Serum vascular endothelial growth factor is elevated in cystic fibrosis and decreases with treatment of acute pulmonary exacerbation

Pulmonary Vascular Dysfunctions in Cystic Fibrosis

Cystic fibrosis (CF) is an inherited disorder caused by a deleterious mutation in the cystic fibrosis transmembrane conductance regulator (CFTR) gene. Given that the CFTR protein is a chloride channel expressed on a variety of cells throughout the human body, mutations in this gene impact several organs, particularly the lungs. For this very reason, research regarding CF disease and CFTR function has historically focused on the lung airway epithelium. Nevertheless, it was discovered more than two decades ago that CFTR is also expressed and functional on endothelial cells. Despite the great strides that have been made in understanding the role of CFTR in the airway epithelium, the role of CFTR in the endothelium remains unclear. Considering that the airway epithelium and endothelium work in tandem to allow gas exchange, it becomes very crucial to understand how a defective CFTR protein can impact the pulmonary vasculature and overall lung function. Fortunately, more recent research has been dedicated to elucidating the role of CFTR in the endothelium. As a result, several vascular dysfunctions associated with CF disease have come to light. Here, we summarize the current knowledge on pulmonary vascular dysfunctions in CF and discuss applicable therapies.

Morphological chest CT changes in cystic fibrosis and massive hemoptysis

BACKGROUND

Massive hemoptysis (MH) is a rare but potentially life-threatening condition of patients with mainly advanced cystic fibrosis (CF). Morphological lung changes are aggravated with disease progression. The aim of this study was to determine whether morphological lung changes differ between patients with CF (pwCF) who have MH and pwCF without MH.

METHODS

Chest computed tomography (CT) scans of pwCF and MH acquired at a maximum of 4 months prior to MH (1/2008 to 2/2015) were evaluated for morphological changes and bronchial artery (BA) diameters. Lung lobes with MH were compared with lobes without MH and with matched control patients with end-stage CF and no hemoptysis using the Helbich scoring system.

RESULTS

The study included 26 patients with MH (PMH; 15 female, median age 29 years, interquartile range [IQR]: 25-33.75) and 17 matched control patients (11 male, median age 24 years, IQR: 19.5-30). No difference in Helbich score was detected between lobes with MH and matched control patients (p = 0.051). Higher scores were detected in lobes with MH compared to lobes without MH in PMH (p = 0.021), but no difference was detected in the subscores. The BA diameters were larger in PMH (p = 0.02); 85% of PMH had unilateral MH, with 65% of MH involving only one or two lobes.

CONCLUSION

Morphological changes are more severe in lobes with MH in the same patient, but there is no difference when compared with matched control patients. Besides abscess/sacculation, no specific changes for MH were identified. Other factors such as BA hypertrophy might play a pivotal role in the pathogenesis of MH in pwCF. Commonly used scores to evaluate chest CT in pwCF cannot be used to assess MH, and other factors, e.g., hypertrophied BA, not represented and not measured in these scores, might be more suitable for assessing the risk for MH.

Pulmonary exacerbations in early cystic fibrosis lung disease are marked by strong modulation of CD3 and PD-1 on luminal T cells

Background

In chronic cystic fibrosis (CF) lung disease, neutrophilic inflammation and T-cell inhibition occur concomitantly, partly due to neutrophil-mediated release of the T-cell inhibitory enzyme Arg1. However, the onset of this tonic inhibition of T cells, and the impact of pulmonary exacerbations (PEs) on this process, remain unknown.

Methods

Children with CF aged 0-5 years were enrolled in a longitudinal, single-center cohort study. Blood (n = 35) and bronchoalveolar lavage (BAL) fluid (n = 18) were collected at stable outpatient clinic visits or inpatient PE hospitalizations and analyzed by flow cytometry (for immune cell presence and phenotype) and 20-plex chemiluminescence assay (for immune mediators). Patients were categorized by PE history into (i) no prior PE, (ii) past history of PE prior to stable visit, or (iii) current PE.

Results

PEs were associated with increased concentration of both pro- and anti-inflammatory mediators in BAL, and increased neutrophil frequency and G-CSF in circulation. PE BAL samples showed a trend toward an increased frequency of hyperexocytic "GRIM" neutrophils, which we previously identified in chronic CF. Interestingly, expression levels of the T-cell receptor associated molecule CD3 and of the inhibitory programmed death-1 (PD-1) receptor were respectively decreased and increased on T cells from BAL compared to blood in all patients. When categorized by PE status, CD3 and PD-1 expression on blood T cells did not differ among patients, while CD3 expression was decreased, and PD-1 expression was increased on BAL T cells from patients with current PE.

Conclusions

Our findings suggest that airway T cells are engaged during early-life PEs, prior to the onset of chronic neutrophilic inflammation in CF. In addition, increased blood neutrophil frequency and a trend toward increased BAL frequency of hyperexocytic neutrophils suggest that childhood PEs may progressively shift the balance of CF airway immunity towards neutrophil dominance.

Coil embolisation for massive haemoptysis in cystic fibrosis

Introduction

Massive haemoptysis is a life-threatening event in advanced cystic fibrosis (CF) lung disease with bronchial artery embolisation (BAE) as standard of care treatment. The aim of our study was to scrutinise short-term and long-term outcomes of patients with CF and haemoptysis after BAE using coils.

Methods

We carried out a retrospective cohort study of 34 adult patients treated for massive haemoptysis with super selective bronchial artery coil embolisation (ssBACE) between January 2008 and February 2015. Embolisation protocol was restricted to the culprit vessel(s) and three lobes maximum. Demographic data, functional end-expiratory volume in 1 s in % predicted (FEV1% pred.) and body mass index before and after ssBACE, sputum colonisation, procedural data, time to transplant and time to death were documented.

Results

Patients treated with ssBACE showed significant improvement of FEV₁% pred. after embolisation (p=0.004) with 72.8% alive 5 years post-ssBACE. Mean age of the patients was 29.9 years (±7.7). Mean FEV₁% pred. was 45.7% (±20.1). Median survival to follow-up was 75 months (0–125). Severe complication rate was 0%, recanalisation rate 8.8% and 5-year-reintervention rate 58.8%. Chronic infection with Pseudomonas aeruginosa was found in 79.4%, Staphylococcus areus in 50% and Aspergillus fumigatus in 47.1%.

Discussion

ssBACE is a safe and effective treatment for massive haemoptysis in patients with CF with good results for controlling haemostasis and excellent short-term and long-term survival, especially in severely affected patients with FEV<40% pred. We think the data of our study support the use of coils and a protocol of careful and prudent embolisation.

Immunomodulation in Cystic Fibrosis: Why and How?

Cystic fibrosis (CF) lung disease is characterized by unconventional mechanisms of inflammation, implicating a chronic immune response dominated by innate immune cells. Historically, therapeutic development has focused on the mutated cystic fibrosis transmembrane conductance regulator (CFTR), leading to the discovery of small molecules aiming at modulating and potentiating the presence and activity of CFTR at the plasma membrane. However, treatment burden sustained by CF patients, side effects of current medications, and recent advances in other therapeutic areas have highlighted the need to develop novel disease targeting of the inflammatory component driving CF lung damage. Furthermore, current issues with standard treatment emphasize the need for directed lung therapies that could minimize systemic side effects. Here, we summarize current treatment used to target immune cells in the lungs, and highlight potential benefits and caveats of novel therapeutic strategies.

Adrenal Insufficiency in Cystic Fibrosis: A Rare Phenomenon?

Background

The prevalence of adrenal insufficiency (AI) in cystic fibrosis (CF) is unknown. The frequent use of glucocorticoids (inhaled or systemic) may induce the long-term suppression of the hypothalamic-pituitary-adrenal axis.

Methods

We reviewed the results of adrenocorticotropic hormone (ACTH) stimulation tests done over a 10-year period to evaluate adrenal function in 69 CF patients of the CHUM CF clinic. Clinical characteristics of AI patients were compared to adrenal-sufficient (AS) patients.

Results

AI was confirmed in 33 of the 69 CF patients. A higher rate of dysglycemia (P=0.022) and of Aspergillus positive culture (P=0.006) was observed in AI patients compared to AS patients. Weight, CFTR genotype, and pulmonary function were comparable between AI and AS patients. The use of systemic corticosteroids (SC) prior to the diagnosis of AI was observed in 42.4% of patients. Compared to AI patients without SC, SC-treated AI patients were older and had a higher rate of allergic bronchopulmonary aspergillosis.

Conclusion

This study is the first to systematically examine the presence of AI in the largest cohort of CF patients studied to date with a prevalence of 8%. Patients treated with corticosteroids and those colonized with Aspergillus have a greater risk of AI.

Establishment and long-term culture of human cystic fibrosis endothelial cells

Endothelial cell (EC) dysfunction has been reported in cystic fibrosis (CF) patients. Thus, the availability of CF EC is paramount to uncover mechanisms of endothelial dysfunction in CF. Using collagenase digestion, we isolated cells from small fragments of pulmonary artery dissected from non-CF lobes or explanted CF lungs. These cells were a heterogeneous mixture, containing variable percentages of EC. To obtain virtually pure pulmonary artery endothelial cells (PAEC), we developed an easy, inexpensive, and reliable method, based on the differential adhesion time of pulmonary artery cells collected after collagenase digestion. With this method, we obtained up to 95% pure non-CF and CF-PAEC. Moreover, we also succeed at immortalizing both PAEC and CF-PAEC, which remained viable and with unchanged phenotype and proliferation rate over the 30th passage. These cells recapitulated cystic fibrosis transmembrane conductance regulator expression and functions of the parental cells. Thus, we isolated for the first time endothelial cells from CF patients, providing a valuable tool to define the emerging role of EC in CF lung and vascular disease.

Comparison of the ameliorative effects of Qingfei Tongluo formula and azithromycin on Mycoplasma pneumoniae pneumonia

Mycoplasma pneumoniae pneumonia (MPP) is a common disease in children. Qingfei Tongluo formula (QTF) has been used for the treatment of MPP clinically, but the therapeutic effect remains unclear compared to conventional treatments with Western medicines. Therefore, the aim of this study was to assess changes in the expression levels of relevant factors associated with microcirculation after MPP and to compare the therapeutic effect of QTF with that of azithromycin (AZM) on experimental mice with MPP. A total of 174 children admitted with clinical diagnoses of pneumonia (80 MPP and 94 non-MPP) were used to identify differences in the expression patterns of factors in the microcirculation using an enzyme-linked immunosorbent assay. A BALB/c mouse model of MPP infection was established to determine the therapeutic effect of QTF. The results showed that the expression level of thrombomodulin (TM), vascular endothelial growth factor (VEGF), d-dimer (D-D), interleukin (IL)-6, and IL-10 were upregulated after MPP both clinically in children and in the mouse model. After 3 days of therapy, the amount of total MPP DNA decreased, especially in the mid- and high-dose QTF treatment groups. The expression levels of VEGF, IL-6, and IL-10 also decreased in response to treatment with QTF or AZM. However, there was no influence on D-D levels. QTF treatment also decreased TM expression. In conclusion, QTF treatment inhibited the progression of MPP, reduced vascular permeability, and improved pulmonary microcirculation more effectively than conventional treatment with Western medicine.

Decreased TGF-β1 and VEGF Release in Cystic Fibrosis Platelets: Further Evidence for Platelet Defects in Cystic Fibrosis

PURPOSE

Cystic fibrosis (CF) patients suffer from chronic lung inflammation. This inflammation may activate platelets. There are limited data on the role of platelet-secreted cytokines in CF. Platelet cytokines with inflammatory effects include vascular endothelial growth factor (VEGF) and transforming growth factor-β1 (TGF-β1). As levels of these cytokines are tenfold greater in serum than plasma due to platelet release, serum levels may be one index of platelet content, but a more specific index is release during the aggregation of isolated platelets. We postulated that altered release of these platelet cytokines occurs in CF.

METHODS

We obtained sera and plasma from CF outpatients (n = 21) and from healthy controls (n = 20), measured VEGF and TGF-β1, assessed for correlations with platelet number, analyzed cytokine release during platelet aggregation to collagen, and analyzed differences in maximal platelet aggregation.

RESULTS

Platelet number and maximal aggregation levels were higher in CF. Plasma and serum levels of TGF-β1 and VEGF were higher in CF, but these levels were similar after adjusting for platelet number (serum cytokines correlated with platelet count). The release of VEGF and TGF-β1 during aggregation was decreased in CF platelets (by 52 and 29 %, respectively).

CONCLUSION

Platelet release is not a source of the elevated blood proinflammatory cytokines TGF-β1 and VEGF in CF, as platelets from CF patients actually release less of these cytokines. These data provide further evidence for platelet defects in CF.

Unravelling druggable signalling networks that control F508del-CFTR proteostasis

Cystic fibrosis (CF) is caused by mutations in CF transmembrane conductance regulator (CFTR). The most frequent mutation (F508del-CFTR) results in altered proteostasis, that is, in the misfolding and intracellular degradation of the protein. The F508del-CFTR proteostasis machinery and its homeostatic regulation are well studied, while the question whether ‘classical’ signalling pathways and phosphorylation cascades might control proteostasis remains barely explored. Here, we have unravelled signalling cascades acting selectively on the F508del-CFTR folding-trafficking defects by analysing the mechanisms of action of F508del-CFTR proteostasis regulator drugs through an approach based on transcriptional profiling followed by deconvolution of their gene signatures. Targeting multiple components of these signalling pathways resulted in potent and specific correction of F508del-CFTR proteostasis and in synergy with pharmacochaperones. These results provide new insights into the physiology of cellular proteostasis and a rational basis for developing effective pharmacological correctors of the F508del-CFTR defect.

DOI:http://dx.doi.org/10.7554/eLife.10365.001

Cystic fibrosis is a genetic disease that commonly affects people of European descent. The condition is caused by mutations in the gene encoding a protein called “cystic fibrosis transmembrane conductance regulator” (or CFTR for short). CFTR forms a channel in the membrane of cells in the lungs that help transport salt across the membrane. Mutated versions of the protein are not as efficient at transporting salts, and eventually this damages the lung tissue. As the damage progresses, individuals become very vulnerable to bacterial infections that further damage the lungs and may eventually lead to death.

One of the reasons CFTR mutations are harmful is that they cause the protein to fold up incorrectly and remain trapped inside the cell. Cells have quality control systems that recognize and destroy poorly folded proteins, and so only a few of the mutated CFTR proteins ever make it to the membrane to move salts. New therapies have been developed that improve folding of the protein and/or help the CFTR proteins that make it to the membrane work better. But more and better treatment options are needed.

Hegde, Parashuraman et al. have now tested drugs that control how proteins fold and move to the membrane to see how they affect gene expression in cells with the most common cystic fibrosis-causing mutation. These drugs are known to improve the activity of the CFTR mutant, but do so too weakly to be of clinical interest. The experiments revealed that the expression of a few hundred genes was changed in response the drugs. Many of these genes were involved in major signalling pathways that control how CFTR is folded and trafficked within cells.

Next, Hegde, Parashuraman et al. tested drugs that inhibit these signalling pathways to see if they improve salt handling in the mutated cells. The experiments demonstrated that these inhibitor drugs efficiently block the breakdown of misfolded CFTR, or boost the likelihood of CFTR making it to the membrane, helping improve salt trafficking in the cells. The inhibitors produced even better results when used in combination with a known CFTR-protecting drug. The results suggest that identifying and targeting signalling pathways involved in the folding, trafficking, and breakdown of CFTR may prove a promising way to treat cystic fibrosis.

DOI:http://dx.doi.org/10.7554/eLife.10365.002

Role of Sphingolipids in the Pathobiology of Lung Inflammation

Sphingolipid bioactivities in the respiratory airways and the roles of the proteins that handle them have been extensively investigated. Gas or inhaled particles or microorganisms come into contact with mucus components, epithelial cells, blood barrier, and immune surveillance within the airways. Lung structure and functionality rely on a complex interplay of polar and hydrophobic structures forming the surfactant layer and governing external-internal exchanges, such as glycerol-phospholipids sphingolipids and proteins. Sphingolipids act as important signaling mediators involved in the control of cell survival and stress response, as well as secreted molecules endowed with inflammation-regulatory activities. Most successful respiratory infection and injuries evolve in the alveolar compartment, the critical lung functional unit involved in gas exchange. Sphingolipid altered metabolism in this compartment is closely related to inflammatory reaction and ceramide increase, in particular, favors the switch to pathological hyperinflammation. This short review explores a few mechanisms underlying sphingolipid involvement in the healthy lung (surfactant production and endothelial barrier maintenance) and in a selection of lung pathologies in which the impact of sphingolipid synthesis and metabolism is most apparent, such as acute lung injury, or chronic pathologies such as cystic fibrosis and chronic obstructive pulmonary disease.

Impact of genetic polymorphisms on paediatric atopic dermatitis

In order to investigate whether polymorphisms of genes encoding some factors of innate and adaptive immunity play a role in the development of, or protection against atopic dermatitis (AD) and condition its severity, we genotyped 33 candidate genes and 47 single nucleotide polymorphisms (SNPs) using Custom TaqMan Array Microfluidic Cards and an ABI 7900HT analyser (Applied Biosystems, Foster City, CA, USA). The study involved 104 children with AD (29 with mild-to-moderate and 75 with severe disease; 42 girls; mean age ± SD, 5.8 ± 3.3 years) and 119 healthy controls (49 girls; mean age, 4.8 ± 3.0 years). IL10-rs1800872T, TG and MBL2-rs500737AG were all significantly more frequent among the children with AD ( P = 0.015, P = 0.004 and P = 0.030), whereas IL10-rs1800896C and TC were more frequent in those without AD ( P = 0.028 and P = 0.032). The VEGFA-rs2146326A and CTLA4-rs3087243AG SNPs were significantly more frequent in the children with mild/moderate AD than in those with severe AD ( P = 0.048 and P = 0.036). IL10-rs1800872T and TG were significantly more frequent in the children with AD and other allergic diseases than in the controls ( P = 0.014 and P = 0.007), whereas IL10-rs1800896TC and C were more frequent in the controls than in the children with AD and other allergic diseases ( P = 0.0055 and P = 0.0034). These findings show that some of the polymorphisms involved in the immune response are also involved in some aspects of the development and course of AD and, although not conclusive, support the immunological hypothesis of the origin of the inflammatory lesions.

EG-VEGF, BV8, and their receptor expression in human bronchi and their modification in cystic fibrosis: Impact of CFTR mutation (delF508)

Enhanced lung angiogenesis has been reported in cystic fibrosis (CF). Recently, two highly homologous ligands, endocrine gland vascular endothelial growth factor (EG-VEGF) and mammalian Bv8, have been described as new angiogenic factors. Both ligands bind and activate two closely related G protein-coupled receptors, the prokineticin receptor (PROKR) 1 and 2. Yet, the expression, regulation, and potential role of EG-VEGF, BV8, and their receptors in normal and CF lung are still unknown. The expression of the receptors and their ligands was examined using molecular, biochemical, and immunocytochemistry analyses in lungs obtained from CF patients vs. control and in normal and CF bronchial epithelial cells. Cystic fibrosis transmembrane conductance regulator (CFTR) activity was evaluated in relation to both ligands, and concentrations of EG-VEGF were measured by ELISA. At the mRNA level, EG-VEGF, BV8, and PROKR2 gene expression was, respectively, approximately five, four, and two times higher in CF lungs compared with the controls. At the cellular level, both the ligands and their receptors showed elevated expressions in the CF condition. Similar results were observed at the protein level. The EG-VEGF secretion was apical and was approximately two times higher in CF compared with the normal epithelial cells. This secretion was increased following the inhibition of CFTR chloride channel activity. More importantly, EG-VEGF and BV8 increased the intracellular concentration of Ca(2+) and cAMP and stimulated CFTR-chloride channel activity. Altogether, these data suggest local roles for epithelial BV8 and EG-VEGF in the CF airway peribronchial vascular remodeling and highlighted the role of CFTR activity in both ligand biosynthesis and secretion.

Influence of Body Mass Index on Inflammatory Profile at Admission in Critically Ill Septic Patients

Introduction. Inflammation is ubiquitous during sepsis and may be influenced by body mass index (BMI). We sought to evaluate if BMI was associated with serum levels of several cytokines measured at intensive care unit admission due to sepsis. Methods. 33 septic patients were included. An array of thirty-two cytokines and chemokines was measured using Milliplex technology. We assessed the association between cytokine levels and BMI by generalized additive model that also included illness severity (measured by SAPS 3 score); one model was built for each cytokine measured. Results. We found that levels of epidermal growth factor, vascular endothelial growth factor, and interleukins 4, 5, and 13 were associated with BMI in a complex, nonlinear way, independently of illness severity. Higher BMI was associated with higher levels of anti-inflammatory interleukins. Conclusion. BMI may influence host response to infection during critical illness. Larger studies should confirm these findings.

Genetic polymorphisms and risk of recurrent wheezing in pediatric age

Background

Wheezing during early life is a very common disorder, but the reasons underlying the different wheezing phenotypes are still unclear. The aims of this study were to analyse the potential correlations between the risk of developing recurrent wheezing and the presence of specific polymorphisms of some genes regulating immune system function, and to study the relative importance of the associations of different viruses and genetic polymorphisms in causing recurrent episodes.

Methods

The study involved 119 otherwise healthy infants admitted to hospital for a first episode of wheezing (74 of whom subsequently experienced recurrent episodes) and 119 age- and sex-matched subjects without any history of respiratory problem randomly selected from those attending our outpatient clinic during the study period. All of the study subjects were followed up for two years, and 47 single nucleotide polymorphisms (SNPs) in 33 candidate genes were genotyped on whole blood using an ABI PRISM 7900 HT Fast Real-time instrument.

Results

IL8-rs4073AT, VEGFA-rs833058CT, MBL2-rs1800450CT and IKBKB-rs3747811AT were associated with a significantly increased risk of developing wheezing (p = 0.02, p = 0.03, p = 0.05 and p = 0.0018), whereas CTLA4-rs3087243AG and NFKBIB-rs3136641TT were associated with a significantly reduced risk (p = 0.05 and p = 0.04). IL8-rs4073AT, VEGFA-rs2146323AA and NFKBIA-rs2233419AG were associated with a significantly increased risk of developing recurrent wheezing (p = 0.04, p = 0.04 and p = 0.03), whereas TLR3-rs3775291TC was associated with a significantly reduced risk (p = 0.03). Interestingly, the study of gene-environment interactions showed that rhinovirus was significantly associated with recurrent wheezing in the presence of IL4Ra-rs1801275GG and G (odds ratio [OR] 6.03, 95% confidence interval [CI]: 1.21-30.10, p = 0.03) and MAP3K1-rs702689AA (OR 4.09, 95% CI: 1.14-14.61, p = 0.03).

Conclusions

This study shows a clear relationship between the risk of wheezing and polymorphisms of some genes involved in the immune response. Although further studies are needed to confirm the results, these findings may be useful for the early identification of children at the highest risk of developing recurrent episodes and possibly subsequent asthma.

Oxidative stress modulates the expression of genes involved in cell survival in ΔF508 cystic fibrosis airway epithelial cells

Although cystic fibrosis (CF) pathophysiology is explained by a defect in CF transmembrane conductance regulator (CFTR) protein, the broad spectrum of disease severity is the consequence of environmental and genetic factors. Among them, oxidative stress has been demonstrated to play an important role in the evolution of this disease, with susceptibility to oxidative damage, decline of pulmonary function, and impaired lung antioxidant defense. Although oxidative stress has been implicated in the regulation of inflammation, its molecular outcomes in CF cells remain to be evaluated. To address the question, we compared the gene expression profile in NuLi-1 cells with wild-type CFTR and CuFi-1 cells homozygous for ΔF508 mutation cultured at air-liquid interface. We analyzed the transcriptomic response of these cell lines with microarray technology, under basal culture conditions and after 24 h oxidative stress induced by 15 μM 2,3-dimethoxy-1,4-naphtoquinone. In the absence of oxidative conditions, CuFi-1 gene profiling showed typical dysregulated inflammatory responses compared with NuLi-1. In the presence of oxidative conditions, the transcriptome of CuFi-1 cells reflected apoptotic transcript modulation. These results were confirmed in the CFBE41o- and corrCFBE41o- cell lines as well as in primary culture of human CF airway epithelial cells. Altogether, our data point to the influence of oxidative stress on cell survival functions in CF and identify several genes that could be implicated in the inflammation response observed in CF patients.

Candidate markers associated with the probability of future pulmonary exacerbations in cystic fibrosis patients

Introduction

Pulmonary exacerbations (PEs) cause significant morbidity and can severely impact disease progression in cystic fibrosis (CF) lung disease, especially in patients who suffer from recurrent PEs. The assessments able to predict a future PE or a recurrent PE are limited. We hypothesized that combining clinical, molecular and patient reported data could identify patients who are at risk of PE.

Methods

We prospectively followed a cohort of 53 adult CF patients for 24 months. Baseline values for spirometry, clinical status using the Matouk Disease Score, quality of life (QOL), inflammatory markers (C-reactive protein (CRP), interleukins (IL)-1β, -6, -8, -10, macrophage inflammatory protein (MIP)-1β, tumor necrosis factor (TNF) and vascular endothelial growth factor (VEGF)), polyunsaturated fatty acids and lipid peroxidation in blood plasma were collected for all patients during periods of stable disease, and patients were monitored for PE requiring PO/IV antibiotic treatment. Additionally, we closely followed 13 patients during PEs collecting longitudinal data on changes in markers from baseline values. We assessed whether any markers were predictors of future PE at baseline and after antibiotic treatment.

Results

Out of 53 patients, 37 experienced PEs during our study period. At baseline, we found that low lung function, clinical scoring and QOL values were associated with increased risk of PE events. PEs were associated with increased inflammatory markers at Day 1, and these biomarkers improved with treatment. The imbalance in arachidonic acid and docosahexaenoic acid levels improved with treatment which coincided with reductions in lipid peroxidation. High levels of inflammatory markers CRP and IL-8 were associated with an early re-exacerbation.

Conclusion

Our results demonstrate that worse clinical and QOL assessments during stable disease are potential markers associated with a higher risk of future PEs, while higher levels of inflammatory markers at the end of antibiotic treatment may be associated with early re-exacerbation.

Systematic review of blood biomarkers in cystic fibrosis pulmonary exacerbations

BACKGROUND

Biomarkers reflective of disease activity in cystic fibrosis (CF) have the potential to improve patient care, particularly during CF pulmonary exacerbations (CFPEs). Although blood-based biomarkers have been studied in CFPE for nearly 3 decades, none have been integrated into routine clinical practice. To facilitate progress in this area, we performed a systematic review evaluating blood-based biomarkers during CFPE.

METHODS

MEDLINE, EMBASE, and CENTRAL were searched to identify relevant studies published from January 1995 to August 2012. We included all full-text studies examining systemic (blood-based) biomarkers to aid in the diagnosis of CFPE, predict outcomes of CFPE, and/or monitor the response to CFPE treatment.

RESULTS

Seventy-eight unique blood-based biomarkers have been studied to date, mainly inflammatory cytokines, acute phase reactants, and markers of oxidative stress. C-reactive protein (CRP) consistently correlated with disease activity, with a statistically significant increase from stable to exacerbation state in five of six studies, and changes in response to CFPE treatment, with a statistically significant decrease from the beginning to the end of CFPE treatment in 18 of 20 studies. Other promising biomarkers of CFPE disease activity include neutrophil elastase antiproteinase complex, IL-6, myeloperoxidase (MPO), lactoferrin, and calprotectin.

CONCLUSIONS

Although there are several blood-based biomarkers with evidence for application within the CFPE setting, CRP has been the most widely studied biomarker demonstrating the potential for clinical usefulness. Further validation studies and clinical trials are required to determine whether blood-based biomarkers can be used to ultimately improve health outcomes in the setting of a CFPE.

Aortopulmonary collateral flow in cystic fibrosis assessed with phase-contrast MRI

BACKGROUND

Cystic fibrosis (CF) is a common genetic disease in Caucasians. Chronic pulmonary disease with progressive destruction of the pulmonary parenchyma is two of the major morbidities, but the relationship between clinical severity of CF and aortopulmonary collateral blood flow has not been assessed.

OBJECTIVE

The purpose of this study is to measure changes in aortopulmonary collateral blood flow by phase-contrast magnetic resonance imaging (MRI) in children with CF across the spectrum of disease severity as measured by the forced expiratory volume in one second as percent predicted value (FEV1% predicted).

MATERIALS AND METHODS

Sixteen patients with CF were prospectively evaluated. Eight were classified as having mild CF lung disease (FEV1 ≥80% predicted) and eight were classified as having moderate to severe CF lung disease (FEV1 <80% predicted). Seventeen age- and gender-matched non-CF subjects without cardiac or lung disease served as controls. Phase-contrast flow was measured at the ascending aorta, main pulmonary artery and both pulmonary arteries. Aortopulmonary collateral blood flow was calculated for each subject. The relationship between collateral flow and FEV1% predicted was modeled using nonparametric regression. Group differences were assessed by analysis of variance.

RESULTS

Aortopulmonary collateral blood flow began to increase as FEV1% predicted in subjects with CF fell below 101.5% with significant further increase in the aortopulmonary collateral blood flow in the subjects with CF with moderate to severe lung disease compared to controls (0.89 vs. 0.20 L/min, P < 0.0001). Aortopulmonary collateral blood flow correlated negatively with FEV1% predicted (r=0.70, P = 0.0050) confirming its relationship to this established marker of disease severity. There was no statistically significant difference in results obtained from two independent observers.

CONCLUSION

These preliminary findings suggest that phase-contrast MRI can be performed reliably with consistent results and without interobserver variability. While the aortopulmonary collateral blood flow is within the normal range in subjects with mild CF disease, it begins to increase even when lung function is still in the normal range. A significant increase in the aortopulmonary collateral blood flow compared to controls is measured in patients with moderate to severe CF lung disease. The studies support the notion that aortopulmonary collateral blood flow may serve as a novel and sensitive biomarker of early pulmonary disease in cystic fibrosis.

Effects of treatment in the levels of circulating cytokines and growth factors in cystic fibrosis and dialyzed patients by multi-analytical determination with a biochip array platform

Chronic inflammatory diseases need non-invasive sensitive, reliable and predictive clinical biomarkers for diagnosis and monitoring therapy. Since inflammation is a complex phenomenon, simultaneous evaluation of different analytes in the same sample may help in defining this complexity and in developing specific anti-inflammatory intervention strategies. In this study, we used a biochip array system capable of measuring 12 cytokines and growth factors (IL-2, IL-4, IL-6, IL-8, IL-10, IL-1 α, IL-1 β, IFN-γ, TNF-α, MCP-1, VEGF, and EGF) in three groups: 97 control subjects; 24 cystic fibrosis (CF) patients before and during the antibiotic treatment (6 and 15days) for acute pulmonary exacerbation as well as 15days after the withdrawal of therapy; 22 children and young adults on chronic hemodialysis (HD) at the beginning and at the end of a standard HD session. CF patients in acute exacerbation displayed higher IL-2, IL-6, VEGF and MCP-1 levels than the control subjects. IL-6 significantly decreased during therapy (P<0.01) but not 15days after the withdrawal of therapy. IL-8 and EGF levels were significantly lower after 15days from the interruption of therapy (P<0.05 and P<0.01 respectively). Regression analysis showed that IL-4 and IL-6 correlated with the amelioration of the respiratory function during therapy. Patients on HD displayed higher IL-6 but lower IL-2, IL-4, IL-8, IFN-γ and EGF levels than control subjects. Serum levels of IL-8, IL-10 and IFN-γ were significantly higher at the end of the HD session (P<0.05 for all three). A biochip array allowed to define a pattern of cytokines/growth factors associated with an acute exacerbation in CF patients and IL-4 and IL-6 as predictors of response to therapy. In younger HD patients, we identified a biomarker pattern which is different from that of older patients. Finally, further studies are warranted to examine the role of these biomarkers in the pathogenesis of complications in HD patients.

Cystic fibrosis: management of haemoptysis

Haemoptysis is a common complication in cystic fibrosis (CF), occurring in approximately 9% of the population. Massive haemoptysis is associated with older patients, more severe disease and carries a high mortality rate. Despite this there are few robust published studies of effective treatments and knowledge of the precise pathogenesis is limited. Current guidelines for treatment from the Cystic Fibrosis Foundation (CFF) are based on consensus opinion of experts. Patients with massive haemoptysis who do not respond to initial medical treatments should undergo bronchial artery embolization. This will control the bleeding in the majority of cases but recurrence rates are high and there are little data to support long-term improved outcomes. Surgery is a last resort in patients with CF.

Expression of IL-23, VEGF and TLR2/TLR4 on mononuclear cells after exposure to Pseudomonas aeruginosa

Pseudomonas aeruginosa is a Gram-negative, aerobic bacillus causing infections of the respiratory and other organ systems in susceptible hosts. Although it does not cause pulmonary infections in immunocompetent individuals, P. aeruginosa causes chronic lung infection in individuals with cystic fibrosis and nosocomial pneumonia resulting in significant morbidity and mortality. Exogenous administration of an important P. aeruginosa virulence factor, lipase, present in P. aeruginosa culture supernatant, induces potent mononuclear cell activation leading to the production of numerous proinflammatory cytokines. In particular, P. aeruginosa culture supernatant stimulated increased proliferation of THP-1 cells and monocytes (MN). The addition of culture supernatant to THP-1 cells and MN also induced Interleukin (IL)-23 and vascular endothelial growth factor (VEGF) release in a time-dependent manner. To investigate whether any compounds present in the supernatant lipase contributed to releasing IL-23 and VEGF, the culture supernatant from P. aeruginosa containing lipase was treated with hexadecylsulfonylfluoride (AMSF). The AMSF-treated culture supernatant (CS) did not show any induction on the IL-23 and VEGF release compared to the cells treated with CS without AMSF. We also showed that Toll-like receptors (TLR)2/TLR4 are expressed in THP-1 cells and MN treated with P. aeruginosa CS in a time-dependent fashion. Flow cytometry analysis revealed a higher TLR4 and a lower TLR2 expression at 48 and 72 h of treatment. The treatment of cells with TLR4 neutralizing antibody, and to a lesser extent with TLR2 neutralizing antibody, resulted in a decrease in P. aeruginosa CS-induced IL-23 and VEGF production.

Serum vascular endothelial growth factor and angiopoietin-2 are associated with the severity of systemic inflammation rather than the presence of hemoptysis in patients with inflammatory lung disease

PURPOSE

Vascular endothelial growth factor (VEGF) and angiopoietin-2 (Ang-2) are major mediators of angiogenesis and are induced by tissue inflammation and hypoxia. The purpose of this study was to investigate whether serum VEGF and Ang-2 are associated with the presence of hemoptysis and the extent of systemic inflammation in patients with inflammatory lung diseases.

MATERIALS AND METHODS

We prospectively enrolled 52 patients with inflammatory lung disease between June 2008 and October 2009.

RESULTS

The median values of VEGF and Ang-2 were 436 pg/mL and 2383 pg/mL, respectively. There was a significant positive correlation between serum Ang-2 and VEGF levels. VEGF levels were not significantly different according to the presence of hemoptysis. C-reactive protein (CRP) and Ang-2 level were significantly higher in patients without hemoptysis (n=26) than in those with hemoptysis (n=26; p<0.001 and p<0.001, respectively). CRP and arterial oxygen tension (PaO₂) were significantly correlated with both serum VEGF (p=0.032 and p=0.016, respectively) and Ang-2 levels (p<0.001 and p=0.041, respectively), after adjusting for other factors. Age and the absence of hemoptysis were factors correlated with serum Ang-2 levels.

CONCLUSION

Our study suggests that serum VEGF and Ang-2 levels are associated with PaO₂ and the severity of inflammation rather than the presence of hemoptysis in patients with inflammatory lung diseases. Thus, hemoptysis may not be mediated by increased serum levels of VEGF and Ang-2 in patients with inflammatory lung diseases, and further studies are required to determine the mechanisms of hemoptysis.

Elevated vascular endothelial growth factor is correlated with elevated erythropoietin in stable, young cystic fibrosis patients

Angiogenesis is an important mechanism of airway remodeling in lung disease. We previously demonstrated that serum vascular endothelial growth factor (VEGF) is elevated in cystic fibrosis (CF) patients and declines with therapy for pulmonary exacerbation. We hypothesized that VEGF is elevated early in the course of CF and is associated with markers of tissue hypoxia. A prospective, single-visit evaluation of thirty stable infants and children with CF was performed. Serum was analyzed for VEGF and for other markers of tissue hypoxia (erythropoietin (EPO), insulin-like growth factor binding protein-1 (IGFBP-1)) and for inflammatory mediators (IL-1 beta, IL-6, IL-8, and tumor necrosis factor alpha (TNFα)) using Meso Scale multi-spot serum immunoassays. Measurements were correlated between assay groups; and with age in months and pulmonary function (FEV0.5 or FEV1). VEGF, EPO, TNFα and IL-8 were elevated compared to published normative values. VEGF levels were not significantly correlated with any inflammatory mediators. However, VEGF correlated with EPO (r=0.505; P<0.05). There was no correlation between lung function and markers of inflammation or tissue hypoxia. VEGF is elevated in young, stable infants and children suggesting angiogenesis as a contributing mechanism for early lung disease in CF. VEGF elevation does not show significant correlation with inflammatory mediators known to be increased in CF, but is significantly correlated with EPO levels. We propose that VEGF elevation and angiogenesis contribute to early lung disease and may result from a direct tissue hypoxia pathway in CF.

Analysis of Inflammatory and Immune Response Biomarkers in Sputum and Exhaled Breath Condensate by a Multi-Parametric Biochip Array in Cystic Fibrosis

Cystic Fibrosis (CF) lung disease is characterized by high levels of cytokines and chemokines in the airways, producing chronic inflammation. Non-invasive biomarkers, which are also specific for the inflammatory and immune responses, are urgently needed to identify exacerbations and evaluate therapeutic efficacy. The aim of this study is to evaluate the association of sputum and exhaled breath condensate (EBC) biomarker changes with clinical exacerbation and response to therapy. We studied the simultaneous presence and concentration of twelve cytokines and growth factors (EGF, IL-1α, IL-1β, IL-2, IL-4, IL-6, IL-8, IL-10, IFN-γ, MCP-1, TNF-α and VEGF) by a multi-parametric biochip array in sputum and EBC of 24 CF patients before, after 6 and 15 days of therapy, and 15 days after the end of treatment for an acute exacerbation. Correlations with functional respiratory tests (FEV1, FVC) and the systemic marker C-reactive protein (CRP) were looked for. In sputum, before therapy, VEGF and IL-1β levels positively correlated with the respiratory function and CRP. Sputum IL-1α, IL-1β IL-4, IL-10, TNF-α, and VEGF significantly decreased, while EGF increased, during therapy. IL-8 and IL-4 levels negatively correlated with the respiratory function at 15 and 30 days from the start of therapy, respectively. IL-4, IL-6, IL-10 and TNF-α positively correlated with CRP during therapy. Although some EBC biomarkers correlated with respiratory function and CRP, no significant associations with these clinical parameters were found. Sputum IL-1β and VEGF might be considered biomarkers of an acute exacerbation in CF patients. A panel of sputum cytokines and growth factors may better describe the response to intravenous antibiotic treatment of CF than one single systemic marker.

Potential of anti-inflammatory treatment for cystic fibrosis lung disease

Cystic fibrosis (CF) is the most common life-shortening genetic disorder in Caucasians. With improved diagnosis and treatment, survival has steadily increased. Unfortunately, the overwhelming majority of patients still die from respiratory failure caused by structural damage resulting from airway obstruction, recurrent infection, and inflammation. Here, we discuss the role of inflammation and the development of anti-inflammatory therapies to treat CF lung disease. The inflammatory host response is the least addressed component of CF airway disease at this time. Current challenges in both preclinical and clinical investigation make the identification of suitable anti-inflammatory drugs more difficult. Despite this, many researchers are making significant progress toward this goal and the CF research community has reason to believe that new therapies will emerge from these efforts.

Mediators leading to fibrosis - how to measure and control them in tissue engineering

Fibrosis is the result of an excessive amount of fibrous connective tissue deposited into the extracellular matrix (ECM) space of damaged tissues from injury or disease. Collagens, particularly types I and III are the main constituents of the fibrotic scar tissue as well as a mixture of fibrotic cells. Severely fibrotic tissue will develop chronic healing problems resulting in tissue/organ dysfunction. More attention needs to be given to the fibrotic differentiation and related effects in bioengineered tissues. The current review provides an update on the mechanism behind fibrosis formation as well as technical measurements and preventions.

The bronchial circulation--worth a closer look: a review of the relationship between the bronchial vasculature and airway inflammation

Until recently, the bronchial circulation has been relatively ignored in the research and clinical arenas, perhaps because of its small volume and seeming dispensability relative to the pulmonary circulation. Although the bronchial circulation only receives around 1% of the cardiac output in health, it serves functions that are critical to maintaining airway and lung function. The bronchial circulation also plays an important role in many lung and airway diseases; through its ability to increase in size, the bronchial circulation is able to provide lung parenchymal perfusion when the pulmonary circulation is compromised, and more recently the role of the bronchial circulation in the pathogenesis of inflammatory airway disease has been explored. Due to the anatomic variability and small volume of the bronchial circulation, much of the research to date has necessitated the use of animal models and invasive procedures. More recently, non-invasive techniques for measuring bronchial blood flow in the mucosal microvascular network have been developed and offer a new avenue for the study of this circulation in humans. In conjunction with molecular research, measurement of airway blood flow (Q(aw)) may help elucidate the role of the bronchial circulation in inflammatory airway disease and become a useful tool for monitoring therapy.

Gene profiling studies in the neonatal ovine lung show enhancing effects of VEGF on the immune response

Preterm and young neonates have an increased predisposition to respiratory distress syndrome (RDS) associated with an immature development of lung surfactant. Glucocorticoids (GCs) are the major immunomodulatory agents used to increase lung development and reduce the mortality and morbidity of preterm infants with RDS. However, their safety remains uncertain, and the precise mechanisms by which they improve lung function are unclear. In previous studies, we found that vascular endothelial growth factor (VEGF) enhances the innate immune response by respiratory epithelial cells, causes a monocytic infiltration into the lung, and reduces the severity of infection by respiratory syncytial virus (RSV), a respiratory pathogen known to affect preterm infants at a high prevalence. The purpose of this study is to measure the effects of VEGF administration on local immune responses in neonatal lambs, as the ovine lung is well suited for comparison to the human lung, due to similarities in alveolar development, immune responses, and RSV susceptibility. We hypothesized that VEGF induces the expression of genes necessary for host immune responses. We analyzed global gene expression profiles in the lungs of neonate lambs treated with VEGF by real-time qPCR. We report that VEGF induced the expression of chemokines (IL-8, RANTES, MCP-1), cytokines (IFN-gamma, IL-6, TNF-alpha, GMCSF), Toll-like receptor (TLR)-4, complement family members (C3, CFB, CFH) and collectins (SP-A, SP-D). These results suggest that VEGF can regulate local immune gene expression in vivo and should be further explored as a potential exogenous therapy for various lung diseases.

Increased serum interleukin-5 and vascular endothelial growth factor in children with acute mycoplasma pneumonia and wheeze

Acute mycoplasma pneumonia may be accompanied by wheeze in some children considered not to have asthma. The aim of the present study was to evaluate cytokine secretion in children with acute mycoplasma pneumonia and wheeze. We studied 58 patients with mycoplasma pneumonia (12 with wheeze, Group 1; 46 without wheeze, Group 2) and 36 patients of non-mycoplasma pneumonia (Group 3). Serum levels of interleukin (IL)-4, IL-5, interferon (IFN)-gamma, and vascular endothelial growth factor (VEGF) were measured using an enzyme-linked immunosorbent assay kits. The mean +/- SD IL-5 level of Group 1 was 97.1 +/- 73.0 pg/ml, which was significantly higher than that of Group 2 (28.2 +/- 32.2 pg/ml) and that of Group 3 (35.7 +/- 42.0 pg/ml). The mean +/- SD VEGF level of Group 1 was 687.5 +/- 385.8 pg/ml, which was significantly higher than that of Group 2 (310.0 +/- 251.9 pg/ml) and that of Group 3 (402.3 +/- 279.5 pg/ml). No significant differences in serum levels of IL-4, IFN-gamma, and IgE were observed between the groups. Our results show that children with mycoplasma pneumonia and wheeze have significantly higher serum levels of IL-5 and VEGF. These increased immune responses may be associated with the pathophysiological mechanisms by which the Mycoplasma pneumoniae contribute to the development of wheeze during acute mycoplasma pneumonia.

Signal transducer and activator of transcription 1 (STAT1) is essential for chromium silencing of gene induction in human airway epithelial cells

Hexavalent chromium (Cr(VI)) promotes lung injury and pulmonary diseases through poorly defined mechanisms that may involve the silencing of inducible protective genes. The current study investigated the hypothesis that Cr(VI) actively signals through a signal transducer and activator of transcription 1 (STAT1)-dependent pathway to silence nickel (Ni)-induced expression of vascular endothelial cell growth factor A (VEGFA), an important mediator of lung injury and repair. In human bronchial airway epithelial (BEAS-2B) cells, Ni-induced VEGFA transcription by stimulating an extracellular regulated kinase (ERK) signaling cascade that involved Src kinase-activated Sp1 transactivation, as well as increased hypoxia-inducible factor-1 alpha (HIF-1 alpha) stabilization and DNA binding. Ni-stimulated ERK, Src, and HIF-1 alpha activities, as well as Ni-induced VEGFA transcript levels were inhibited in Cr(VI)-exposed cells. We previously demonstrated that Cr(VI) stimulates STAT1 to suppress VEGFA expression. In BEAS-2B cells stably expressing STAT1 short hairpin RNA, Cr(VI) increased VEGFA transcript levels and Sp1 transactivation. Moreover, in the absence of STAT1, Cr(VI), and Ni coexposures positively interacted to further increase VEGFA transcripts. This study demonstrates that metal-stimulated signaling cascades interact to regulate transcription and induction of adaptive or repair responses in airway cells. In addition, the data implicate STAT1 as a rate limiting mediator of Cr(VI)-stimulated gene regulation and suggest that cells lacking STAT1, such as many tumor cell lines, have opposite responses to Cr(VI) relative to normal cells.

Endoscopic narrow-band imaging-quantitative assessment of airway vascularity after lung transplantation

In lung transplant recipients, the submucosal vascular plexus of the airway wall potentially represents one of the key structures of graft injury. Narrow band imaging is a novel endoscope technique that allows visual enhancement of the mucosa vasculature. It was our aim to investigate the ability of narrow-band imaging in combination with computerized image analysis to quantitatively assess airway vascularity in lung transplant recipients. In consecutive lung transplant recipients, in addition to the routine procedures, optical analysis of the main carina (autologous tissue) and the upper lobe carina (allogeneic tissue) were performed. From every site, three representative pictures were chosen. A total of 63 bronchoscopies were analyzed. The intraclass correlation coefficient (measure for test-retest reliability) of the three measurements were 0.69 and 0.74 for the main carina and the upper lobe carina, respectively. A mixed linear regression revealed increased vascularity in autologous tissue of patients with cystic fibrosis (p=0.06) and decreased vascularity in allogeneic tissue with time after transplantation (p=0.09). Endoscopic narrow-band imaging (NBI) in combination with computerized image analysis allows consistent assessment of airway vascularity in vivo. In lung transplant recipients, there might be differences in airway vascularity in both autologous and allogeneic large airways.

Circulating vascular endothelial growth factor and systemic inflammatory markers in patients with stable and exacerbated chronic obstructive pulmonary disease

The aim of the present study was to assess circulating levels of VEGF (vascular endothelial growth factor), a biomarker with prognostic significance in cardiovascular disease, and markers of systemic inflammation in patients with stable and exacerbated COPD (chronic obstructive pulmonary disease). Lung function parameters, arterial blood gas analysis and circulating levels of VEGF, IL-6 (interleukin-6), TNF-alpha (tumour necrosis factor-alpha), CRP (C-reactive protein), fibrinogen and the peripheral blood neutrophil cell count were assessed in 30 patients on admission to the hospital for acute exacerbation of COPD, in 30 age-, gender- and BMI (body mass index)-matched patients with stable COPD, and 30 matched controls with normal lung function. Patients with acute exacerbated COPD had higher circulating concentrations of VEGF (P<0.001), IL-6 (P<0.05) and CRP (P<0.01) and an increased blood neutrophil cell count (P<0.05) compared with patients with stable COPD and healthy controls. VEGF levels in exacerbated COPD correlated with systemic inflammatory markers, such as CRP (r=0.61, P<0.005), IL-6 (r=0.46; P<0.01) and fibrinogen (r=0.39, P<0.05). In patients with stable COPD, there was a significant relationship between circulating VEGF levels and the percentage of the predicted FEV(1) (forced expiratory volume in 1 s) (r=0.47, P<0.01). Recovery from the exacerbation resulted in a significant decrease in both circulating VEGF levels and markers of systemic inflammation. In conclusion, circulating levels of VEGF and markers of systemic inflammation are up-regulated in patients with acute exacerbated COPD and decrease after recovery from the exacerbation.

Fibrous capsule formation around titanium and copper

Previous studies suggest that implant material properties influence the quality and quantity of fibrous capsule around the implant. However, the precise relation between material surface chemistry, early inflammatory response, and fibrous subsequent repair outcome is still unknown. Titanium (Ti) and copper (Cu), surfaces with different inflammatory potential, were implanted subcutaneously in rats and retrieved fibrous capsules were analyzed after 28 and 56 days. Histological examinations show pronounced differences in capsule morphology. The fibrous capsule around Ti was thinner than that around Cu, with less number of the inflammatory cells in the layer close to the implant surface, and less and smaller blood vessels. The capsule around Cu was thick, with a large number of the inflammatory cells, particularly macrophages and giant cells, and increased number of blood vessels. Our study suggests that material surface properties, which initiate early, multiple cellular inflammatory events, are also associated with increased fibrosis and angiogenesis during repair phase.

Hemoptysis in Israeli CF patients--prevalence, treatment, and clinical characteristics

OBJECTIVE

To identify the characteristics of CF patients with hemoptysis in Israel and to compare clinical features and risk factors to a control group of CF patients without hemoptysis.

DESIGN

Retrospective chart review.

PATIENTS

All CF patients in Israel who experienced hemoptysis between 2001 and 2005 and a control group of sex- and age-matched patients with no history of hemoptysis.

RESULTS

40/440 CF patients (9.1%) experienced hemoptysis during the study period, 50% were male. Ten patients (25%) were under 13 years old at the first hemoptysis episode. Pulmonary exacerbation was the precipitating factor in 90%. Twenty three patients showed moderate or major hemoptysis. 35/40 patients responded well to conservative therapy. Bronchial artery embolization (BAE) was performed in 5 patients with no recurrence of bleed within 24 h. However all of these patients experienced recurrent hemoptysis. One patient died during the follow-up period because of end stage lung disease. Pulmonary function tests, body-mass index, coagulation tests, pancreatic status, presence of bronchiectasis, sputum cultures and genetic mutations were similar in the two groups. A high incidence (57.5%) of associated diseases including cystic fibrosis related diabetes, cirrhosis and portal hypertension, and distal intestinal obstruction syndrome was found among hemoptysis patients, compared to only 5.2% in the control group (p<0.001).

CONCLUSIONS

Hemoptysis, even major, did not seem to be a risk factor for mortality in our patients. A higher incidence of hemoptysis was found in our pediatric patients compared to other series. BAE shows a high immediate rate of success in controlling hemoptysis, but does not prevent future disease.

Sputum biomarkers of inflammation in cystic fibrosis lung disease

Pulmonary biomarkers are being used more frequently to monitor disease activity and evaluate response to treatment in individuals with cystic fibrosis (CF). This article summarizes the current state of knowledge of biomarkers of inflammation relevant to CF lung disease, and the tools to measure inflammation, with specific emphasis on sputum. Sputum is a rich, noninvasive source of biomarkers of inflammation and infection. Sputum induction, through the inhalation of hypertonic saline, has expanded the possibilities for monitoring airway inflammation and infection, especially in individuals who do not routinely expectorate sputum. We critically examine the existing data supporting the validity of sputum biomarkers in CF, with an eye toward their application as surrogate endpoints or outcome measures in CF clinical trials. Further validation studies are needed regarding the variability of inflammatory biomarker measurements, and to evaluate how these biomarkers relate to disease severity, and to longitudinal changes in lung function and other clinical endpoints. We highlight the need to incorporate sputum collection, by induction if necessary, and measurement of sputum biomarkers into routine CF clinical care. In the future, pulmonary biomarkers will likely be useful in predicting disease progression, indicating the onset and resolution of a pulmonary exacerbation, and assessing response to current therapies or candidate therapeutics.

Intrinsic pro-angiogenic status of cystic fibrosis airway epithelial cells

Cystic fibrosis is a common genetic disorder characterized by a severe lung inflammation and fibrosis leading to the patient's death. Enhanced angiogenesis in cystic fibrosis (CF) tissue has been suggested, probably caused by the process of inflammation, as similarly described in asthma and chronic bronchitis. The present study demonstrates an intrinsic pro-angiogenic status of cystic fibrosis airway epithelial cells. Microarray experiments showed that CF airway epithelial cells expressed several angiogenic factors such as VEGF-A, VEGF-C, bFGF, and PLGF at higher levels than control cells. These data were confirmed by real-time quantitative PCR and, at the protein level, by ELISA. Conditioned media of these cystic fibrosis cells were able to induce proliferation, migration and sprouting of cultured primary endothelial cells. This report describes for the first time that cystic fibrosis epithelial cells have an intrinsic angiogenic activity. Since excess of angiogenesis is correlated with more severe pulmonary disease, our results could lead to the development of new therapeutic applications.

Recipient vascular endothelial growth factor serum levels predict primary lung graft dysfunction

Primary graft dysfunction (PGD) is a severe complication in lung transplantation. Therapeutic strategies are limited and there exist no predictive markers for PGD. To investigate whether vascular endothelial growth factor (VEGF) that regulates vascular permeability could predict PGD, pretransplant VEGF serum concentrations were measured in 150 lung transplant patients and 12 controls by ELISA. PGD was scored from 0 to 3 using chest radiographs and PaO(2)/FiO(2) ratios according to the International Society for Heart and Lung Transplantation guidelines. The mean graft ischemia time was 5 h 47 min and the donors' PaO(2)/FiO(2) ratios were >300. PGD grades 0-3 occurred in 23%, 44%, 21%, and 11% of patients, respectively. Pre-operative VEGF serum concentrations were significantly higher in PGD grade 3 (p < 0.0001) versus grade 0-2 and controls. VEGF concentrations significantly predicted PGD grade 3 versus 0-2 in logistic regression analysis (p < 0.0001) and receiver operating analysis (AUC = 0.778). At a cut-off level of > or =650 pg/mL VEGF had 86% sensitivity and 62% specificity to identify PGD grade 3 versus 0-2. Pre-operative VEGF serum concentrations could identify lung transplant recipients with high PGD risk.

Regulation of surfactant protein and defensin mRNA expression in cultured ovine type II pneumocytes by all-trans retinoic acid and VEGF

Beta-defensins and surfactant proteins are components of the pulmonary innate immune system. Their gene expression is regulated by development, hormones, growth and immunoregulatory factors. It was our hypothesis that growth and differentiation factors such as all-trans retinoic acid (RA) and vascular endothelial growth factor (VEGF) may affect expression of selected innate immune genes by respiratory epithelial cells. Ovine JS7 cells (alveolar type II pneumocytes) were incubated in serum-free Dulbecco's modified Eagle's medium (DMEM) complete media that contained: no treatment (negative control), RA (500 nM), or VEGF (100 ng/ml) for 6, 12 or 24 h incubation. Total RNA was isolated, cDNA synthesized, and relative mRNA levels of surfactant protein A (SP-A) and SP-D, and sheep beta-defensin-1 (SBD-1) were determined by real-time reverse transcriptase-polymerase chain reaction (RT-PCR). Cells had significantly increased expression of SP-D mRNA at 6 h and 24 h, decreased expression of SP-A mRNA at 12 h, and unchanged levels of SBD-1 mRNA after the treatment with RA compared with their respective negative controls. VEGF did not alter the expression of the three innate immune genes. These findings suggest that SP-A and SP-D have different transcription regulation pathways, and that expression of SBD-1 is not inducible by RA similar to its human homolog HBD-1. The lack of changes induced by VEGF treatment suggests that VEGF does not have a direct effect on epithelial cells, but may affect gene expression indirectly.

Clinical implications for vascular endothelial growth factor in the lung: friend or foe?

Vascular endothelial growth factor (VEGF) is a potent mediator of angiogenesis which has multiple effects in lung development and physiology. VEGF is expressed in several parts of the lung and the pleura while it has been shown that changes in its expression play a significant role in the pathophysiology of some of the most common respiratory disorders, such as acute lung injury, asthma, chronic obstructive pulmonary disease, obstructive sleep apnea, idiopathic pulmonary fibrosis, pulmonary hypertension, pleural disease, and lung cancer. However, the exact role of VEGF in the lung is not clear yet, as there is contradictory evidence that suggests either a protective or a harmful role. VEGF seems to interfere in a different manner, depending on its amount, the location, and the underlying pathologic process in lung tissue. The lack of VEGF in some disease entities may provide implications for its substitution, whereas its overexpression in other lung disorders has led to interventions for the attenuation of its action. Many efforts have been made in order to regulate the expression of VEGF and anti-VEGF antibodies are already in use for the management of lung cancer. Further research is still needed for the complete understanding of the exact role of VEGF in health and disease, in order to take advantage of its benefits and avoid its adverse effects. The scope of the present review is to summarize from a clinical point of view the changes in VEGF expression in several disorders of the respiratory system and focus on its diagnostic and therapeutic implications.

The importance of the airway microvasculature in asthma

PURPOSE OF REVIEW

The microvasculature in asthma has been known to contribute to airway-wall thickening and oedema from early post-mortem series. Current concepts of airway inflammation in asthma highlight the importance of the role of the Th2 lymphocyte in the atopic response to aeroallergens, the importance of mast-cell mediators in airway remodelling, potential actions of the vascular response in determining airway thickness and mechanisms of angiogenesis involving endogenous as well as homing progenitor cells with angioblastic potential.

RECENT FINDINGS

The development of animal models of asthmatic airway inflammation and remodelling have given new insight into mechanisms of angiogenesis in asthma. The central role of vascular endothelial growth factor in angiogenesis, vessel leakage and vascular homeostasis is now recognized. A more recent finding is the influence of this factor in enhancing the Th2 response in airway inflammation. The ability of bone marrow-derived angioblasts to migrate to sites of inflammation and contribute to angiogenesis indicates a pivotal role of stem cells in this process.

SUMMARY

These findings now provide logical links between the inflammatory response, stem-cell mobilization, angiogenesis and airflow obstruction in the remodelled airway of asthma. Future studies examining airway-wall thickness will be able to account for the contribution of the vasculature and airway-wall oedema. Therapies aimed at vascular mechanisms may be useful adjuncts to current treatments and the recognition of stem cells as key players in airway remodelling may provide strategies to reduce fixed airflow obstruction in severe disease.

Serum vascular endothelial growth factor in pediatric patients with community-acquired pneumonia and pleural effusion

This study investigated the serum vascular endothelial growth factor (VEGF) levels in children with community-acquired pneumonia. Serum VEGF levels were measured in patients with pneumonia (n=29) and in control subjects (n=27) by a sandwich enzyme-linked immunosorbent assay. The pneumonia group was classified into bronchopneumonia with pleural effusion (n=1), bronchopneumonia without pleural effusion (n=15), lobar pneumonia with pleural effusion (n=4), and lobar pneumonia without pleural effusion (n=9) groups based on the findings of chest radiographs. We also measured serum IL-6 levels and the other acute inflammatory parameters. Serum levels of VEGF in children with pneumonia were significantly higher than those in control subjects (p<0.01). Children with lobar pneumonia with or without effusion showed significantly higher levels of serum VEGF than children with bronchopneumonia. For lobar pneumonia, children with pleural effusion showed higher levels of VEGF than those without pleural effusion. Children with a positive urinary S. pneumonia antigen test also showed higher levels of VEGF than those with a negative result. Serum IL-6 levels did not show significant differences between children with pneumonia and control subjects. Serum levels of VEGF showed a positive correlation with the erythrocyte sedimentation rate in the children with pneumonia. In conclusion, VEGF may be one of the key mediators that lead to lobar pneumonia and parapneumonic effusion.

Acute hypoxia decreases plasma VEGF concentration in healthy humans

Vascular endothelial growth factor (VEGF) is known to be upregulated by hypoxia in vitro. However, in vivo data about VEGF regulation in chronic hypoxic diseases are conflicting. We investigated the effects of hypoxia on plasma VEGF concentration in healthy subjects. To control known confounders, such as insulin, glucose concentrations, or exercise, hypoxic effects on VEGF were studied during experimentally clamping glucose concentrations at rest. In a double-blind crossover study design, we induced hypoxia for 30 min by decreasing oxygen saturation to 75% (vs. normoxic control) in 14 healthy men. Plasma VEGF concentration was determined at baseline, immediately after hypoxia had ended, and after a further 150 min. Levels of its soluble (s)Flt-1 receptor were assessed at baseline and at the end of the clamp. In parallel, catecholamine and cortisol levels were monitored. To investigate potential effects of glucose administration on the release of VEGF, we performed a third session, reducing glucose infusion for 30 min while serum insulin was held stable thereby inducing hypoglycemia. Hypoxia decreased VEGF levels compared with the normoxic control (P<0.05). VEGF concentrations increased during hypoglycemia (P<0.02) but were comparable to the normoglycemic control at the end of the clamp (P>0.80). sFlt-1 receptor concentration remained unchanged during hypoxia and hypoglycemia compared with control (both P>0.4). Epinephrine concentration (P<0.01) increased upon hypoxia, whereas norepinephrine and cortisol did not change. Contrary to in vitro studies, in healthy humans hypoxia decreases plasma VEGF concentration, suggesting that systemic VEGF concentration may be differently regulated than the expression on cellular basis.