| 1. |
- Alving, Kjell, et al.
(författare)
-
Basic aspects of exhaled nitric oxide
- 2010
-
Ingår i: European Respiratory Monograph. - : European Respiratory Society. - 1025-448X .- 2075-6674. ; 49, s. 1-31
-
Forskningsöversikt (refereegranskat)abstract
- Nitric oxide (NO) in orally exhaled air mainly originates fromthe respiratory epithelium. NO is produced by inducible NOsynthase (iNOS), which is regulated by signal transducer andactivator of transcription (STAT)-1 under the influence ofhomeostatic interferon-c. In patients with asthma, iNOSexpression is upregulated by interleukin (IL)-4 and IL-13 viathe activation of STAT-6 in the bronchial epithelium. Thus,exhaled NO primarily signals local T-helper cell type 2-driveninflammation in the bronchial mucosa. With these character-istics, exhaled NO will be a suitable marker for predicting theresponse to inhaled corticosteroids, and to monitor the anti-inflammatory effect.The methodology for measuring exhaled NO has beenstandardised based on international consensus. The determi-nants of exhaled NO levels are fairly well characterised, withthe most important being cigarette smoking, nitrate intake, airpollution, allergen sensitisation and exposure, along withheight, sex and age. A future development may be the estima-tion of peripheral airway inflammation by measuring exhaledNO at multiple exhalation flow rates.
|
|
| 2. |
- Brussino, L., et al.
(författare)
-
Oxidative stress and airway inflammation after allergen challenge evaluated by exhaled breath condensate analysis
- 2010
-
Ingår i: Clinical and Experimental Allergy. - : Wiley. - 0954-7894 .- 1365-2222. ; 40:11, s. 1642-1647
-
Tidskriftsartikel (refereegranskat)abstract
- Background Allergen exposure may increase airway oxidative stress, which causes lipid membrane peroxidation and an increased formation of 8-isoprostane. Objective The aim of the study was to investigate oxidative stress induced by allergen challenge in mild asthmatics, by measuring 8-isoprostane in exhaled breath condensate (EBC), and to examine their relationship with mediators derived from arachidonic acid. Methods 8-isoprostane, cysteinyl leukotrienes (cys-LTs) and prostaglandin E2 (PGE(2)) concentrations in EBC were measured at baseline and after allergen challenge in 12 patients with mild allergic asthma sensitized to cat allergen. Results At 24 h after allergen challenge, compared with baseline values, EBC 8-isoprostane increased [48.64 pg/mL (44.14-53.61) vs. 21.56 pg/mL (19.92, 23.35), P < 0.001], cys-LTs increased [27.37 pg/mL (24.09-31.10) vs. 13.28 pg/mL (11.32, 15.57), P < 0.001] and PGE(2) decreased [18.69 pg/mL (12.26, 28.50) vs. 39.95 pg/mL (34.37, 46.43), P < 0.001]. The trend of increasing 8-isoprostane after allergen challenge was significantly correlated with the trend of increasing cys-LTs (R2=0.85, P < 0.001) whereas the trend of decreasing PGE(2) after allergen challenge was significantly correlated with the trend of increasing cys-LTs (R2=0.52, P=0.001). Conclusions and Clinical Relevance The increase in EBC 8-isoprostane observed after allergen challenge indicates that allergen exposure increases airway oxidative stress in allergic asthma. The strict correlation between cys-LTs and 8-isoprostane underlines the relationship between allergic inflammation and oxidative stress. A shift of arachidonic acid metabolism towards lipoxygenase pathway is induced by the allergen challenge. Airway oxidative stress occurs after allergen challenge even in patients with mild intermittent allergic asthma.
|
|
| 3. |
- Ek, A., et al.
(författare)
-
Chronic rhinosinusitis in asthma is a negative predictor of quality of life: results from the Swedish GA(2)LEN survey
- 2013
-
Ingår i: Allergy. - : Wiley. - 0105-4538 .- 1398-9995. ; 68:10, s. 1314-1321
-
Tidskriftsartikel (refereegranskat)abstract
- BackgroundAsthma and chronic rhinosinusitis (CRS) both impair quality of life, but the quality-of-life impact of comorbid asthma and CRS is poorly known. The aim of this study was to evaluate the impact of CRS and other relevant factors on quality of life in asthmatic subjects. MethodsThis Swedish cohort (age 17-76years) consists of 605 well-characterized asthmatics with and without CRS, 110 individuals with CRS only, and 226 controls and is part of the Global Allergy and Asthma European Network (GA(2)LEN) survey. The Mini Asthma Quality of Life Questionnaire (mAQLQ), the Euro Quality of Life (EQ-5D) health questionnaire, spirometry, skin prick test (SPT), exhaled nitric oxide (FeNO), smell test, and peak nasal inspiratory flow were used. ResultsSubjects having both asthma and CRS have lower mAQLQ scores in all domains (P<0.001) and a lower EQ-5D index value and EQ-5D VAS value (P<0.001) compared to those with asthma only. Asthmatics with CRS have significantly lower FEV1%pred and FVC%pred (88.4 [85.1-91.7] and 99.9 [96.7-103.0], respectively) compared with asthma only (91.9 [90.3-93.4] and 104.0 [102.5-105.5], respectively P<0.05). Multiple regression analysis shows that low asthma quality of life is associated with having CRS (P<0.0001), lower lung function (P=0.008), current smoking (P=0.01), BMI>30kg/m(2) (P=0.04), high age (P=0.03), and a negative SPT (P=0.04). ConclusionsComorbid CRS was a significant and independent negative predictor of quality of life in asthmatics. Other negative factors were lower lung function, current smoking, obesity, advanced age, and having nonatopic asthma.
|
|
| 4. |
- Farkhooy, Amir, et al.
(författare)
-
Impaired Carbon Monoxide Diffusing Capacity is the Strongest Predictor of Exercise Intolerance in COPD
- 2013
-
Ingår i: COPD. - : Informa UK Limited. - 1541-2555 .- 1541-2563. ; 10:2, s. 180-185
-
Tidskriftsartikel (refereegranskat)abstract
- Background: Exercise intolerance is a hallmark of chronic obstructive pulmonary disease (COPD) and forced expiratory volume in one second (FEV1) is the traditional metric used to define the severity of COPD. However, there is dissociation between FEV1 and exercise capacity in a large proportion of subjects with COPD. The aim of this study was to investigate whether other lung function parameters have an additive, predictive value for exercise capacity and whether this differs according to the COPD stage. Methods: Spirometry, body plethysmography and diffusing capacity for carbon monoxide (DLCO) were performed on 88 patients with COPD GOLD stages II-IV. Exercise capacity (EC) was determined in all subjects by symptom-limited, incremental cycle ergometer testing. Results: Significant relationships were found between EC and the majority of lung function parameters. DLCO, FEV1 and inspiratory capacity (IC) were found to be the best predictors of EC in a stepwise regression analysis explaining 72% of EC. These lung function parameters explained 76% of EC in GOLD II, 72% in GOLD III and 40% in GOLD IV. DLCO alone was the best predictor of exercise capacity in all GOLD stages. Conclusions: Diffusing capacity was the strongest predictor of exercise capacity in all subjects. In addition to FEV1, DLCO and IC provided a significantly higher predictive value regarding exercise capacity in COPD patients. This suggests that it is beneficial to add measurements of diffusing capacity and inspiratory capacity when clinically monitoring COPD patients.
|
|
| 5. |
- Guida, Giuseppe, et al.
(författare)
-
Determinants of Exhaled Nitric Oxide in Chronic Rhinosinusitis
- 2010
-
Ingår i: Chest. - : Elsevier BV. - 0012-3692 .- 1931-3543. ; 137:3, s. 658-664
-
Tidskriftsartikel (refereegranskat)abstract
- Background: Chronic rhinosinusitis (CRS) has been reported to be associated with increased values of exhaled nitric oxide (ENO), which could not be entirely explained by the association between CRS and asthma. The aim of this study was to investigate the variables associated with increased ENO in patients with CRS. Methods: This was a prospective cross-sectional descriptive study of 93 consecutive patients with CRS. The effect on ENO of age, gender, atopy, asthma, respiratory symptoms without bronchial hyperresponsiveness (BHR), and nasal polyps was evaluated by multiple regression analysis. Results: Nasal polyps (P=.01), asthma (P<.001), and respiratory symptoms without BHR (P=.01) were the only independent variables associated with increased ENO. The prevalence of asthma was significantly higher in subjects with nasal polyps (61% vs 29.4%), P=.005, whereas the prevalence of respiratory symptoms without BHR was higher in those without nasal polyps (44.1% vs 15.3%, P=.003). Respiratory symptoms without BHR were associated with significantly higher ENO and prevalence of sputum eosinophilia (eosinophils>3%) in patients with nasal polyps compared with those without nasal polyps (68.2 vs 24.0 ppb, P=.001; 60% vs 8.3%, P=.03, respectively). Conclusions: The presence of nasal polyps in patients with CRS was associated with increased asthma prevalence as well as increased ENO levels. Respiratory symptoms without BHR were associated with eosinophilic airway inflammation and increased ENO only in patients with nasal polyps. These findings suggest important clinical and biologic differences between the two types of CRS, with and without nasal polyps.
|
|
| 6. |
|
|
| 7. |
- Heijkenskjöld-Rentzhog, Charlotte, et al.
(författare)
-
Alveolar and exhaled NO in relation to asthma characteristics : effects of correction for axial diffusion
- 2014
-
Ingår i: Allergy. European Journal of Allergy and Clinical Immunology. - : Wiley. - 0105-4538 .- 1398-9995. ; 69:8, s. 1102-1111
-
Tidskriftsartikel (refereegranskat)abstract
- Background: Inflammation in the small airways might contribute to incomplete asthma disease control despite intensive treatment in some subgroups of patients. Exhaled NO (FeNO) is a marker of inflammation in asthma and the estimated NO contribution from small airways (Calv(NO)) is believed to reflect distal inflammation. Recent studies recommend adjustments of Calv(NO) for trumpet model and axial diffusion (TMAD-adj). This study aimed to investigate the clinical correlates of Calv(NO), both TMAD-adjusted and unadjusted. Methods: Asthma symptoms, asthma control, lung function, bronchial responsiveness, blood eosinophils, atopy and treatment level were assessed in 410 subjects, aged 10-35 years. Exhaled NO was measured at different flow-rates and Calv(NO) calculated, with TMAD-adjustment according to Condorelli. Results: Trumpet model and axial diffusion-adjusted Calv(NO) was not related to daytime wheeze (P = 0.27), FEF50 (P = 0.23) or bronchial responsiveness (P = 0.52). On the other hand, unadjusted Calv(NO) was increased in subjects with daytime wheeze (P < 0.001), decreased FEF50 (P = 0.02) and with moderate-to-severe compared to normal bronchial responsiveness (P < 0.001). All these characteristics correlated with increased FeNO (all P < 0.05). Unadjusted Calv(NO) was positively related to bronchial NO flux (J'aw(NO)) (r = 0.22, P < 0.001) while TMAD-adjCalv(NO) was negatively related to J'awNO (r = -0.38, P < 0.001). Conclusions: Adjusted Calv(NO) was not associated with any asthma characteristics studied in this large asthma cohort. However, both FeNO and unadjusted Calv(NO) related to asthma symptoms, lung function and bronchial responsiveness. We suggest a potential overadjustment by current TMAD-corrections, validated in healthy or unobstructed asthmatics. Further studies assessing axial diffusion in asthmatics with different degrees of airway obstruction and the validity of proposed TMAD-corrections are warranted.
|
|
| 8. |
|
|
| 9. |
- Heijkenskjöld-Rentzhog, Charlotte, et al.
(författare)
-
The fraction of NO in exhaled air and estimates of alveolar NO in adolescents with asthma : methodological aspects
- 2012
-
Ingår i: Pediatric Pulmonology. - : Wiley. - 8755-6863 .- 1099-0496. ; 47:10, s. 941-949
-
Tidskriftsartikel (refereegranskat)abstract
- RationaleThis study investigated the oral contribution to exhaled NO in young people with asthma and its potential effects on estimated alveolar NO (CalvNO), a proposed marker of inflammation in peripheral airways. Secondary aims were to investigate the effects of various exhalation flow-rates and the feasibility of different proposed adjustments of (CalvNO) for trumpet model and axial diffusion (TMAD).MethodsExhaled NO at flow rates of 50–300 ml/sec, and salivary nitrite was measured before and after antibacterial mouthwash in 29 healthy young people (10–20 years) and 29 with asthma (10–19 years). CalvNO was calculated using the slope–intercept model with and without TMAD adjustment.ResultsExhaled NO at 50 ml/sec decreased significantly after mouthwash, to a similar degree in asthmatic and healthy subjects (8.8% vs. 9.8%, P = 0.49). The two groups had similar salivary nitrite levels (56.4 vs. 78.4 µM, P = 0.25). CalvNO was not significantly decreased by mouthwash. CalvNO levels were similar when flow-rates between 50–200 or 100–300 ml/sec were used (P = 0.34 in asthmatics and P = 0.90 in healthy subjects). A positive association was found between bronchial and alveolar NO in asthmatic subjects and this disappeared after the TMAD-adjustment. Negative TMAD-adjusted CalvNO values were found in a minority of the subjects.ConclusionsYoung people with and without asthma have similar salivary nitrite levels and oral contributions to exhaled NO and therefore no antibacterial mouthwash is necessary in routine use. TMAD corrections of alveolar NO could be successfully applied in young people with asthma and yielded negative results only in a minority of subjects.
|
|
| 10. |
- Högman, Marieann, et al.
(författare)
-
Added value with extended NO analysis in atopy and asthma
- 2011
-
Ingår i: Clinical Physiology and Functional Imaging. - 1475-0961 .- 1475-097X. ; 31:4, s. 294-299
-
Tidskriftsartikel (refereegranskat)abstract
- INTRODUCTION: Assessments of the usefulness of exhaled nitric oxide (NO) in the treatment of asthma have given conflicting results. It is not always obvious if atopic status has been tested in these evaluations. OBJECTIVES: The aim of the study is to use extended NO analysis to characterize subjects from a random sample populations with focus on rhinitis and asthma. METHODS: Data were extracted from the European Community Respiratory Health Survey II. A subgroup from the Uppsala site that had had their NO measured at multiple flow rates was included (n = 284). The nonlinear model for NO parameters was used. Atopy was defined as having a titre against at least one of the tested allergens ≥0·35 kU l(-1) . Bronchial responsiveness was assessed by methacholine challenge. RESULTS: Subjects with non-atopic rhinitis or non-atopic asthma could not be separated from healthy subjects regarding NO parameters. There was a gradual increase with atopy in airway diffusion rate (D(aw) NO); healthy subject 8·0 (7·3, 8·8), healthy atopic 8·8 (6·7, 11·5), atopic rhinitis 10·6 (9·0, 12·4) and atopic asthma 11·2 (9·9, 28·3) ml s(-1) [geometrical mean (CI(95%) )]. There was a correlation between bronchial responsiveness and D(aw) NO in atopic rhinitis (r = -0·41, P<0·01), and bronchial responsiveness and airway wall content of NO (C(aw) NO) in atopic asthma (r = -0·56, P<0·001). CONCLUSION: It is of importance to characterize atopic status when evaluating the association between NO and asthma. Our results indicate that the use of extended NO analysis, with particular attention to D(aw) NO and C(aw) NO, may be useful in monitoring treatment for rhinitis and asthma.
|
|
