Exhaled nitric oxide and bronchial responsiveness to adenosine 5'-monophosphate in subjects with allergic rhinitis

Effects of atopy and rhinitis on exhaled nitric oxide values - a systematic review

Background

Atopy and rhinitis are among the factors affecting exhaled nitric oxide (FeNO) values and may contribute to difficulties in the clinical interpretation of FeNO measurements. However, data assessing their effects on FeNO values had never been summarized. This review aims to evaluate the effect of atopy and rhinitis in FeNO values in otherwise healthy individuals.

Methods

A systematic review was performed in Pubmed, Scopus and ISI Web of Knowledge. A two-step selection process was completed, and from 2357 references 19 were included. The inclusion criteria were: participants without known diseases other than rhinitis; atopy assessement by SPT or Specific IgE; and FeNO measurements according to ATS/ERS recommendations.

Results

The 8 articles measuring FeNO in children showed higher values in both allergic rhinitis and atopic children when compared with healthy children. The 11 articles performed in adults observed higher FeNO in AR patients comparatively with either healthy or atopic individuals. However, adult healthy and atopic individuals had similar FeNO values.

Conclusions

FeNO values are higher in individuals with rhinitis and/or atopy without other health problems. These effects are small, seem to be independent and should be further studied using multivariate models. The effect of atopy was observed only in children. The combined effect of atopy and rhinitis produced higher FeNO values in adults. These results support that both atopy and rhinitis should be considered when interpreting or when defining FeNO reference values.

sICAM-1 and TNF-α in asthma and rhinitis: relationship with the presence of atopy

BACKGROUND

A genetically determined overproduction of specific immunoglobulin E (IgE) underlies many diseases like asthma or allergic rhinitis. IgE as well as tumor necrosis factor-α (TNF-α), and intercellular adhesion molecule-1 (ICAM-1) play a critical role in the induction and maintenance of inflammation. While the correlation between IgE and atopy is inseparable, little is known about the correlation of atopy with markers of inflammation.

OBJECTIVE

We investigated the relationship between the serum concentrations of TNF-α, soluble ICAM-1 (sICAM-1), and the presence of atopy in patients with persistent rhinitis or asthma.

METHODS

Serum concentrations of sICAM-1, TNF-α, and total IgE were investigated in 64 adults with persistent allergic rhinitis, 17 subjects with nonatopic rhinitis, 90 patients with asthma, and 21 healthy individuals. Atopy was diagnosed on the basis of positive family history, skin prick tests, and serum IgE concentration.

RESULTS

Total IgE concentration was significantly higher in patients with atopic rhinitis or asthma when compared with nonatopic patients and healthy individuals and was the highest in patients suffering from severe atopic asthma who were not treated with systemic glucocorticosteroids. Although there were marked alterations in IgE in atopic and nonatopic patients, there were no significant differences between atopic and corresponding groups of nonatopic rhinitic and asthmatic patients in sICAM-1 and TNF-α concentrations. (sICAM-1 in rhinitis: atopic vs. nonatopic patients: 224.02 and 221.08 ng/ml, respectively, p > .05; in mild/moderate asthma: atopic vs. nonatopic: 306.22 and 326.39 ng/ml, respectively, p > .05; severe asthma without oral corticosteroids therapy: atopic vs. nonatopic: 418.03 and 468.09 ng/ml, respectively, p > .05; and severe asthma with oral corticosteroids therapy: atopic vs. nonatopic: 320.66 and 308.09 ng/ml, respectively, p > .05).

CONCLUSIONS

Concentrations of sICAM-1 and TNF-α are significantly higher in patients with asthma compared with those observed in patients with rhinitis, but they are independent of the presence of atopy.

Comparison of bronchial hyperresponsiveness to methacholine and adenosine and airway inflammation markers in patients with suspected asthma

BACKGROUND

Bronchial hyperresponsiveness is usually measured by bronchial challenge test with direct (e.g., methacholine) and indirect (e.g., adenosine) agonists. There are few studies comparing both types of agents and they have had conflicting concordance.

OBJECTIVE

We sought to compare the results of both tests in a population with symptoms suggestive of asthma so as to determine their relationship with bronchial inflammatory markers.

METHODS

Seventy-nine patients whose age ranged from 14 to 81 years were recruited for this study. Challenge tests were performed using the tidal volume method. PC₂₀ methacholine and PC₁₅ and PC₂₀ adenosine were calculated. Induced sputum and fraction of exhaled nitric oxide measurements were also performed.

RESULTS

Atopy was found in 69% of the patients. Methacholine PC₂₀ and adenosine PC₁₅ were positive in 32 patients (40.5%), both having a sensitivity of 73%. Percentage of agreement was 45.45% and κ index was only 0.369. Adenosine PC₂₀ elicited lower sensitivity and agreement. No correlation between methacholine PC₂₀ and adenosine PC₁₅ was observed. Higher fraction of exhaled nitric oxide values and sputum eosinophil counts were seen in patients with positive adenosine challenge results. The use of adenosine PC₁₅ or PC₂₀ did not alter the association with inflammatory markers.

CONCLUSIONS

The concordance between both techniques was low. Methacholine is not a reliable predictor of hyperresponsiveness to adenosine, leading us to conclude that the two tests are complementary but not interchangeable in clinical practice. Additionally, responsiveness to the two bronchoconstrictor stimuli does not indicate presence of the same airway abnormality. Indirect stimuli provide a better reflection of bronchial inflammation.

Effect of montelukast on symptoms and exhaled nitric oxide levels in 7- to 14-year-old children with seasonal allergic rhinitis

BACKGROUND

Cysteinyl leukotrienes have been found to exert potent inflammatory effects in the upper airways and play a fundamental role in the pathogenesis of allergic rhinitis. Previous studies have reported increased levels of exhaled nitric oxide (eNO) in patients with allergic rhinitis without asthma symptoms.

OBJECTIVE

To investigate the role of treatment with montelukast on symptoms, eNO levels, and peripheral eosinophil counts of children with seasonal allergic rhinitis during pollen season.

METHODS

A randomized, double-blind, parallel-group study performed between April and June 2005 in 57 children aged 7 to 14 years with seasonal allergic rhinitis was performed. The study comprised a 1-week screening period, a 1-week run-in period, and a 2-week treatment period with once daily montelukast, 5 mg, or matching placebo.

RESULTS

No significant difference at baseline was found in symptom scores, eNO levels, and blood eosinophil counts between the treatment and placebo groups. After 2 weeks of montelukast treatment, improvements from the baseline in the daytime nasal, composite, and daytime eye symptoms scores were significantly greater in the montelukast group compared with the placebo group (P < .001, P < .001, and P < .01, respectively). A significant decrease was also found in eosinophil counts (P < .001) in the montelukast group compared with the placebo group after treatment. Montelukast treatment did not produce a significant effect on eNO levels compared with placebo (P = .96).

CONCLUSION

Montelukast treatment provided significant improvement in symptoms and peripheral eosinophil counts of school-age children with seasonal allergic rhinitis; however, it did not show a significant effect on eNO levels.

Intercellular adhesion molecule 1 and tumor necrosis factor alpha in asthma and persistent allergic rhinitis: relationship with disease severity

BACKGROUND

Tumor necrosis factor alpha (TNF-alpha) is involved in the up-regulation of intercellular adhesion molecule 1 (ICAM-1). Allergic rhinitis is often associated with bronchial hyperresponsiveness.

OBJECTIVE

We investigated the relationship between allergic airway disease severity and serum concentrations of soluble ICAM-1 (sICAM-1) and TNF-alpha and nasal expression of ICAM-1.

METHODS

Serum concentrations of TNF-alpha and sICAM-1 were investigated in 85 adults with persistent rhinitis and 90 patients with asthma. Seventy patients with rhinitis were challenged with methacholine. Nasal biopsy for ICAM-1 expression was performed in 6 patients with moderate-severe rhinitis and in 6 patients with mild rhinitis.

RESULTS

In patients with rhinitis, serum sICAM-1 concentrations were as follows: group without bronchial hyperresponsiveness (n = 29), 206.85 ng/mL; group with bronchial hyperresponsiveness but without asthma symptoms (n = 20), 233.39 ng/mL; and group with newly recognized asthma (n = 21), 260.06 ng/mL. The sICAM-1 level was significantly lower in patients with mild rhinitis (216.21 ng/mL) than in patients with moderate-severe rhinitis (244.08 ng/mL). Nasal ICAM-1 expression was significantly higher in the moderate-severe rhinitis group than in the mild rhinitis group. In patients with asthma, serum concentrations of sICAM-1 were as follows: patients with mild asthma, 272.8 ng/mL; patients with moderate asthma, 340.16 ng/mL; patients with severe asthma without oral corticosteroids therapy, 426.74 ng/mL; and patients with severe asthma with oral corticosteroids therapy, 314 ng/mL. The serum TNF-alphaa concentration differed between patients with rhinitis (n = 15) (1.065 pg/mL) and patients with asthma (n = 12) (3.46 pg/mL). Among patients with asthma, TNF-alpha concentrations were similar in all groups classified according to the disease severity.

CONCLUSIONS

sICAM and ICAM-1 expression correlates with airways diseases severity.

Correlation of exhaled nitric oxide, spirometry and asthma symptoms

Asthma is the most common chronic disease of childhood. Asthma severity is monitored by spirometry. However, this does not directly measure airway inflammation. Exhaled nitric oxide (FeNO) is a proposed method to measure airway inflammation non-invasively. Previous studies have shown that FeNO correlates with endobronchial biopsies and symptoms in patients with asthma. We monitored daily asthma symptoms compared to monthly spirometry and FeNO. Total monthly symptom scores correlated with both forced expiratory volume at 1 sec (FEV1) and FeNO. FeNO had a strong correlation than FEV1. FeNO and FEV1 were not correlated. We propose that FeNO should be used as an additional monitoring tool for asthma.

Effect of omalizumab on adenosine 5'-monophosphate responsiveness in subjects with allergic asthma

BACKGROUND

The objective of this study was to evaluate the effects of omalizumab on bronchoconstriction induced by methacholine and adenosine 5'-monophosphate (AMP).

METHODS

Thirty-four subjects with mild to moderate allergic asthma were randomized to receive placebo (n = 16) or omalizumab (n = 18) subcutaneously during 12 weeks. Airway responsiveness to AMP was measured at baseline and after 4 and 12 weeks of treatment, whereas the response to methacholine was measured at baseline and after 12 weeks of treatment.

RESULTS

After 4 weeks of treatment, the increase in AMP PC(20) (provocative concentration required to produce a 20% fall in FEV(1)) was significantly greater in the omalizumab group than in the placebo group, the mean difference in the change between the groups being 1.52 doubling concentrations (95% CI, 0.25-2.79, p = 0.02). Compared with baseline, the mean AMP PC(20) values at 12 weeks were increased by 1.91 doubling concentrations with omalizumab (p < 0.001) and 1.01 doubling concentrations with placebo (p = 0.16), but changes were not significantly different between the treatment groups. Changes in methacholine PC(20) values were not significantly different between the omalizumab and placebo groups.

CONCLUSIONS

In subjects with allergic asthma, omalizumab reduces the response to AMP without decreasing the response to methacholine. These findings are consistent with the conclusion that the contribution of IgE to the development of AMP bronchoconstriction is more important than their role in the induction of methacholine hyperresponsiveness.

Exhaled nitric oxide levels and airway responsiveness to adenosine 5'-monophosphate in subjects with nasal polyposis

BACKGROUND

It is widely appreciated that asthma is an inflammatory disease of the airways associated with airway hyperresponsiveness, and that nasal polyposis and asthma are related diseases. The objective of this study was to determine differences in exhaled nitric oxide (ENO) levels and airway responsiveness to adenosine 5'-monophosphate (AMP) between nonasthmatic patients with nasal polyposis and healthy controls.

METHODS

Twenty patients without asthma with nasal polyposis and 16 healthy control subjects were enrolled in the study. Participants were challenged with increasing concentrations of AMP and methacholine. ENO was measured with the single-exhalation method.

RESULTS

Bronchoconstriction in response to AMP was detected in 7 (35%) subjects with nasal polyposis. The geometric mean (95% CI) of ENO for subjects with nasal polyposis was 33.1 parts per billion (ppb) (24.0-45.7 ppb) compared with 12.3 ppb (8.5-18.2 ppb) for the healthy controls (p = 0.0002). ENO values were significantly higher in atopic than in nonatopic subjects with nasal polyposis [51.3 ppb (32.3-83.2 ppb) vs. 24.5 ppb (16.2-37.1 ppb), p = 0.02]. Nonatopic subjects with nasal polyposis also had higher concentrations of ENO than healthy control subjects (p = 0.016).

CONCLUSIONS

Inhaled AMP causes airway narrowing in a significantly higher proportion of nonasthmatic subjects with nasal polyposis than in healthy controls. Furthermore, increased concentrations of ENO are detected in atopic and nonatopic subjects with nasal polyposis. These results suggest that bronchial inflammation is present in nonasthmatic subjects with nasal polyposis.

Airway responsiveness to adenosine 5'-monophosphate and exhaled nitric oxide measurements: predictive value as markers for reducing the dose of inhaled corticosteroids in asthmatic subjects

OBJECTIVES

To investigate the utility of the determination of airway responsiveness to inhaled adenosine 5'-monophosphate (AMP) and exhaled nitric oxide (ENO) levels as markers for safely reducing the dose of inhaled corticosteroids (ICS) in patients with asthma well controlled with a moderately high ICS dose.

METHODS

A total of 37 patients with asthma well controlled for at least 3 months by treatment with a moderately high ICS dose (beclomethasone dipropionate, 500 to 1,000 microg or equivalent daily) were included in the study. Patients were treated for a 2-week run-in (baseline) period with their usual dose of ICS. For the next 12 weeks, patients were treated with ICS at half the previous dose, maintaining the same inhalation device. At the end of the baseline period and after 2 weeks, 8 weeks, and 12 weeks of treatment with a reduced dose of ICS, measurements were made in the following order: ENO, spirometry, and AMP challenge. Furthermore, patients completed a diary twice daily recording peak expiratory flow, daytime and nighttime symptoms, and use of rescue albuterol.

RESULTS

Ten patients had an asthma exacerbation. Using a Kaplan-Meier survival analysis, the significant predictors of a failure of ICS reduction were having both bronchoconstriction in response to AMP and ENO levels > or = 15 parts per billion (ppb) at baseline (p = 0.006), as well as having both bronchoconstriction in response to AMP and ENO levels > or = 20 ppb at baseline (p = 0.033). Having a decrease in the provocative concentration of AMP causing a 20% fall in FEV(1) of at least one doubling concentration 2 weeks after the dose of ICS was halved was a borderline significant predictor for failure of ICS reduction (p = 0.062).

CONCLUSION

These observations suggest that in asthmatic patients well controlled with ICS, the determination of AMP responsiveness and ENO levels may be useful to identifying those subjects whose condition will or will not deteriorate when the dose of ICS is reduced.

Nitric oxide in allergic airway inflammation

PURPOSE OF REVIEW

Exhaled nitric oxide has been proposed as a useful noninvasive marker of airway inflammation in asthma. Great efforts have been made to standardize the methodology for exhaled nitric oxide measurement in both children and adults. As a consequence there is now an opportunity to establish the precise relationship between exhaled nitric oxide, atopy and airway inflammation, and to investigate whether or not there is a role for the measurement of exhaled nitric oxide in the management of patients with asthma.

RECENT FINDINGS

A number of recent studies have investigated the relationship between exhaled nitric oxide and airway inflammation in asthma measured directly, using sputum induction, bronchoalveolar lavage and endobronchial biopsy. These measurements suggest that exhaled nitric oxide reflects eosinophilic airway inflammation in asthma, although there is no evidence for any relationship between exhaled nitric oxide and other airway inflammatory cells. Exhaled nitric oxide levels were found to be higher in atopic compared with nonatopic groups. These levels, however, are further elevated in atopic patients with asthma, suggesting that exhaled nitric oxide is not simply a marker of atopy. Although there is little evidence to support the routine use of measurement of exhaled nitric oxide in the management of patients with asthma, it may prove to be useful in assessing adherence to treatment with inhaled corticosteroids, or in the identification of patients in whom respiratory symptoms are associated with eosinophilic airway inflammation.

SUMMARY

There is good evidence that exhaled nitric oxide reflects eosinophilic airway inflammation in asthma. Well designed, long-term studies are needed to evaluate whether the addition of exhaled nitric oxide measurements to clinical and lung function assessment results in improved asthma control.

Effect of cigarette smoking on airway responsiveness to adenosine 5'-monophosphate in subjects with allergic rhinitis

STUDY OBJECTIVES

The objective of this study was to determine differences in airway responsiveness to adenosine 5'-monophosphate (AMP) between smokers and nonsmokers with allergic rhinitis.

METHODS

A total of 41 adults with allergic rhinitis (16 smokers and 25 nonsmokers) were challenged with increasing concentrations of methacholine and AMP. Airflow was assessed after each concentration, and the response to each bronchoconstrictor agent was measured by the provocative concentration required to produce a 20% fall in FEV(1) (PC(20)).

RESULTS

The geometric mean PC(20) AMP values were significantly lower in smokers than in nonsmokers: 72.4 mg/mL (95% confidence interval [CI], 33.9 to 154.9) vs 204.2 mg/mL (95% CI, 120.2 to 346.7) [p = 0.021]. The proportion of subjects with bronchoconstriction in response to AMP was higher in smokers (12 of 16 subjects) than in nonsmokers (7 of 25 subjects) [p = 0.005].

CONCLUSIONS

We conclude that smokers with allergic rhinitis have a greater AMP sensitivity than nonsmokers.

The role of adenosine as a novel bronchoprovocant in asthma

PURPOSE OF REVIEW

There is evidence that bronchial hyperresponsiveness to inhaled adenosine may be a better marker of airway allergic inflammation than bronchial hyperresponsiveness to other spasmogens. Here the authors review the most recent development in this area of rapidly evolving clinical research, focusing on the putative role of adenosine as a useful bronchoprovocant in asthma.

RECENT FINDINGS

New studies have provided evidence that hyperresponsiveness to AMP strongly correlates with sputum, blood/bronchial tissue eosinophilia and exhaled nitric oxide, whereas hyperresponsiveness to methacholine is related to changes in forced expiratory volume in 1 s, thus reflecting changes in airway caliber and functional state. Other recent studies have emphasized that the state of atopy is critically important in the bronchial response to inhaled AMP. The early finding that in people with asthma treatment with inhaled glucocorticosteroids significantly reduces airway responsiveness to AMP, as compared with other spasmogens such as methacholine or bradykinin, has been confirmed by recent reports which have also outlined that this is an early phenomenon.

SUMMARY

Taken together these studies evidence that hyperresponsiveness to inhaled adenosine may be a better marker of airway allergic inflammation than hyperresponsiveness to other spasmogens. This peculiar property of adenosine suggests that bronchial provocation with inhaled adenosine could provide a reliable noninvasive tool for monitoring asthma activity/progression, and assessing the response to antiinflammatory treatments.

Concentrations of exhaled nitric oxide in asthmatics and subjects with allergic rhinitis sensitized to the same pollen allergen

BACKGROUND

Some studies have reported that the levels of exhaled nitric oxide (ENO) in asthmatics are similar to those in subjects with allergic rhinitis, and it has been postulated that atopic status might be the determinant of enhanced nitric oxide production in asthma.

OBJECTIVES

The aim of this study was to determine differences in ENO levels between asthmatics and subjects with allergic rhinitis sensitized to the same allergen, and to correlate these levels with airway responsiveness.

METHODS

Nineteen patients with asthma and 18 subjects with allergic rhinitis monosensitized to Parietaria pollen were enrolled in the study. ENO values and airway responsiveness to methacholine and adenosine 5'-monophosphate (AMP) were measured during the pollen season. The response to each bronchoconstrictor agent was measured by the provocative concentration required to produce a 20% fall in FEV1 (PC20). ENO was measured with the single-exhalation method.

RESULTS

The geometric mean (95% confidence interval) ENO values were significantly higher in asthmatics than in subjects with allergic rhinitis: 72.4p.p.b. (54.9-93.3p.p.b) vs. 44.7p.p.b. (30.9-64.6p.p.b., P = 0.03). In asthmatics, a significant correlation was found between ENO and PC20 AMP values (p = -0.57, P=0.02), whereas no correlation was detected between ENO and PC20 methacholine (p = -0.35, P = 0.14).

CONCLUSIONS

Our results suggest that atopy is not the only determinant of increased ENO levels detected in subjects with asthma, and that responsiveness to AMP may be a more sensitive marker for assessing airway inflammation in asthma compared to methacholine.