Angiogenic molecule Tie-2 and VEGF in the pathogenesis of pleural effusions

Pleural effusion guidelines from ICS and NCCP Section 1: Basic principles, laboratory tests and pleural procedures

Pleural effusion is a common problem in our country, and most of these patients need invasive tests as they can't be evaluated by blood tests alone. The simplest of them is diagnostic pleural aspiration, and diagnostic techniques such as medical thoracoscopy are being performed more frequently than ever before. However, most physicians in India treat pleural effusion empirically, leading to delays in diagnosis, misdiagnosis and complications from wrong treatments. This situation must change, and the adoption of evidence-based protocols is urgently needed. Furthermore, the spectrum of pleural disease in India is different from that in the West, and yet Western guidelines and algorithms are used by Indian physicians. Therefore, India-specific consensus guidelines are needed. To fulfil this need, the Indian Chest Society and the National College of Chest Physicians; the premier societies for pulmonary physicians came together to create this National guideline. This document aims to provide evidence based recommendations on basic principles, initial assessment, diagnostic modalities and management of pleural effusions.

[Analysis of endothelial dysfunction in the context of pleural effusions of various origins using skin thermometry]

OBJECTIVE

To analyze the mechanisms and severity of endothelial dysfunction in patients with pleural effusion of various origins using skin thermometry.

MATERIAL AND METHODS

We studied microcirculation in 135 patients with pleural effusions of various origins. Local skin thermometry and computer wavelet analysis were performed in 3-5 days after thoracoscopy with pleural biopsy using Microtest-100WF device with a temperature measuring resolution of 0.001°C. We estimated endothelial, myogenic and neurogenic indices using spectral analysis of skin temperature fluctuations in a range 0.0095-2 Hz. The control group comprised 40 healthy participants aged 23-36 years.

RESULTS

Three groups of patients were distinguished depending on the cause of effusion: malignant pleural effusions (n=65, 48.1%); inflammatory pleural effusions (para-pneumonic, post-traumatic, pancreatogenic, tuberculous) (n=58, 43%); transudates (hepatogenic, cardiogenic, and nephrogenic) (n=12, 8.9%). There were no significant differences in vascular tone in response to local heating of the second finger of the hand up to 40°C. Measurements were carried out within 10 min in all groups. Patients with diabetes mellitus and cardiovascular diseases (n=48, 35.6%) had significant decrease of thermal vasodilation index in endothelial range up to 2.93±1.77, in the control group - up to 4.21±2.40 (p=0.041).

CONCLUSION

Endothelial dysfunction is a universal non-specific aspect in pathogenesis of various diseases. This process is essential in pleural effusion. Local thermometry and computer wavelet analysis revealed no significant differences between patients with malignant, inflammatory and transudative pleural effusions. Pleural effusions in the context of cardiovascular pathology and/or diabetes mellitus occur due to impaired vasodilatation mechanisms in endothelial range.

Clinical characteristics and prognosis of serous body cavity effusions in patients with sepsis: a retrospective observational study

Background

Cavity effusion is common in patients with infectious diseases. However, the incidence rate and characteristics of serous cavity effusions (SCE) in septic patients are not clear to date. The objective of this study was to investigate the incidence and characteristics of SCE in septic patients and to explore the correlations between the bloody effusions and the illness severity/prognosis in septic patients.

Methods

From January 2010 to January 2015, a total of 214 patients with severe sepsis and septic shock were enrolled in this retrospective observational study. Thoracentesis or abdominal paracentesis was performed in 45 septic patients because of massive pleural effusions or ascites. The serum concentrations of VEGF, VEGFR, Ang, sICAM-1, sVCAM-1, E-selectin, Serpine1 and VE-cadherin in 45 septic patients underwent paracentesis were measured by enzyme-linked immunosorbent assay (ELISA).

Results

Of the 214 septic patients, 155 (72.4%) had SCE according to imaging or ultrasound manifestations. 45 subjects with SCE underwent therapeutic thoracentesis or abdominal paracentesis. Effusion laboratory analysis showed that exudates were predominant when compared with transudates (95.6% vs. 4.4%), and 16 (35.6%) patients suffered bloody effusions. Compared with patients with non-bloody effusions, those with bloody effusions showed higher critical illness scores (13 vs. 17 for APACHE II; 7 vs. 9 for SOFA), and higher mortality (6.9% vs. 62.5%). Moreover, patients with bloody effusions had delayed TT and APTT, increased D-dimer concentration, and higher serum levels of CRP and PCT (P < 0.05). In addition, the serum levels of Ang2, sVCAM-1 and E-selectin were significantly higher in patients with bloody effusions than in those with non-bloody effusions (P < 0.05). However, the serum level of VEGFR2 was lower in patients with bloody fluids (P = 0.025).

Conclusions

The incidence of serous cavity effusion is high in patients with sepsis. The septic patients with bloody effusions suffer a more inflammatory burden and a worse prognosis compared to septic patients with non-bloody effusions.

Systematic review and meta-analysis of vascular endothelial growth factor as a biomarker for malignant pleural effusions

Conventional methods may fail to identify the cause of pleural effusion (PE), thus establishing reliable biomarkers is deemed necessary. This study aimed at examining the role of vascular endothelial growth factor (VEGF) as a biomarker in the differentiation between malignant and benign PEs in adults. A comprehensive literature search in PubMed (Medline), Scopus (ELSEVIER), and Cochrane Central Register of Controlled Trials (CENTRAL) databases was conducted using keywords. We included studies that evaluated pleural and/or serum levels of VEGF among patients presenting with undiagnosed PE and the association between these levels and the final diagnosis. We performed a meta‐analysis to calculate the summary effect using the random effects model. Statistical analysis was performed with the statistical package for meta‐analysis Comprehensive Meta‐Analysis. Twenty studies were included in the systematic review, while 11 of them in the meta‐analysis. Pleural fluid VEGF levels among patients with malignant PE were increased by 1.93 ng/mL as compared to patients with benign PE (95% CI: 1.32–2.54, Q = 173, df (Q): 10, I² = 94.2%, P < 0.05). Serum VEGF levels among patients with malignant PE were increased respectively by 1.90 ng/mL (95% CI: 0.93–2.88, Q = 182, df (Q): 6, I² = 96.7%, P < 0.05). This study showed that malignant PEs were associated with higher levels of both pleural fluid and serum VEGF. VEGF appears to represent a promising biomarker for the differential diagnosis between benign and malignant PEs.

Novel biomarker analysis of pleural effusion enhances differentiation of tuberculous from malignant pleural effusion

Lymphocytic pleurisy is commonly observed in tuberculosis and cancer. Noninvasive biomarkers are needed to distinguish tuberculous pleural effusion (TPE) from malignant pleural effusion (MPE) because current clinical diagnostic procedures are often invasive. We identified immune response biomarkers that can discriminate between TPE and MPE. Fourteen pleural effusion biomarkers were compared in 22 MPE patients and five TPE patients. Of the innate immunity biomarkers, the median levels of interleukin (IL)-1β and interferon-induced protein-10 (IP-10) were higher in TPE patients than in MPE patients (P<0.05 and P<0.01, respectively). Of the adaptive immunity biomarkers, the median levels of IL-13 and interferon-γ (IFN-γ) were higher in TPE patients than in MPE patients (P<0.05). In addition, the levels of basic fibroblast growth factor were higher in MPE patients than in TPE patients (P<0.05). Receiver operator characteristic analysis of these biomarkers was performed, resulting in the highest area under the curve (AUC) for IP-10 (AUC =0.95, 95% confidence interval, P<0.01), followed by IL-13 (AUC =0.86, 95% confidence interval, P<0.05). Our study shows that five biomarkers (IL-1β, IP-10, IFN-γ, IL-13, and basic fibroblast growth factor) have a potential diagnostic role in differentiating TPE from MPE, particularly in lung cancer-related MPE.

VEGF correlates with inflammation and fibrosis in tuberculous pleural effusion

Objective. To investigate the relationship among angiogenic cytokines, inflammatory markers, and fibrinolytic activity in tuberculous pleural effusion (TBPE) and their clinical importance. Methods. Forty-two patients diagnosed with TBPE were studied. Based on chest ultrasonography, there were 26 loculated and 16 nonloculated TBPE patients. The effusion size radiological scores and effusion vascular endothelial growth factor (VEGF), interleukin- (IL-) 8, plasminogen activator inhibitor type-1 (PAI-1), and tissue type plasminogen activator (tPA) were measured. Treatment outcome and pleural fibrosis, defined as radiological residual pleural thickening (RPT), were assessed at 6-month follow-up. Results. The effusion size and effusion lactate dehydrogenase (LDH), VEGF, IL-8, PAI-1, and PAI-1/tPA ratio were significantly higher, while effusion glucose, pH value, and tPA were significantly lower, in loculated than in nonloculated TBPE. VEGF and IL-8 correlated positively with LDH and PAI-1/tPA ratio and negatively with tPA in both loculated and nonloculated TBPE. Patients with higher VEGF or greater effusion size were prone to develop RPT (n = 14; VEGF, odds ratio 1.28, P = 0.01; effusion size, odds ratio 1.01, P = 0.02), and VEGF was an independent predictor of RPT in TBPE (receiver operating characteristic curve AUC = 0.985, P < 0.001). Conclusions. Effusion VEGF correlates with pleural inflammation and fibrosis and may be targeted for adjunct therapy for TBPE.

Effect of tumor microenvironment on tumor VEGF during anti-VEGF treatment: systems biology predictions

BACKGROUND

Vascular endothelial growth factor (VEGF) is known to be a potent promoter of angiogenesis under both physiological and pathological conditions. Given its role in regulating tumor vascularization, VEGF has been targeted in various cancer treatments, and anti-VEGF therapy has been used clinically for treatment of several types of cancer. Systems biology approaches, particularly computational models, provide insight into the complexity of tumor angiogenesis. These models complement experimental studies and aid in the development of effective therapies targeting angiogenesis.

METHODS

We developed an experiment-based, molecular-detailed compartment model of VEGF kinetics and transport to investigate the distribution of two major VEGF isoforms (VEGF121 and VEGF165) in the body. The model is applied to predict the dynamics of tumor VEGF and, importantly, to gain insight into how tumor VEGF responds to an intravenous injection of an anti-VEGF agent.

RESULTS

The model predicts that free VEGF in the tumor interstitium is seven to 13 times higher than plasma VEGF and is predominantly in the form of VEGF121 (>70%), predictions that are validated by experimental data. The model also predicts that tumor VEGF can increase or decrease with anti-VEGF treatment depending on tumor microenvironment, pointing to the importance of personalized medicine.

CONCLUSIONS

This computational study suggests that the rate of VEGF secretion by tumor cells may serve as a biomarker to predict the patient population that is likely to respond to anti-VEGF treatment. Thus, the model predictions have important clinical relevance and may aid clinicians and clinical researchers seeking interpretation of pharmacokinetic and pharmacodynamic observations and optimization of anti-VEGF therapies.

Clinical importance of angiogenic cytokines, fibrinolytic activity and effusion size in parapneumonic effusions

OBJECTIVE

To investigate the relationship among angiogenic cytokines, fibrinolytic activity and effusion size in parapneumonic effusion (PPE) and their clinical importance.

METHODS

From January 2008 through December 2010, 26 uncomplicated (UPPE) and 38 complicated (CPPE) PPE were studied. Based on chest ultrasonography, there were non-loculated in 30, uni-loculated in 12, and multi-loculated effusions in 22 patients. The effusion size radiological scores, and effusion vascular endothelial growth factor (VEGF), interleukin (IL)-8, plasminogen activator inhibitor type-1 (PAI-1) and tissue type plasminogen activator (tPA) were measured on admission. Treatment outcome and pleural fibrosis, defined as radiological residual pleural thickening (RPT), were assessed at 6-month follow-up.

RESULTS

The effusion size and effusion VEGF, IL-8 and PAI-1/tPA ratio were significantly higher in CPPE than in UPPE, and significantly higher in multi-loculated PPE than in non-locualted and uni-loculated PPE, respectively. VEGF (cutoff value 1975 pg/ml) and IL-8 (cutoff value 1937 pg/ml) seemed best to discriminate between UPPE and CPPE. VEGF, IL-8 and effusion size correlated positively with PAI-1/tPA ratio in both UPPE and CPPE. Moreover, the level of VEGF, but not IL-8, correlated positively with effusion size in all patients (r = 0.79, p<0.001) and in UPPE (r = 0.64, p<0.001) and CPPE (r = 0.71, p<0.001) groups. The patients with higher VEGF or greater effusion were prone to have medical treatment failure (n = 10; VEGF, odds ratio 1.01, p = 0.02; effusion size, odds ratio 1.26, p = 0.01). Additionally, ten patients with RPT had larger effusion size and higher levels of VEGF and PAI-1/tPA ratio than did those without.

CONCLUSIONS

In PPE, VEGF and IL-8 levels are valuable to identify CPPE, and higher VEGF level or larger effusion is associated with decreased fibrinolytic activity, development of pleural loculation and fibrosis, and higher risk of medical treatment failure.

Cytokines in pericardial effusion of patients with inflammatory pericardial disease

BACKGROUND

The role of inflammatory and angiogenic cytokines in patients with inflammatory pericardial effusion still remains uncertain.

METHODS

We assessed pericardial and serum levels of VEGF, bFGF, IL-1β and TNF-α by ELISA in patients with inflammatory pericardial effusion (PE) of autoreactive (n = 22) and viral (n = 11) origin, and for control in pericardial fluid (PF) and serum (n = 26) of patients with coronary artery disease (CAD) undergoing coronary artery bypass graft surgery.

RESULTS

VEGF levels were significantly higher in patients with autoreactive and viral PE than in patients with CAD in both PE (P = 0.006 for autoreactive and P < 0.001 for viral PE) and serum (P < 0.001 for autoreactive and P < 0.001 for viral PE). Pericardial bFGF levels were higher compared to serum levels in patients with inflammatory PE and patients with CAD (P ≤ 0.001 for CAD; P ≤ 0.001 for autoreactive PE; P = 0, 005 for viral PE). Pericardial VEGF levels correlated positively with markers of pericardial inflammation, whereas pericardial bFGF levels showed a negative correlation. IL-1β and TNF-α were detectable only in few PE and serum samples.

CONCLUSIONS

VEGF and bFGF levels in pericardial effusion are elevated in patients with inflammatory PE. It is thus possible that VEGF and bFGF participate in the pathogenesis of inflammatory pericardial disease.

Diagnostic accuracy of vascular endothelial growth factor for malignant pleural effusion: A meta-analysis

Since the diagnostic accuracy of conventional examinations for malignant pleural effusion (MPE) is limited, a number of studies have investigated the utility of pleural vascular endothelial growth factor (VEGF) in the diagnosis of MPE. The present meta-analysis aimed to determine the overall accuracy of a VEGF test in the diagnosis of MPE. A systematic review of studies published in English was conducted and the data concerning the accuracy of pleural VEGF assays in the diagnosis of MPE were pooled with random effects models. The overall test performance was summarized using receiver operating characteristic curves. Ten studies, based on 1,025 patients, met the inclusion criteria for the meta-analysis and the summary estimates for VEGF in the diagnosis of MPE were: sensitivity 0.75 [95% confidence interval (CI), 0.72-0.79], specificity 0.72 (95% CI, 0.68-0.76), positive likelihood ratio 2.94 (95% CI, 1.97-4.41), negative likelihood ratio 0.38 (95% CI, 0.27-0.51) and diagnostic odds ratio 9.05 (95% CI, 4.60-17.80). The summary receiver operating characteristic curve indicated that the maximum joint sensitivity and specificity was 0.75; the area under the curve was 0.82. Our findings suggest that the determination of pleural VEGF may improve the accuracy of MPE diagnosis, while the results of VEGF assays should be interpreted in parallel with conventional test results and other clinical findings.

Vascular endothelial growth factor in malignant and benign pericardial effusion

BACKGROUND

The pathogenetic role of vascular endothelial growth factor (VEGF) in malignant pericardial effusion and diagnostic value of pericardial VEGF levels to discriminate malignant from benign pericardial effusions are uncertain.

HYPOTHESIS

We hypothesized that pericardial VEGF levels would be higher in malignant than benign pericardial effusion and that VEGF would be a useful marker for the diagnosis of malignant pericardial effusion.

METHODS

Using an enzyme-linked immunosorbent assay, we assessed pericardial and serum VEGF levels in patients with malignant pericardial effusion (n = 19), in patients with nonmalignant pericardial effusion (n = 30), and for control, in patients without pericardial disease (n = 26).

RESULTS

Vascular endothelial growth factor pericardial levels in malignant pericardial effusion (13 593.8 ± 22 410.24 pg/mL) were significantly higher compared with VEGF in nonmalignant effusion (610.63 ± 1289.08 pg/mL; P = 0.001) and pericardial fluid (5.5 ± 15.97 pg/mL; P < 0.001). In serum, VEGF was significantly higher in patients with nonmalignant pericardial effusion (188.3 ± 240.35 pg/mL) compared with patients with malignant pericardial effusion (67.52 ± 125.77 pg/mL; P = 0.024) and coronary artery disease patients (29.13 ± 76.26 pg/mL; P < 0.001). Pericardial VEGF levels were significantly higher than matched serum levels only in patients with malignant pericardial effusion (P = 0.023). Pericardial VEGF levels ≥2385 pg/mL had 75% sensitivity and 90% specificity for the recognition of malignant pericardial effusion in patients with breast or lung cancer.

CONCLUSIONS

Vascular endothelial growth factor levels in pericardial effusion are markedly elevated in patients with malignant pericardial effusion, indicating abundant local release within the pericardial cavity. It is thus possible that VEGF participates in the pathogenesis of malignant pericardial effusion. Measurement of VEGF in pericardial effusion offers potential as a diagnostic tool to discriminate malignant from benign effusions in patients with breast or lung cancer.

A phase II study of sunitinib in patients with recurrent epithelial ovarian and primary peritoneal carcinoma: an NCIC Clinical Trials Group Study

PURPOSE

Sunitinib is a multitargeted receptor tyrosine kinase inhibitor. We conducted a two-stage phase II study to evaluate the objective response rate of oral sunitinib in recurrent epithelial ovarian cancer.

PATIENTS AND METHODS

Eligibility required measurable disease and one or two prior chemotherapies, at least one platinum based. Platinum-sensitive or -resistant disease was allowed. Initial dose schedule was sunitinib 50 mg daily, 4 of 6 weeks. Observation of fluid accumulations during off-treatment periods resulted in adoption of continuous 37.5 mg daily dosing in the second stage of accrual.

RESULTS

Of 30 eligible patients, most had serous histology (67%), were platinum sensitive (73%) and had two prior chemotherapies (60%). One partial response (3.3%) and three CA125 responses (10%) were observed, all in platinum-sensitive patients using intermittent dosing. Sixteen (53%) had stable disease. Five had >30% decrease in measurable disease. Overall median progression-free survival was 4.1 months. Common adverse events included fatigue, gastrointestinal symptoms, hand-foot syndrome and hypertension. No gastrointestinal perforation occurred.

CONCLUSIONS

Single-agent sunitinib has modest activity in recurrent platinum-sensitive ovarian cancer, but only at the 50 mg intermittent dose schedule, suggesting that dose and schedule may be vital considerations in further evaluation of sunitinib in this cancer setting.

Anti-tumor effects of a novel chimeric peptide on S180 and H22 xenografts bearing nude mice

In recent years, many endogenous peptides have been identified by screening combinatory phage display peptide library, which play important roles in the process of angiogenesis. A heptapeptide, ATWLPPR, binds specifically to NRP-1 and selectively inhibits VEGF165 binding to VEGFR-2. Another heptapeptide, NLLMAAS, blocks both Ang-1 and Ang-2 binding to Tie-2 in a dose-dependent manner. In the present study, we aimed to connect ATWLPPR (V1) with NLLMAAS (V2) via a flexible linker, Ala-Ala, to reconstruct a novel peptide ATWLPPRAANLLMAAS (V3). We firstly investigated the anti-tumor and anti-angiogenic effects of peptide V3 on sarcoma S180 and hepatoma H22 bearing BALB/c nude mice. Mice were continuously subcutaneously administrated with normal saline, V1 (320microg/kg/d), V2 (320microg/kg/d), V1+V2 (320microg/kg/d), and V3 (160, 320 and 480microg/kg/d), for 7 days. Treatment with peptide V3 could significantly reduce the tumor weight and volume. Pathological examination showed that the tumors treated with peptide V3 had a larger region of necrosis than that of peptide V1, V2, and V1+V2 at the same dose. A significant decrease of microvessel density (MVD) in a dose-dependent manner was observed in each group of peptide V3. The results of pathological examination on normal tissue, lung, heart, liver, spleen, kidney and white blood cells showed that peptide V3 might have no significant toxicity. In conclusion, our results demonstrated that peptide V3 could be more effective on inhibiting tumor growth and angiogenesis than that of V1, V2, and V1+V2. Peptide V3 could be considered as a novel chimeric peptide with potent anti-tumor activity.

The angiogenetic pathway in malignant pleural effusions: Pathogenetic and therapeutic implications

Increased permeability of the pleural microvasculature is generally attributed to the substances that are released in inflammatory and malignant pleural effusions, although the exact pathogenetic mechanisms of malignant pleural effusions are unclear. Current therapies used to prevent the re-accumulation of pleural fluid and relieve symptoms are of variable efficacy and may cause serious adverse effects. Understanding the mechanisms of fluid accumulation would hopefully permit the development of more specific, effective and safer treatment modalities. Angiogenesis, pleural vascular increased permeability and inflammation are considered central to the pathogenesis of malignant pleural effusions. Vascular endothelial growth factor (VEGF) is a member of the VEGF/platelet-derived factor gene family and consists of at least six isoforms. Since it was shown that VEGF contributes to the formation of malignant pleural effusions, there have been some attempts to implicate, therapeutically, this finding using different molecules (ZD6474, PTK 787 and bevacizumab). However, the role of the biological axis of VEGF and angiopoietins needs further investigation in both the pathogenesis and the treatment of malignant pleural effusion. In both non-small-cell lung carcinoma and breast cancer, it has been shown that the ligand for CXCR4, CXCL12 or SDF-1α, exhibited peak levels of expression in organs that were the preferred destination for their respective metastases. Recent findings imply that new therapeutic strategies aimed at blocking the SDF-1-CXCR4 axis may have significant applications for patients by modulating the trafficking of hemato/lymphopoietic cells and inhibiting the metastatic behavior of tumor cells as well. The purpose of this report is to review novel pathogenetic and therapeutic implications regarding the angiogenetic pathways in malignant pleural effusions.