab-treated ovarian cancer patients. Using advanced MRI and circulating biomarkers we have extended these findings in metastatic colorectal cancer (n = 70). Bevacizumab (10 mg/kg) was administered to elicit a biomarker response, followed by FOLFOX6-bevacizumab until disease progression. Bevacizumab induced a correlation between Tie2 and the tumor vascular imaging biomarker, Ktrans (R:-0.21 to 0.47) implying that Tie2 originated from the tumor vasculature. Tie2 trajectories were independently associated with pre-treatment tumor vascular characteristics, tumor response, progression free survival (HR for progression = 3.01, p = 0.00014; median PFS 248 vs. 348 days p = 0.0008) and the modeling of progressive disease (p < 0.0001), suggesting that Tie2 should be monitored clinically to optimize VEGF inhibitor use. A vascular response is defined as a 30% reduction in Tie2; vascular progression as a 40% increase in Tie2 above the nadir. Tie2 is the first, validated, tumor vascular response biomarker for VEGFi.

The role of biomarkers of endothelial activation in predicting morbidity and mortality in patients with severe sepsis and septic shock in intensive care: A prospective observational study.

INTRODUCTION: Endothelial dysfunction plays an essential role in the pathogenesis of sepsis. The study aimed to illustrate the associations between the dynamic change (from day 1 to day 7) in biomarker concentration of endothelial dysfunction and outcomes in severe sepsis and septic shock in the intensive care unit (ICU). MATERIALS AND METHODS: We studied 102 patients enrolled in the Beijing Chao-yang Hospital affiliated with the Capital Medical University. A receiver operating characteristic (ROC) curve were used to assess the prognostic values of the circulating adhesion Angiopoietin-2/Angiopoietin-1 ratio (Ang-2/Ang-1) and Angiopoietin-1/Tie-2 ratio (Ang-1/Tie-2), intercellular adhesion molecule (ICAM)-1, vascular cell adhesion molecule (VCAM)-1 and thrombomodulin (TM). Spearman's rank correlation and a multiple regression analysis were used to assess the relationship between the change in sequential organ failure assessment (Δ SOFA) score (SOFA score at day 7 minus SOFA score at day 1) and the levels of Δ Ang-2/Ang-1 and Δ Ang-1/Tie-2 ratios, ΔsICAM-1, ΔsVCAM-1 and Δ sTM. RESULTS: The Ang-2/Ang-1 ratio, sICAM-1, sVCAM-1 and sTM levels significantly increased from day 1 to day 7 (all p = 0.045), and the Ang-1/Tie-2 ratio level markedly decreased from day 1 and day 7 (p = 0.027) in non-survivors. The biomarkers at Days 1 and 7 had significant prognostic value for 90-day mortality in severe sepsis and septic shock in ICU. The difference in biomarkers for endothelial dysfunction were suggested to be effective, independent predictors of changes in Δ SOFA. CONCLUSIONS: Endothelial dysfunction may constitute an independent contributor to sepsis-associated outcomes in ICU.

Circulating Vascular Growth Factors and Magnetic Resonance Imaging Markers of Small Vessel Disease and Atrophy in Middle-Aged Adults.

Background and Purpose- Little is known about associations between vascular growth factors and magnetic resonance imaging (MRI) markers in midlife. We investigated the association of serum VEGF (vascular endothelial growth factor), Ang2 (angiopoietin 2), sTie2 (soluble tyrosine kinase with immunoglobulin-like and EGF-like domains 2), and HGF (hepatocyte growth factor) concentrations with MRI markers of brain aging in middle-aged adults. Methods- We evaluated 1853 participants (mean age, 46±9 years; 46% men) from the Framingham Heart Study. Serum growth factor concentrations were measured using standardized immunoassays. Outcomes included total brain, cortical and subcortical gray matter, white matter, cerebrospinal fluid, and white matter hyperintensity volumes derived from MRI; as well as fractional anisotropy in white matter tracts from diffusion tensor imaging. We related VEGF, Ang2, sTie2, and HGF to MRI measures using multivariable regression models adjusting for vascular risk factors. We tested for interactions with APOE (apolipoprotein E) genotype and CRP (C-reactive protein). Results were corrected for multiple comparisons. Results- Higher sTie2 was associated with smaller total brain (estimate by SD unit±SE=-0.08±0.02, P=0.002) and larger white matter hyperintensity (0.08±0.02, P=0.002) volumes. Furthermore, higher Ang2 (0.06±0.02, P=0.049) and HGF (0.09±0.02, P=0.001) were associated with larger cerebrospinal fluid volumes. Finally, higher Ang2 was associated with decreased fractional anisotropy, in APOE-ε4 carriers only. Conclusions- Vascular growth factors are associated with early MRI markers of small vessel disease and neurodegeneration in middle-aged adults.

The effect of subacute lead exposure on selected blood inflammatory biomarkers and angiogenetic factors.

OBJECTIVES: The aim of the study was to examine blood levels of selected pro-inflammatory cytokines, C reactive protein (CRP), and selected factors that influence angiogenesis in workers exposed to lead for a short period of time. METHODS: The study population consisted of 36 male workers (mean age 41 ± 14 years) exposed to lead for 40 days. RESULTS: The mean blood lead level (BLL) was 10.7 ± 7.67 µg/dl at the beginning of the study, and increased to 49.1 ± 14.1 µg/dl at the end of the study period. The levels of macrophage inflammatory protein 1-α (MIP-1α) were significantly higher after the studied exposure to lead compared to the baseline by 71%. Similarly, the values of CRP increased by 35%. Conversely, the values of soluble vascular endothelial growth factor receptor-1 (sVEGFR-1) and fibroblast growth factor-basic (FGF-basic) decreased by 14% and 21%, respectively. After the examined period of lead exposure, analysis of correlations showed positive correlations between vascular endothelial growth factor (VEGF) levels and the levels of interleukin 1ß (IL-1ß) (R = 0.39), interleukin 6 (IL-6) (R = 0.42), and MIP-1α (R = 0.54). Positive correlations were identified between MIP-1α and FGF-basic (R = 0.38), soluble angiopoietin receptor (sTie-2) (R = 0.41), and sVEGFR-1 (R = 0.47). DISCUSSION: Short-term exposure to lead induces the inflammatory response; however, these mechanisms seem to be different from those observed in chronic lead exposure. Subacute exposure to lead may dysregulate angiogenesis via modifications in the levels of angiogenic factors.

Angiopoietin-2 and Survival in Peripheral Artery Disease Patients.

Survival of peripheral arterial disease (PAD) patients increased over the last decade due to increased use of secondary preventive medication and rapid revascularization of PAD patients. Angiogenetic markers such as vascular endothelial growth factor (VEGF), angiopoietin-2 (Ang-2) and its receptor Tie-2 might be useful markers to assess the residual risk for mortality in PAD patients. The aim of this study was to evaluate angiogenetic markers for the prediction of mortality in a PAD cohort. For this purpose, 366 patients (mean age: 69 ± 10 years) with PAD Fontaine stage I or II were included and followed up over a 5-year study period. Serum Ang-2, Tie-2 and VEGF levels were measured by bead-based multiplex assay. All-cause mortality and major cardiovascular events (MACE) including all-cause death, non-fatal stroke and non-fatal myocardial infarction were analysed by Kaplan-Meier and Cox regression analyses after 5 years. Ang-2 was associated with Tie-2 (R = 0.151, p = 0.006) and VEGF levels (R = 0.160, p = 0.002). However, only Ang-2 was linked to all all-cause mortality in PAD patients (hazard ratio [HR]: 1.55 [1.23-2.15], p = 0.008) even after adjustment for age and gender, haemoglobin A1c, low-density lipoprotein cholesterol, systolic blood pressure and glomerular filtration rate (HR: 1.44 [1.03-2.00], p = 0.032). Furthermore, an association of Ang-2 and MACE in PAD patients (HR: 1.36 (1.03-1.78), p = 0.028) was found. This result implies that Ang-2 might be used as an additional marker to stratify PAD patients to predict poor mid-term life expectancy.

Tuberculous lymphadenitis is associated with altered levels of circulating angiogenic factors.

BACKGROUND: Angiogenic factors are important in granuloma formation and serve as biomarkers in pulmonary tuberculosis (PTB). The relationship between these markers and tuberculous lymphadenitis (TBL) is not known. OBJECTIVE AND DESIGN: To examine the association of vascular endothelial growth factor (VEGF) and angiopoietin (Ang) family molecules in TBL, we measured systemic levels of VEGF-A, C, D, R1 (VEGF-receptor 1), R2, R3, Ang-1, Ang-2 and TIE2 (tyrosine kinase with immunoglobulin-like and epidermal growth factor-like domains 2) levels in TBL, latent tuberculous infection (LTBI) and lymph node culture supernatants (VEGF-A, C and Ang-2) of the same TBL patients. RESULTS: Circulating levels of VEGF-A and VEGF-C were significantly diminished, whereas VEGF-R2, R3, Ang-2 and TIE2 levels were significantly increased, in TBL. Likewise, VEGF-A, C and Ang-2 levels were significantly increased in lymph node supernatants compared with plasma in individuals with TBL. Receiver operating characteristic curve analysis showed that VEGF-C and VEGF-R2 markers clearly distinguished TBL from LTBI. Following treatment, VEGF-C and Ang-1 levels were significantly altered. No association was observed between angiogenic factors and culture grade or lymph node size, except for VEGF-A. VEGF-A was also significantly decreased in multiple lymph nodes compared with single lymph nodes. CONCLUSIONS: Our data suggest that altered levels of circulating angiogenic factors in TBL might reflect underlying vasculo-endothelial dysfunction. Reversal of angiogenic markers after anti-tuberculosis treatment suggests that these angiogenic markers may serve as biomarkers of disease severity or response to treatment in TBL.

Circulating angiopoietin-2 and its soluble receptor Tie-2 concentrations are related to inflammatory markers in the general population.

BACKGROUND: The Angiopoietin/Tie (Tyrosine kinase with Ig and EGF homology domains) signaling axis has crucial influences on angiogenesis and the vasculature's reorganization. Moreover, angiopoietin-2 (Ang2) is discussed as a biomarker for diseases' severity and development. Previous studies reported increased Ang2 levels in patients with inflammatory diseases and associations of Ang2 with inflammation markers in relatively small samples. We aimed to assess the relation of Ang2 and Tie2 with inflammation markers in the general population. METHODS AND RESULTS: Data of 6624 participants of the population-based Study of Health in Pomerania (SHIP-1) and the independent SHIP-Trend were used. Ang2, Tie2 and inflammatory biomarkers, including fibrinogen, high-sensitive C-reactive protein (hsCRP) and white blood cell count (WBC), were measured. Adjusted analysis of variance (ANOVA) and linear/logistic regression models were performed in the entire sample and in individuals free of hypertension and diabetes. ANOVA [adjusted means of the 1st vs. 4th Ang2 quartile: fibrinogen 3.0 vs. 3.2 g/l; hsCRP 1.2 vs. 1.6 mg/l; WBC 5.9 vs. 6.6 Gpt/l] and regression models adjusted for potential confounders revealed positive relations of Ang2 with all considered inflammation markers. These associations persisted after the exclusion of individuals with hypertension and diabetes. In contrast, Tie2 showed no clear association pattern with the investigated inflammatory markers even if a trend toward a positive relation with fibrinogen became apparent. CONCLUSION: Ang2 was positively associated with fibrinogen, hsCRP and WBC in a large population-based setting. These findings partly agree with previous results, largely obtained in clinical samples. Ang2 has diverse postulated effects on inflammation processes, like increase of vascular leakage or influences on the adhesion of leukocytes to the vessel wall. The proinflammatory character of these effects is similar to these of fibrinogen which conforms to our findings of relations between the markers. However, further research is needed to elucidate possible functional mechanisms.