Association between exhaled nitric oxide and nasal polyposis in severe asthma

Real-Life Response to Biologics in Severe Asthma with Nasal Polyposis: Insights from the Belgian Severe Asthma Registry

BACKGROUND

Nasal polyposis (NP) is a comorbidity of type 2 severe asthma (SA) which could influence response to SA biologics.

METHODS

We evaluated (super-) response in SA patients with (NP +) and without NP (NP-) enrolled in the Belgian Severe Asthma Registry (BSAR).

RESULTS

914 patients, of whom 31% NP + , were included. At enrollment, NP + patients had higher annual exacerbation rates, higher number of emergency room visits and more elevated type 2 biomarkers. In the longitudinal subanalysis of 104 patients, both groups had significant and similar asthma responses to asthma biologics, except for a greater increase in FEV1 in the NP + group. Super-response was achieved in 33 patients (32%), irrespective of NP status or type of biologic.

CONCLUSION

In conclusion, both NP + and NP - patients had positive treatment responses, with some able to achieve super-response. In SA patients with NP, a greater FEV1 improvement as compared to SA patients without NP was observed.

Evaluation of multiple-flows exhaled nitric oxide and its clinical significance in severe asthmatic patients treated with biologics: a prospective real-life study

BACKGROUND

Specific biomarkers, such as eosinophilia in peripheral blood or fractional exhaled nitric oxide (FeNO), can guide us in the choice of biologic therapy, allowing a more personalized approach. Although there are multiple evidences in the literature about the role of FeNO as a predictor of response to different biologic treatments, there are no data on the relationship between FeNO changes and clinical response to the four biologic drugs currently in use.

OBJECTIVE

To evaluate and to compare the expression of multiple-flows FeNO parameters in a cohort of patients with severe asthma (SA) before and during the treatment with biologics to evaluate the performance of these biomarkers in predicting the achievement of clinical remission.

METHODS

We prospectively enrolled 50 patients with severe asthma eligible for biologic therapy. Patients underwent clinical and functional monitoring at baseline (T0) and after 1, 6, and 12 months of treatment (T1, T6, T12), including multiple flows FeNO assessment.

RESULTS

A statistically significant reduction of FeNO50 values and J'awNO was observed only in benralizumab and dupilumab subgroups. Among biomarkers, the reduction of FeNO 50 values at T1 was associated with a higher probability of achieving clinical remission at T12 (p = 0.003), which was also confirmed by ROC curve analysis (AUC 0.758, p = 0.002; sensitivity 60% and specificity 74% for a reduction of 16 ppb).

CONCLUSION

These data confirm the potential of this biomarker in predicting clinical response to biologic treatment in patients with severe asthma in order to guide clinical decisions and evaluate a shift to other biologic therapy.

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.

The Role of Fractional Exhaled Nitric Oxide in Diagnosing Asthmatic Type 2 Chronic Rhinosinusitis With Nasal Polyps

BACKGROUND

Fractional exhaled nitric oxide (FeNO) is useful in the management of asthma and predicting the efficacy of standard corticosteroids and biologics. However, the diagnostic value of FeNO in asthmatic chronic rhinosinusitis with nasal polyps (CRSwNP) remains unclear.

OBJECTIVE

We assessed FeNO levels in patients with CRSwNP and evaluated the diagnostic value of FeNO for screening type 2 CRSwNP (T2-CRSwNP) with asthma.

METHODS

We enrolled 94 patients who were diagnosed with CRSwNP and underwent functional endoscopic sinus surgery. FeNO levels, the blood eosinophil percentage, total IgE, spirometry tests (FEV1/FVC), Lund-Mackay CT score, and percentage of patients with comorbid asthma were compared among CRSwNP subgroups. Spearman rank correlation test was used to assess the degree of association between variables. ROC curve analysis was conducted to evaluate the diagnostic capability to differentiate T2-CRSwNP based on clinical and histological classifications.

RESULTS

FeNO levels and the blood eosinophil percentage were significantly higher in patients with T2-CRSwNP(h) based on histological data (P < .05). FeNO was correlated with the blood eosinophil percentage (r = 0.420, P < .001) and FEV1/FVC (r = -0.324, P = .001). A FeNO level of 27 ppb had a good ability to discriminate patients with asthmatic T2-CRSwNP(h) (AUC = 0.848; 95% CI = 0.7602-0.9361; sensitivity = 90.9%; specificity = 63.9%). The optimal cutoff values for FeNO and the blood eosinophil percentage for diagnosing asthmatic T2-CRSwNP(h) were 68 ppb and 5.6% (sensitivity = 95.5%; specificity = 86.1%; AUC = 0.931; 95% CI = 0.8832-0.9791). In the diagnosis of severe T2-CRSwNP(c) based on clinical data, a FeNO level of 36 ppb showed the highest AUC (0.816; 95% CI = 0.7173-0.914; sensitivity = 72.7%; specificity = 79.2%).

CONCLUSION

FeNO is a useful marker for screening asthmatic T2-CRSwNP even prior to biopsy or asthma evaluation and may assist in selecting a proper treatment.

International consensus statement on allergy and rhinology: Allergic rhinitis - 2023

BACKGROUND

In the 5 years that have passed since the publication of the 2018 International Consensus Statement on Allergy and Rhinology: Allergic Rhinitis (ICAR-Allergic Rhinitis 2018), the literature has expanded substantially. The ICAR-Allergic Rhinitis 2023 update presents 144 individual topics on allergic rhinitis (AR), expanded by over 40 topics from the 2018 document. Originally presented topics from 2018 have also been reviewed and updated. The executive summary highlights key evidence-based findings and recommendation from the full document.

METHODS

ICAR-Allergic Rhinitis 2023 employed established evidence-based review with recommendation (EBRR) methodology to individually evaluate each topic. Stepwise iterative peer review and consensus was performed for each topic. The final document was then collated and includes the results of this work.

RESULTS

ICAR-Allergic Rhinitis 2023 includes 10 major content areas and 144 individual topics related to AR. For a substantial proportion of topics included, an aggregate grade of evidence is presented, which is determined by collating the levels of evidence for each available study identified in the literature. For topics in which a diagnostic or therapeutic intervention is considered, a recommendation summary is presented, which considers the aggregate grade of evidence, benefit, harm, and cost.

CONCLUSION

The ICAR-Allergic Rhinitis 2023 update provides a comprehensive evaluation of AR and the currently available evidence. It is this evidence that contributes to our current knowledge base and recommendations for patient evaluation and treatment.

Increase in FeNO Levels Following IL5/IL5R-Targeting Therapies in Severe Asthma: A Case Series

Purpose

Monoclonal antibodies targeting interleukin-5 (IL5) and its receptor (IL5R), used for severe asthma treatment, reduce eosinophils to almost complete depletion. Fractional exhaled nitric oxide (FeNO), a surrogate marker of eosinophilic airway inflammation, is expected to decrease after their initiation. Our center noticed increased FeNO levels in a few patients in whom anti-IL5/IL5R therapy was initiated. Limited data are available on the kinetics of T2 inflammation biomarkers after initiation of a biologic in that population. This study aims to identify if a subgroup of severe asthma patients experiences increased FeNO levels after initiation of anti-IL5/IL5R therapy and to describe their clinical characteristics.

Patients and Methods

This is a retrospective case series of 5 patients on Benralizumab (4M:1F) and 8 on Mepolizumab (5M:3F) who showed a significant increase in FeNO (>20% AND >25 ppb) following initiation of an anti-IL5/IL5R treatment. Clinical data, expiratory flows, and inflammation were extracted from the patients’ chart at initiation of treatment (T₀), 3 months (T₁) and 12 months (T₂) post-treatment. Descriptive statistics were used.

Results

In patients treated with Benralizumab, the increase in FeNO was observed between T₀ and T₁ (mean delta = 82 ± 72 ppb) with a subsequent decrease (N = 3). In most patients taking Mepolizumab (N = 6), the FeNO increase was observed between T₁ and T₂ (mean delta = 57 ± 35 ppb). Under treatment, no Benralizumab patient experienced asthma exacerbation while two on Mepolizumab did. All patients had a significant decrease in blood eosinophils.

Conclusion

Although initiation of anti-IL5/IL5R may cause a transient rise in FeNO levels in a subgroup of patients, it does not appear to affect clinical outcomes. A compensatory mechanism involving other inflammatory pathways such as IL13 or IL4, both involved in FeNO production, could theoretically explain these findings. Further investigation is needed to elucidate the actual underlying mechanisms.

WAO-ARIA consensus on chronic cough - Part III: Management strategies in primary and cough-specialty care. Updates in COVID-19

Background

Chronic cough management necessitates a clear integrated care pathway approach. Primary care physicians initially encounter the majority of chronic cough patients, yet their role in proper management can prove challenging due to limited access to advanced diagnostic testing. A multidisciplinary approach involving otolaryngologists and chest physicians, allergists, and gastroenterologists, among others, is central to the optimal diagnosis and treatment of conditions which underly or worsen cough. These include infectious and inflammatory, upper and lower airway pathologies, or gastro-esophageal reflux. Despite the wide armamentarium of ancillary testing conducted in cough multidisciplinary care, such management can improve cough but seldom resolves it completely. This can be due partly to the limited data on the role of tests (eg, spirometry, exhaled nitric oxide), as well as classical pharmacotherapy conducted in multidisciplinary specialties for chronic cough. Other important factors include presence of multiple concomitant cough trigger mechanisms and the central neuronal complexity of chronic cough. Subsequent management conducted by cough specialists aims at control of cough refractory to prior interventions and includes cough-specific behavioral counseling and pharmacotherapy with neuromodulators, among others. Preliminary data on the role of neuromodulators in a proof-of-concept manner are encouraging but lack strong evidence on efficacy and safety.

Objectives

The World Allergy Organization (WAO)/Allergic Rhinitis and its Impact on Asthma (ARIA) Joint Committee on Chronic Cough reviewed the recent literature on management of chronic cough in primary, multidisciplinary, and cough-specialty care. Knowledge gaps in diagnostic testing, classical and neuromodulator pharmacotherapy, in addition to behavioral therapy of chronic cough were also analyzed.

Outcomes

This third part of the WAO/ARIA consensus on chronic cough suggests a management algorithm of chronic cough in an integrated care pathway approach. Insights into the inherent limitations of multidisciplinary cough diagnostic testing, efficacy and safety of currently available antitussive pharmacotherapy, or the recently recognized behavioral therapy, can significantly improve the standards of care in patients with chronic cough.

Cross-sectional study on exhaled nitric oxide in relation to upper airway inflammatory disorders with regard to asthma and perennial sensitization

BACKGROUND

Fractional exhaled nitric oxide (FeNO) is a well-known marker of type-2 inflammation. FeNO is elevated in asthma and allergic rhinitis, with IgE sensitization as a major determinant.

OBJECTIVE

We aimed to see whether there was an independent association between upper airway inflammatory disorders (UAID) and FeNO, after adjustment for asthma and sensitization, in a multi-centre population-based study.

METHODS

A total of 741 subjects with current asthma and 4155 non-asthmatic subjects participating in the second follow-up of the European Community Respiratory Health Survey (ECRHS III) underwent FeNO measurements. Sensitization status was based on measurement of IgE against airborne allergens; information on asthma, UAID and medication was collected through interview-led questionnaires. Independent associations between UAID and FeNO were assessed in adjusted multivariate regression models and test for interaction with perennial sensitization and asthma on the relation between UAID and FeNO were made.

RESULTS

UAID were associated with higher FeNO after adjusting for perennial sensitization, asthma and other confounders: with 4.4 (0.9-7.9) % higher FeNO in relation to current rhinitis and 4.8 (0.7-9.2) % higher FeNO in relation to rhinoconjunctivitis. A significant interaction with perennial sensitization was found in the relationship between current rhinitis and FeNO (p = .03) and between rhinoconjunctivitis and FeNO (p = .03). After stratification by asthma and perennial sensitization, the association between current rhinitis and FeNO remained in non-asthmatic subjects with perennial sensitization, with 12.1 (0.2-25.5) % higher FeNO in subjects with current rhinitis than in those without.

CONCLUSIONS & CLINICAL RELEVANCE

Current rhinitis and rhinoconjunctivitis was associated with higher FeNO, with an interaction with perennial sensitization. This further highlights the concept of united airway disease, with correlations between symptoms and inflammation in the upper and lower airways and that sensitization needs to be accounted for in the relation between FeNO and rhinitis.

Impact of nasal polyps on endotype and phenotype in patients with moderate to severe asthma

BACKGROUND

Nasal polyps (NPs) are a common comorbidity of asthma. Differences in disease endotype and phenotype may have treatment implications for these concomitant conditions, including biologic therapies.

OBJECTIVE

To determine putative differences in type 2 biomarkers, lung function, and asthma control in patients with asthma with NPs (AwNPs) and those with asthma alone (A).

METHODS

A total of 140 consecutive patients with moderate to severe asthma with or without endoscopic NPs taking a daily inhaled corticosteroid dose of greater than or equal to 800 µg and at least 1 second-line controller were identified from our National Health Service specialist respiratory and rhinology clinics. Data were collected before starting on biologics, including peripheral blood eosinophils (PBEs), fractional exhaled nitric oxide (FeNO), allergy status, spirometry, impulse oscillometry, Asthma Control Questionnaire, oral corticosteroid requiring asthma exacerbations, NP score, and Lund-Mackay score.

RESULTS

The PBE count and FeNO levels were significantly higher (P < .01), whereas specific and total immunoglobulin E levels (P < .05) were significantly lower in AwNPs vs A. In addition, FeNO had sensitivity of 81% and specificity of 67% for detecting NPs (area under the curve = 0.76; P = .001). Patients with AwNPs had less severe asthma than those with asthma without NPs (A), as reflected by fewer exacerbations (P < .001), lower inhaled corticosteroid dose (P < .001), and less impairment of impulse oscillometry (P < .05).

CONCLUSION

Patients with moderate to severe asthma with NPs have higher levels of PBE and FeNO despite better asthma control and lower total and specific allergy than those without NPs.

A snapshot of exhaled nitric oxide and asthma characteristics: experience from high to low income countries

Nitric oxide is a gas produced in the airways of asthmatic subjects and related to T2 inflammation. It can be measured as fractional nitric oxide (FeNO) in the exhaled air and used as a non-invasive, easy to evaluate, rapid marker. It is now widely used in many settings to determine airway inflammation. The aim of this narrative review is to report relationship between FeNO and the physiopathologic characteristics of asthmatic patients. Factors affecting FeNO levels have also been analysed as well as the impact of corticosteroid, target therapies and rehabilitation programs. Considering the availability of the test, spreading this methodology to low income countries has also been considered as a possibility for evaluating airway inflammation and monitoring adherence to inhaled corticosteroid therapy. PubMed data search has been performed restricted to English language papers. Research was limited to studies in adults unless studies in children were the only ones reported for a particular issue. This revision could be useful to summarize the role of FeNO in relation to asthma characteristics and help in the use of FeNO in different clinical settings particularly in low income countries.

Impaired small airway function in non-asthmatic chronic rhinosinusitis with nasal polyps

BACKGROUND

There is clinical evidence for impaired lung function in chronic rhinosinusitis with nasal polyps (CRSwNP) patients, which may be due to a high incidence of asthma comorbidity. The lung function characteristics of non-asthmatic CRSwNP patients are not known. Small airway dysfunction (SAD) is involved in the pathogenesis of asthma. However, whether SAD is detected in non-asthmatic patients with CRSwNPs remains unclear.

OBJECTIVE

This study analysed the lung function of non-asthmatic patients with CRSwNPs and evaluated its clinical relevance in CRSwNPs.

METHODS

The clinical data for 191 consecutive CRSwNP patients (73 asthmatic and 118 non-asthmatic) and 30 control subjects were prospectively collected. The patients were followed up for at least 3 years (mean [standard deviation], 42.47 ± 8.38 months). Serum and tissue total IgE levels were measured in 95 and 93 patients, respectively. Tissue eosinophil counts were documented in 63 patients.

RESULTS

Non-asthmatic CRSwNP patients had decreased forced expiratory flow at 75% of the FVC (FEF₇₅ ) and FEF₅₀ compared to the control subjects, and this difference was related to the severity of CRSwNP. The risk factors for impaired lung function in asthmatic and non-asthmatic patients were duration of asthma and smoking. A multivariate logistic analysis showed that decreased FEF₅₀ was associated with the recurrence of non-asthmatic CRSwNPs. The lung function of CRSwNP patients negatively correlated with the degree of type-2 inflammation, which was defined by the levels of Eos and IgE in polyp tissues and blood. The SAD of non-asthmatic CRSwNP patients was related to serum IgE levels.

CONCLUSIONS AND CLINICAL RELEVANCE

This study provides evidence that non-asthmatic CRSwNP patients may have SAD, which correlated with the severity and recurrence of CRSwNP. The decreased lung function of patients with CRSwNP was related to the degree of type-2 inflammation.

The Prevalence of Subtypes of Type 2 Inflammation in an Unselected Population of Patients with Severe Asthma

BACKGROUND

With the introduction of different targeted therapies for type 2 (T2)-high asthma, there is an urgent need for markers to guide the choice of treatment. T2-high asthma includes different clinical phenotypes of asthma, but the prevalence and impact of activation of different T2 inflammatory pathways is unknown.

OBJECTIVE

To describe the level of coexpression of clinically available T2 inflammatory markers in patients with severe asthma, and the relationship with clinical characteristics and comorbidities.

METHODS

Patients with severe asthma according to European Respiratory Society/American Thoracic Society guidelines were examined prospectively including sputum induction and grouped according to T2 biomarkers: blood eosinophilia (≥0.3 × 10⁹/L), total IgE (≥150 U/mL), and fractional exhaled nitric oxide (≥25 parts per billion).

RESULTS

We found 116 (70%) of the 166 patients to have at least 1 T2 biomarker elevated: 39% had 2 or more elevated biomarkers, whereas 31% had only 1 biomarker elevated. Concomitant airway and systemic eosinophilia was present in 28% of all patients, corresponding to half (53%) of the patients with either. Expression patterns of the T2 biomarkers were associated with differences in allergic sensitization and the coexistence of nasal polyposis.

CONCLUSIONS

Most patients with severe asthma showed at least 1 T2 inflammatory trait. Coexpression of T2 biomarkers was highly heterogeneous, and different expression patterns were associated with distinct clinical characteristics.

Pragmatic Clinical Perspective on Biologics for Severe Refractory Type 2 Asthma

Patients with severe refractory asthma present a challenging clinical conundrum for practicing clinicians. Biologics that target key mediators in the type 2 inflammation cascade, including IL-4, IL-5, IL-13, and IgE, can be effective strategies for these patients. However, with various biologics available, choosing the optimal one for a particular patient becomes a nuanced decision. We propose a pragmatic algorithm that identifies the optimal biologic class for patients who have specific type 2 disease endotypes. Patients with eosinophilic endotypes fare well with anti-IL-5(rα) medications, comprising mepolizumab, benralizumab, and reslizumab because they have been shown to reduce exacerbations in severe eosinophilic asthma by approximately 50%. In patients with fractional exhaled nitric oxide-high endotypes, anti-IL-4rα such as dupilumab is deemed to be most effective and has demonstrated a 47% reduction in asthma exacerbations. For patients with severe uncontrolled allergic asthma, anti-IgE (omalizumab) is effective and has been shown to confer a 25% reduction in asthma exacerbations. Type 2 comorbidities including chronic rhinosinusitis with nasal polyps, atopic dermatitis, chronic idiopathic urticaria, and eosinophilic esophagitis are important to bear in mind before the prescription of biologics. Further head-to-head studies are indicated to compare biologics in patients with mixed endotypes according to peripheral blood eosinophils, fractional exhaled nitric oxide, and allergic status. The evidence strongly supports endotype-driven prescribing of biologics to achieve clinically relevant outcomes in severe refractory asthma and related comorbidities.

Effectiveness of omalizumab in patients with severe allergic asthma with and without chronic rhinosinusitis with nasal polyps: a PROXIMA study post hoc analysis

Background

A significant proportion of patients with severe asthma may also suffer from nasal polyposis, which is commonly defined as chronic rhinosinusitis with nasal polyps (CRSwNP), the presence of which may adversely affect asthma treatment outcomes. The biologic agent omalizumab is effective as add-on therapy in patients with severe allergic asthma. The aim of this post hoc analysis of the PROXIMA study was to compare the efficacy of omalizumab between patients with severe allergic asthma, with and without comorbid CRSwNP.

Methods

PROXIMA was a prospective observational 2-part study conducted in Italy in adult patients with severe allergic asthma, where, in the second part, patients eligible for add-on omalizumab initiated treatment for 12 months. Patient baseline data such as comorbidities and history of exacerbations were collected. Outcomes were asthma control (Asthma Control Questionnaire [ACQ]), lung function (forced expiratory volume in 1 s [FEV₁]) and exacerbation rate. The post hoc analysis compared these outcomes between the cohort with comorbid CRSwNP and the cohort without CRSwNP.

Results

Of 123 patients included in this analysis, 17 (13.8%) were in the CRSwNP cohort. There was no significant difference between cohorts in baseline clinical characteristics or in change from baseline at 12 months in ACQ values,  % of predicted FEV₁ or annual asthma exacerbation rate, although results were numerically in favor of the CRSwNP cohort versus the non-CRSwNP cohort. The proportion of patients who achieved an improvement in all three outcomes was numerically greater in the CRSwNP cohort (35.7% vs 23.0%).

Conclusions

In an observational real-world setting, add-on omalizumab for severe allergic asthma was effective in improving asthma control, lung function and in reducing exacerbations, including in those patients with CRSwNP.