Airway inflammation in subjects with gastro-oesophageal reflux and gastro-oesophageal reflux-related asthma

Role of alveolar nitric oxide in gastroesophageal reflux-associated cough: prospective observational study

BACKGROUND

Fractional exhaled nitric oxide (FeNO) measured at multiple exhalation flow rates can be used as a biomarker to differentiate central and peripheral airway inflammation. However, the role of alveolar nitric oxide (CaNO) indicating peripheral airway inflammation remains unclear in gastroesophageal reflux-associated cough (GERC).

OBJECTIVES

We aimed to characterize the changes in alveolar nitric oxide (CaNO) and determine its clinical implication in GERC.

DESIGN

This is a single-center prospective observational study.

METHODS

FeNOs at exhalation flow rates of 50 and 200 ml/s were measured in 102 patients with GERC and 134 patients with other causes of chronic cough (non-GERC). CaNO was calculated based on a two-compartment model and the factors associated with CaNO were analyzed. The effect of anti-reflux therapy on CaNO was examined in 26 GERC patients with elevated CaNO.

RESULTS

CaNO was significantly elevated in GERC compared with that in non-GERC (4.6 ± 4.4 ppb versus 2.8 ± 2.3 ppb, p < 0.001). GERC patients with high CaNO (>5 ppb) had more proximal reflux events (24 ± 15 versus 9 ± 9 episodes, p = 0.001) and a higher level of pepsin (984.8 ± 492.5 versus 634.5 ± 626.4 pg/ml, p = 0.002) in sputum supernatant than those with normal CaNO. More GERC patients with high CaNO required intensified anti-reflux therapy (χ2 = 3.963, p = 0.046), as predicted by a sensitivity of 41.7% and specificity of 83.3%. Cough relief paralleled a significant improvement in CaNO (8.3 ± 3.0 versus 4.8 ± 2.6 ppb, p < 0.001).

CONCLUSION

Peripheral airway inflammation can be assessed by CaNO measurement in GERC. High CaNO indicates potential micro-aspiration and may predict a necessity for intensified anti-reflux therapy.

Inflammatory Biomarkers in Exhaled Breath Condensate: A Systematic Review

Inflammation is a comprehensive set of physiological processes that an organism undertakes in response to a wide variety of foreign stimuli, such as viruses, bacteria, and inorganic particles. A key role is played by cytokines, protein-based chemical mediators produced by a broad range of cells, including the immune cells recruited in the inflammation site. The aim of this systematic review is to compare baseline values of pro/anti-inflammatory biomarkers measured in Exhaled Breath Condensate (EBC) in healthy, non-smoking adults to provide a summary of the concentrations reported in the literature. We focused on: interleukin (IL)-1β, IL-4, IL-6, IL-8, IL-10, tumour necrosis factor-alpha (TNF-α), and C reactive protein (CRP). Eligible articles were identified in PubMed, Embase, and Cochrane CENTRAL. Due to the wide differences in methodologies employed in the included articles concerning EBC sampling, storage, and analyses, research protocols were assessed specifically to test their adherence to the ATS/ERS Task Force guidelines on EBC. The development of reference intervals for these biomarkers can result in their introduction and use in both research and clinical settings, not only for monitoring purposes but also, in the perspective of future longitudinal studies, as predictive parameters for the onset and development of chronic diseases with inflammatory aetiology.

Prophylaxis and Treatment of Complications After Tracheal Resection

Tracheal resections are major surgical procedures with a complication rate as high as 44%. Early detection of complications followed by a structured and expedited course of action is critical for achieving a successful outcome. The prevention of complications after tracheal resection starts with a correct indication for resection. A thorough preoperative evaluation, meticulous surgical technique, and good postoperative care in a center that performs airway surgery routinely are important factors for achieving good results.

Combined multichannel intraluminal impedance-pH monitoring should be used to diagnose reflux-related otitis media with effusion in children

AIM

This study investigated the diagnostic usefulness of combined multichannel intraluminal impedance-pH monitoring (MII-pH) in children with suspected reflux-related otitis media with effusion (OME) as existing data were scarce.

METHODS

This was a prospective study that included children up to seven years of age who underwent MII-pH due to OME lasting more than three months. The study was conducted in the Children's Hospital Zagreb, Croatia, from January 2014 to August 2016.

RESULTS

The study comprised 63 children (63% male) with a mean age of 4.7 years. Gastroesophageal reflux (GER) disease was detected by impedance in 22 (35%) of the children and by pH-metry in nine (14%). In children with OME, MII-pH found a median number of 24 proximal GER episodes, of which a median of nine was acidic and a median of 11 was weakly acidic. There was a significant positive correlation between the number of GER episodes and the presence of eosinophils in nasal swabs.

CONCLUSION

Both acidic and weakly acidic refluxes seemed to play a significant role in the pathogenesis of OME. Localised nasal eosinophilia may serve as a marker of extraoesophageal reflux in children with suspected reflux-related OME.

Classifying oxidative stress by F2-isoprostane levels across human diseases: A meta-analysis

The notion that oxidative stress plays a role in virtually every human disease and environmental exposure has become ingrained in everyday knowledge. However, mounting evidence regarding the lack of specificity of biomarkers traditionally used as indicators of oxidative stress in human disease and exposures now necessitates re-evaluation. To prioritize these re-evaluations, published literature was comprehensively analyzed in a meta-analysis to quantitatively classify the levels of systemic oxidative damage across human disease and in response to environmental exposures.

In this meta-analysis, the F₂-isoprostane, 8-iso-PGF_2α, was specifically chosen as the representative marker of oxidative damage. To combine published values across measurement methods and specimens, the standardized mean differences (Hedges’ g) in 8-iso-PGF_2α levels between affected and control populations were calculated.

The meta-analysis resulted in a classification of oxidative damage levels as measured by 8-iso-PGF_2α across 50 human health outcomes and exposures from 242 distinct publications. Relatively small increases in 8-iso-PGF_2α levels (g<0.8) were found in the following conditions: hypertension (g=0.4), metabolic syndrome (g=0.5), asthma (g=0.4), and tobacco smoking (g=0.7). In contrast, large increases in 8-iso-PGF_2α levels were observed in pathologies of the kidney, e.g., chronic renal insufficiency (g=1.9), obstructive sleep apnoea (g=1.1), and pre-eclampsia (g=1.1), as well as respiratory tract disorders, e.g., cystic fibrosis (g=2.3).

In conclusion, we have established a quantitative classification for the level of 8-iso-PGF_2α generation in different human pathologies and exposures based on a comprehensive meta-analysis of published data. This analysis provides knowledge on the true involvement of oxidative damage across human health outcomes as well as utilizes past research to prioritize those conditions requiring further scrutiny on the mechanisms of biomarker generation.

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Oxidative damage is highly variable in human conditions as measured by F₂-isoprostanes.

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Respiratory tract and urogenital diseases have the highest F₂-isoprostanes.

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Cancer and cardiovascular diseases have surprisingly low F₂-isoprostanes.

Biomarkers in adult asthma: a systematic review of 8-isoprostane in exhaled breath condensate

OBJECTIVES

We aimed to assess the evidence for the use of 8-isoprostane in exhaled breath condensate (EBC) as a biomarker in adult asthma.

DESIGN

A systematic review and meta-analysis of EBC 8-isoprostane.

METHODS

We searched a number of online databases (including PubMed, Embase and Scopus) in January 2016. We included studies of adult non-smokers with EBC collection and asthma diagnosis conducted according to recognised guidelines. We aimed to pool data using random effects meta-analysis and assess heterogeneity using I ².

RESULTS

We included twenty studies, the findings from which were inconsistent. Seven studies (n = 329) reported 8-isoprostane levels in asthma to be significantly higher than that of control groups, whilst six studies (n = 403) did not. Only four studies were appropriate for inclusion in a random effects meta-analysis of mean difference. This found a statistically significant between-groups difference of 22 pg ml^-1. Confidence in the result is limited by the small number of studies and by substantial statistical heterogeneity (I ² = 94).

CONCLUSION

The clinical value of EBC 8-isoprostane as a quantitative assessment of oxidative stress in asthma remains unclear due to variability in results and methodological heterogeneity. It is essential to develop a robust and standardised methodology if the use of EBC 8-isoprostane in asthma is to be properly evaluated.

Respiratory symptoms, sleep-disordered breathing and biomarkers in nocturnal gastroesophageal reflux

BACKGROUND

Nocturnal gastroesophageal reflux (nGER) is associated with respiratory symptoms and sleep-disordered breathing (SDB), but the pathogenesis is unclear. We aimed to investigate the association between nGER and respiratory symptoms, exacerbations of respiratory symptoms, SDB and airway inflammation.

METHODS

Participants in the European Community Respiratory Health Survey III in Iceland with nGER symptoms (n = 48) and age and gender matched controls (n = 42) were studied by questionnaires, exhaled breath condensate (EBC), particles in exhaled air (PEx) measurements, and a home polygraphic study. An exacerbation of respiratory symptoms was defined as an episode of markedly worse respiratory symptoms in the previous 12 months.

RESULTS

Asthma and bronchitis symptoms were more common among nGER subjects than controls (54 % vs 29 %, p = 0.01; and 60 % vs 26 %, p < 0.01, respectively), as were exacerbations of respiratory symptoms (19 % vs 5 %, p = 0.04). Objectively measured snoring was more common among subjects with nGER than controls (snores per hour of sleep, median (IQR): 177 (79-281) vs 67 (32-182), p = 0.004). Pepsin (2.5 ng/ml (0.8-5.8) vs 0.8 ng/ml (0.8-3.6), p = 0.03), substance P (741 pg/ml (626-821) vs 623 pg/ml (562-676), p < 0.001) and 8-isoprostane (3.0 pg/ml (2.7-3.9) vs 2.6 pg/ml (2.2-2.9), p = 0.002) in EBC were higher among nGER subjects than controls. Albumin and surfactant protein A in PEx were lower among nGER subjects. These findings were independent of BMI.

CONCLUSION

In a general population sample, nGER is associated with symptoms of asthma and bronchitis, as well as exacerbations of respiratory symptoms. Also, nGER is associated with increased respiratory effort during sleep. Biomarker measurements in EBC, PEx and serum indicate that micro-aspiration and neurogenic inflammation are plausible mechanisms.

A 12-month follow-up study on the preventive effect of oral lansoprazole on acute exacerbation of chronic obstructive pulmonary disease

The objective of this study was to evaluate the preventive effects of oral administration of lansoprazole on acute exacerbation of chronic obstructive pulmonary disease (COPD). Patients with COPD in groups C and D in the stable phase were stratified into a group with neither gastroesophageal reflux nor lansoprazole therapy (group A) and a group subjected to oral lansoprazole therapy (group B1 ) and a group not subjected to oral lansoprazole therapy (group B2 ). The frequency scale for the symptoms of gastroesophageal reflux disease (FSSG) questionnaire, COPD assessment test (CAT) questionnaire, pulmonary function test and the 6-minute walk test were applied; in addition, arterial blood gas, white blood cell (WBC), hs-CRP, liver function and the levels of IL-1β, IL-6, IL-8, TNF-α and GM-CSF in sputum were monitored during follow-up. In the 12-month follow-up period, the frequency of exacerbation in group B2 was statistically higher than that in groups A and B1 (P < 0.05). After a 3-month follow-up, the score of groups A and B1 in the FSSG questionnaire was significantly lower than that of group B2 (P < 0.05). After the 1-year follow-up, the CAT score, FEV1 , 6-min walk test, the total number of WBC, hs-CRP, alanine aminotransferase, aspartate aminotransferase, pH of the arterial blood, PaO2 , PaCO2 and the levels of IL-1β, IL-6, IL-8, TNF-α and GM-CSF in the sputum were statistically different in group B2 compared with groups A and B1 (P < 0.05). Oral lansoprazole therapy decreased the frequency of acute exacerbation of COPD by alleviating gastroesophageal reflux and lowering the levels of IL-1β, IL-6, IL-8, TNF-α and GM-CSF in the sputum.

Exhaled Breath Condensate: Technical and Diagnostic Aspects

Purpose. The aim of this study was to evaluate the 30-year progress of research on exhaled breath condensate in a disease-based approach. Methods. We searched PubMed/Medline, ScienceDirect, and Google Scholar using the following keywords: exhaled breath condensate (EBC), biomarkers, pH, asthma, gastroesophageal reflux (GERD), smoking, COPD, lung cancer, NSCLC, mechanical ventilation, cystic fibrosis, pulmonary arterial hypertension (PAH), idiopathic pulmonary fibrosis, interstitial lung diseases, obstructive sleep apnea (OSA), and drugs. Results. We found 12600 related articles in total in Google Scholar, 1807 in ScienceDirect, and 1081 in PubMed/Medline, published from 1980 to October 2014. 228 original investigation and review articles were eligible. Conclusions. There is rapidly increasing number of innovative articles, covering all the areas of modern respiratory medicine and expanding EBC potential clinical applications to other fields of internal medicine. However, the majority of published papers represent the results of small-scale studies and thus current knowledge must be further evaluated in large cohorts. In regard to the potential clinical use of EBC-analysis, several limitations must be pointed out, including poor reproducibility of biomarkers and absence of large surveys towards determination of reference-normal values. In conclusion, contemporary EBC-analysis is an intriguing achievement, but still in early stage when it comes to its application in clinical practice.

Prevalence of gastroesophageal reflux in cystic fibrosis and implications for lung disease

Gastroesophageal reflux (GER) is common in patients with cystic fibrosis (CF) and is often regarded as playing a role in the pathogenesis of CF lung disease. Individuals with CF have many predisposing factors to the development of GER, with a reported prevalence ranging from 35 to 81%. Several studies have suggested that patients with CF who have coexisting GER have more severe lung disease with lower pulmonary function and increased numbers of respiratory exacerbations. Furthermore, GER may alter the respiratory microbiology in CF. Both the acid and nonacid components of GER may have an effect on lung disease. More than 50% of U.S. patients with CF were being treated with proton pump inhibitors in 2012; however, data regarding safety and efficacy of these agents in CF are lacking. Pharmacologic and surgical treatment of GER may improve respiratory morbidity, although prospective controlled studies have not been performed. Given the lack of evidence-based guidelines for evaluation, diagnosis, and treatment of GER in CF, initiation of treatment for symptomatic GER should be based on standard guidelines for the general population. Because there is no clear evidence that GER leads to worse respiratory outcomes in CF or that treatment of GER improves pulmonary outcomes, invasive testing for GER in patients without reflux symptoms is not warranted. Further studies to determine the role of GER in CF lung disease and the risks and benefits of surgical and pharmacologic therapy for GER are warranted.

Risk factors for respiratory symptoms in adults: the Busselton Health Study

BACKGROUND AND OBJECTIVE

The prevalence of reported doctor-diagnosed 'asthma' increased between 1990 and 2005-2007 in Busselton, Western Australia, accompanied by increased reported cough and phlegm but not recent wheeze. Possible reasons for the increase in diagnosed asthma include environmental exposures and diagnostic transfer. The aim of this study was to relate subject characteristics and exposures to the presence of wheeze and/or current cough/phlegm in the 2005-2007 survey.

METHODS

A gender- and age-stratified random sample of 2862 adults from the Busselton shire completed questionnaires regarding doctor-diagnosed asthma, respiratory symptoms and environmental exposures; and measures of anthropometry, spirometry, exhaled nitric oxide (eNO), airway hyperresponsiveness (AHR) and atopy. Associations between respiratory symptoms and subject characteristics were assessed in 2656 subjects.

RESULTS

Wheeze was reported by 23% of subjects, cough/phlegm by 22% and both by 9%. The significant and independent correlates of wheeze were reflux symptoms, lung function, AHR, eNO, atopy, body mass index and smoking. The significant and independent correlates of cough/phlegm were reflux symptoms, lung function, smoking and dusty job. Subjects more likely to report only wheeze than only cough/phlegm were female, aged <40 years, atopic, had lower percentage predicted forced expiratory volume in one second (FEV1) or higher percentage predicted force vital capacity.

CONCLUSIONS

A variety of risk factors was associated with wheeze or cough/phlegm or both. Increased non-allergic exposures may account for increased prevalence of reported cough and phlegm and may contribute to increased reported asthma in adults.

Exacerbations of COPD and symptoms of gastroesophageal reflux: a systematic review and meta-analysis

OBJECTIVE:

To examine the relationship between gastroesophageal reflux (GER) and COPD exacerbations.

METHODS:

We conducted a systematic search of various electronic databases for articles published up through December of 2012. Studies considered eligible for inclusion were those dealing with COPD, COPD exacerbations, and GER; comparing at least two groups (COPD vs. controls or GER vs. controls); and describing relative risks (RRs) and prevalence ratios-or ORs and their respective 95% CIs (or presenting enough data to allow further calculations) for the association between GER and COPD-as well as exacerbation rates. Using a standardized form, we extracted data related to the study design; criteria for GER diagnosis; age, gender, and number of participants; randomization method; severity scores; methods of evaluating GER symptoms; criteria for defining exacerbations; exacerbation rates (hospitalizations, ER visits, unscheduled clinic visits, prednisone use, and antibiotic use); GER symptoms in COPD group vs. controls; mean number of COPD exacerbations (with symptoms vs. without symptoms); annual frequency of exacerbations; GER treatment; and severity of airflow obstruction.

RESULTS:

Overall, GER was clearly identified as a risk factor for COPD exacerbations (RR = 7.57; 95% CI: 3.84-14.94), with an increased mean number of exacerbations per year (mean difference: 0.79; 95% CI: 0.22-1.36). The prevalence of GER was significantly higher in patients with COPD than in those without (RR = 13.06; 95% CI: 3.64-46.87; p < 0.001).

CONCLUSIONS:

GER is a risk factor for COPD exacerbations. The role of GER in COPD management should be studied in greater detail.

Effect of esomeprazole versus placebo on pulmonary exacerbations in cystic fibrosis

Background

Gastro esophageal reflux (GER) is common in cystic fibrosis (CF) and may contribute to lung disease. Approximately 50% of patients with cystic fibrosis are being treated with proton pump inhibitors (PPIs).

Methods

In a randomized controlled study in adults, we compared treatment with esomeprazole 40 mg twice daily versus placebo in patients with CF and frequent respiratory exacerbations over a thirty-six week treatment period to determine effect on time to first exacerbation and other health related outcomes.

Results

17 patients without symptoms of GER were randomized and 15 completed the study. 13 subjects underwent 24 hour ambulatory pH probe monitoring; 62% had pH probe evidence of GER. Forty one percent of subjects had a pulmonary exacerbation during the study. There was no significant difference in time to first pulmonary exacerbation (log rank test p = 0.3169). Five of nine subjects in the esomeprazole group compared with 2 of eight subjects in the placebo group experienced exacerbations (esomeprazole vs. placebo: odds ratio = 3.455, 95% CI = (0.337, 54.294), Fisher’s exact test: p = 0.334). There was no change in Forced Expiratory Volume in one second, Gastroesophageal Symptom Assessment Score or CF Quality of Life score between the two treatment groups.

Conclusions

There was a trend to earlier exacerbation and more frequent exacerbations in subjects randomized to esomeprazole compared with placebo. The effect of proton pump inhibitors on pulmonary exacerbations in CF warrants further investigation.

Clinical trials registration

Clinicaltrials.gov, NCT01983774

Obstructive sleep apnea and asthma: associations and treatment implications

Obstructive sleep apnea (OSA) and asthma are highly prevalent respiratory disorders and are frequently co-morbid. Risk factors common to the two diseases include obesity, rhinitis, and gastroesophageal reflux (GER). Observational and experimental evidence implicates airways and systemic inflammation, neuromechanical effects of recurrent upper airway collapse, and asthma-controlling medications (corticosteroids) as additional explanatory factors. Therefore, undiagnosed or inadequately treated OSA may adversely affect control of asthma and vice versa. It is important for clinicians to be vigilant and specifically address weight-control, nasal obstruction, and GER in these populations. Utilizing validated screening instruments to affirm high risk of co-morbid OSA or asthma in persistently symptomatic patients will allow clinicians to cost-effectively test and treat appropriate patients, potentially improving outcomes. While non-invasive ventilation in acute asthma improves outcomes, the role of chronic continuous positive airway pressure (CPAP; the first-line treatment for OSA) in improving long-term asthma control is not known. Future research should focus on the impact of optimal CPAP therapy and adherence on asthma symptoms and outcomes.

The effect of gastric juice on interleukin-8 production by cystic fibrosis primary bronchial epithelial cells

CF patients are often treated with proton pump inhibitors (PPIs) to reduce acidic gastro-esophageal reflux (GER) and bronchial aspiration of duodeno-gastric contents is common in CF. We have previously demonstrated that gastric juice (GJ) from patients "on" PPI can induce interleukin-8 (IL-8) production by bronchial epithelial cells in culture. We hypothesized that such effect would be more pronounced in CF patients known to have high inflammatory susceptibility. We aimed to evaluate the effect of GJ on IL-8 production by primary bronchial epithelial cells (PBEC), derived from a CF patient and a healthy subject.

METHODS

PBEC obtained from one donor (normal PBEC) and one receptor (CF-PBEC) for lung transplantation were stimulated with GJ from patients "off" and "on" PPI. IL-8 levels were measured in the supernatant.

RESULTS

GJ from patients "on" PPI provoked a significant higher IL-8 production compared to GJ from patients "off" PPI, both in normal PBEC [462 (200-1468) vs. 11 (4-28) pg/ml, p=0.0001] as in CF-PBEC [1468 (841-2449) vs. 85 (26-131) pg/ml, p<0.0001]. Exposure of the cells to GJ "off" PPI and "on" PPI provoked significantly higher IL-8 production in the CF-PBEC compared to the normal PBEC ["off" PPI 85 (26-131) vs. 11 (4-28) pg/ml, p=0.01; "on" PPI 1468 (841-2449) vs. 462 (200-1468) pg/ml, p=0.01]. Filtration (0.20 μm) of the GJ "on" PPI, to eliminate large particles and bacterial sub-products, resulted in a significant decrease of IL-8 production.

CONCLUSION

Patients with CF, treated with PPIs, have GJ with high pH and high endotoxin levels. These patients often have GER and bronchial aspiration. The aspirated material (GJ "on" PPI) has a significantly enhanced inflammatory effect on CF bronchial epithelial cells in culture. As chronic PPI treatment in CF may result in a paradoxically increased inflammatory effect in the airways, alternative anti-reflux therapies should be considered in CF.

Biomarkers for gastroesophageal reflux in respiratory diseases

Gastroesophageal reflux (GER) is commonly associated with respiratory symptoms, either through a vagal bronchoconstrictive reflex or through microaspiration of gastric contents. No diagnostic test is available, however, to diagnose when respiratory illnesses are caused by GER and when not, but research in this field has been moving forward. Various biomarkers in different types of biosamples have been studied in this context. The aim of this review is to summarize the present knowledge in this field. GER patients with respiratory diseases seem to have a different biochemical profile from similar patients without GER. Inflammatory biomarkers differ in asthmatics based on GER status, tachykinins are elevated in patients with GER-related cough, and bile acids are elevated in lung transplant patients with GER. However, studies on these biomarkers are often limited by their small size, methods of analysis, and case selections. The two pathogenesis mechanisms are associated with different respiratory illnesses and biochemical profiles. A reliable test to identify GER-induced respiratory disorders needs to be developed. Bronchoalveolar lavage is too invasive to be of use in most patients. Exhaled breath condensate samples need further evaluation and standardization. The newly developed particles in exhaled air measurements remain to be studied further.

Respiratory pathogens adopt a chronic lifestyle in response to bile

Chronic respiratory infections are a major cause of morbidity and mortality, most particularly in Cystic Fibrosis (CF) patients. The recent finding that gastro-esophageal reflux (GER) frequently occurs in CF patients led us to investigate the impact of bile on the behaviour of Pseudomonas aeruginosa and other CF-associated respiratory pathogens. Bile increased biofilm formation, Type Six Secretion, and quorum sensing in P. aeruginosa, all of which are associated with the switch from acute to persistent infection. Furthermore, bile negatively influenced Type Three Secretion and swarming motility in P. aeruginosa, phenotypes associated with acute infection. Bile also modulated biofilm formation in a range of other CF-associated respiratory pathogens, including Burkholderia cepacia and Staphylococcus aureus. Therefore, our results suggest that GER-derived bile may be a host determinant contributing to chronic respiratory infection.

Different gastoroesophageal reflux symptoms of middle-aged to elderly asthma and chronic obstructive pulmonary disease (COPD) patients

Symptomatic differences and the impact of gastroesophageal reflux disease (GERD) have not been clarified in patients with asthma and chronic obstructive pulmonary disease (COPD). The purpose of this study is to assess the differences of GERD symptoms among asthma, COPD, and disease control patients, and determine the impact of GERD symptoms on exacerbation of asthma or COPD by using a new questionnaire for GERD. A total of 120 subjects underwent assessment with the frequency scale for the symptoms of GERD (FSSG) questionnaire, including 40 age-matched patients in each of the asthma, COPD, and disease control groups. Asthma and control patients had more regurgitation-related symptoms than COPD patients (p<0.05), while COPD patients had more dysmotility-related symptoms than asthma patients (p<0.01) or disease control patients (p<0.01). The most distinctive symptom of asthma patients with GERD was an unusual sensation in the throat, while bloated stomach was the chief symptom of COPD patients with GERD, and these symptoms were associated with disease exacerbations. The presence of GERD diagnosed by the total score of FSSG influences the exacerbation of COPD. GERD symptoms differed between asthma and COPD patients, and the presence of GERD diagnosed by the FSSG influences the exacerbation of COPD.

Bile acids in sputum and increased airway inflammation in patients with cystic fibrosis

BACKGROUND

Up to 80% of patients with cystic fibrosis (CF) may have increased gastroesophageal reflux and aspiration of duodenogastric contents into the lungs. We aimed to assess aspiration in patients with CF by measuring duodenogastric components in induced sputum and to investigate whether the presence of bile acids (BAs) in sputum was correlated with disease severity and markers of inflammation.

METHODS

In 41 patients with CF, 15 healthy volunteers, 29 patients with asthma, and 28 patients with chronic cough, sputum was obtained after inhalation of hypertonic saline. Sputum supernatant was tested for BA and neutrophil elastase. Spirometry and BMI were assessed on the day of sputum collection.

RESULTS

Two of 15 healthy patients (13%), eight of 29 patients (28%) with asthma, four of 28 patients (14%) with chronic cough, and 23 of 41 patients (56%) with CF had BA in sputum. BA concentrations were similar in patients who are positive for BA with genotype F508del homozygote, F508del heterozygote, and other CF mutations and were not related with BMI and age. Patients with CF with BA in sputum had a higher concentration of neutrophil elastase compared with patients without BA in sputum (31.25 [20.33-54.78] μg/mL vs 14.45 [7.11-27.88] μg/mL, P < .05). There was a significant correlation between BA concentrations and dynamic lung volumes (FEV(1) % predicted [r = -0.53, P < .01], FVC% [r = -0.59, P < .01]) as well as with number of days of antibiotic IV treatment (r = 0.58, P < .01).

CONCLUSIONS

BAs are present in the sputum of more than one-half of patients with CF, suggesting aspiration of duodenogastric contents. Aspiration of BA was associated with increased airway inflammation. In patients with BA aspiration, the levels of BA were clearly associated with the degree of lung function impairment as well as the need for IV antibiotic treatment.

Histological examination of the relationship between respiratory disorders and repetitive microaspiration using a rat gastro-duodenal contents reflux model

Microaspiration due to gastroesophageal reflux (GER) has been suggested as a factor contributing to the development and exacerbation of several respiratory disorders. To explore the relationship between GER and respiratory disorders, we histologically examined the bilateral lungs of a rat gastroduodenal contents reflux model, which was previously used to investigate the histogenesis of Barrett's esophagus and esophageal carcinoma. GER was surgically induced in male Wistar rats. The bilateral lungs of the reflux rats were examined with hematoxylin and eosin (HE), PAS-Alcian blue, and Azan staining at 10 and 20 weeks after surgery. Immunohistochemical staining of CD68 and α-SMA was also performed. Aspiration pneumonia with severe peribronchiolar neutrophilic and lymphocytic infiltrates, goblet cell hyperplasia, prominence of blood vessels, and increased thickness of the smooth muscle layer were detected. Bronchiolitis obliterans (BO)-like lesions comprising granulation tissue with macrophages, spindle cells, and multinucleated giant cells in the lumen of respiratory bronchioles were observed in the bilateral lungs of the reflux animals. These findings suggest that the severe inflammation and the BO-like lesions may play a role in exacerbation of the forced expiratory volume in 1 second (FEV 1) in human cases. In conclusion, we speculate that repetitive microaspiration due to GER may contribute to the exacerbation of various respiratory diseases, particularly asthma and chronic obstructive pulmonary disease (COPD), and the development of BO syndrome following lung transplantation. The reflux model is a good tool for examining the causal relationships between GER and respiratory disorders.

Exhaled breath marker in asthma patients with gastroesophageal reflux disease

Prevention of acid is important in gastroesophageal reflex disease (GERD)-related asthma therapy. Proton pump inhibitors (PPI) and H₂-receptor blockers have been reported as useful therapies for improving asthma symptoms. GERD prevalence is high in asthma; however, methods for validating GERD existence based on questionnaire, endoscopic examination and 24h-pH monitoring do not directly determine GERD influence on the airway. Exhaled breath condensate analysis is a novel and non-invasive tool for assessing information directly from the airway. Breath collected by cooling can be applied to pH, 8-isoprostane and cytokine analysis in patients with GERD-related asthma, and the pH and 8-isoprostane levels have been shown to reflect the effects of PPI therapy in these patients. Although the analysis of cooled breath has not yet been established in a clinical setting, this method is expected to provide a novel tool for monitoring airway acidification associated with GERD.

Pepsin and bile acids in induced sputum of chronic cough patients

One of the theories which explain, why gastroesophageal reflux disease (GORD) may provoke cough, is the occurrence of aspiration of gastric content into the airways. The aim of the study was to assess the presence of aspiration markers: pepsin and bile acids (BA) in induced sputum in gastroesophageal reflux-related (GOR-related) chronic cough (CC) patients. Forty-one CC patients and 20 healthy controls were enrolled in the study. GORD as cause of CC was diagnosed by presence of GORD-related symptoms, gastroscopy and/or improvement of cough upon treatment with proton pump inhibitors (PPI). Patients were divided into two groups based on the response to PPI treatment. In all patients and healthy controls induced sputum was obtained and differential cell counts were calculated. Levels of pepsin and BA were measured in sputum supernatants. Pepsin was detectable in 48.8% samples in CC patients and in 60% healthy controls (p = NS). In pepsin positive samples no significant difference in pepsin concentration could be found between CC patients and control subjects. Pepsin levels in pepsin positive samples were significantly decreased in patients treated with PPI compared to non-treated patients. BA were detectable in 56% samples of CC patients and in 70% healthy controls (p = NS). BA concentration in BA positive samples in CC group was not different from healthy controls. There was also no difference when comparing patients who took PPI and those who did not. Patients characterized as PPI-responders and PPI-non-responders had similar pepsin and BA concentrations. Airway cellularity was not significantly different between groups of patients with or without pepsin or BA in induced sputum. Our results demonstrated the lack of differences in gastric content aspiration between patients with probable GOR-related CC and healthy control subjects. This might imply that the reflex cough theory may be more relevant than the reflux-associated aspiration theory in the pathophysiology of GORinduced chronic cough.

[Lung diseases and gastro-oesophageal reflux disease]

Gastro -oesophageal Reflux Disease is a consequence of pathological reflux from stomach to oesophagus. Whenever the refluxed contents extended beyond the oesophagus itself, is called Extraoesophageal Reflux Disease. The author proposes a review about pulmonary disorders and gastroesophageal reflux. Previously, it is evaluated in an abridged way, the concepts of each diseases and after that, in a systematic form, it is discussed the prevalence of gastro -oesophageal reflux in lung diseases, all the mechanisms studies and the impact of gastro -oesophageal treatment on lung disorders. The author concludes that is undeniable the link between Gastro -oesophageal reflux and lung diseases and further reaserch is mandatory in order to corroborate this association.

Biomarkers of airway acidity and oxidative stress in exhaled breath condensate from grain workers

RATIONALE

Grain workers report adverse respiratory symptoms due to exposures to grain dust and endotoxin. Studies have shown that biomarkers in exhaled breath condensate (EBC) vary with the severity of airway inflammation.

OBJECTIVES

The purpose of the study was to evaluate biomarkers of airway acidity (pH and ammonium [NH(4)(+)]) and oxidative stress (8-isoprostane) in the EBC of grain workers.

METHODS

A total of 75 workers from 5 terminal elevators participated. In addition to EBC sampling, exposure monitoring for inhalable grain dust and endotoxin was performed; spirometry, allergy testing, and a respiratory questionnaire derived from that of the American Thoracic Society were administered.

MEASUREMENTS AND MAIN RESULTS

Dust and endotoxin levels ranged from 0.010 to 13 mg/m(3) (median, 1.0) and 8.1 to 11,000 endotoxin units/m(3) (median, 610) respectively. EBC pH values varied from 4.3 to 8.2 (median, 7.9); NH(4)(+) values from 22 to 2,400 microM (median, 420); and 8-isoprostane values from 1.3 to 45 pg/ml (median, 11). Univariate and multivariable analyses revealed a consistent effect of cumulative smoking and obesity with decreased pH and NH(4)(+), and intensity of grain dust and endotoxin with increased 8-isoprostane. Duration of work on the test day was associated with decreased pH and NH(4)(+), whereas duration of employment in the industry was associated with decreased 8-isoprostane.

CONCLUSIONS

Chronic exposures are associated with airway acidity, whereas acute exposures are more closely associated with oxidative stress. These results suggest that the collection of EBC may contribute to predicting the pathological state of the airways of workers exposed to acute and chronic factors.

Proton pump inhibitor improves breath marker in moderate asthma with gastroesophageal reflux disease

BACKGROUND

Gastroesophageal reflux disease (GERD) influences the symptoms of asthma with acid and oxidative stress.

OBJECTIVES

The purpose of this study was to determine the usefulness of measurement of the acid stress marker pH and the oxidative stress marker 8-isoprostane by exhaled breath condensate in proton pump inhibitor (PPI) therapy effect on moderate asthma patients with GERD.

METHODS

The pH and the concentration of 8-isoprostane were measured in the exhaled breath condensate of patients with moderate asthma (n = 36) and healthy subjects (n = 26). Two months of PPI therapy (lansoprazole at 30 mg/day) were done in the asthma patients with (n = 13) or without (n = 13) GERD according to a questionnaire for the diagnosis of reflux disease, and exhaled markers were measured.

RESULTS

The pH was lower (7.3 +/- 0.3) and the 8-isoprostane level was higher (27.7 +/- 2.3) in the asthma patients than in the healthy control subjects (pH 7.5 +/- 0.2 and 8-isoprostane 6.6 +/- 1.2). Two months of PPI therapy improved the pH (from 7.2 +/- 0.1 to 7.3 +/- 0.1) and the 8-isoprostane concentration (from 32.7 +/- 3.4 to 19.2 +/- 3.4) in the asthma patients with GERD, along with improvement of GERD symptoms. However, these markers did not change in the asthma patients without GERD.

CONCLUSIONS

Measurement of the pH and 8-isoprostane level of exhaled breath condensate may be useful to evaluate the influence of GERD on asthma, as well as to determine the timing of intermittent PPI therapy.

The characteristics of different diagnostic tests in adult mild asthmatic patients: comparison with patients with asthma-like symptoms by gastro-oesophageal reflux

BACKGROUND

Diagnosing asthma cannot be always easy. It is important to consider the validity of the diagnostic tests, and/or how much more commonly they are positive in patients with asthma compared to healthy subjects and, particularly, to patients with asthma-like symptoms.

OBJECTIVE

To evaluate the validity of diagnostic tests for asthma, in terms of sensitivity, specificity, positive and negative predictive values, in patients with bronchial asthma compared to patients affected by gastro-oesophageal reflux disease (GERD) with asthma-like symptoms, and healthy control subjects without asthma and gastro-oesophageal reflux (GER).

DESIGN

Single-center, cross-sectional, observational study.

PATIENTS

We studied 60 patients with mild asthma, 30 patients with GERD and asthma-like symptoms and 25 healthy control subjects.

MEASUREMENTS

We measured provocative concentration of methacholine causing a 20% fall in the forced expiratory volume in 1s (MCh PC(20)/FEV(1)), the amplitude percent mean of peak expiratory flow (A%M of PEF), derived from twice-daily readings for >2 weeks, the FEV(1)/forced vital capacity (FEV(1)/FVC) ratio, the eosinophil count in blood and in induced sputum and the serum eosinophil cationic protein (ECP) levels.

RESULTS

FEV(1)/FVC ratio, A%M of PEF, blood eosinophils counts and serum ECP levels were less sensitive and specific when the reference population was composed of patients with asthma-like symptoms by GER. While, MCh PC(20)/FEV(1) and induced sputum eosinophils count were the most sensitive (both 90%) and specific (89% and 92%, respectively) tests.

CONCLUSION

Our findings demonstrate that MCh PC(20)/FEV(1) and the induced sputum eosinophil count are the most useful objective tests in patients with mild asthma. All patients with asthma presented both an MCh PC(20)/FEV(1) <1500 microg and eosinophils count in the induced sputum >1%.