Nitric oxide as a clinical guide for asthma management

Relationship Between Air Pollution and the Concentration of Nitric Oxide in the Exhaled Air (FeNO) in 8-9-Year-Old School Children in Krakow

The consequences of air pollution pose one of the most serious threats to human health, and especially impact children from large agglomerations. The measurement of nitric oxide concentration in exhaled air (FeNO) is a valuable biomarker in detecting and monitoring airway inflammation. However, only a few studies have assessed the relationship between FeNO and the level of air pollution. The study aims to estimate the concentration of FeNO in the population of children aged 8–9 attending the third grade of public primary schools in Krakow, as well as to determine the relationship between FeNO concentration and dust and gaseous air pollutants. The research included 4580 children aged 8–9 years who had two FeNO measurements in the winter–autumn and spring–summer periods. The degree of air pollution was obtained from the Regional Inspectorate of Environmental Protection in Krakow. The concentration of pollutants was obtained from three measurement stations located in different parts of the city. The FeNO results were related to air pollution parameters. The study showed weak but significant relationships between FeNO and air pollution parameters. The most significant positive correlations were found for CO8h (r = 0.1491, p < 0.001), C₆H₆ (r = 0.1420, p < 0.001), PM₁₀ (r = 0.1054, p < 0.001) and PM_2.5 (r = 0.1112, p < 0.001). We suggest that particulate and gaseous air pollutants impact FeNO concentration in children aged 8–9 years. More research is needed to assess the impact of air pollution on FeNO concentration in children. The results of such studies could help to explain the increase in the number of allergic and respiratory diseases seen in children in recent decades.

Rheotaxially Grown and Vacuum Oxidized SnOx Nanolayers for NO2 Sensing Characteristics at Ppb Level and Room Temperature

* Correspondence: Barbara [...].

Measurement of Fractional Exhaled Nitric Oxide: Comparison of Three Different Analysers

BACKGROUND

Fractional exhaled nitric oxide (FeNO) is a surrogate marker for airway inflammation, supporting the diagnostic pathway and treatment decisions for asthma patients.

OBJECTIVES

Aim of this study was to compare the new analyser Vivatmo pro (Bosch, BV) with NIOX VERO (Circassia, CN) and CLD (Ecomedics, EC).

METHODS

In 100 asthmatics (median 53 years [range 20-87], 62% female, 86% on inhaled corticosteroids [mean 1,300 μg beclomethasone dipropionate or equivalent], 35% treated with biologics) 2 FeNO measurements per device were performed. Additionally, the success rate to achieve a valid NO value was evaluated.

RESULTS

Sixty-eight percent of the patients had FeNO values below 50 ppb. Median NO concentrations were 31 ppb (range 6-194) for BV, 33 ppb (9-164) for CN and 31ppb (7-353) for EC. Bland-Altman plots suggested an agreement within the predefined limits of ±5 ppb for all analysers within the therapeutically relevant range (0-70 ppb). The highest agreement in FeNO levels were between BV and EC with mean differences of -0.26 (95% CI -1.48 to 0.95) vs. 1.52 (95% CI 0.4-2.6) ppb for CN and EC. The results indicate an equivalence of the methods (two-one sided t test-equivalence test: p < 0.0001, ±5 ppb margins). Acceptance of the measurements was high for all devices (97%). The highest success rate to obtain 2 valid NO values without failed attempts was achieved with the BV analyser (73 vs. 62% for the CN analyser and 46% for the EC analyser).

CONCLUSIONS

For the range between 0 and 70 ppb, FeNO concentrations measured with all 3 devices were statistically equivalent within predefined acceptance criteria and did not differ in a clinically relevant way.

Asthma and exercise-induced respiratory disorders in athletes. The position paper of the Polish Society of Allergology and Polish Society of Sports Medicine

Exercise-induced respiratory symptoms describe acute airway narrowing that occurs as a result of exercise. It includes exercise-induced bronchoconstriction (EIB) and exercise-induced asthma (EIA) issues. To provide clinicians with practical guidelines, a multidisciplinary panel of stakeholders was convened to review the pathogenesis of EIB/EIA and to develop evidence-based guidelines for the diagnosis and treatment. Recommendations for the diagnosis and treatment of EIB were developed. High-intensity exercise in polluted environment (cold air, humidity, contamination, allergens) may increase the risk of EIB and asthma symptoms in athletes. Diagnostic procedures should include history taking, physical examination, atopy assessment and functional tests of the respiratory system. A strong recommendation was made for regular use of inhaled glucocorticosteroids and avoidance of short-acting β₂-agonists as the only treatment. The treatment of asthma in athletes should always take into account current anti-doping regulations. This position paper reflects the currently available evidence.

Chronic lifestyle diseases display seasonal sensitive comorbid trend in human population evidence from Google Trends

Seasonal and human physiological changes are important factors in the development of many diseases. But, the study of genuine seasonal impact on these diseases is difficult to measure due to many other environment and lifestyle factors which directly affect these diseases. However, several clinical studies have been conducted in different parts of the world, and it has clearly indicated that certain groups of population are highly subjected to seasonal changes, and their maladaptation can possibly lead to several disorders/diseases. Thus, it is crucial to study the significant seasonal sensitive diseases spread across the human population. To narrow down these disorders/diseases, the study hypothesized that high altitude (HA) associated diseases and disorders are of the strong variants of seasonal physiologic changes. It is because, HA is the only geographical condition for which humans can develop very efficient physiological adaptation mechanism called acclimatization. To study this hypothesis, PubMed was used to collect the HA associated symptoms and disorders. Disease Ontology based semantic similarity network (DSN) and disease-drug networks were constructed to narrow down the benchmark diseases and disorders of HA. The DSN which was further subjected to different community structure analysis uncovered the highly associated or possible comorbid diseases of HA. The predicted 12 lifestyle diseases were assumed to be “seasonal (sensitive) comorbid lifestyle diseases (SCLD)”. A time series analyses on Google Search data of the world from 2004–2016 was conducted to investigate whether the 12 lifestyle diseases have seasonal patterns. Because, the trends were sensitive to the term used as benchmark; the temporal relationships among the 12 disease search volumes and their temporal sequences similarity by dynamic time warping analyses was used to predict the comorbid diseases. Among the 12 lifestyle diseases, the study provides an indirect evidence in the existence of severe seasonal comorbidity among hypertension, obesity, asthma and fibrosis diseases, which is widespread in the world population. Thus, the present study has successfully addressed this issue by predicting the SCLD, and indirectly verified them among the world population using Google Search Trend. Furthermore, based on the SCLD seasonal trend, the study also classified them as severe, moderate, and mild. Interestingly, seasonal trends of the severe seasonal comorbid diseases displayed an inverse pattern between USA (Northern hemisphere) and New Zealand (Southern hemisphere). Further, knowledge in the so called “seasonal sensitive populations” physiological response to seasonal triggers such as winter, summer, spring, and autumn become crucial to modulate disease incidence, disease course, or clinical prevention.

Comparison of Antileukotrienes and Antihistamines in the Treatment of Allergic Rhinitis

Background

The aim of this study was to compare the effect of antileukotriene (anti-LT), antihistamine, and a combination of anti-LT and antihistamine on the symptoms and nasal resistance in allergic rhinitis patients.

Methods

We performed a placebo-controlled study, with 120 persistent, moderate to severe allergic rhinitis patients randomly selected to receive the different treatments for 4 weeks: no treatment, 10 mg of cetirizine once per day, 20 mg of zafirlukast once per day, 20 mg of zafirlukast twice per day, a combination of 20 mg of zafirlukast and 10 mg of cetirizine once per day, or a combination of 20 mg of zafirlukast twice per day and 10 mg cetirizine once per day. The nasal secretion nitric oxide (NO) concentration, nasal symptom score, and nasal resistance were measured before and after treatment.

Results

Total symptom scores improved in each treated group compared with the control group (p < 0.05). Nasal obstruction significantly improved in the anti-LT-treated groups (p < 0.05). High-dose anti-LT or the combination of low-dose anti-LT and antihistamine significantly improved allergy symptoms compared with no treatment, low-dose anti-LT, or antihistamine alone (p < 0.05). Furthermore, anti-LT decreased NO concentration in nasal secretions (p < 0.05), regardless of the dose administered.

Conclusion

These results suggest that high-dose anti-LT alone or the combination of low-dose anti-LY and antihistamine can effectively treat allergic rhinitis.

Microbial growth in building material samples and occupants' health in severely moisture-damaged homes

There is no commonly approved approach to detect and quantify the health-relevant microbial exposure in moisture-damaged buildings. In 39 single-family homes with severe moisture damage, we studied whether concentrations of viable microbes in building material samples are associated with health among 71 adults and 68 children, and assessed with symptoms questionnaires, exhaled NO, and peak expiratory flow (PEF) variability. Symptoms were grouped into three scores: upper respiratory symptoms, lower respiratory symptoms, and general symptoms. The homes were divided into three groups based on viable counts of fungi, actinomycetes, and total bacteria cultivated from building material samples. Highest group of actinomycete counts was associated with more general symptoms, worse perceived health, and higher daily PEF variability (aOR 12.51; 1.10-141.90 as compared to the lowest group) among adults, and with an increase in lower respiratory symptoms in children, but the confidence intervals were wide. We observed significant associations of fungal counts and total microbial score with worse perceived health in adults. No associations with exhaled NO were observed.

Association between fractional exhaled nitric oxide (FeNO) cutoff values (25 ppb) and risk factors of cough

INTRODUCTION

Cough is among the most common symptoms for patients to seek medical attention.

OBJECTIVES

The purpose of this study is to evaluate the association between fractional exhaled nitric oxide (FeNO) cutoff values (25 ppb) and risk factors related to cough, hoping to evaluate the feasibility of the FeNO cut point values (25 ppb) for clinical prediction of cough in etiology.

METHODS

In 107 adult patients with acute, subacute, or chronic cough, the FeNO, forced expiratory volume for 1 second (FEV1), forced vital capacity (FVC), blood routine (white blood cell and neutrophil), immunoglobulin E (IgE), lymphocyte eosinophils, and hemoglobin were measured. The Student's t-test was used to test the differences of FeNO levels compared with FEV1/FVC, lymphocyte, and hemoglobin level. For evaluating the correlation of FeNO levels with IgE, eosinophil, blood routine, pulmonary infection, and smoking status, the chi-square test was performed.

RESULTS

FeNO cutoff value (25 ppb) significantly correlated with serum IgE (P < .0001) between ≥200 IU/mL and <200 IU/mL level, eosinophil (P = .039) between ≥5% and <5% level, lymphocyte percentage (P = .032) and the ratio of FEV1/FVC (P = .032), while weakly correlated with pulmonary infection, blood routine (white blood cell and neutrophil), hemoglobin, and smoking.

CONCLUSION

The cutoff values of FeNO (≥25 ppb or <25 ppb) are useful for etiological detection of cough with high sensitivity.

Fraction of exhaled nitric oxide in healthy elderly Tunisian subjects

INTRODUCTION

Exhaled-fraction-of-nitric-oxide (Fe_NO) norms are absent in healthy elderly North-African subjects.

OBJECTIVES

i) to identify Fe_NO influencing factors of elderly Tunisians older 50 years and more; ii) to assess the applicability of some published Fe_NO norms for elderly in local population; iii) to set-up Fe_NO norms and to prospectively evaluate their validity in two elderly validation-groups (healthy and asthmatic subjects).

METHODS

A convenience sample of healthy and asthmatic elderly Tunisians was recruited. Subjects responded to a medical questionnaire and then Fe_NO levels were measured by an online method (Medisoft, Sorinnes (Dinant), Belgium). Clinical, anthropometric and spirometric data were collected. Three groups of subjects were identified: group I (healthy-elderly; n = 100, 57 females); group II (healthy-validation; n = 17, 4 females) and group III (asthmatic-validation; n = 10, 9 females). ANOVA was performed to compare the three groups' data.

RESULTS

No significant factor, among those evaluated, influenced Tunisian elderly Fe_NO values. The available published Fe_NO norms did not reliably predict Fe_NO in Tunisian elderly population. The mean ± SD (minimum-maximum) of Fe_NO (ppb) for group I was 14 ± 6 (3-34). For Tunisian people, each elderly Fe_NO value higher than 34 ppb will be considered as abnormal. There was no statistical significant difference between Fe_NO (ppb) mean values of group I and groups II (15 ± 8) or III (18 ± 13). No subject of group II had a Fe_NO value higher than 34 ppb. Thirty percent of group III subjects had a Fe_NO value higher than 34 ppb.

CONCLUSION

In practice, Fe_NO value of more than 34 ppb is considered abnormal in elderly Tunisian population.

The effect of beclometasone dipropionate/formoterol extra-fine fixed combination on the peripheral airway inflammation in controlled asthma

BACKGROUND

Suppression of small airway inflammation may contribute to achieving asthma control. We aimed to evaluate the additional effect of beclometasone dipropionate/formoterol (BDP/F) hydrofluoroalkane (HFA) pressurized metered dose inhaler (pMDI) (BDP/F-HFA 100/6 μg pMDI) on airway inflammation and functional parameters in asthma cases, who were optimally controlled by maintenance therapy.

METHODS

Ninety-five controlled asthmatic patients were included. They were grouped as Group 1 [budesonide/formoterol 320/9 μg dry powder inhaler (DPI)] and Group 2 (fluticasone/salmeterol 500/50 μg DPI) according to the combination they used. Then Group 3 was established by random selection from these two groups, and BDP/F-HFA 100/6 μg pMDI treatment was prescribed. All patients were evaluated in the beginning of the study and were re-evaluated at the end of a 3-week treatment period by spirometry, exhaled nitric oxide (eNO) levels, and small airway functional indices, namely, Sacin and Scond values.

RESULTS

There was no significant statistical difference in terms of age, height, weight, disease duration, symptoms, and spirometric parameters between the groups. There was a significant decrease in eNO levels in asthma cases who were on BDP/F-HFA therapy (p=0.001). A significant improvement in Sacin values at the end of the treatment period was observed in cases treated with BDP/F-HFA (p=0.001), indicating that inflammation was suppressed in peripheral airways.

CONCLUSIONS

These results emphasize that asthma treatment has mainly focused on the strategy to keep the disease under control; maintaining optimal functional level might be underestimated. BDP/F-HFA may have an additional favorable effect on the peripheral airway inflammation in the controlled asthma.

The chitinase-like protein YKL-40 is not a useful biomarker for severe persistent asthma in children

BACKGROUND

The chitinase-like protein YKL-40 is thought to play a role in inflammation and tissue remodeling. In adults with severe asthma, YKL-40 is expressed in the airway and YKL-40 levels are elevated in the serum.

OBJECTIVE

To compare YKL-40 levels in children with severe persistent asthma with those in adults with severe persistent asthma and to determine whether YKL-40 levels correlate with increasing asthma severity in childhood asthma.

METHODS

In this prospective, cross-sectional study, 23 adults and 19 children with severe persistent asthma, 23 children with moderate persistent asthma, and 19 children with mild persistent asthma were enrolled. The following data were collected on each patient: spirometry, exhaled nitric oxide, percutaneous skin testing results to aeroallergens, peripheral eosinophils, serum IgE levels, and serum YKL-40 levels.

RESULTS

Compared with adults, children with severe persistent asthma had significantly lower YKL-40 levels, higher values for forced vital capacity and forced expiration volume in 1 second, higher serum IgE levels, and higher exhaled nitric oxide levels. YKL-40 levels did not correlate with increasing asthma severity in the pediatric cohort.

CONCLUSION

Severe persistent asthma in childhood is not associated with elevated YKL-40 levels, unlike in adults with severe persistent asthma. YKL-40 is not a useful biomarker for asthma severity in childhood asthma.

Inhaled and systemic corticosteroid response in severe asthma assessed by alveolar nitric oxide: a randomized crossover pilot study of add-on therapy

AIMS

Alveolar nitric oxide (CA(NO)) is a potential biomarker of small airway inflammation. We investigated effects on CA(NO) of the addition of coarse and fine particle inhaled corticosteroids to standard therapy in severe asthma.

METHODS

Severe asthmatics taking ≥1600 µg day(-1) budesonide or equivalent performed a randomized open-label crossover study. Subjects with FEV(1) < 80%, gas trapping and CA(NO) ≥2 ppb entered a 6 week dose-ramp run-in of fluticasone/salmeterol(FPSM) 250/50 µg twice daily for 3 weeks, then 500/50 µg twice daily for 3 weeks. Patients then received additional HFA-beclomethasone diproprionate (BDP) 200 µg twice daily or FP 250 µg twice daily for 3 weeks in a crossover. Participants then received prednisolone(PRED) 25 mg day(-1) for 1 week. Nitric oxide, lung function, mannitol challenge, systemic inflammatory markers and urinary cortisol were measured.

RESULTS

Fifteen completed per protocol: mean (SD) age 51 (12) years, FEV(1) 58 (13)% predicted, residual volume 193 (100)% predicted and mannitol(PD10) 177 (2.8) µg. There was no significant difference between FPSM and add-on therapy for CA(NO). FPSM/BDP and FPSM/PRED suppressed broncial flux (Jaw(NO)) and FE(NO) compared with FPSM alone, but there was no significant difference between FPSM/BDP and FPSM/FP. ECP, e-selectin and ICAM-1 were suppressed by FPSM/PRED compared with FPSM and FPSM/FP but not FPSM/BDP. Plasma cortisol was significantly suppressed by FPSM/PRED.

CONCLUSION

In severe asthma, CA(NO) is insensitive to changes in dose and delivery of inhaled corticosteroids and is not suppressed by systemic corticosteroids. Additional inhaled HFA-BDP reduced FE(NO) and Jaw(NO) without adrenal suppression. There was a trend to reduction in FE(NO) and Jaw(NO) with additional FP but this did not reach statistical significance. PRED reduced FE(NO) and Jaw(NO) with suppression of systemic inflammatory markers and urinary cortisol.

Personalised medicine and asthma diagnostics/management

Human beings come in all shapes and sizes. Heterogeneity makes life interesting, but leads to inter-individual variation in disease susceptibility and response to therapy. One major health challenge is to develop "personalised medicine"; therapeutic interventions tailored to an individual to ensure optimal treatment of disease. Asthma is a heterogeneous disease with several different phenotypes triggered by multiple gene-environment interactions. Inhaled corticosteroids and β2-agonists have been the mainstay asthma therapies for 30 years, but they are not effective in all patients, while high costs and side-effects also drive the need for better targeted treatment of asthma. Pharmacogenetics is the study of variations in the genetic code for proteins in signaling pathways targeted by pharmacological therapies. Biomarkers are biological markers obtained from patients that can aid in asthma diagnosis, prediction of treatment response, and monitoring of disease control. This review presents a broad discussion of the use of genetic profiling and biomarkers to better diagnose, monitor, and tailor the treatment of asthmatics. We also discuss possible future developments in personalised medicine, including the construction of artificially engineered airway tissues containing a patient's own cells for use as personalised drug-testing tools.

Disagreement among common measures of asthma control in children

BACKGROUND

Asthma is a worldwide problem. It cannot be prevented or cured, but it is possible, at least in principle, to control asthma with modern management. Control usually is assessed by history of symptoms, physical examination, and measurement of lung function. A practical problem is that these measures of control may not be in agreement. The aim of this study was to describe agreement among different measures of asthma control in children.

METHODS

A prospective sequential sample of children aged 4 to 11 years with atopic asthma attending a routine follow-up evaluation were studied. Patients were assessed with the following four steps: (1) fraction of exhaled nitric oxide (FENO), (2) spirometry, (3) Childhood Asthma Control Test (cACT), and (4) conventional clinical assessment by a pediatrician. The outcome for each test was coded as controlled or uncontrolled asthma. Agreement among measures was examined by cross-tabulation and κ statistics.

RESULTS

Eighty children were enrolled, and nine were excluded. Mean FENO in pediatrician-judged uncontrolled asthma was double that of controlled asthma (37 parts per billion vs 15 parts per billion, P < .005). There was disagreement among measures of control. Spirometric indices revealed some correlation, but of the unrelated comparisons, those that agreed with each other most often (69%) were clinical assessment by the pediatrician and the cACT. Worst agreement was noted for FENO and cACT (49.3%).

CONCLUSION

Overall, different measures to assess control of asthma showed a lack of agreement for all comparisons in this study.

Comparison of two exhaled nitric oxide analyzers: the NIOX MINO hand-held electrochemical analyzer and the NOA280i stationary chemiluminescence analyzer

BACKGROUND AND OBJECTIVE

Measurement of the fraction of nitric oxide (FeNO) in exhaled air is useful in the management of asthma. A new hand-held nitric oxide (NO) analyzer, the NIOX MINO, is simple and easy to use in clinical practice. In this study, FeNO values measured using the NIOX MINO were compared with those obtained using a stationary chemiluminescence analyzer, the Sievers NOA280i.

METHODS

FeNO was measured in 100 adults, using both the NIOX MINO and the NOA280i. Nine (9.0%) of these subjects had asthma. The first acceptable measurement with the NIOX MINO and the mean of two acceptable measurements with the NOA280i were compared.

RESULTS

There was a significant correlation between FeNO concentrations measured with the two devices (r = 0.876, P < 0.001). A Bland-Altman plot showed a high degree of agreement between the two devices: the mean inter-device difference was 3.3 parts per billion (ppb), and the 95% limits of agreement were -7.0 and 13.6 ppb. In addition, the mean relative difference was 14.5%, with the 95% limits of agreement being -33.7 and 62.7%. The mean value (± standard error of the mean) for FeNO as measured with the NIOX MINO (18.8 ± 0.9 ppb) was significantly lower than that measured with the NOA280i (22.1 ± 1.2 ppb, P < 0.001).

CONCLUSIONS

There was a significant correlation, but only moderate agreement, between FeNO values measured with the NIOX MINO and those measured with the NOA280i, with the NIOX MINO values being significantly lower than the NOA280i values. Significant differences in FeNO values obtained with these two NO analyzers should be considered when interpreting the results of FeNO measurements.

A technical report on exhaled nitric oxide measurement: asthma monitoring in athletes

Exhaled NO (FE(NO)) measurements have been utilized as a marker to diagnose asthma as well as a non-invasive tool for monitoring airway inflammation and the response to anti-inflammatory medications. One area where this non-invasive monitoring may be helpful is for asthmatic athletes as they train for competitive events. We hypothesized that in the course of training an asthmatic individual may experience worsening of lung inflammation reflected in FE(NO) levels that may be too subtle to detect by conventional methods like spirometry. Data were collected from an asthmatic patient (n = 1) over the course of endurance training using both the desktop (NIOX) and the portable NO (MINO) analyzers daily for eight weeks. We found that average NO levels measured in the desktop system correlated well with the two portable analyzers (r(2) =0.73, r(2) = 0.74 p < 0.0001); additionally, there was a strong correlation between the two MINO devices (r(2) = 0.88; p < 0.0001). A strong negative relationship existed between the number of miles run and NO, regardless of the device used. FEV(1) and PEF, however, did not change significantly as the miles run increased. Exercise training in asthmatics was associated with a decrease (improvement) in NO levels but no significant change in FEV(1) and PEF. This suggests that exhaled NO levels may be more sensitive to changes in the airway as a result of exercise than traditional pulmonary function testing.

Exhaled nitric oxide in asthma: progress since the introduction of standardized methodology

The measurement of nitric oxide (NO) in exhaled breath has given us the ability to learn about and monitor the inflammatory status of the airway through a non-invasive method that is easy to perform and repeat. This has been most useful in the diagnosis and management of asthma and has promised a seemingly unlimited potential for evaluating the airways and how clinical decisions are made (Grob N M and Dweik R A 2008 Chest133 837-9). The exhaled NO field was initially limited, however, due to the absence of standardized methodology. The ATS and ERS jointly released recommendations for standardized methods of measuring and reporting exhaled NO in 1999 that were revised in 2005 (1999 Am. J. Respir. Crit. Care. Med. 160 2104-17; 2005 Am. J. Respir. Crit. Care. Med. 171 912-30). In this paper, we summarize the literature that followed this standardization. We searched the literature for all papers that included the term 'exhaled nitric oxide' and selected those that followed ATS guidelines for online measurement for further review. We also reviewed cut-off values suggested by groups studying exhaled nitric oxide. We found a wide range of NO values reported for normal and asthma populations. The geometric mean for FE(NO) ranged from 10 ppb to 33 ppb in healthy adult control populations. For asthma, the FE(NO) geometric mean ranged from 6 ppb to 98 ppb. This considerable variation likely reflects the different clinical settings and purposes of measurement. Exhaled NO has been used for a multitude of reasons that range from screening, to diagnosis, to monitoring the effect of therapy. The field of exhaled NO has made undeniable progress since the standardization of the measurement methods. Our challenge now is to have guidelines to interpret exhaled NO levels in the appropriate context. As the utility of exhaled NO continues to evolve, it can serve as a good example of the crucial role of the standardization of collection and measurement methods to propel any new test in the right direction as it makes its way from a research tool to a clinically useful test.

Clinical update on the use of biomarkers of airway inflammation in the management of asthma

Biological markers are already used in the diagnosis and treatment of cardiovascular disease and cancer. Biomarkers have great potential use in the clinic as a noninvasive means to make more accurate diagnoses, monitor disease progression, and create personalized treatment regimes. Asthma is a heterogeneous disease with several different phenotypes, generally triggered by multiple gene-environment interactions. Pulmonary function tests are most often used objectively to confirm the diagnosis. However, airflow obstruction can be variable and thus missed using spirometry. Furthermore, lung function measurements may not reflect the precise underlying pathological processes responsible for different phenotypes. Inhaled corticosteroids and β(2)-agonists have been the mainstay of asthma therapy for over 30 years, but the heterogeneity of the disease means not all asthmatics respond to the same treatment. High costs and undesired side effects of drugs also drive the need for better targeted treatment of asthma. Biomarkers have the potential to indicate an individual's disease phenotype and thereby guide clinicians in their decisions regarding treatment. This review focuses on biomarkers of airway inflammation which may help us to identify, monitor, and guide treatment of asthmatics. We discuss biomarkers obtained from multiple physiological sources, including sputum, exhaled gases, exhaled breath condensate, serum, and urine. We discuss the inherent limitations and benefits of using biomarkers in a heterogeneous disease such as asthma. We also discuss how we may modify our study designs to improve the identification and potential use of potential biomarkers in asthma.

Comparison of central and peripheral airway involvement before and during methacholine, mannitol and eucapnic hyperventilation challenges in mild asthmatics

INTRODUCTION

Testing for airway hyperresponsiveness with indirect stimuli as exercise or mannitol has been proposed to better reflect underlying airway inflammation, as compared with methacholine (MCh), believed to act directly on airway smooth muscle cells.

OBJECTIVE

To investigate whether different direct and indirect stimuli induces different patterns of obstruction, recorded as central and peripheral resistance, and to see whether baseline resistance could predict a positive response to direct or indirect provocation.

METHODS

Thirty-four mild asthmatics and 15 controls underwent MCh, mannitol and eucapnic voluntary hyperventilation (EVH) challenge tests. The response was evaluated with spirometry and impulse oscillometry (IOS).

RESULTS

Twenty-three out of 34 asthmatics were positive to either EVH (22) or mannitol (13). Those positive to mannitol had a significant increased baseline value of IOS parameters such as ΔR5-R20 and AX. Twelve of the asthmatics had a 10% fall or more in forced expiratory volume in 1 s (FEV(1)) in all three challenge tests. However, the response pattern measured by IOS did not differ between the tests. When the limit for a positive mannitol provocation was set to 10% fall in FEV(1), 16 out of 19 mannitol-positive patients were also positive to EVH.

CONCLUSION

Even in mild asthmatics, a substantial number had a positive indirect test. Mannitol FEV(1) provocative dose to decrease FEV(1) by 10% from baseline (PD10) was closely associated to EVH10%. No difference in bronchoconstrictive pattern could be seen between the different provocation tests, but those positive to mannitol had more peripheral airway involvement at baseline. This supports the idea that peripheral airway involvement is an important predictor of asthma airway reactivity.

Human exhaled breath analysis

OBJECTIVE

To review the fast-developing topic of assessment of exhaled breath components to improve the diagnosis and monitoring of respiratory and systemic diseases.

DATA SOURCES

Review of the literature available in monographs and journals.

STUDY SELECTION

Articles and overviews on the broad spectrum of existing experimental and routinely applied methods to assess different aspects of human exhaled breath analysis were selected for presentation in this review.

RESULTS

Exhaled breath constitutes more than 3,500 components, the bulk of which are volatile organic compounds in miniature quantities. Many of these characterize the functioning of the organism as a whole (systemic biomarkers), but some are related to processes taking place in the respiratory system and the airways in particular (lung biomarkers). Assessment of lung biomarkers has proven useful in airway inflammatory diseases. It involves direct measurement of gases such as nitric oxide and inflammatory indicators in exhaled breath condensate such as oxidative stress markers (eg, hydrogen peroxide and isoprostanes), nitric oxide derivatives (eg, nitrate and nitrates), arachidonic acid metabolites (eg, prostanoids, leukotrienes, and epoxides), adenosine, and cytokines. Integral approaches have also been suggested, such as exhaled breath temperature measurement and devices of the "electronic nose" type, which enable the capture of approaches have also been suggested, such as exhaled breath temperature measurementexhaled molecular fingerprints (breath prints). Technical factors related to standardization of the different techniques need to be resolved to reach the stage of routine applicability.

CONCLUSIONS

Examination of exhaled breath has the potential to change the existing routine approaches in human medicine. The rapidly developing new analytical and computer technologies along with novel, unorthodox ideas are prerequisites for future advances in this field.

Exhaled nitric oxide discriminates children with and without allergic sensitization in a population-based study

BACKGROUND

Fraction of exhaled nitric oxide (FeNO) as a biomarker of airway inflammation in children warrants better clarification.

OBJECTIVE

To identify the determinants of FeNO in children and assess the validity of FeNO as a discriminative tool for asthma, rhinitis or allergic sensitization in a population setting.

METHODS

Children aged 5-18 years (N=1717) were evaluated using online FeNO measurements, questionnaires, anthropometric measurements, pulmonary function tests and total and specific serum IgE.

RESULTS

FeNO levels were age-dependent, with an average increase of 7.4% per year of age. It decreased with increasing body mass index (BMI), estimated at 1.5% decrease per kg/m(2) . Children with allergic sensitization had elevated FeNO independent of allergic symptoms. In the combined analyses of asthma, rhinitis and allergic sensitization, elevated FeNO levels were confined mainly to children having allergic sensitization. After adjusting for allergic sensitization, a significant association between rhinitis and FeNO remained, but no such association was seen with asthma. The sensitivity, specificity, and positive (PPV) and negative predictive values (NPV) of FeNO at the optimum cut-off of 28 p.p.b. for diagnosing asthma were 64.3%, 69.9%, 8.8%, and 97.7%, respectively (area under the ROC curve [AUC] 0.67), and were slightly better for diagnosing allergic asthma: 70.0%, 70.4%, 9.0%, 98.3%, respectively (AUC 0.71). FeNO had modest accuracy in discriminating rhinitis with an AUC value of 0.70, and performed better in discriminating allergic rhinitis (AUC 0.78). FeNO was a robust discriminator of allergic sensitization independent of symptoms at a cut-off of 15.4 p.p.b. (AUC 0.80; sensitivity 72.2%; specificity 71.2%; PPV 76.9%; NPV 65.8%).

CONCLUSION AND CLINICAL RELEVANCE

FeNO measurement discriminates children with and without allergic sensitization independent of allergic symptoms. On the other hand, low FeNO levels in children may help exclude allergic asthma but high levels may be caused by allergic sensitization, older age, rhinitis, and lower BMI, in addition to asthma.

Measurement of exhaled nitric oxide: comparison of different analysers

BACKGROUND AND OBJECTIVE

Exhaled nitric oxide (NO) is used as a surrogate marker to monitor eosinophilic airway inflammation, assist in diagnosis, and support treatment decisions for asthma patients. The aim of this study was to compare five NO analysers: Medisoft (M), Aerocrine Niox (N), Aerocrine Niox flex (NF), Aerocrino Niox mino (NM) and EcoMedics (E).

METHODS

In 85 subjects (25 asthma patients, 25 COPD patients, 35 healthy volunteers; median age 36.5 years, range 23-79, 47% female), three NO measurements per individual were performed, using each analyser according to the American Thoracic Society/European Respiratory Society guidelines. Subjects evaluated the devices on the basis of comfort and ease of performing the measurement.

RESULTS

Median NO concentrations were 24.8 parts per billion (ppb) (range 6.3-262.7) for M, 14.5 ppb (0.0-196.6) for N, 15.2 ppb (5.6-67.7) for NF, 16.3 ppb (5.0-208.3) for NM, and 13.1 ppb (4.0-103.0) for E. There was significant correlation among the absolute NO values measured with all the devices (0.743 for M vs NF < r < 0.979 for N vs NF). Bland-Altman plots suggested an acceptable degree of agreement among the results obtained with the three Niox analysers. Measurements obtained with the Medisoft and Ecomedics analysers were not directly comparable with those obtained with the other devices. The greatest differences in absolute NO levels for individual patients were between measurements with the M and E analysers (8.3 ppb, range 27.4-159.7, P < 0.001). Acceptance of the measurements by patients was high, independent of the device used.

CONCLUSIONS

Exhaled NO values obtained with different devices were not directly comparable and may differ to a clinically relevant extent, depending on which device is used.

Monitoring asthma therapy using indirect bronchial provocation tests

OBJECTIVES

Bronchial provocation tests that assess airway hyperresponsiveness (AHR) are known to be useful in assisting the diagnosis of asthma and in monitoring inhaled corticosteroid therapy. We reviewed the use of bronchial provocation tests that use stimuli that act indirectly for monitoring the benefits of inhaled corticosteroids.

DATA SOURCE

Published clinical trials investigating the effect of inhaled corticosteroids on bronchial hyperresponsiveness in persons with asthma were used for this review.

STUDY SELECTION

Studies using indirect stimuli to provoke airway narrowing such as exercise, eucapnic voluntary hyperventilation, cold air hyperventilation, hypertonic saline, mannitol, or adenosine monophosphate (AMP) to assess the effect of inhaled corticosteroids were selected.

RESULTS

Stimuli acting indirectly result in the release of a variety of bronchoconstricting mediators such as leukotrienes, prostaglandins, and histamine, from cells such as mast cells and eosinophils. A positive response to indirect stimuli is suggestive of active inflammation and AHR that is consistent with a diagnosis of asthma. Persons with a positive response to indirect stimuli benefit from daily treatment with inhaled corticosteroids. Symptoms and lung function are not useful to predict the long-term success of inhaled corticosteroid dose as they usually resolve rapidly, and well before inflammation and AHR has resolved. Following treatment, AHR to indirect stimuli is attenuated. Further, during long-term treatment, asthmatics can become as non-responsive as non-asthmatic healthy persons, suggesting that asthma is not active.

CONCLUSIONS

Non-responsiveness to indirect bronchial provocation tests following inhaled corticosteroids occurs weeks to months following the resolution of symptoms and lung function. Non-responsiveness to indirect stimuli may provide a goal for adequate therapy with inhaled corticosteroids.

Reference values and determinants of exhaled nitric oxide in healthy Korean adults

BACKGROUND

Measuring fractional exhaled nitric oxide (FeNO) provides an indication of airway inflammation and is used as an inflammatory marker for asthma management. However, reference values and determinants of FeNO levels are not well defined in healthy Asian adults. This study aimed to establish FeNO reference values in nonsmoking, healthy Asian adults and to determine the factors related to FeNO levels.

METHODS

The authors measured FeNO in 166 nonsmoking, healthy Korean adults and collected data regarding factors possibly associated with FeNO, including age, height, weight, and respiratory symptoms. Lung function was measured using spirometry, and atopic status was determined based on the skin-prick test.

RESULTS

In a multivariate linear regression analysis, FeNO levels were positively associated with male gender (p = .008) and atopy (p = .044) after adjusting for age, height, weight, forced expiratory volume in one second (FEV(1)), and chronic rhinitis. Reference values were presented according to gender and atopic status, and the mean FeNO value was highest in male atopic subjects (37.3 +/- 12.1 ppb), followed by nonatopic males (33.9 +/- 14.3 ppb), atopic females (28.6 +/- 17.7 ppb), and nonatopic females (24.1 +/- 10.6 ppb). In healthy Korean adults, FeNO levels showed a significant and independent association with male gender and atopy.

CONCLUSIONS

We believe that the presented FeNO reference values and the determining factors could be useful for research and clinical practice in the adult Asian population.

Genetic factors in the treatment of bronchial asthma

Owing to the recent vast progress in analytical tools and procedures to elucidate the relationship between genes and diseases, many candidate genes leading to the development of bronchial asthma have been reported. However, the quantitative phenotypes of asthma, such as decrease in forced expiratory volume in the first second, serum hyper-IgE, bronchial hyperresponsiveness and blood hyper-eosinophilia, do not represent this disease completely. On the other hand, eosinophilic inflammation of the bronchial mucosa represents accurately the feature of bronchial asthma, although accurate quantification of its status is difficult. While the production of interleukin (IL)-5 in peripheral CD4(+) T cells probably correlates with eosinophilic inflammation of the airway, the effectiveness of anti-IL-5 antibody for the treatment of bronchial asthma is controversial. Since intervention with asthma-causing gene products may not be sufficient for the treatment of this disease, identification of therapy-responsive genes should become more important in the near future.

Exhaled nitric oxide in the diagnosis and management of childhood asthma

The management of asthma in children and adolescents is currently guided by assessment of clinical symptoms, exacerbation risk and spirometric measure of lung function. The use of biomarkers, an objective measure which indicates normal or pathophysiologic processes and/or the response to a treatment intervention, could greatly enhance the efficacy and safety of current algorithms. Measurement of the fraction of expired nitric oxide in exhaled air (FeNO) has been suggested as a readily determined biomarker that can aid in the diagnosis and management of asthma. FeNO has been used to identify steroid responsive patients, adjust the dose of controller medications, most notably inhaled corticosteroids, and predict relapse during medication taper. In spite of early enthusiasm for the utility of this measure, more recent data suggest a more limited role for FeNO. This review will focus on the use of FeNO in the diagnosis and management of asthma in children and adolescents.

Exhaled nitric oxide in a Taiwanese population: age and lung function as predicting factors

BACKGROUND/PURPOSE

The fractional concentration of exhaled nitric oxide (FE(NO)) has been reported to be elevated in asthma and many other lung diseases. The present study investigated reference values and determinants of FE(NO) in a Taiwanese non-smoking, healthy adult population.

METHODS

We used a chemiluminescence analyzer according to American Thoracic Society/European Respiratory Society recommendations to measure FE(NO) values in 356 adults who received a health check-up and a detailed respiratory questionnaire at Taichung Veterans General Hospital, Taiwan. Among the volunteers, 249 fulfilled our definition of healthy adults: no history of smoking or physician-diagnosed asthma; no recent upper airway infection; no chronic respiratory symptoms; and no allergic rhinitis and urticaria.

RESULTS

Among the 249 non-smoking and non-asthmatic adults, the mean (5th to 95th percentile reference range) FE(NO) was 27.9 (12.5-58.0) parts per billion. In multivariate regression analyses, age and lung function (forced vital capacity or forced expiratory volume in 1 second) were associated positively with FE(NO) values. Sex, height, weight, and ambient NO values were not associated significantly with FE(NO) values.

CONCLUSION

Age and lung function were predictors of FE(NO) in this population, and these factors should be considered for clinical applications of FE(NO) measurements.

Exhaled nitric oxide in pediatric asthma

Exhaled nitric oxide can now be measured in a clinical setting as a noninvasive, reproducible, facile, point-of-service test to measure airway inflammation, a central component of asthma that had not been assessed previously. An excellent surrogate marker of steroid-responsive eosinophilic airway inflammation, it serves to identify steroid-sensitive asthmatic patients and enables clinical monitoring of the response to steroid therapy and titration of the dose. Standardization of methodology and technological advances, such as the recent availability of handheld analyzers, individualized patient cards to store serial test measurements, and the assignment of coding procedural terminology, make this a necessary adjunct to clinical and functional assessment of airway obstruction and hyperresponsiveness in ambulatory pediatric and adult asthma practices.

[Airways inflammation evaluation. Upper and lower airways]

It is done a review of evaluation methods of the inflammation in upper airways and bronchi used for diagnosis, therapeutic approach and prognosis of pathologies like rhinosinusitis and asthma. It is also analysed methods that supply relevant information of inflammation in COPD. The chronic inflammation of the airways is associated to respiratory distress, obstruction in basal lung function tests and to bronchial and nasal hyperreactivity. Computerized tomography informs about lumen dimensions, bronchial walls thickness and pulmonary density. These changes are associated to inflammation and to remodelling of the airways. Localized inflammation in respiratory tract can be detected by modifications of systemic inflammatory markers. The direct evaluation of inflammatory airways changes are based on immune, histological and chemical analysis of lung tissue obtained by biopsies and by fluids recoil in basal conditions or after stimulation. The eosinophils are increased in biopsies and in nasal and bronchoalveolar lavage in asthma and rhinitis and can change with therapy. Proteins and mRNA expression of cellular activation mediators are also observed. The induced sputum identifies eosinophilic inflammation that is inversely associated with lung function parameters. In each respiratory cycle the air is enriched in organic volatile compounds produced by cellular breathing. FENO is the bio marker more deeply studied in asthma and its increase is well documented in this disorder. In the exhaled air condensed, reactive oxygen species, membrane mediators, cytokines, and chemokines are identified. If the non invasive evaluation of inflammation became reliable and reproducible it will be indispensable in monitoring the airways diseases.

Update on the pathogenesis and management of childhood asthma

PURPOSE OF REVIEW

To review and summarize trends in the current literature in childhood asthma with implications for current management and future research.

RECENT FINDINGS

There have been several articles in the last year that address the pathogenesis and pharmacogenomics of asthma. Recent consensus guidelines have been published that emphasize a stepwise approach to management, which will be briefly reviewed here. Several publications have proposed novel treatments to attempt to attenuate asthmatic lower airway inflammation. In terms of measuring this inflammation, a portable exhaled nitric oxide analyzer has been developed.

SUMMARY

Evidence shows that various early life exposures (high house dust mite levels, early antibiotic use) may predispose susceptible individuals to the development of asthma, but the early introduction of solid foods, even so-called allergenic foods, does not appear to be one of these factors. Newly identified pharmacogenomic markers may be the first step in tailoring each asthmatic patient's therapy on the basis of genotype, and management tailored specifically toward each patient's level of airway inflammation is already coming into wider clinical use. Several novel treatments for asthma have shown promise in early studies. On the basis of the most recent evidence, the National Education and Prevention Program's Guidelines for the Diagnosis and Management of Asthma is a comprehensive, stepwise management guide for asthma.

Complexity of chronic asthma and chronic obstructive pulmonary disease: implications for risk assessment, and disease progression and control

Although assessment of asthma control is important to guide treatment, it is difficult since the temporal pattern and risk of exacerbations are often unpredictable. In this Review, we summarise the classic methods to assess control with unidimensional and multidimensional approaches. Next, we show how ideas from the science of complexity can explain the seemingly unpredictable nature of bronchial asthma and emphysema, with implications for chronic obstructive pulmonary disease. We show that fluctuation analysis, a method used in statistical physics, can be used to gain insight into asthma as a dynamic disease of the respiratory system, viewed as a set of interacting subsystems (eg, inflammatory, immunological, and mechanical). The basis of the fluctuation analysis methods is the quantification of the long-term temporal history of lung function parameters. We summarise how this analysis can be used to assess the risk of future asthma episodes, with implications for asthma severity and control both in children and adults.

The use of fraction of exhaled nitric oxide in pulmonary practice

The measurement of the fractional concentration of exhaled nitric oxide (FeNO) is a convenient, noninvasive, point-of-service office test for airway inflammation. The first half of this practice management review presents the methodological, interpretative, and clinical applications of FeNO. The second half discusses practical management issues, including current and future technology, equipment specifications, US Food and Drug Administration regulations, cost, current procedural terminology coding, and reimbursement. The measurement of FeNO is helpful in the diagnosis of asthma. It is predictive of a response to inhaled corticosteroids (ICSs). Monitoring FeNO is useful in maintaining asthma control by allowing the assessment of adherence to medication and dose titration of ICSs. An elevated level of FeNO is predictive of asthma relapse following corticosteroid withdrawal especially in children. The advances in technology, ease of use, and clinical utility will lead to greater availability, acceptance, and routine application in the care of asthma.

Natural history of asthma: persistence versus progression-does the beginning predict the end?

Environmental exposures during the early years and airway obstruction that develops during this time, in conjunction with genetic susceptibility, are important factors in the development of persistent asthma in childhood. Established risk factors for childhood asthma include frequent wheezing during the first 3 years, a parental history of asthma, a history of eczema, allergic rhinitis, wheezing apart from colds, and peripheral blood eosinophilia, as well as allergic sensitization to aeroallergens and certain foods. Risk factors for the development of asthma in adulthood remain ill defined. Moreover, reasons for variability in the clinical course of asthma--persistence in some individuals and progression in others--remain an enigma. The distinction between disease persistence and disease progression suggests that these are different entities or phenotypes. There is currently no consensus on whether disease progression requires either airway inflammation or airway remodeling or the combination of the two. For patients with irreversible airway obstruction, inflammation might, in part, be necessary but perhaps not entirely sufficient to induce the irreversible component, some of which could be attributed to alterations in the structure of the bronchial wall. Intervening with intermittent or daily inhaled corticosteroids in high-risk infants and children does not prevent disease progression or impaired lung growth. These findings, however, might not apply to adults, and further study in adults is needed to determine the effect of inhaled corticosteroid therapy on disease progression.

Airway inflammation in obese and nonobese patients with difficult-to-treat asthma

BACKGROUND

Asthma and obesity are associated disorders, but the contribution of obesity to difficult-to-treat asthma as well as the mechanisms responsible for this relationship are unclear. The aim of this study was to investigate the relationship between obesity (body mass index >/= 30) and factors related with asthma severity in patients with difficult-to-treat asthma.

METHODS

One hundred and thirty-six nonsmoking asthmatic adults with persistent symptoms despite high doses of inhaled or oral corticosteroids and long-acting bronchodilators were studied [70% female, median (range) age 44.6 (18-75) years, 32% on daily oral corticosteroids]. The association between obesity, lung function parameters [forced expiratory volume in 1 s (FEV(1)), functional residual capacity/total lung capacity (FRC/TLC)], inflammatory markers [blood eosinophils, sputum eosinophils and neutrophils, exhaled nitric oxide (FE(NO)), airway hyperresponsiveness, C-reactive protein (CRP)] and aggravating co-morbid factors (severe chronic sinus disease, gastro-esophageal reflux, recurrent respiratory infections, psychopathology and obstructive sleep apnea) was investigated.

RESULTS

Obese patients (n = 29) had a higher FEV(1)%pred (P = 0.05) and a lower FRC/TLC%pred (P < 0.01) compared with nonobese patients (n = 107). Body mass index was inversely related with sputum eosinophils (r = -0.36, P < 0.01) and FE(NO) (r = -0.30, P < 0.01). Obese patients had an increased risk for gastro-esophageal reflux (OR = 2.3) and sleep apnea (OR = 3.1).

CONCLUSION

Obesity in patients with difficult-to-treat asthma is inversely related with sputum eosinophils and FE(NO), and positively associated with the presence of co-morbid factors and reduced lung volumes. This suggests that other factors than airway inflammation alone explain the relationship between obesity and asthma severity.

Exhaled nitric oxide in children with asthma and sinusitis

Exhaled nitric oxide (FE(NO)) is a surrogate marker of eosinophilic airway inflammation. The measurement of this gas can be easily performed in children and the result is immediately available. Because of these characteristics, measurement of FE(NO) is slowly becoming part of the routine clinical evaluation of an asthmatic patient. FE(NO) measurement may have a role both in the diagnosis of asthma and as a guide in therapy algorithms. For example when FE(NO) levels are persistently normal and the asthmatic child is asymptomatic, the steroid therapy may be decreased or even stopped. In patients with acute or chronic rhinosinusitis the levels of nasal nitric oxide (nNO) are significantly decreased, while they rise up after a course of antibiotics. The measurement of nasal NO has been proposed as a functional test to evaluate sinus ventilation. Nasal NO is significantly reduced also in primary ciliary dyskinesia and can be used as a screening tool to identify patients affected by this condition.

Exhaled nitric oxide daily evaluation is effective in monitoring exposure to relevant allergens in asthmatic children

BACKGROUND

Though asthma is an airway inflammatory disease, the assessment of treatment efficacy is mainly based on symptom monitoring and the evaluation of lung function parameters. This study was aimed to evaluate the feasibility of exhaled nitric oxide monitoring in allergic asthmatic children who were exposed to relevant allergens in their homes.

METHODS

Twenty-two children allergic to mites underwent twice-daily fractional exhaled nitric oxide (FeNO) therapy using a portable device (NIOX MINO; Aerocrine AB; Stockholm, Sweden) and peak expiratory flow (PEF) measurements before, during, and after periods of natural exposure to mite allergens. The children were admitted to the study if they had lived in a mite-free environment for 3 months. They were observed in this environment for 10 days and then were moved to a site with natural mite exposure at sea level for 19 days. Finally, they were relocated to the mite-free environment for a period of 6 days for follow-up measurements.

RESULTS

Significant differences were seen between the mite-free baseline FeNO level (26.4 parts per billion [ppb]; range, 19.3 to 36.2 ppb) and FeNO levels measured during natural mite exposure (37.3 ppb; 27.3 to 51 ppb) and after natural mite exposure (34.9 natural mite exposure; 25.2 to 48.2 ppb). Six children reported asthma symptoms during the mite exposure, and an increase in FeNO was observed in each case (p<0.031); PEF values showed no significant differences, whether between the different environments or between different periods.

CONCLUSIONS

These data give further evidence for a possible role of frequent determinations of FeNO in order to promptly assess changes in the level of airway inflammation in asthmatic children.

Weight loss and asthma control in severely obese asthmatic females

BACKGROUND

Obesity is proposed to represent an important predisposing condition to serious respiratory disturbances including asthma. The effects of consistent weight loss on asthma control are not well known. We investigated the effect of weight reduction induced by bariatric surgery on asthma control in severely obese asthmatic patients.

PATIENTS AND METHODS

A consecutive series of 12 asthmatic obese females who had laparoscopic adjustable gastric banding (OB group) and 10 non-operated asthmatic obese females as control group (CG). Body mass index (BMI), Asthma Control Test (ACT), pulmonary function test (PFT), exhaled nitric oxide (NO) were evaluated at baseline and after 1 year.

RESULTS

Mean BMI (kg/m(2)) of OB group decreased from 45.2+/-4.7 before surgery to 34.8+/-4.2 post-operatively. After surgery the overall ACT score in OB group significantly improved from 18.7 to 22.2 (p<0.001), while it remained unchanged in CG (from 18.8 to 18.6, p=0.73). In particular, in OB group the parameters of shortness of breath and rescue medication use were significantly improved respectively from 3.2 and 3.9 before surgery to 4.2 and 4.6 after surgery (always p<0.05). Accordingly, none of the CG who did not experience any weight loss was able to obtain a full asthma control. In the OB group after the surgery PFT significantly improved as compared to CG. No significant difference in exhaled NO was found both in OB group after surgery as compared to before surgery.

CONCLUSION

Consistent weight loss in severely obese patients with asthma is associated to improvement in respiratory symptoms and lung function. However, the mechanisms underlying the effect of large body mass changes on asthma would require further studies.

Methacholine challenge testing: identifying its diagnostic role, testing, coding, and reimbursement

Methacholine challenge testing (MCT), also sometimes described as bronchoprovocation testing, is widely performed for both research and diagnostic purposes. MCT is clinically useful when the patient presents with a history of symptoms suggesting asthma, but spirometry findings are normal. Typically, MCT is performed in a pulmonary function laboratory, a clinic, or a physician's office. MCT requires time, effort, and understanding. Two standard testing regimes are identified along with proper coding and reimbursement methodologies.

Peripheral nitric oxide is increased in rhinitic patients with asthma compared to bronchial hyperresponsiveness

Allergic rhinitis is a predisposing factor for developing clinical asthma. Moreover, allergic rhinitis is often associated with bronchial hyperresponsiveness (BHR). We hypothesise that patients with asthma have more small airway involvement than those with allergic rhinitis and BHR alone. The aim of this study was to assess peripheral and proximal NO concentration in rhinitic subjects, and to correlate the peripheral NO concentration to the peripheral obstruction in response to methacholine. Patients with allergic rhinitis with or without BHR, or clinical asthma were investigated in and out of the allergy season. Healthy subjects served as controls. Fractional exhaled NO was performed, and peripheral NO concentration and proximal flux of NO was calculated. Methacholine test was performed including impulse oscillometry. Rhinitic patients with asthma demonstrate an increase in both proximal and peripheral NO compared to those with rhinitis alone or those with BHR. There is a trend of increased peripheral NO from patients with rhinitis only, rhinitis and BHR, to rhinitis with asthma. The increase in peripheral NO correlated with an increased peripheral obstruction in response to methacholine. Patients with seasonal allergic rhinitis demonstrated a decrease in both proximal and peripheral NO in the off-season. The results support our hypothesis that rhinitic patients with asthma have more peripheral lung inflammation and small airway involvement compared to rhinitic patients with BHR alone.