The role of exhaled nitric oxide in asthma control

Porast prevalencije alergijskih bolesti uzrokovan modernim načinom življenja zahtijeva što bržu dijagnozu i kontrolu tih bolesti. Kontrola podrazumijeva što dulje remisije bolesti uz što manju potrebu za lijekovima, osobito kortikosteroidima u slučaju astme. Frakcija izdahnutog dušikova oksida (NO) koristi se kao biomarker u dijagnozi i praćenju bolesti, odnosno kao indikator uspješnosti liječenja astme u odraslih i djece. Astmatičari imaju povišene vrijednosti frakcije izdahnutog dušikova oksida. Ova je pretraga jednostavna za izvođenje, a izuzetna je pomoć pri postavljanju dijagnoze astme, procjene odgovora na terapiju i njene reevaluacije. Broj studija koje govore o vrijednosti testa izdahnutog dušikova oksida je u eksponencijalnom porastu od početka primjene testa, no još se uvijek radi o malom broju ispitanika, te su potrebna daljnja istraživanja.The rate of allergic diseases is increasing which is caused by the modern way of life. Therefore it is crucial to have better control and faster diagnosis of these diseases. The disease is under control if remission persists as long as possible combined with minimal use of drugs such as corticosteroids. The fraction of exhaled nitric oxide is very significant in the diagnosis and follow-up in treatment of allergic diseases in adults and children. This test is simple to perform and has great value in diagnosing asthma, evaluation of drug response and re-evaluation of drugs in use. The number of studies show exponential growth over the years of using this test, but the number of subjects in studies is still rather modest so it requires furthermore research

Evaluate of Antioxidant Enzymes Superoxide Dismutase, Glutathione Peroxidase and Catalase Levels in Asthma Patients

Asthma is a chronic airway inflammation which involves the interplay of different types of inflammatory cells and cytokines in the airway. The present study evaluates the antioxidant enzymes including superoxide dismutase, glutathione peroxidase and Catalase levels. The results showed a significant increase (P˂0.05) in erythrocyte superoxide dismutase (SOD) activity in asthmatic patients as compared to control group. While there were a significant decrease in glutathione peroxidase (GPx) (P˂0.05) and Catalase (CAT) (P˂0.05) activities in patients as compared to control group, in accordance with age, severity, smoking and family history. But, there were no significant changes in the enzymes levels between males and females. The results indicated that antioxidant enzymes could play an important role in gen- environment interaction in complex lung disease such as asthma. Keywords: MDA: Malondialdehyde, SOD: Superoxide dismutase, GPx: Glutathione peroxidase, CAT: Catalase, ROS: Reactive oxygen species

Effect of inhaled nitric oxide on pulmonary function in cystic fibrosis

AbstractConcentrations of nitric oxide (NO) have been found to be reduced in both the upper and lower airway of patients with cystic fibrosis (CF). As NO modulates bronchomuscular tone, low NO levels may contribute to the obstructive lung disease in these patients. To assess whether increasing inspiratory NO concentrations has any impact on lung function, we have studied 13 CF patients aged 14–38 years in a clinically stable condition and nine healthy controls. NO was applied via a mixing chamber for 5 min with NO concentrations of 100 parts per billion, 1 and 40 parts per million. Spirometry was performed at baseline and after inhalation on each occasion.There were no clinical side-effects at any NO concentration and no changes in oxygen saturation were observed. Lung function remained unchanged in all subjects throughout the study period. Sputum nitrate and nitrite concentrations before and after inhalation of high NO concentrations (40 ppm) in eight CF patients did not show any significant changes, even though a tendency to higher nitrate levels was observed (399 ± 231 vs. 556 ± 474 μmoll−1). Therefore, inhaled NO at either the physiological levels present in the upper airway of normal individuals or those used therapeutically to treat pulmonary hypertension has no immediate effect on bronchomuscular tone in patients with cystic fibrosis

Effect of atmospheric nitric oxide (NO) on measurements of exhaled NO in asthmatic children

The measurement of exhaled nitric oxide concentrations [NO] may provide a simple, noninvasive means for measuring airway inflammation. However, several measurement conditions may influence exhaled NO levels, and ambient NO may be one of these. We measured exhaled NO levels in 47 stable asthmatic children age 5 to 17 years and in 47 healthy children, gender and age matched. Exhaled [NO] in expired air was measured by a tidal breathing method with a chemiluminescence analyzer, sampling at the expiratory side of the mouthpiece. NO steady\u2010state levels were recorded. In order to keep the soft palate closed and avoid nasal contamination, the breathing circuit had a restrictor providing an expiratory pressure of 3\u20134 cm H2O at the mouthpiece. To evaluate the effect of [NO] in ambient air, measurements were randomly performed by breathing ambient air or NO\u2010free air from a closed circuit. Breathing NO\u2010free air, exhaled [NO] in asthmatics (mean \ub1 SEM) was 23.7 \ub1 1.4 ppb, significantly higher (P < 0.001) than in healthy controls (8.7 \ub1 0.4 ppb). Exhaled NO concentrations measured during ambient air breathing were higher (49 \ub1 4.6 ppb, P < 0.001) than when breathing NO\u2010free air (23.7 \ub1 1.4 ppb) and were significantly correlated (r = 0.89, P < 0.001) with atmospheric concentrations of NO (range 3\u2013430 ppb). These findings show that (1) exhaled [NO] values of asthmatic children are significantly higher than in healthy controls, and (2) atmospheric NO levels critically influence the measurement of exhaled [NO]. Therefore, using a tidal breathing method the inhalation of NO\u2010free air during the test is recommended. Pediatr Pulmonol. 1998; 26:30\u201334. \ua9 1998 Wiley\u2010Liss, Inc

Assessment of Fractionated Exhaled Nitric Oxide as a Biomarker for the Treatment of Eosinophilic Esophagitis

Diagnosis of eosinophilic esophagitis (EoE) and determination of response to therapy is based on histological assessment of the esophagus, which requires upper endoscopy. In children, in whom a dietary approach is commonly used, multiple endoscopies are needed, because foods are eliminated and then gradually reintroduced. Ideally, noninvasive methods could supplement or replace upper endoscopy to facilitate management. Fractionated exhaled nitric oxide (FeNO) has been proposed as a useful measure for monitoring disease activity in studies of patients with eosinophil-predominant asthma and in other atopic disorders. Thus, we evaluated whether FeNO levels could be a useful biomarker to assess the response to therapy in EoE patients. This study was designed to determine whether there is a change in FeNO levels during treatment with topical corticosteroids and whether changes correlated with clinical response. This was a prospective, multicenter study that enrolled nonasthmatic patients with established EoE. FeNO levels and symptom scores were measured at baseline, biweekly during 6-week swallowed fluticasone treatment, and 4 weeks posttreatment. Twelve patients completed the trial. We found a statistically significant difference between median pre- and posttreatment FeNO levels [20.3 ppb (16.0–29.0 ppb) vs 17.6 ppb (11.7–27.3 ppb), p=0.009]. However, neither the pretreatment FeNO level, a change of FeNO level after 2 weeks of treatment, nor the FeNO level at the end of treatment confidently predicted a clinical or histological response. Although our findings suggest nitric oxide possibly has a physiological role in EoE, our observations do not support a role of FeNo determination for management of EoE

Performance of a new hand-held device for exhaled nitric oxide measurement in adults and children

BACKGROUND: Exhaled nitric oxide (NO) measurement has been shown to be a valuable tool in the management of patients with asthma. Up to now, most measurements have been done with stationary, chemiluminescence-based NO analysers, which are not suitable for the primary health care setting. A hand-held NO analyser which simplifies the measurement would be of value both in specialized and primary health care. In this study, the performance of a new electrochemical hand-held device for exhaled NO measurements (NIOX MINO) was compared with a standard stationary chemiluminescence unit (NIOX). METHODS: A total of 71 subjects (6–60 years; 36 males), both healthy controls and atopic patients with and without asthma were included. The mean of three approved exhalations (50 ml/s) in each device, and the first approved measurement in the hand-held device, were compared with regard to NO readings (Bland-Altman plots), measurement feasibility (success rate with 6 attempts) and repeatability (intrasubject SD). RESULTS: Success rate was high (≥ 84%) in both devices for both adults and children. The subjects represented a FE(NO )range of 8–147 parts per billion (ppb). When comparing the mean of three measurements (n = 61), the median of the intrasubject difference in exhaled NO for the two devices was -1.2 ppb; thus generally the hand-held device gave slightly higher readings. The Bland-Altman plot shows that the 95% limits of agreement were -9.8 and 8.0 ppb. The intrasubject median difference between the NIOX and the first approved measurement in the NIOX MINO was -2.0 ppb, and limits of agreement were -13.2 and 10.2 ppb. The median repeatability for NIOX and NIOX MINO were 1.1 and 1.2 ppb, respectively. CONCLUSION: The hand-held device (NIOX MINO) and the stationary system (NIOX) are in clinically acceptable agreement both when the mean of three measurements and the first approved measurement (NIOX MINO) is used. The hand-held device shows good repeatability, and it can be used successfully on adults and most children. The new hand-held device will enable the introduction of exhaled NO measurements into the primary health care

In Healthy Subjects Nasal Nitric Oxide Does Not Correlate with Olfactory Sensitivity, Trigeminal Sensitivity, and Nasal Airflow

Objective: The aim of the study was to determine the relationship between nasal nitric oxide (nNO) and olfactory sensitivity, trigeminal sensitivity and nasal airflow in healthy subjects. Study design: This is a correlational study. Setting: This study was carried out in a tertiary referral centre. Participants: Forty healthy participants were recruited. Main outcome measures: nNO was measured using a chemiluminescence analyser (Niox Vero® , Circassia AB, Uppsala, Sweden), olfactory sensitivity was determined using phenyl ethyl alcohol odour thresholds using the 'Sniffin' Sticks', trigeminal sensitivity was assessed with carbon dioxide delivered by an automated device, and nasal airflow was measured using the peak nasal inspiratory flow (PNIF). Results: The median nNO was 518 ppb (IQR =333) in the right nostril, and it was 567 ppb (IQR = 314) in the left nostril. The median odour threshold was 7.1 (IQR = 4.4), the median CO2 threshold was 919 ms (IQR = 1297) and the mean PNIF was 108 L/min (SEM = 4.9). nNO did not correlate significantly with odour threshold, CO2 threshold or PNIF (Spearman's |ρ| .18). Conclusion: In healthy subjects, nNO does not appear to be associated with olfactory sensitivity, trigeminal sensitivity and PNIF.info:eu-repo/semantics/publishedVersio

Usefulness of the Measurement of Fractional Exhaled Nitric Oxide in Asthmatic Patients :Correlation with Pulmonary Function, Asthma Control and Health Status

Background and objective:This study was conducted to investigate whether or not FeNO correlates with lung function tests, the Asthma Control Test (ACT) for assessing asthma control or the Asthma Health Questionnaire (AHQ-33) for evaluating the health status in asthmatics. Methods :FeNO was compared with the results of spirometry,ACT and AHQ-33 in 57 non-smoking patients with asthma and 17 healthy individuals without pulmonary diseases who had never smoked. Sixteen of 57 asthmatics treated with inhaled corticosteroid (ICS)underwent step-down therapy if they showed good/total control or step-up therapy if they showed poor control, and were evaluated by spirometry, ACT and AHQ- 33 prior to and more than one month after starting step-down or step-up therapy. Results :FeNO in asthmatics was significantly higher than that in the control group.There were no significant correlations between FeNO and FEV1, ACT score or AHQ-33 scores. However, there were significant correlations between the changes in FeNO and changes in FEV1, ACT score or AHQ-33 scores following stepdown or step-up therapy. Conclusion :FeNO is a useful marker not only for the diagnosis of asthma but also for asthma control and determining the health status in an individual patient, although it is variable without any correlation with symptoms and lung function among asthmatics. Shinshu Med J 59 : 239 ―247, 2011Article信州医学雑誌 59(4): 239-247(2011)departmental bulletin pape

Nitric oxide metabolites in patients with asthma: induced sputum versus blood

AbstractNitric oxide (NO) plays an important role in physiological regulation of the airways. The monitoring of airway inflammation has being observed in bronchial asthma directly, by sputum examination, and indirectly, by measurements in peripheral blood. To investigate the diagnostic value of these two methods, we compared NO metabolites in induced sputum and serum obtained in patients with asthma and control subjects. Hypertonic saline induced sputum and serum were obtained in 13 patients with asthma and 10 control subjects. NO metabolite level was assayed by using modified Griess reaction. Eosinophil cationic protein (ECP) was measured by fluoroimmunoassay, and detected interleukin (IL)-5 by a sandwich ELISA. The accuracy of the tests was measured by plotting the data in receiver operating characteristic (ROC) curves and comparing the area under the curve for NO metabolites. Asthmatic patients, compared with control subjects, had significantly higher NO metabolites in induced sputum (1252·5±203·3 moll−1 vs. 557·2±101±.5 mol l−1, P < 0·01) but not in serum. IL-5 in induced sputum was detected more frequently in patients with asthma than in control subjects [1113 (84·6%) vs. 110 (10%), P < 0·01]. Asthmatic patients, compared with control subjects, had significantly higher ECP concentration in induced sputum (1270·0 ± 197·9 g 1 vs. 154·6 ± 47·4 g l−1, P < 0·01). There were significant positive correlations between NO metabolites in induced sputum and eosinophils, ECP in induced sputum (r=0·58 P<0·05; r=0·64, P<0·01) in patients with asthma but not in serum. The area under the ROC curve showed that NO metabolites in induced sputum (0·78) are more accurate marker than NO metabolites in serum (0·53) (P<0·05). These findings suggest that NO metabolites in induced sputum is a more valuable indicator to monitor asthmatic airway inflammation than those in serum