Exhaled nitric oxide measures allergy not symptoms in children with allergic rhinitis in primary care: a prospective cross-sectional and longitudinal cohort study

Exhaled Nitric Oxide as Biomarker of Type 2 Diseases

Nitric oxide (NO) is a short-lived gas molecule which has been studied for its role as a signaling molecule in the vasculature and later, in a broader view, as a cellular messenger in many other biological processes such as immunity and inflammation, cell survival, apoptosis, and aging. Fractional exhaled nitric oxide (FeNO) is a convenient, easy-to-obtain, and non-invasive method for assessing active, mainly Th2-driven, airway inflammation, which is sensitive to treatment with standard anti-inflammatory therapy. Consequently, FeNO serves as a valued tool to aid the diagnosis and monitoring of several asthma phenotypes. More recently, FeNO has been evaluated in several other respiratory and/or immunological conditions, including allergic rhinitis, chronic rhinosinusitis with/without nasal polyps, atopic dermatitis, eosinophilic esophagitis, and food allergy. In this review, we aim to provide an extensive overview of the current state of knowledge about FeNO as a biomarker in type 2 inflammation, outlining past and recent data on the application of its measurement in patients affected by a broad variety of atopic/allergic disorders.

2020 Focused Updates to the Asthma Management Guidelines: A Report from the National Asthma Education and Prevention Program Coordinating Committee Expert Panel Working Group

The 2020 Focused Updates to the Asthma Management Guidelines: A Report from the National Asthma Education and Prevention Program Coordinating Committee Expert Panel Working Group was coordinated and supported by the National Heart, Lung, and Blood Institute (NHLBI) of the National Institutes of Health. It is designed to improve patient care and support informed decision making about asthma management in the clinical setting. This update addresses six priority topic areas as determined by the state of the science at the time of a needs assessment, and input from multiple stakeholders:A rigorous process was undertaken to develop these evidence-based guidelines. The Agency for Healthcare Research and Quality's (AHRQ) Evidence-Based Practice Centers conducted systematic reviews on these topics, which were used by the Expert Panel Working Group as a basis for developing recommendations and guidance. The Expert Panel used GRADE (Grading of Recommendations, Assessment, Development and Evaluation), an internationally accepted framework, in consultation with an experienced methodology team for determining the certainty of evidence and the direction and strength of recommendations based on the evidence. Practical implementation guidance for each recommendation incorporates findings from NHLBI-led patient, caregiver, and clinician focus groups. To assist clincians in implementing these recommendations into patient care, the new recommendations have been integrated into the existing Expert Panel Report-3 (EPR-3) asthma management step diagram format.

Identification of volatile active components in Acori Tatarinowii Rhizome essential oil from different regions in China by C6 glioma cells

Background

Acori Tatarinowii Rhizome (ATR) is a well-recognized Chinese herbal medicine prescribed to treat neurological disorders. The essential oil (ATEO) is considered as the active fraction of ATR and the content of ATEO is used as the only indicator for ATR content determination. The quality of ATEO varies widely due to region difference; however, little is known about how to study ATEO quality chemically and biologically in response to region difference. Thus, it is of great importance to identify volatile active components in ATEO to conduct quality study. In this study, we analyzed ATEO from different regions in China using chemical component analysis combined with biological activity evaluation.

Methods

GC-MS was used to obtain different volatile component profiles of ATEO and significantly changed volatile components were screened out. The neuroprotective activities of ATEO, including anti-oxidation, anti-inflammation and neurotrophic functions, were revealed in C6 glioma cells. The correlation study between the bioactivities and the components was performed.

Results

57 volatile components, including terpenoids, phenylpropanoids, aromatic compounds, and other aliphatic compounds, were identified. 8 volatile components (β-asarone, cis-methyl isoeugenol, γ-asarone, methyleugenol, calarene, longifolene, β-caryophyllene and caryophyllene oxide) from ATEO were significantly changed due to region difference and 2 of them (β-asarone and γ-asarone) showed strong correlation with neuroprotective activities.

Conclusions

Our results reveal that ATEO from different regions in China show great changes in chemical composition and biological activity. Moreover, phenylpropanoids (β-asarone and γ-asarone) present strong correlation with the bioactivities, which are considered as volatile active components in ATEO. The findings will be useful for the development of quality study of ATEO.

Comparison of exhaled nitric oxide levels in pediatric patients with allergic rhinitis

OBJECTIVE

To determine whether the measurement of exhaled nitric oxide (eNO) can help distinguish children with allergic rhinitis (AR) from healthy controls and whether eNO in children with AR correlates with disease severity.

METHODS

From August 2015 to 2016, children aged 5-15 years of age grouped into those with allergic rhinitis (n = 40) and those classified as healthy control subjects (n = 40) had exhaled nitric oxide (eNO) levels measured. The eNO level was additionally compared to the patient's clinical disease severity according to the ARIA (Allergic Rhinitis and its Impact on Asthma) classification.

RESULTS

Mean eNO in children with AR (12.64 ± 14.67 ppb) was significantly higher than that in the healthy control group (7.00 ± 6.33 ppb) (p-value = 0.046). In the persistent AR group (17.11 ± 18.40 ppb), eNO level was significantly higher than individuals in the intermittent AR group (8.59 ± 8.88 ppb, p-value = 0.024) and the healthy control group (7.00 ± 6.33 ppb, p-value = 0.008). Among children with AR, eNo was not significantly different with relationship to gender, age, weight and passive smoking exposure.

CONCLUSIONS

Exhaled nitric oxide may be elevated in children with AR that do not have concomitant asthma. This suggests exhaled nitric oxide may show utility as a parameter to monitor the severity of allergic rhinitis and to monitor the efficacy of the treatment. Physicians should consider comorbid AR when utilizing exhaled nitric oxide as a monitoring parameter in the treatment of asthma.

Prevalence and risk factors for allergic rhinitis in two resource-limited settings in Peru with disparate degrees of urbanization

BACKGROUND

Allergic rhinitis is a disease with a high global disease burden, but risk factors that contribute to this condition are not well understood.

OBJECTIVE

To assess the prevalence and risk factors of allergic rhinitis in two Peruvian populations with disparate degrees of urbanization.

METHODS

We conducted a population-based, cross-sectional study on 1441 children aged 13-15 years at enrollment (mean age 14.9 years, 51% boys) to investigate the prevalence of allergic disease. We used a standardized, Spanish validated questionnaire to determine the prevalence of allergic rhinitis and asked about sociodemographics and family history of allergies. Children also underwent spirometry, exhaled nitric oxide, allergy skin testing to 10 common household allergens and provided a blood sample for measurement of 25OH vitamin D and total serum IgE.

RESULTS

Overall prevalence of allergic rhinitis was 18% (95% CI 16% to 20%). When stratified by site, the prevalence of allergic rhinitis was 23% Lima vs. 13% in Tumbes (P < 0.001); however, this difference was no longer significant after controlling for subject-specific factors (P = 0.95). There was a strong association with other allergic diseases: 53% of children with asthma had allergic rhinitis vs. 15% in those without asthma (P < 0.001) and 42% of children with eczema vs. 17% of those without eczema (P < 0.001). Important risk factors for allergic rhinitis were parental rhinitis (adjusted OR = 3.0, 95% CI 1.9-4.7 for 1 parent and adjusted OR = 4.4, 95% CI 1.5-13.7 for 2 parents); allergic sensitization to common household aeroallergens (1.6, 1.1-2.3); being overweight (1.5, 1.0-2.3); exhaled nitric oxide ≥ 20 ppb (1.9, 1.3-2.7); and total serum IgE ≥ 95th percentile (2.4, 1.2-4.8). Population attributable risk of important factors for allergic rhinitis were 25% for high exhaled nitric oxide, 22% for allergic sensitization to common household aeroallergens, 22% for paternal rhinitis, 10% for being overweight and 7% for an elevated total serum IgE.

CONCLUSION AND CLINICAL RELEVANCE

Allergic rhinitis was prevalent in both settings, and important risk factors include elevated exhaled nitric oxide, allergic sensitization to common household aeroallergens, parental rhinitis, being overweight and high total serum IgE. When considering subject-specific factors, the difference in prevalence between the urban and rural settings became non-important.

Exhaled NO: Determinants and Clinical Application in Children With Allergic Airway Disease

Nitric oxide (NO) is endogenously released in the airways, and the fractional concentration of NO in exhaled breath (FeNO) is now recognized as a surrogate marker of eosinophilic airway inflammation that can be measured using a noninvasive technique suitable for young children. Although FeNO levels are affected by several factors, the most important clinical determinants of increased FeNO levels are atopy, asthma, and allergic rhinitis. In addition, air pollution is an environmental determinant of FeNO that may contribute to the high prevalence of allergic disease. In this review, we discuss the mechanism for airway NO production, methods for measuring FeNO, and determinants of FeNO in children, including host and environmental factors such as air pollution. We also discuss the clinical utility of FeNO in children with asthma and allergic rhinitis and further useful directions using FeNO measurement.

The role of fractional exhaled nitric oxide in asthma management

Measuring fractional exhaled nitric oxide (FeNO) is a relatively new option for assessing allergic inflammation in the lungs. Clinical management of asthma is challenging, and measuring exhaled nitric oxide can provide another type of data to assist in meeting this challenge. FeNO is easy to perform, and the equipment is not forbiddingly expensive. FeNO provides a complement to traditional measures of asthma control and can help guide diagnostic and treatment choices. This article explains what it is, how the measurements are performed, what the norms are, and its use and limitations in the management of asthma.

[Personalised medicine for the diagnosis and treatment of allergic diseases]

Immunoglobulin E (IgE) mediated allergic diseases are characterised by heterogeneous clinical phenotypes and a large variety of different sensitisation patterns. Apart from genetic predisposition several environmental factors play a role in sensitisation and elicitation of symptoms. Since the majority of clinically relevant allergens are now available as purified recombinant allergens component-resolved in vitro diagnosis allows the sensitization profile of allergic patients to be determined at the molecular level. Such data may allow physicians to draw conclusions on the severity and persistence of a given allergic disease and to predict the outcome of allergen-specific immunotherapy (SIT) However, the potential of this approach needs to be demonstrated in controlled clinical trials. Moreover, in the context of atopic dermatitis, allergic rhinitis, allergic bronchial asthma as well as the atopic march several screening-biomarkers, diagnostic and prognostic biomarkers, biomarkers of severity and predictive biomarkers are presented and discussed in this article. Traditionally a relevant proportion of allergen-specific immunotherapies is performed in a personalised manner using named patient products manufactured on the basis of an individual prescription. Such named patient products are often mixtures containing several allergen extracts from different sources. However, there is no proven evidence for the safety and efficacy of this approach. In Germany the Therapy Allergen Ordinance ("Therapieallergene-Verordnung", TAV) regulates that in the future allergen products for SIT of insect venom allergies, allergies to pollen of early flowering trees and grass pollen and house dust mite allergies cannot be marketed as named patient products, but always require a marketing authorisation. Thus personalised SIT with named patient products is restricted to the treatment of less prevalent allergies, for which the generation of state-of-the-art clinical data is more difficult. Several recombinant allergens are currently evaluated in phase III clinical trials. In contrast to allergen extracts recombinant allergens offer the possibility to treat patients with a precisely adjusted mixture of the disease-eliciting allergen molecules. However, the implementation of this personalised approach to SIT within the given regulatory framework represents a challenge to regulators.

Allergic rhinitis quality of life in urban children with asthma

BACKGROUND

Urban children with asthma and allergic rhinitis (AR) are at risk for experiencing worse AR-related quality of life (QOL). Although AR may be underdiagnosed and undertreated in urban minority children, research has not considered which illness-related indicators (eg, AR control) may contribute to AR QOL in this population.

OBJECTIVE

To examine associations among AR control, asthma control, allergy symptoms, asthma symptoms, and AR QOL in a sample of 195 urban caregivers and their children with asthma (7-9 years of age) from African American, Latino, and non-Latino white backgrounds. Racial and ethnic differences in AR QOL were also examined.

METHODS

Families resided in 1 of 4 cities selected as recruitment sources because of their high concentrations of ethnic minority and non-Latino white, urban families. Caregivers and children completed a series of interview-based and clinician-based assessments across one academic year and 4-week periods to track daily asthma and nasal symptoms.

RESULTS

Better AR control was associated with higher AR QOL (β = -.32, P < .01) and all QOL subscales. AR control predicted AR QOL over and above asthma control (β = -.28, P < .01). Controlling for AR control, non-Latino white children reported better QOL related to practical problems than both Latino and African American children (P < .05).

CONCLUSION

Findings suggest that strategies to enhance AR control in urban children with asthma may assist in improving AR QOL. Non-Latino white children may experience less impairment of their AR QOL because of practical problems (eg, blow nose) than African American or Latino children with asthma.

Longitudinal assessment of high versus low levels of fractional exhaled nitric oxide among children with asthma and atopy

PURPOSE

Fractional exhaled nitric oxide (FeNO) has emerged as an important biomarker in asthma. Increasing evidence points to atopy as a confounding factor in the interpretation of elevated FeNO. We conducted a longitudinal study to understand the clinical significance of FeNO as an inflammatory biomarker.

METHODS

We identified 19 children aged 13-15 years at baseline with a significant elevation in FeNO ≥ 80 parts per billion (ppb) and randomly selected a group of children of similar age with a moderate elevation (40-79 ppb) and normal-to-low FeNO (<40 ppb). Between November 2010 and July 2011, three additional study visits were conducted.

RESULTS

Ninety-three children participated in the study. There were 16, 24, and 53 participants in the high, mid, and low FeNO groups. During 1.5 years of follow-up, mean FeNO levels were 82.6 ppb (standard deviation [SD] = 65.9) for atopic asthmatics, 50.6 ppb (SD = 42.6) for nonasthmatic atopics, 17.0 ppb (SD = 10.8) for nonatopic asthmatics, and 17.8 ppb (SD = 13.9) for nonatopic nonasthmatics (p < 0.001). FeNO levels remained stable: 63 % of the high FeNO group had a FeNO ≥ 80 across all 4 measurements and 87 % of the normal-to-low FeNO group had a FeNO of <40 across all 4 measurements. The high FeNO group also was found to have an elevation in IL-5 (p = 0.04), IL-6 (p = 0.003), IL-10 (p = 0.002), and total serum IgE (p < 0.001), after adjustment by age, sex, height, body mass index, and atopy and asthma status.

CONCLUSIONS

An elevation of FeNO appears to indicate an atopic phenotype regardless of an asthma diagnosis, clinical symptoms, or corticosteroid use. An elevation of FeNO also is associated with a systemic elevation in inflammatory cytokines.