Cellular and plasma oxidative stress biomarkers are raised in adults with bronchiectasis

Bronchial Asthma as a Cardiovascular Risk Factor: A Prospective Observational Study

Introduction: Asthma as a chronic inflammatory disorder has been suggested as a risk factor for endothelial dysfunction (ED), but studies on the association between asthma and cardiovascular disease (CVD) risk are limited. Background: We assessed associations of ED with the severity of asthma, eosinophilic inflammation, lung function, and asthma control. Methods: 52 young asthmatics (median age of 25.22 years) and 45 healthy individuals were included. Demographic, clinical, and laboratory findings were recorded. We evaluated microvascular responsiveness by recording the reactive hyperemia index (RHI) indicating post-occlusive peripheral endothelium-dependent changes in vascular tone using the Itamar Medical EndoPAT2000. VCAM-1, ADMA, high-sensitive CRP (hsCRP), and E-selectin were measured. Results: Asthmatics had considerably lower RHI values (p < 0.001) with a dynamic decreasing trend by asthma severity and higher hsCRP levels (p < 0.001). A substantial increase in hsCRP and E-selectin with asthma severity (p < 0.05) was also observed. We confirmed a higher body mass index (BMI) in asthmatics (p < 0.001), especially in women and in severe asthma. Conclusions: We demonstrated the progression of CVD in asthmatics and the association of the ongoing deterioration of ED with the inflammatory severity, suggesting that the increased risk of CVD in young asthmatics is dependent on disease severity. The underlying mechanisms of risk factors for CVD and disease control require further study.

Peripheral Neutrophil-to-Lymphocyte Ratio in Bronchiectasis: A Marker of Disease Severity

Most patients with bronchiectasis have a predominantly neutrophilic inflammatory profile, although other cells such as lymphocytes (as controllers of bronchial inflammation) and eosinophils also play a significant pathophysiological role. Easy-to-interpret blood biomarkers with a discriminative capacity for severity or prognosis are needed. The objective of this study was to assess whether the peripheral neutrophil-to-lymphocyte ratio (NLR) is associated with different outcomes of severity in bronchiectasis. A total of 1369 patients with bronchiectasis from the Spanish Registry of Bronchiectasis were included. To compare groups, the sample was divided into increasing quartiles of NLR ratio. Correlations between quantitative variables were established using Pearson's P test. A simple linear regression (with the value of exacerbations as a quantitative variable) was used to determine the independent relationship between the number and severity of exacerbations and the NLR ratio. The area under the curve (AUC)-ROC was used to determine the predictive capacity of the NLR for severe bronchiectasis, according to the different multidimensional scores. Mean age: 69 (15) years (66.3% of women). The mean NLR was 2.92 (2.03). A higher NLR was associated with more severe bronchiectasis (with an especially significant discriminative power for severe forms) according to the commonly used scores (FACED, E-FACED and BSI), as well as with poorer quality of life (SGRQ), more comorbidities (Charlson index), infection by pathogenic microorganisms, and greater application of treatment. Furthermore, the NLR correlated better with severity scores than other parameters of systemic inflammation. Finally, it was an independent predictor of the incident number and severity of exacerbations. In conclusion, the NLR is an inexpensive and easy-to-measure marker of systemic inflammation for determining severity and predicting exacerbations (especially the most severe) in patients with bronchiectasis.

Links between Disease Severity, Bacterial Infections and Oxidative Stress in Cystic Fibrosis

Cystic fibrosis (CF) is one of the most common, yet fatal genetic diseases in Caucasians. The presence of a defective CF transmembrane conductance regulator and the massive neutrophils influx into the airways contribute to an imbalance in epithelial cell processes and extracellular fluids and lead to excessive production of reactive oxygen species and intensification of oxidative stress. The study included 16 controls and 42 participants with CF aged 10 to 38. The products of protein oxidation, total antioxidant capacity (TAC) and markers of lipid peroxidation were estimated in the serum of the subjects. Furthermore, we compared the level of oxidative stress in patients with CF according to the severity of disease and type of bacterial infection. Thiol groups and serum TAC decreased significantly in patients with CF (p < 0.05). Elevated levels of 3-nitrotyrosine, malondialdehyde and 8-isoprostane were observed in CF subjects (p < 0.05). Furthermore, as the severity of the disease increased, there was a decrease in the thiol groups and TAC levels, as well as an increase in the concentration of 3-nitrotyrosine and 8-isoprostane. CF participants infected with Pseudomonas aeruginosa had elevated 3-nitrotyrosine concentration levels (p < 0.05), while those infected with Staphylococcus aureus noted a decrease in thiol groups (p < 0.05). Elevated levels of oxidative stress markers were found in the serum of CF patients. Furthermore, oxidative stress progressively increased over the years and along with the severity of the disease. The presence of bacterial infection with P. aeruginosa or S. aureus had a slight effect on oxidative stress, while co-infection by two species did not affect the level of oxidative stress.

Evaluation of Thiol/Disulfide Homeostasis in Bronchiectasis

Purpose

Thiols are sulfhydryl-containing organic compounds that have an important role in preventing cellular oxidative stress. This study compares the blood oxidative stress marker levels in bronchiectasis cases during their stable periods with healthy controls.

Materials and Methods

Seventy-seven patients (49 patients with stable bronchiectasis/28 healthy controls), followed up by the chest disease clinic, were included in the study. Peripheral blood thiol-disulfide parameters (NT: native thiol (−SH); TT: total thiol (−SH + SS); SS: disulfide (−SS); SS-SH: disulfide/native thiol index; SS-TT: disulphide/total thiol index; SH-TT: native thiol/total thiol index), and ischemia-modified albumin (IMA) levels were examined in the stable bronchiectasis group and the control group. Thiol-disulfide homeostasis was evaluated using a novel and automated assay. Findings and Result. Blood native thiol levels in patients with stable bronchiectasis were found to be significantly higher compared with healthy controls. A positive correlation between the total airway disease score and IMA levels was present. Our findings revealed that native thiol levels, which constitute a part of the antioxidant defense system, are increased in patients with stable bronchiectasis.

Age-Related Progression of Microvascular Dysfunction in Cystic Fibrosis: New Detection Ways and Clinical Outcomes

There are concerns about altered vascular functions that could play an important role in the pathogenesis and influence the severity of chronic disease, however, increased cardiovascular risk in paediatric cystic fibrosis (CF) has not been yet fully understood. Aim was to analyse vascular disease risk and investigate changes over times in CF and controls. We prospectively enrolled 22 CF subjects (a median age of 16.07 years), and 22 healthy demographically matched controls (a median age of 17.28 years) and determined endothelial function. We utilised a combined diagnostic approach by measuring the plethysmographic Reactive Hyperemia Index (RHI) as the post-to preocclusive endothelium-dependent changes of vascular tone, and biomarkers that are known to be related to endothelial dysfunction (ED): asymmetric dimethyl arginine (ADMA), high-sensitive CRP (hsCRP), VCAM-1 and E-selectin. RHI values were significantly lower in CF young adults (p<0.005). HsCRP (p<0.005), E-selectin (p<0.001) and VCAM-1 (p<0.001) were significantly increased in CF patients since childhood. The findings have provided a detailed account of the ongoing process of microvascular dysfunction with gradual progression with the age of CF patients, making them further at risk of advanced vascular disease. Elevations of biomarkers in CF children with not yet demonstrated RHI changes but with significantly reduced RHI in adulthood and lipid profile changes indicate the possible occurrence of ED with CF-related specific risk factors over time and will enable us to provide the best possible support.

Do Redox Balance and Inflammatory Events Take Place in Mild Bronchiectasis? A Hint to Clinical Implications

We hypothesized that in mild bronchiectasis patients, increased systemic inflammation and redox imbalance may take place and correlate with clinical parameters. In plasma samples from patients with very mild bronchiectasis, inflammatory cells and molecules and redox balance parameters were analyzed. In the patients, lung function and exercise capacity, nutritional status, bacterial colonization, and radiological extension were assessed. Correlations between biological and clinical variables were determined. Compared to healthy controls, levels of acute phase reactants, neutrophils, IgG, IgA, myeloperoxidase, protein oxidation, and GSH increased and lung function and exercise capacity were mildly reduced. GSH levels were even greater in ex-smoker and Pseudomona-colonized patients. Furthermore, radiological extension inversely correlated with airway obstruction and, disease severity, and positively correlated with neutrophil numbers in mild bronchiectasis patients with no nutritional abnormalities. In stable patients with mild bronchiectasis, several important inflammatory and oxidative stress events take place in plasma. These findings suggest that the extension of bronchiectasis probably plays a role in the development of redox imbalance and systemic inflammation in patients with mild bronchiectasis. These results have therapeutic implications in the management of bronchiectasis patients.

[Pillars for excellence in nutrition units - research]

Introduction

Research in clinical nutrition and dietetics consists of "carrying out intellectual and experimental activities in a systematic way with the purpose of increasing knowledge on this topic." The biomedical research carried out in clinical nutrition and dietetics units (UNCyDs) must be clinical-translational, which is understood as the fastest way to ensure that new scientific knowledge is transferred not only to clinical research but also to clinical practice. When UNCyDs conduct research, regardless of type and extent, they achieve higher quality standards in the health care they provide to their users. Clinical practice and scientific research are activities that constitute a continuous, indissoluble action. For this reason, both those responsible for health management and nutrition units and all their members have an obligation to promote research. In this article, a brief historical review of the birth of clinical nutrition as a scientific discipline is made, the legislation that supports biomedical research is briefly mentioned, the main keys to promote research in UNCyD are proposed, and finally orientation is offered on the main funding for biomedical research programs, and how to transfer and disseminate results.

Systemic Inflammation and Oxidative Stress in Adults with Bronchiectasis: Association with Clinical and Functional Features

OBJECTIVES

To compare the inflammatory and oxidative stress (OS) states of adults with bronchiectasis with those of healthy controls and correlate inflammatory and OS levels with lung function and physical capacity.

METHODS

This study used a cross-sectional design. Seventy-four adults with bronchiectasis (age: 49±15 years, forced expiratory volume in 1 second [FEV1]: 52.5±25.6%) and 42 healthy controls (age: 44±17 years, FEV1: 95.9±14.0%) performed cardiopulmonary exercise tests and incremental shuttle walking tests. Their physical activity in daily life, inflammatory cytokine, and antioxidant levels in plasma were measured.

RESULTS

Compared to that of the controls, the levels of interleukin (IL)-6 (p<0.001), IL-10 (p<0.001), carbonylated proteins (p=0.001), and superoxide anions (p=0.046) were significantly increased in adults with bronchiectasis. Catalase activity was also reduced in this group (p<0.001). The inflammatory markers IL-1β, IL-6, and tumor necrosis factor-α correlated negatively with aerobic capacity (r=-0.408, r=-0.308, and r=-0.207, respectively). We observed similar correlations with OS markers (thiobarbituric acid and carbonyls; r=-0.290 and r=0.379, respectively), and these markers also significantly correlated with the aerobic capacity.

CONCLUSIONS

Adults with bronchiectasis presented an increased systemic inflammatory response that correlated negatively with physical capacity.

Metagenomics Reveals a Core Macrolide Resistome Related to Microbiota in Chronic Respiratory Disease

Rationale: Long-term antibiotic use for managing chronic respiratory disease is increasing; however, the role of the airway resistome and its relationship to host microbiomes remains unknown.Objectives: To evaluate airway resistomes and relate them to host and environmental microbiomes using ultradeep metagenomic shotgun sequencing.Methods: Airway specimens from 85 individuals with and without chronic respiratory disease (severe asthma, chronic obstructive pulmonary disease, and bronchiectasis) were subjected to metagenomic sequencing to an average depth exceeding 20 million reads. Respiratory and device-associated microbiomes were evaluated on the basis of taxonomical classification and functional annotation including the Comprehensive Antibiotic Resistance Database to determine airway resistomes. Co-occurrence networks of gene-microbe association were constructed to determine potential microbial sources of the airway resistome. Paired patient-inhaler metagenomes were compared (n = 31) to assess for the presence of airway-environment overlap in microbiomes and/or resistomes.Measurements and Main Results: Airway metagenomes exhibit taxonomic and metabolic diversity and distinct antimicrobial resistance patterns. A "core" airway resistome dominated by macrolide but with high prevalence of β-lactam, fluoroquinolone, and tetracycline resistance genes exists and is independent of disease status or antibiotic exposure. Streptococcus and Actinomyces are key potential microbial reservoirs of macrolide resistance including the ermX, ermF, and msrD genes. Significant patient-inhaler overlap in airway microbiomes and their resistomes is identified where the latter may be a proxy for airway microbiome assessment in chronic respiratory disease.Conclusions: Metagenomic analysis of the airway reveals a core macrolide resistome harbored by the host microbiome.

Oxidative and inflammatory effects of pulmonary rehabilitation in patients with bronchiectasis. A prospective, randomized study

Introduction

Background: systemic inflammation and oxidative stress are important factors in the pathogenesis of bronchiectasis. Pulmonary rehabilitation (PR) is recommended for bronchiectasis, but there is no data about its effect on the inflammatory and REDOX status of these patients. Aims: to investigate the effect of PR in non-cystic-fibrosis bronchiectasis (NCFB) patients, and to compare it with the effect of PR plus a hyperproteic oral nutritional supplement (PRS) enriched with beta-hydroxy-beta-methylbutyrate (HMB) on serum inflammatory and oxidative biomarkers. Materials and methods: this was an open randomized, controlled trial. Thirty individuals (65 years old or younger with a body mass index over 18.5, older than 65 years with a body mass index over 20) were recruited from September 2013 to September 2014, and randomly assigned to receive PR or PRS. Total neutrophils, and inflammatory and oxidative biomarker levels were measured at baseline, and then at 3 and 6 months. Results: in the PRS group neutrophil levels were decreased from baseline at 6 months. A significantly different fold change was found between the PR and PRS groups. In the PR group, IL-6 and adiponectin were increased by the end of the study while TNFα levels were decreased from baseline at 6 months. REDOX biomarkers remained stable throughout the study except for 8-isoprostane levels, which were increased from baseline at 6 months in both groups of patients. Conclusions: a PR program induced a pro-oxidative effect accompanied by changes in circulating inflammatory cytokine levels in NCFB patients. Our results would also suggest a possible beneficial effect of the HMB enriched supplement on neutrophil level regulation in these patients. The information provided in this study could be useful for choosing the right therapeutic approach in the management of bronchiectasis.

Total oxidant and antioxidant status and paraoxonase 1 levels of children with noncystic fibrosis bronchiectasis

Background/aim

To evaluate total oxidant status (TOS), total antioxidant capacity (TAC), and paraoxonase 1 (PON1) levels in children with noncystic fibrosis (CF) bronchiectasis (BE), and to compare these levels with those of healthy controls. The study parameters were also evaluated according to some demographic, anthropometric, and clinical characteristics, as well as lung functions.

Materials and methods

Enrolled in the study were 118 children with non-CF BE and 68 healthy controls. Serum TOS, TAC, and PON1 levels were determined. Lung function tests were performed by spirometry.

Results

Serum TOS was higher in the patients [median 9.54 (IQR 25–75 = 7.05–13.30) μmol H2O2 Eq/L] than in the healthy subjects [6.64 (5.45–9.53) μmol H2O2 Eq/L] (P < 0.001). TAC was higher in patients with non-CF BE [1.07 (1.0–1.07) mmol Trolox Eq/L] than in the healthy controls [0.87 (0.77–0.98) mmol Trolox Eq/L] (P < 0.001). In addition, serum PON1 levels were significantly higher in the patients [106.5 (42.5–154.2) U/L] than in the controls [47.7 (27.5–82.1) U/L] (P < 0.001). The patients with low FEV1 had decreased TAC when compared to those who had normal FEV1 in non-CF BE.

Conclusion

The present study demonstrated that compared with the control group the children with non-CF BE had elevated oxidative status, antioxidant defenses parameters, and PON1 values.

Circulating biomarkers of antioxidant status and oxidative stress in people with cystic fibrosis: A systematic review and meta-analysis

Introduction

Oxidative stress may play an important role in the pathophysiology of cystic fibrosis (CF). This review aimed to quantify CF-related redox imbalances.

Methods

Systematic searches of the Medline, CINAHL, CENTRAL and PsycINFO databases were conducted. Mean content of blood biomarkers from people with clinically-stable CF and non-CF controls were used to calculate the standardized mean difference (SMD) and 95% confidence intervals (95% CI).

Results

Forty-nine studies were eligible for this review including a total of 1792 people with CF and 1675 controls. Meta-analysis revealed that protein carbonyls (SMD: 1.13, 95% CI: 0.48 to 1.77), total F₂-isoprostane 8-iso-prostaglandin F_2α (SMD: 0.64, 95% CI: 0.23 to 1.05) and malondialdehyde (SMD: 1.34, 95% CI: 0.30 to 2.39) were significantly higher, and vitamins A (SMD: −0.66, 95% CI -1.14 to −0.17) and E (SMD: −0.74, 95% CI: −1.28 to −0.20), β-carotene (SMD: −1.80, 95% CI: −2.92 to −0.67), lutein (SMD: −1.52, 95% CI: −1.83 to −1.20) and albumin (SMD: −0.98, 95% CI: −1.68 to −0.27) were significantly lower in the plasma or serum of people with CF versus controls.

Conclusions

This systematic review and meta-analysis found good evidence for reduced antioxidant capacity and elevated oxidative stress in people with clinically-stable CF.

•

Blood biomarkers of oxidative stress were elevated in stable CF vs non-CF controls.

•

Lipid peroxidation was positively correlated with age and immune cell count in CF.

•

Antioxidants vitamins A & E, β-carotene, lutein and albumin were lower in stable CF.

•

Antioxidants were positively correlated with body mass index and lung function in CF.

The Efficacy of Therapeutic Respiratory Muscle Training Interventions in People with Bronchiectasis: A Systematic Review and Meta-Analysis

Background: Respiratory muscle dysfunction is an important health problem with high morbidity and mortality and associated costs in patients with bronchiectasis (BC). The aim of this study was to analyse the effects of therapeutic respiratory muscle training (RMT) interventions on improving sputum clearance, ventilator function, muscle strength and functional capacity in BC. Methods: Systematic review and meta-analysis were conducted following PRISMA guidelines. Two independent investigators searched using several electronic databases. The methodological quality of nine studies was assessed using the PEDro scale. Study selection/eligibility criteria: The following were included: randomised controlled trials, randomised crossover trials and pilot studies of patients with BC that used the intervention as RMT (inspiratory/expiratory) and evaluations of respiratory muscle strength (maximal expiratory pressure/maximal inspiratory pressure). This systematic review was registered in PROSPERO (CRD42017075101). Nine studies were included, five of which obtained an A recommendation grade, three with B, and one with C. Study quality was poor to good (mean PEDro Score of 6.375 out of 10). Studies had small sample sizes (8–98). Results show improvements on PImax in favour of therapeutic respiratory muscle training intervention (MD = 6.08; 95% CI = 1.38, 10.77; p < 0.01; I² = 92%). However, high heterogeneity was identified on meta-analysis.

Serum oxidative stress in patients with pulmonary Mycobacterium avium complex disease

Background

The mechanism of progressive airway destruction in incurable chronic infection of the lung – termed pulmonary Mycobacterium avium complex (pMAC) disease – is currently unknown. The involvement of oxidative stress in a variety of progressive chronic respiratory diseases has been previously reported. It has been hypothesized that oxidative stress may be involved in the progression of airway destruction in pMAC disease.

Patients and methods

The study included 28 untreated patients with pMAC disease. The level of serum oxidative stress was quantitatively evaluated through the diacron reactive oxygen metabolites (d-ROMs) test, which indirectly measures the level of hydroperoxide in the serum. In addition, patients were divided into three groups based on the severity shown in the computed tomographic image.

Results

The level of serum oxidative stress exceeded the normal range (250–300 U.Carr [Carratelli Units]) in all patients with pMAC disease (mean: 495.5 ± 102.6 U.Carr; minimum–maximum: 340–734 U.Carr). The level of serum oxidative stress in patients with severe disease was significantly higher compared with that observed in patients with mild disease (434.6 ± 30.2 vs. 583.4 ± 95.1, respectively, p = 0.009).

Conclusions

In patients with pMAC disease, an elevation was observed in the level of serum oxidative stress. This increase in oxidative stress was more pronounced in patients with severe disease.

Osteopenia and Osteoporosis in Patients with Bronchiectasis: Association with Respiratory Parameters, Body Composition, Muscle Strength and Bone Remodeling Biomarkers

The prevalence of osteopenia/osteoporosis has not been sufficiently studied in people with bronchiectasis not due to cystic fibrosis (BC), nor has its relationship with other variables (clinical, body composition and bone turnover and inflammation markers) been sufficiently studied. Our aim was to determine the prevalence of osteopenia and osteoporosis and related factors in patients with BC. We did a cross-sectional study in people with BC in a clinically stable state. Spirometric parameters, annual exacerbations and analysis with bone turnover markers (BTM) and inflammation markers were evaluated. Densitometry (DXA) was performed for body composition, bone mineral density (BMD) and handgrip strength. 123 patients were studied (65% women, mean age 49.6 ± 18.8, Body Mass Index (BMI) 24.8 ± 4.7 kg/m²). 62.8% and 62.5% of men and women, respectively, had normal bone mineral density, 30.2% and 22.2% osteopenia and 7% and 15% osteoporosis. 52 patients (56.2%) had low fat-free mass: 68.9% women and 28.6% men. Patients with decreased bone mass had significantly lower muscle strength, maximum expiratory volume in the first second (FEV1%), vitamin D, higher levels of C-terminal telopeptide of type 1 collagen (CTX) and total osteocalcin and underarboxylated osteocalcin (ucOC). We observed significant and negative correlations between BMD and the number of serious exacerbations per year CTX and undercarboxylated osteocalcin. We observed significant positive correlations between BMD, fat free mass index (FFMI) and handgrip dynamometry. The study suggest that the prevalence of osteoporosis was high in relation to the demographic characteristics. Respiratory parameters, body composition, muscle strength and bone remodeling markers were associated with a lower bone mineral density.

Oxidative stress and abnormal bioactive lipids in early cystic fibrosis lung disease

BACKGROUND

Clinical data indicate that airway inflammation in children with cystic fibrosis (CF) arises early, is associated with structural lung damage, and predicts progression. In bronchoalveolar lavage fluid (BALF) from CFTR mutant mice, several aspects of lipid metabolism are abnormal that contributes to lung disease. We aimed to determine whether lipid pathway dysregulation is also observed in BALF from children with CF, to identify biomarkers of early lung disease and potential therapeutic targets.

METHODS

A comprehensive panel of lipids that included Sphingolipids, oxylipins, isoprostanes and lysolipids, all bioactive lipid species known to be involved in inflammation and tissue remodeling, were measured in BALF from children with CF (1-6 years, N = 33) and age-matched non-CF patients with unexplained inflammatory disease (N = 16) by HPLC-MS/MS. Lipid data were correlated with chest CT scores and BALF inflammation biomarkers.

RESULTS

The ratio of long chain to very long chain ceramide species (LCC/VLCC) and lysolipid levels were enhanced in CF compared to non-CF patients, despite comparable neutrophil counts and bacterial load. In CF patients both LCC/VLCC and lysolipid levels correlated with inflammation and chest CT scores. The ceramide precursors Sphingosine, Sphinganine, Sphingomyelin, correlated with inflammation, whilst the oxidative stress marker isoprostane correlated with inflammation and chest CT scores. No correlation between lipids and current bacterial infection in CF (N = 5) was observed.

CONCLUSIONS

Several lipid biomarkers of early CF lung disease were identified, which point toward potential disease monitoring and therapeutic approaches that can be used to complement CFTR modulators.

Effect of N-acetylcysteine on exacerbations of bronchiectasis (BENE): a randomized controlled trial

Background

N-acetylcysteine is a classic mucolytic agent. This study aimed to investigate the efficacy of N-acetylcysteine on reducing the risk of exacerbations in bronchiectasis patients.

Methods

A prospective, randomized, controlled trial was conducted between April 1, 2014 and December 31, 2016 in five general hospitals in Shandong Province, China. Adult bronchiectasis patients with at least two exacerbations in the past year were potentially eligible. Patients were randomly assigned to receive oral N-acetylcysteine (600 mg, twice daily, 12 months) or on-demand treatment.

Results

A total of 161 patients were eligible for randomization (81 to the N-acetylcysteine group and 80 to the control group). During the 12-month follow-up, the incidence of exacerbations in the N-acetylcysteine group was significantly lower than that in the control group (1.31 vs. 1.98 exacerbations per patient-year; risk ratio, 0.41; 95% CI, 0.17–0.66; P = 0.0011). The median number of exacerbations in the N-acetylcysteine group was 1 (0.5–2), compared with 2 (1–2) in the control group (U = − 2.95, P = 0.003). A total of 24.7% of the N-acetylcysteine group patients and 11.3% of the control group patients remained exacerbation-free throughout the 12-month follow-up (χ² = 4.924, P = 0.026). Compared with the control group, the volume of 24-h sputum in the N-acetylcysteine group was significantly reduced (t = − 3.091, P = 0.002). Additionally, the N-acetylcysteine group showed a significant improvement in the quality of life. No severe adverse events were reported in the intervention group.

Conclusion

The long-term use of N-acetylcysteine is able to reduce the risk of exacerbations for bronchiectasis patients in Shandong Province, China. The results of this study should be verified in a larger randomized controlled trial.

Trial registration

ClinicalTrials.gov (NCT02088216) (Registered date: March 5, 2014).

Pharmacotherapeutic strategies for treating bronchiectasis in pediatric patients

INTRODUCTION

The social and medical costs of bronchiectasis in children are becoming considerable due to its increasing prevalence. Early identification and intensive treatment of bronchiectasis are needed to decrease the morbidity and mortality associated with bronchiectasis in children.

AREAS COVERED

This review presents the current pharmacotherapeutic strategies for treating bronchiectasis in children with a focus on non-cystic fibrosis bronchiectasis.

EXPERT OPINION

Evidence for the effectiveness of diverse treatment strategies in bronchiectasis is lacking, particularly in children, although the disease burden is substantial for bronchiectasis. Most treatment strategies for non-cystic fibrosis bronchiectasis in children have been extrapolated from those in adults with bronchiectasis or children with cystic fibrosis. Antibiotics combined with an active airway clearance therapy via the inhalation of mucoactive agents can stabilize bronchiectasis. The timely and intensive administration of antibiotics during acute exacerbation of bronchiectasis is essential to prevent its progression in children. To suppress the bacterial loads in the airway, systemic or inhaled antibiotics can be administered intermittently or continuously. However, studies on these protocols, including the appropriate duration and effective dosages are lacking. Long-term administration of azithromycin for 12-24 months may reduce the exacerbation frequency with the increased carriage rate of azithromycin-resistant bacteria.

Determinants of Peripheral Muscle Strength and Activity in Daily Life in People With Bronchiectasis

BACKGROUND

Bronchiectasis is characterized by a progressive structural lung damage, recurrent infections and chronic inflammation which compromise the exertion tolerance, and may have an impact on skeletal muscle function and physical function.

OBJECTIVE

The purpose of this study was to compare peripheral muscle strength, exercise capacity, and physical activity in daily life between participants with bronchiectasis and controls and to investigate the determinants of the peripheral muscle strength and physical activity in daily life in bronchiectasis.

DESIGN

This study used a cross-sectional design.

METHODS

The participants' quadriceps femoris and biceps brachii muscle strength was measured. They performed the incremental shuttle walk test (ISWT) and cardiopulmonary exercise testing, and the number of steps/day was measured by a pedometer.

RESULTS

Participants had reduced quadriceps femoris muscle strength (mean difference to control group = 7 kg, 95% CI = 3.8-10.1 kg), biceps brachii muscle strength (2.1 kg, 95% CI = 0.7-3.4 kg), ISWT (227 m, 95% CI = 174-281 m), peak VO2 (6.4 ml/Kg/min, 95% CI = 4.0-8.7 ml/Kg/min), and number of steps/day (3,332 steps/day, 95% CI = 1,758-4,890 steps/day). A lower quadriceps femoris strength is independently associated to an older age, female sex, lower body mass index (BMI), higher score on the modified Medical Research Council scale, and shorter distance on the ISWT (R2 = 0.449). Biceps brachii strength is independently associated with sex, BMI, and dyspnea (R2 = 0.447). The determinants of number of daily steps were dyspnea and distance walked in ISWT, explaining only 27.7% of its variance.

LIMITATIONS

Number of steps per day was evaluated by a pedometer.

CONCLUSIONS

People with bronchiectasis have reduced peripheral muscle strength, and reduced aerobic and functional capacities, and they also are less active in daily life. Modifiable variables such as BMI, dyspnea, and distance walked on the ISWT are associated with peripheral muscle strength and physical activity in daily life.

Subclinical atherosclerosis in adults with steady-state bronchiectasis: A case-control study

BACKGROUND AND OBJECTIVE

Bronchiectasis has been associated with increased risks of cardiovascular disease, in which early-stage endothelial dysfunction might have played pivotal roles. We aimed to investigate endothelial function in bronchiectasis patients, by measuring flow-mediated dilatation (FMD) and carotid intima-media thickness (CIMT) as compared with control subjects, and to elucidate the impact of different risk factors on subclinical atherosclerosis.

METHODS

The study included 80 bronchiectasis patients and 80 age- and sex-matched healthy subjects. Vascular endothelial function was evaluated with FMD in the brachial artery in response to reactive hyperemia, and CIMT was measured with high-resolution ultrasonography. Disease severity was evaluated with Bronchiectasis Severity Index and FACED scores. Demographic, disease duration, radiology, spirometry, sputum bacteriology and systemic inflammatory indices were also assessed.

RESULTS

FMD was significantly lower in bronchiectasis patients than in control subjects (8.92 ± 2.70% vs. 11.17 ± 3.44%, P < 0.001). FMD significantly correlated with Bronchiectasis Severity Index (rho = -0.60, P < 0.001) and FACED score (rho = -0.39, P < 0.001). In multivariate regression analysis, age, body-mass index, Pseudomonas aeruginosa colonization and high-resolution computed tomography scores were independent factors influencing on the FMD in bronchiectasis patients, even after adjustment for other clinical variables. No significant difference in CIMT was detected between bronchiectasis patients and healthy subjects (P > 0.05).

CONCLUSIONS

Compared with healthy subjects, bronchiectasis patients have greater risks of endothelial dysfunction which is independent of previously well-studied risk factors, calling for the vigilance to screen early for vascular changes to minimize the future risks of cardiovascular events.

Redox theory of aging: implications for health and disease

Genetics ultimately defines an individual, yet the phenotype of an adult is extensively determined by the sequence of lifelong exposures, termed the exposome. The redox theory of aging recognizes that animals evolved within an oxygen-rich environment, which created a critical redox interface between an organism and its environment. Advances in redox biology show that redox elements are present throughout metabolic and structural systems and operate as functional networks to support the genome in adaptation to environmental resources and challenges during lifespan. These principles emphasize that physical and functional phenotypes of an adult are determined by gene-environment interactions from early life onward. The principles highlight the critical nature of cumulative exposure memories in defining changes in resilience progressively during life. Both plasma glutathione and cysteine systems become oxidized with aging, and the recent finding that cystine to glutathione ratio in human plasma predicts death in coronary artery disease (CAD) patients suggests this could provide a way to measure resilience of redox networks in aging and disease. The emerging concepts of cumulative gene-environment interactions warrant focused efforts to elucidate central mechanisms by which exposure memory governs health and etiology, onset and progression of disease.

Inflammation and Oxidation Biomarkers in Patients with Cystic Fibrosis: The Influence of Azithromycin

OBJECTIVE

In addition to their antibiotic effect, macrolides appear to modulate the inflammatory response in cystic fibrosis (CF) and could influence oxidative stress. The objective of this study was to assess oxidation biomarkers and levels of inflammation and to determine whether there is an association between these parameters and the intake of macrolides.

MATERIALS AND METHODS

The subjects included in this cross-sectional study were, on the one hand, clinically stable patients with CF and, on the other, healthy controls. The following serum and plasma inflammatory and oxidative stress biomarkers were measured: interleukin-6 (IL-6), reactive C protein (RCP), tumor necrosis alpha (TNF-α), glutathione peroxidase (GPx), total antioxidant capacity (TAC), catalase (CAT), and superoxide dismutase (SOD), together with markers of lipid peroxidation (8-isoprostanes and thiobarbituric acid reactive substances [TBARS]). Clinical, anthropometric, lung function, radiological, and analytical variables (albumin, prealbumin, vitamins, and zinc) were also recorded.

RESULTS

We studied 36 adults with CF and 41 controls. No differences were observed in age, gender, or anthropometric variables. The patients had significantly higher levels of IL-6, TNF-α, RCP, TBARS, and isoprostanes, and lower levels of SOD than the controls. Twenty-three of the patients were treated with azithromycin, and they had more severe clinical and radiological parameters than those who were not but nevertheless presented significantly lower levels of TNF-α. No differences were observed in the markers of oxidation.

CONCLUSION

Inflammation and oxidation biomarkers were increased in patients with CF compared with controls. The use of azithromycin was associated with reduced TNF-α levels and did not influence oxidation parameters.

Pediatric bronchiectasis: No longer an orphan disease

Bronchiectasis is described classically as a chronic pulmonary disorder characterized by a persistent productive cough and irreversible dilatation of one or more bronchi. However, in children unable to expectorate, cough may instead be wet and intermittent and bronchial dilatation reversible in the early stages. Although still considered an orphan disease, it is being recognized increasingly as causing significant morbidity and mortality in children and adults in both affluent and developing countries. While bronchiectasis has multiple etiologies, the final common pathway involves a complex interplay between the host, respiratory pathogens and environmental factors. These interactions lead to a vicious cycle of repeated infections, airway inflammation and tissue remodelling resulting in impaired airway clearance, destruction of structural elements within the bronchial wall causing them to become dilated and small airway obstruction. In this review, the current knowledge of the epidemiology, pathobiology, clinical features, and management of bronchiectasis in children are summarized. Recent evidence has emerged to improve our understanding of this heterogeneous disease including the role of viruses, and how antibiotics, novel drugs, antiviral agents, and vaccines might be used. Importantly, the management is no longer dependent upon extrapolating from the cystic fibrosis experience. Nevertheless, substantial information gaps remain in determining the underlying disease mechanisms that initiate and sustain the pathophysiological pathways leading to bronchiectasis. National and international collaborations, standardizing definitions of clinical and research end points, and exploring novel primary prevention strategies are needed if further progress is to be made in understanding, treating and even preventing this often life-limiting disease.