Exhaled nitric oxide to predict corticosteroid responsiveness and reduce asthma exacerbation rates

Dupilumab Reduces Exacerbations Independent of Changes in Biomarkers in Moderate-to-Severe Asthma

BACKGROUND

Changes from baseline in fractional exhaled nitric oxide (FeNO) and blood eosinophil count (Eos) may be related to efficacy outcomes in dupilumab-treated patients with moderate-to-severe asthma.

OBJECTIVE

This post hoc analysis investigated biomarker changes in placebo- and dupilumab-treated patients with uncontrolled moderate-to-severe asthma enrolled in QUEST (NCT02414854).

METHODS

Spline analyses of annualized severe exacerbation rate (AER) and change from baseline in pre-bronchodilator (BD) forced expiratory volume in 1 second (FEV1) at week 52 were performed as a function of the fold change in FeNO at week 52 and the maximum fold change in Eos over weeks 0-12 (also change from baseline in pre-BD FEV1 at week 12).

RESULTS

The combined placebo and dupilumab groups comprised 638 and 1264 patients, respectively. FeNO levels declined rapidly by week 2 and then gradually to week 52 in patients treated with dupilumab versus placebo; Eos, after initially increasing with dupilumab, declined slightly from baseline in both treatment groups. AER during QUEST showed no significant association with the change in biomarkers in either treatment group. The change from baseline in pre-BD FEV1 at week 52 was inversely associated with the fold change in FeNO in both groups, with a significant difference between the dupilumab and placebo curves (P = .014), and was positively associated with the fold change in Eos in both groups (P = .022).

CONCLUSIONS

Relative changes in FeNO and Eos were not associated with AER, regardless of treatment arm. However, changes in both biomarkers showed a predictive value for lung function improvement; for FeNO, this was specific to the dupilumab treatment arm.

Nitric oxide as a double-edged sword in pulmonary viral infections: Mechanistic insights and potential therapeutic implications

In the face of the global pandemic caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), researchers are tirelessly exploring novel therapeutic approaches to combat coronavirus disease 2019 (COVID-19) and its associated complications. Nitric oxide (NO) has appeared as a multifaceted signaling mediator with diverse and often contrasting biological activities. Its intricate biochemistry renders it a crucial regulator of cardiovascular and pulmonary functions, immunity, and neurotransmission. Perturbations in NO production, whether excessive or insufficient, contribute to the pathogenesis of various diseases, encompassing cardiovascular disease, pulmonary hypertension, asthma, diabetes, and cancer. Recent investigations have unveiled the potential of NO donors to impede SARS-CoV- 2 replication, while inhaled NO demonstrates promise as a therapeutic avenue for improving oxygenation in COVID-19-related hypoxic pulmonary conditions. Interestingly, NO's association with the inflammatory response in asthma suggests a potential protective role against SARS-CoV-2 infection. Furthermore, compelling evidence indicates the benefits of inhaled NO in optimizing ventilation-perfusion ratios and mitigating the need for mechanical ventilation in COVID-19 patients. In this review, we delve into the molecular targets of NO, its utility as a diagnostic marker, the mechanisms underlying its action in COVID-19, and the potential of inhaled NO as a therapeutic intervention against viral infections. The topmost significant pathway, gene ontology (GO)-biological process (BP), GO-molecular function (MF) and GO-cellular compartment (CC) terms associated with Nitric Oxide Synthase (NOS)1, NOS2, NOS3 were arginine biosynthesis (p-value = 1.15 x 10-9) regulation of guanylate cyclase activity (p-value = 7.5 x 10-12), arginine binding (p-value = 2.62 x 10-11), vesicle membrane (p-value = 3.93 x 10-8). Transcriptomics analysis further validates the significant presence of NOS1, NOS2, NOS3 in independent COVID-19 and pulmonary hypertension cohorts with respect to controls. This review investigates NO's molecular targets, diagnostic potentials, and therapeutic role in COVID-19, employing bioinformatics to identify key pathways and NOS isoforms' significance.

Efficacy of Bhramari pranayama and Om chanting on asthma control, quality of life, and airway inflammation in asthmatic children: an open-label randomized controlled trial

OBJECTIVES

To explore the efficacy of combination of Bhramari pranayama and om chanting as an adjunct to standard pharmacological treatment on asthma control, quality of life, pulmonary function, and airway inflammation in asthmatic children.

METHODS

Children (n = 110; 8-15 years) with uncontrolled or partly controlled asthma were recruited from the Pediatric Chest Clinic of All India Institute of Medical Sciences, New Delhi. Eligible participants were randomized to either home-based online Bhramari pranayama and om chanting plus standard treatment (YI + ST) group, or standard treatment (ST) alone group. Primary outcome measures were 12-week change in level of asthma symptom control; asthma control questionnaire (ACQ) score, spirometry indices, impulse oscillometry parameters, and pediatric asthma quality of life questionnaire (PAQLQ) score. Secondary outcome was a change in fractional exhaled nitric oxide (FeNO) levels at 12 weeks. Beginning from the enrollment, every participant was evaluated at 0, 2, 6, and 12 weeks.

RESULTS

After 12 weeks of intervention, higher proportion (68.2%) of children were found to have controlled asthma symptoms in the YI + ST group as compared to ST group (38.5%) according to per protocol analysis (p = 0.03). When compared to ST group, children in YI + ST group showed significantly lower ACQ score, higher PAQLQ score and reduced FeNO levels. No significant changes were observed for the lung function parameters.

CONCLUSION

Children practicing Bhramari pranayama and om chanting for 12 weeks have better asthma symptom control, quality of life, and reduced airway inflammation than those taking standard pharmacotherapy alone.

Association of serum YKL-40 and DPP4 with T2-high asthma in Chinese adults

This study aimed to assess the utility of serum YKL-40 and serum dipeptidyl peptidase IV (DPP4) as biomarkers for distinguishing between type 2 (T2)-high and T2-low asthma in the Chinese population. Additionally, we sought to explore the associations of serum YKL-40 and DPP4 levels with asthma characteristics and conventional markers. A real-world observational cross-sectional study was conducted, involving a total of 75 adult asthma patients. We collected general information, including demographics and medical history. Measurements included complete blood count, fractional exhaled nitric oxide (FeNO), post-bronchodilator spirometry, serum YKL-40 and serum DPP4 levels. Asthma endotypes, T2-high and T2-low, were defined through a comprehensive review of existing literature and expert group discussions. Logistic and linear regression models were employed. Our findings indicated no significant association between serum YKL-40 or serum DPP4 levels and T2-high asthma across all models. In the fully adjusted model, their odds ratios (OR) were 0.967 (95% CI: 0.920-1.017) and 0.997 (95% CI: 0.993-1.001), respectively. Notably, serum YKL-40 exhibited a positive correlation with FeNO (β = 0.382, 95% CI: 0.230-0.533) after adjusting for confounding factors. This association, however, diminished in patients under 40 years old (P = .24), males (P = .25), and those with FEV1%pred of 80% or higher (P = .25). Serum DPP4 demonstrated a negative correlation with FEV1/FVC in the fully adjusted model (β: -0.005, 95% CI: -0.009, -0.000). Among Chinese adult asthma patients, a positive correlation was observed between serum YKL-40 levels and FeNO in females aged over 40 with FEV1%pred less than 80%. Additionally, a weak negative correlation was found between serum DPP4 levels and FEV1/FVC. However, neither serum YKL-40 nor serum DPP4 levels exhibited the capability to differentiate between T2-high and T2-low asthma.

Severity of adult-onset asthma - a matter of blood neutrophils and severe obesity

BACKGROUND

Adult-onset asthma is associated with a poor treatment response. The aim was to study associations between clinical characteristics, asthma control and treatment in adult-onset asthma.

METHODS

Previous participants within the population-based Obstructive Lung Disease in Northern Sweden studies (OLIN) were in 2019-2020 invited to clinical examinations including structured interviews, spirometry, fractional exhaled nitric oxide (FeNO), skin prick test and blood sampling. In total, n = 251 individuals with adult-onset asthma (debut >15 years of age) were identified. Uncontrolled asthma was defined according to ERS/ATS and treatment step according to GINA (2019).

RESULTS

Among individuals with uncontrolled asthma (34%), severe obesity (16.3% vs 7.9%, p = 0.041) and elevated levels of blood neutrophils, both regarding mean level of blood neutrophils (4.25*109/L vs 3.67*109/L, p = 0.003), and proportions with ≥4*109/L (49.4% vs 33.3%, p = 0.017) and ≥5*109/L (32.1% vs 13.7%, p < 0.001) were more common than among those with controlled asthma. Adding the dimension of GINA treatment step 1-5, individuals with uncontrolled asthma on step 4-5 treatment had the highest proportions of blood neutrophils ≥5*109/L (45.5%), severe obesity (BMI≥35, 26.1%), dyspnea (mMRC≥2) (34.8%), and most impaired lung function in terms of FEV1%<80% of predicted (42.9%), FEV1

CONCLUSION

This study indicates that in adult-onset asthma, primarily non-type-2 characteristics such as obesity and blood neutrophils associate with poor asthma control and higher doses of inhaled corticosteroids.

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Key Words

• Body mass index
• Eosinophils
• Epidemiology
• Follow-up studies
• Neutrophils
• Sweden

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MESH Headings

• Humans
• Adult
• Neutrophils
• Obesity, Morbid/complications
• Nitric Oxide/therapeutic use
• Asthma/drug therapy
• Eosinophils
• Obesity/complications

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Affiliation(s)

Sofia Winsa-Lindmark Umeå University, Department of Public Health and Clinical Medicine, Section for Sustainable Health/The OLIN Unit, Sweden.
Caroline Stridsman Umeå University, Department of Public Health and Clinical Medicine, The OLIN Unit, Sweden
Axel Sahlin Umeå University, Department of Public Health and Clinical Medicine, Section for Sustainable Health/The OLIN Unit, Sweden
Linnea Hedman Umeå University, Department of Public Health and Clinical Medicine, Section for Sustainable Health/The OLIN Unit, Sweden
Nikolai Stenfors Umeå University, Department of Public Health and Clinical Medicine, The OLIN Unit, Sweden
Tomi Myrberg Umeå University, Department of Surgical and Perioperative Sciences, Anesthesiology and Intensive Care Medicine, Sweden
Anne Lindberg Umeå University, Department of Public Health and Clinical Medicine, The OLIN Unit, Sweden
Eva Rönmark Umeå University, Department of Public Health and Clinical Medicine, Section for Sustainable Health/The OLIN Unit, Sweden
Helena Backman Umeå University, Department of Public Health and Clinical Medicine, Section for Sustainable Health/The OLIN Unit, Sweden

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Economic impact of a more extensive use of FENO testing on the Italian population with asthma

BACKGROUND

Asthma is a common chronic inflammatory airway affecting over 260 million people worldwide, and characterized, in the large majority of cases, by the so-called "type 2 inflammation". Fractional exhaled nitric oxide (FE_NO) testing is noninvasive point-of-care tool to assess type 2 inflammation and therefore improve asthma management. It has been suggested to determine eligibility for a specific biologic therapy and predict likelihood to respond. The aim of this study was to estimate the overall economic impact of an extensive use of FE_NO testing on the Italian population with asthma, including extra costs of testing and savings generated by more appropriate prescriptions, increased adherence and lower frequency of exacerbations.

METHODS

A cost of illness analysis was firstly performed to estimate the yearly economic burden from the National Healthcare Service (NHS) perspective in Italy of the management of asthmatic patients with standard of care (SOC) according to the application of GINA (Global Initiative for Asthma) guidelines; then, we evaluated the changes in the economic burden in patient management by introducing FE_NO testing into clinical practice. The cost items considered were: visits/exams, exacerbations, drugs, management of adverse events caused by short-term oral corticosteroids use. Efficacy of FeNO test and SOC is based on literature evidence. Costs refer to published data or Diagnosis Related Group/outpatient tariffs.

RESULTS

Considering one asthma visit every 6 months, the total yearly cost for the management of patients with asthma in Italy is 1,599,217,876€ (409.07€ per patient), while for FE_NO testing strategy this figure is 1,395,029,747€ (356.84€ per patient). An increased utilization rate of FE_NO testing from 50 to 100% of patients may lead to savings for the NHS from about 102 to 204 million € compared to SOC.

CONCLUSIONS

Our study showed that FeNO testing strategy may improve the management of asthmatic patients leading to significant savings for the NHS.

Guidelines for the management of chronic cough in adults. Endorsed by the French speaking society of respiratory diseases (Société de Pneumologie de Langue Française, SPLF), the Société Française d'Oto-Rhino-Laryngologie et de Chirurgie de la Face et du Cou (SFORL), the Société Française de Phoniatrie et de Laryngologie (SFPL), the Société Nationale Française de Gastro-entérologie (SNFGE)

Patients with chronic cough experience a high alteration of quality of life. Moreover, chronic cough is a complex entity with numerous etiologies and treatments. In order to help clinicians involved in the management of patients with chronic cough, guidelines on chronic cough have been established by a group of French experts. These guidelines address the definitions of chronic cough and the initial management of patients with chronic cough. We present herein second-line tests that might be considered in patients with cough persistence despite initial management. Experts also propose a definition of unexplained or refractory chronic cough (URCC) in order to better identify patients whose cough persists despite optimal management. Finally, these guidelines address the pharmacological and non-pharmacological interventions useful in URCC. Thus, amitryptilline, pregabalin, gabapentin or morphine combined with speech and/or physical therapy are a mainstay of treatment strategies in URCC. Other treatment options, such as P2 × 3 antagonists, are being developed.

[Guidelines for the management of chronic cough in adults]

Patients with chronic cough experience major alteration in their quality of life. Given its numerous etiologies and treatments, this disease is a complex entity. To help clinicians involved in patient management of patients, guidelines have been issued by a group of French experts. They address definitions of chronic cough and initial management of patients with this pathology. We present herein the second-line tests that might be considered in patients whose coughing has persisted, notwithstanding initial management. The experts have also put forward a definition of unexplained or refractory chronic cough (URCC), the objective being to more precisely identify those patients whose cough persists despite optimal management. Lastly, these guidelines indicate the pharmacological and non-pharmacological interventions of use in URCC. Amitriptyline, pregabalin, gabapentin or morphine combined with speech and/or physical therapy are mainstays in treatment strategies. Other treatment options, such as P2X3 antagonists, are being developed and have generated high hopes among physicians and patients alike.

Baseline FeNO Independently Predicts the Dupilumab Response in Patients With Moderate-to-Severe Asthma

BACKGROUND

FeNO may have a role as both a prognostic and predictive biomarker in combination with eosinophils for assessing responsiveness to some biological therapies.

OBJECTIVE

We evaluated the value of baseline FeNO, adjusted for baseline blood eosinophil levels and other clinical characteristics, as an independent predictor of treatment response to dupilumab in patients with uncontrolled moderate-to-severe asthma.

METHODS

We performed a post hoc analysis of LIBERTY ASTHMA QUEST (NCT02414854), a phase 3, double-blind study in patients aged 12 years and older with uncontrolled moderate-to-severe asthma, who received dupilumab 200 or 300 mg, or placebo every 2 weeks up to 52 weeks. We assessed the annualized event rate of severe exacerbations and least-squares mean change from baseline in prebronchodilator FEV₁ at weeks 12 and 52 in relationship to baseline FeNO, adjusted for eosinophils and other clinical characteristics.

RESULTS

The annualized event rate increased with increasing baseline FeNO in placebo and decreased in dupilumab groups. The relative risk of severe exacerbations was 22·7%, 58·3%, and 69·3% lower for dupilumab versus placebo for the FeNO less than 25, 25 to less than 50, and 50 and greater parts per billion subgroups. The magnitude of FEV₁ improvement increased with higher baseline FeNO for dupilumab and was consistent across the continuum of FeNO levels in placebo. Both findings were independent of blood eosinophil levels. Significant differences were observed between FeNO subgroups.

CONCLUSIONS

Increased baseline FeNO was associated with greater clinical effects in dupilumab versus placebo independently of eosinophil levels and other clinical characteristics.

Corticosteroid Responsiveness Following Mepolizumab in Severe Eosinophilic Asthma-A Randomized, Placebo-Controlled Crossover Trial (MAPLE)

BACKGROUND

Mepolizumab inhibits IL-5 activity and reduces exacerbation frequency and maintenance oral corticosteroid (OCS) dosage in patients with severe eosinophilic asthma (SEA). Some patients remain dependent on OCS despite anti-IL-5 treatment, suggesting residual corticosteroid-responsive mechanisms.

OBJECTIVE

To determine the clinical and anti-inflammatory effects of OCS in patients with SEA on mepolizumab.

METHODS

We conducted a randomized, triple-blind, placebo-controlled crossover trial of prednisolone (0.5 mg/kg/d, maximum 40 mg/d, for 14 ± 2 days) in adults with SEA after 12 or more weeks of mepolizumab. We compared change in asthma symptoms, quality of life, lung function measured by spirometry and airwave oscillometry, fractional exhaled nitric oxide, and blood and sputum eosinophil cell count after prednisolone and placebo treatment.

RESULTS

A total of 27 patients completed the study. Prednisolone did not improve 5-item Asthma Control Questionnaire (mean difference in change for prednisolone vs placebo, -0.23; 95% CI, -0.58 to 0.11), mini-Asthma Quality of Life Questionnaire (0.03; 95% CI, -0.26 to 0.42), St. George's Respiratory Questionnaire (0.24; 95% CI, -3.20 to 3.69), or Visual Analogue Scale scores for overall asthma symptoms (0.11; 95% CI, -0.58 to 0.80). The mean difference for FEV₁ in favor of prednisolone was 105 mL (95% CI, -4 to 213 mL); forced expiratory flow at 25% and 75% 484 mL/s (95% CI, 151 to 816 mL/s); fractional exhaled nitric oxide reduction 41% (95% CI, 25% to 54%); blood eosinophil count reduction 49% (95% CI, 31% to 62%); and percentage of sputum eosinophil reduction 71% (95% CI, 26% to 89%).

CONCLUSIONS

OCS improved small-airway obstruction and reduced biomarkers of type 2 inflammation but had no significant effect on symptoms or quality of life in patients with SEA receiving treatment with mepolizumab.

Fractional Exhaled Nitric Oxide as a Marker of Mucosal Inflammation in Chronic Rhinosinusitis

BACKGROUND

Fractional exhaled nitric oxide (FeNO) is a cost-effective, noninvasive point-of-care test that has proven valuable in identifying patients with lower airway inflammation and predicting the likelihood of responsiveness to inhaled corticosteroid therapy in asthma. The utility of FeNO in upper airway disease, specifically in CRS, remains to be determined.

OBJECTIVE

The goal of this study was to test whether FeNO could serve as a noninvasive marker of sinonasal mucosal inflammation in CRS patients.

METHODS

FeNO was obtained using a nitric oxide analyzer (NIOX VERO) as well as nasal mucus, the 22-item Sinonasal Outcome Test (SNOT-22), University of Pennsylvania Smell Identification Test (UPSIT), and Lund-Kennedy endoscopic scores concurrently in 112 CRS patients. Nasal mucus was analyzed for cytokine expression using solid-phase sandwich ELISA. Linear regression with Spearman correlation coefficient was used to determine strength of relationship between variables.

RESULTS

CRS patients showed elevated FeNO levels with asthma (47.12 ± 5.21 ppb) or without asthma (43.24 ± 9.810 ppb). Elevated FeNO levels correlated with sinonasal mucosal inflammation, as determined by increased levels of CCL26 and TNFα in nasal mucus obtained from CRS patients. Furthermore, elevated FeNO levels selectively correlated with worsened SNOT-22 nasal symptoms (P = 0.03) and Lund-Kennedy endoscopic scores (P = 0.007), but did not correlate with UPSIT scores.

CONCLUSIONS

FeNO levels correlated with increased sinonasal mucosal inflammation and symptom severity in CRS regardless of asthma status. FeNO measurements may serve as a quick and noninvasive marker in evaluating CRS patients.

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.

Fractional exhaled NO in a metalworking occupational cohort

PURPOSE

Secondary metalworking carries exposure to relatively heavy levels of respirable particulate. We investigated the extent to which metalworking is associated with increased exhaled nitric oxide (FeNO), an established inflammatory biomarker.

METHODS

We studied 80 metalworking factory employees in Kazakhstan. Informed by industrial hygiene data, we categorized them into three groups: (1) machine operators (41%); (2) welders or assemblers (33%); and (3) all others, including administrative and ancillary staff (26%). Participants completed questionnaires covering occupational history, smoking, home particulate sources, respiratory symptoms, and comorbidities. We measured exhaled carbon monoxide (CO), exhaled fractional nitric oxide (FeNO), and spirometric function. We used mixed-effects modeling to test the associations of occupational group with FeNO, adjusted for covariates.

RESULTS

The median age was 51.5 (interquartile range 20.5) years; 7% were women. Occupational group (p < 0.01), daily current cigarette smoking intensity (p < 0.05), and age (p < 0.05), each was statistically associated with FeNO. Welders, or assemblers (Group 2), who had intermediate particulate exposure, manifested significantly higher exhaled FeNO compared to machinists (Group 1, with the highest particulate exposure) and all others (Groups 3, the lowest particulate): adjusted Group 2 mean 44.8 ppb (95% confidence interval (CI) 33.8-55.9) vs. Group 1 24.6 ppb (95% 20.5-28.7) and Group 3, 24.3 ppb (95% CI 17.7-30.9). Secondhand smoking and height were not associated with FeNO.

CONCLUSION

In a metalworking industrial cohort, welders/assemblers manifested significantly higher levels of FeNO. This may reflect respiratory tract inflammation associated with airborne exposures specific to this group.

IL-17 Promotes Nitric Oxide Production in Non-Small-Cell Lung Cancer

Introduction: Lung cancer is the second most frequent malignancy worldwide, but its aetiology is still unclear. Inflammatory cytokines and Th cells, including Th17, are now emerging as being involved in NSCLC pathways, thus postulating a role of IL-17 in tumour angiogenesis by stimulating the vascular endothelial growth factor and the release of nitric oxide. Despite the fact that many biomarkers are used for chest malignancy diagnosis, data on FeNO levels and inflammatory cytokines in NSCLC are still few. Our study aimed to evaluate the relationship between pulmonary nitric oxide production and VEGF and Th17-related cytokines in the EBC of patients affected by early-stage NSCLC. Methods: FeNO measurement and lung function tests were performed in both patients affected by NCSLC and controls; EBC samples were also taken, and Th1 (IL-1, IL-6, IL-12, IFN-g, TNF-a), Th17 (IL-17, IL-23) and Th2 (IL-4, IL-5, IL-13) related cytokines were measured. Results: Th1 and Th17-related cytokines in EBC, except for IFN-gamma and TNF-alpha, were significantly higher in patients than in healthy controls, whereas no differences were seen for Th2-related cytokines. FeNO at the flow rate of 50 mL/s, JawNO and CalvNO levels were significantly higher in patients affected by NSCLC compared to controls. Significant correlations were found between FeNO 50 mL/s and IL-17, IL-1 and VEGF. JawNO levels positively correlated with IL-6, IL-17 and VEGF. No correlations were found between FeNO and Th2-related cytokines. Conclusion: This is the first report assessing a relationship between FeNO levels and Th17-related cytokines in the EBC of patients affected by early-stage NSCLC. IL-17, which could promote angiogenesis through the VEGF pathway, might be indirectly responsible for the increased lung production of NO in patients with NSCLC.

Exacerbations in US Severe Asthma: Incidence, Characteristics, Predictors, and Effects of Biologic Treatments

BACKGROUND

Patients with severe asthma (SA) have a heightened risk of exacerbations, including hospitalization. The real-world, specialist-verified incidence and characteristics of exacerbations among patients with SA in the United States (US) have not been described.

OBJECTIVE

To describe the real-world incidence, characteristics, and predictors of exacerbations among patients with SA in the US.

METHODS

CHRONICLE is an ongoing observational study of specialist-treated US adults with SA receiving biologic treatment or maintenance systemic corticosteroids (SCS), or uncontrolled by high-dosage inhaled corticosteroids with additional controllers. For patients enrolled February 2018 to February 2020, annualized rates and characteristics of exacerbation-related events were summarized by treatment category for 12 months before enrollment and after enrollment through the latest data collection. Results were further analyzed for subgroups of interest.

RESULTS

Among 1884 enrolled patients, 53.5% and 12.3% experienced an exacerbation and asthma hospitalization, respectively (0.81 and 0.14 per person-year). Of all exacerbations, 36%, 9%, and 15% required an unscheduled healthcare provider visit, emergency department visit without hospitalization, and hospitalization, respectively. Among patients not receiving biologics or SCS, higher blood eosinophil count, higher fractional exhaled nitric oxide, and lower total immunoglobulin E level were associated with higher exacerbation rates. Exacerbation rates decreased after starting or switching biologics (n = 1299). Multivariate analyses of enrolled patients showed prior-year exacerbations/hospitalizations, lack of asthma control, and geographic region also predicted event risk.

CONCLUSION

In this real-world cohort of specialist-treated US adults with SA, there was a substantial burden of exacerbations and associated healthcare resource utilization. Patients receiving biologics had a lower exacerbation burden.

Baseline FeNO as a prognostic biomarker for subsequent severe asthma exacerbations in patients with uncontrolled, moderate-to-severe asthma receiving placebo in the LIBERTY ASTHMA QUEST study: a post-hoc analysis

BACKGROUND

Fractional exhaled nitric oxide (FeNO) has potential as a prognostic biomarker in asthma, but its prognostic value among other recognised indicators is unclear. We assessed the added prognostic value of baseline FeNO to blood eosinophil count and prior severe asthma exacerbations for subsequent exacerbations.

METHODS

In this post-hoc analysis of the 52-week, double-blind, phase 3 LIBERTY ASTHMA QUEST study, we identified 620 patients with moderate-to-severe asthma who were randomly assigned to placebo; had uncontrolled asthma with inhaled glucocorticoids plus up to two controllers; one or more exacerbations in the previous year; FEV₁ percent predicted 40-80%; FEV₁ reversibility of 12% or higher and 200 mL; Asthma Control Questionnaire (ACQ-5) score of 1·5 or higher; and complete data on baseline type 2 biomarkers (FeNO, eosinophils, and total IgE) with no baseline minimum requirement. Annualised severe exacerbation rate was assessed by baseline FeNO (<25 ppb, ≥25 to <50 ppb, ≥50 ppb; negative binomial model) and cross-classified by baseline blood eosinophils (<150 cells per μL, ≥150 to <300 cells per μL, ≥300 cells per μL) and prior exacerbations (one, two or more), all adjusted for baseline ACQ-5, postbronchodilator FEV₁, and other clinical characteristics. Post-hoc analyses were done in the intention-to-treat population. The LIBERTY ASTHMA QUEST STUDY is registered on ClinicalTrials.gov, NCT02414854, and is complete.

FINDINGS

Patients with baseline FeNO of 50 ppb or higher (n=144) had a 1·54-times higher exacerbation rate than patients with FeNO of less than 25 ppb (n=291; relative risk 1·54 [95% CI 1·11-2·14]; p=0·0097). Patients with baseline FeNO of 25 to <50 ppb (n=185) had a 1·33-times higher exacerbation rate than patients with FeNO of less than 25 ppb (1·33 [0·99-1·78]; p=0·0572). Patients with baseline FeNO of 25 ppb or higher, a blood eosinophil count of 150 cells per μL or higher, and two or more prior exacerbations (n=157) had an exacerbation rate 3·62-times higher than patients with FeNO of less than 25 ppb, a blood eosinophil count of less than 150 cells per μL, and one prior exacerbation (n=116; 3·62 [1·67-7·81]; p=0·0011).

INTERPRETATION

In uncontrolled, moderate-to-severe asthma, higher baseline FeNO levels were associated with greater risk of severe asthma exacerbations, particularly in combination with elevated eosinophil count and prior exacerbations, supporting the added value of FeNO as a prognostic biomarker. Further research is needed to confirm FeNO as an independent predictor for asthma exacerbations.

FUNDING

Sanofi and Regeneron Pharmaceuticals.

Economic Evaluation of the Use of FeNO for the Diagnosis and Management of Asthma Patients in Primary Care in Sweden

OBJECTIVE

To determine the economic impact of the fraction of exhaled nitric oxide (FeNO) in asthma diagnosis and management in primary care in Sweden.

METHODS

An economic model has been developed to determine the economic impact of the fraction of exhaled nitric oxide (FeNO) in asthma diagnosis and management in primary care in Sweden. The model includes the use and cost of commonly used tests, the associated outcomes and diagnostic accuracy. We compared FeNO with spirometry and reversibility testing, methacholine challenge test, allergy testing, and blood eosinophil count. One-way sensitivity analyses were performed to confirm the robustness of results.

RESULTS

Adding FeNO measurement in asthma diagnosis resulted in cost savings of SEK 672 per patient by the fourth year. The use of FeNO testing in asthma management proved to be a dominant strategy when compared with each other test except methacholine challenge test. Sensitivity analyses confirmed the robustness of the results.

CONCLUSION

Introducing FeNO testing in clinical practice for the diagnosis and management of asthma in primary care in Sweden is less costly than standard methods while providing similar health benefits.

Overlap of allergic, eosinophilic and type 2 inflammatory subtypes in moderate-to-severe asthma

Background

Current biologic therapies target allergic, eosinophilic or type 2 inflammation phenotypic asthma. However, frequency and degree of overlap among these subtypes is unclear.

Objective

To characterize overlap among allergic, eosinophilic and type 2 asthma phenotypes.

Methods

Post hoc analyses of baseline data were performed in two adult populations: (a) not selected for any asthma subtype (N = 935) and (b) selected for allergic asthma (N = 1049). Degree of overlap was examined using commonly accepted phenotypic definitions to guide treatment for allergic asthma (skin prick–positive and/or positive serum–specific immunoglobulin E > 0.35 kU/L) and eosinophilic asthma (blood eosinophil high count ≥ 300 cells/µL; low cut‐off ≥ 150 cells/µL). Consistent with previous studies, fractional exhaled nitric oxide high level of ≥ 35 ppb and low cut‐off of ≥ 25 ppb were selected as local markers of type 2 inflammation and to prevent overlap with the systemic eosinophilic asthma definition.

Results

In the non‐subtype–selected population, 78.0% had allergic asthma; of these, 39.5% had eosinophilic asthma and 29.5% had type 2 asthma. Within patients with eosinophilic asthma (40.6% of total), 75.8% had allergic asthma and 41.3% had type 2 asthma. Within patients with type 2 asthma (28.3% of total), 81.1% had allergic asthma and 59.2% had eosinophilic asthma. In the allergic asthma–selected population, 38.3% had eosinophilic asthma and 29.2% had type 2 asthma. Within patients with eosinophilic asthma, 46.3% had type 2 asthma. Within patients with type 2 asthma, 60.8% had eosinophilic asthma. Overlaps among subtypes increased at low cut‐off values.

Conclusions and clinical relevance

In this post hoc analysis in adults with moderate‐to‐severe asthma, allergic asthma was the most prevalent phenotype, followed by eosinophilic and type 2 asthma. Despite observed overlaps, a considerable proportion of patients had only a predominantly allergic subtype. Understanding the degree of overlap across phenotypes will help patient management and guide treatment options.

Personalised exhaled nitric oxygen fraction (F ENO)-driven asthma management in primary care: a F ENO subgroup analysis of the ACCURATE trial

Background

The aim of this study was to identify patients who benefit most from exhaled nitric oxide fraction (F_ENO)-driven asthma management in primary care, based on prespecified subgroups with different levels of F_ENO.

Methods

We used data from 179 adults with asthma from a 12-month primary care randomised controlled trial with 3-monthly assessments of F_ENO, asthma control, medication usage, costs of medication, severe asthma exacerbations and quality of life. In the original study, patients were randomised to either a symptom-driven treatment strategy (controlled asthma (Ca) strategy) or a F_ENO+symptom-driven strategy (FCa). In both groups, patients were categorised by their baseline level of F_ENO as low (<25 ppb), intermediate (25–50 ppb) and high (>50 ppb). At 12 months, we compared, for each prespecified F_ENO subgroup, asthma control, asthma-related quality of life, medication usage, and costs of medication between the Ca and FCa strategy.

Results

We found a difference between the Ca and FCa strategy for the mean dosage of beclomethasone strategy of 223 µg (95% CI 6–439), p=0.04) and for the total costs of asthma medication a mean reduction of US$159 (95% CI US$33–285), p=0.03) in patients with a low baseline F_ENO level. No differences were found for asthma control, severe asthma exacerbations and asthma-related quality of life in patients with a low baseline F_ENO level. Furthermore, in patients with intermediate or high level of F_ENO, no differences were found.

Conclusions

In primary care, F_ENO-driven asthma management is effective in patients with a low F_ENO level, for whom it is possible to down-titrate medication, while preserving asthma control and quality of life.

In primary care, F_ENO-driven asthma management is effective in patients with a low F_ENO, for whom it is possible to down-titrate medication while preserving asthma control and quality of lifehttps://bit.ly/2wC25N7d

Accurate real-time FENO expirograms using complementary optical sensors

The fraction of exhaled nitric oxide (F_ENO) is an important biomarker for the diagnosis and management of asthma and other pulmonary diseases associated with airway inflammation. In this study we report on a novel method for accurate, highly time-resolved, real time detection of F_ENO at the mouth. The experimental arrangement is based on a combination of optical sensors for the determination of the temporal profile of exhaled NO and CO₂ concentrations. Breath CO₂ and exhalation flow are measured at the mouth using diode laser absorption spectroscopy (at 2 μm) and differential pressure sensing, respectively. NO is determined in a sidestream configuration using a quantum cascade laser based, cavity-enhanced absorption cell (at 5.2 μm) which simultaneously measures sidestream CO₂. The at-mouth and sidestream CO₂ measurements are used to enable the deconvolution of the sidestream NO measurement back to the at-mouth location. All measurements have a time resolution of 0.1 s, limited by the requirement of a reasonable limit of detection for the NO measurement, which on this timescale is 4.7 ppb (2 σ). Using this methodology, NO expirograms (F_ENOgrams) were measured and compared for eight healthy volunteers. The F_ENOgrams appear to differ qualitatively between individuals and the hope is that the dynamic information encoded in these F_ENOgrams will provide valuable additional insight into the location of the inflammation in the airways and potentially predict a response to therapy. A validation of the measurements at low-time resolution is provided by checking that results from previous studies that used a two-compartment model of NO production can be reproduced using our technology.

Predicting asthma exacerbation by impulse oscillometry evaluation of small airway function and fractional exhaled nitric oxide in preschool children

OBJECTIVE

To study impulse oscillometry (IOS) indices of peripheral airway function and FeNO as predictors of future loss of asthma control in preschool children.

METHODS

Patients aged 3 to 6 years who were actively being treated for asthma and children without asthma were enrolled in the study. Participants had no change in medication on visit 1 and returned for a follow-up visit within 8 to 12 weeks. At the first visit, nursing assessment, symptom history, IOS analysis, FeNO, and physician evaluation were repeated.

RESULTS

Fifty-one (64.6%) subjects had lost asthma control (UC-Group) and 28 (35.4%) subjects had maintained asthma control (C-Group) at their follow-up visit. Thirty-two children without asthma were enrolled in the study as a normal control group (N-Group). R5, R5-20, AX, and Z5 values were all significantly higher in subjects whose symptoms remained uncontrolled compared with those in the controlled asthma group (P < .01) and also significantly higher than those in the normal control group (P < .01). FeNO showed no significant difference between the UC-Group and C-Group (P = .399). Four indices-R5, R5-20, AX, and Z5-had an estimated area under the curve (AUC) of greater than 0.8 and were thus easily able to distinguish the UC-Group from the C-Group.

CONCLUSIONS

AX had the highest overall AUC (0.884) of the investigated parameters, and the optimal cut-off point of 37.435 cm H₂ O/L was able to predict future loss of asthma control in preschool children.

Fractional exhaled nitric oxide response to oral corticosteroids in children with mild-to-moderate asthma: Influence of race

BACKGROUND

Fractional exhaled nitric oxide (FeNO) is a noninvasive biomarker of type 2 asthma that can predict response to inhaled corticosteroid therapy. Little is known regarding the magnitude of FeNO reduction after an oral corticosteroid (OCS) course, and less is known whether there are differential responses based on race in children with mild-to-moderate asthma.

OBJECTIVE

To assess the effect of a short course of OCS on FeNO in children with asthma and to determine whether the effect is influenced by race.

METHODS

Children presenting with an acute asthma exacerbation, who had a FeNO measurement within the past 6 months when clinically stable, were enrolled. Spirometry and FeNO were obtained at the time of exacerbation and after a short course of prednisone.

RESULTS

A total of 92 children were identified (aged 11 ± 3.3 years; white, n = 46 [50%], Hispanics, n = 30 [33%], African Americans [AAs], n = 16 [7%]). At baseline, AAs were more atopic and had higher mean FeNO values than both white (48.9 vs 25.6 ppb; P < .05) and Hispanic children (22.5 ppb; P < .05), despite being prescribed similar inhaled corticosteroid doses. During the exacerbation, AAs had the highest FeNO values, whereas there was no difference in lung function between AAs and non-AAs. After prednisone therapy, there was a 56.6% reduction in FeNO, and although AAs maintained the highest FeNO levels, the relative reduction was similar between AAs and non-AAs (53.9% vs 57.8%, respectively).

CONCLUSION

FeNO levels reduced by more than 50% after an OCS course. African American children had a greater degree of type 2-driven airway inflammation at baseline, during an exacerbation and after a short course of OCS, compared with non-AAs, although the relative reduction in FeNO was similar between the groups.

Patients with psoriatic arthritis have higher levels of FeNO than those with only psoriasis, which may reflect a higher prevalence of a subclinical respiratory involvement

BACKGROUND

Psoriatic arthritis (PsA) patients are often affected by numerous comorbidities. However, contrasting results have been reported with regard to the respiratory involvement in PsA patients. The aim of this study was to evaluate the presence of subclinical airway inflammation in non-smoking PsA patients compared to patients with only psoriasis using the fraction of exhaled nitric oxide (FeNO) as an indirect marker of airway inflammation.

METHODS

The study included 164 non-smoking psoriatic patients (Psoriasis Area of Severity Index or PASI score > 10): 82 with and 82 without PsA, who underwent FeNO tests at different flow rates (30, 50, 100, 200 mL/s). PsA patients were evaluated with Disease Activity in PSoriatic Arthritis Score (DAPSA). Both study groups were compared in terms of FeNO values and its association with the PASI score. The correlations between the variables were evaluated by means of Pearson's coefficient.

RESULTS

Patient with PsA had higher levels of FeNO than those with psoriasis but without arthritis (at 30 mL/s, 71.09 ± 18.40 ppb vs 66.88 ± 19.12 ppb (NS); at 50 mL/s, 36.61 ± 9.30 ppb vs 30.88 ± 9.73 ppb (p < 0.001); at 100 mL/s, 19.09 ± 4.66 ppb vs 16.63 ± 4.90 ppb (p < 0.001); and at 200 mL/s, 10.88 ± 2.53 ppb vs 9.43 ± 2.55 ppb (p < 0.001), respectively). PASI score correlated to FeNO only in psoriatic patients without arthritis. However, CASPAR index correlated with FeNO (FeNO30: r = 0.81, p < 0.001; FeNO50: r = 0.84, p < 0.001; FeNO100: r = 0.71, p < 0.001; FeNO200: r = 0.58, p < 0.001). DAPSA was also correlated with FeNO to all flows (FeNO30: r = 0.43, p < 0.001; FeNO50: r = 0.33, p < 0.001; FeNO100: r = 0.34, p < 0.001; FeNO200: r = 0.25, p < 0.001).

CONCLUSIONS

PsA patients seem to have more commonly subclinical airway inflammation than those with only psoriasis. Further studies are needed to replicate these findings. Key Points • Fraction of exhaled nitric oxide (FeNO) is a useful device to detect and monitor airway inflammation not only in asthma but also in systemic inflammatory diseases such as psoriatic arthritis and psoriasis. • Clinicians should be aware to check respiratory diseases in patients with psoriatic arthritis.

Clinical utility of fractional exhaled nitric oxide in severe asthma management

Asthma is a chronic inflammatory disease of the airways, affecting over 350 million people worldwide and placing a significant burden on healthcare providers and wider society. Approximately 5-10% of asthma patients are diagnosed with severe asthma and typically are associated with increased risk of hospitalisation from exacerbations, increased morbidity, mortality and higher asthma-associated healthcare costs. Nitric oxide (NO) is an important regulator of immune responses and is a product of inflammation in the airways that is over-produced in asthma. Fractional exhaled NO (F _eNO) is predominantly used as a predictor of response to inhaled corticosteroids (ICSs), to monitor adherence and as a diagnostic tool in ICS-naïve patients. In the UK, the National Institute for Health and Care Excellence (NICE) guidelines recommend the use of F _eNO for the initial diagnosis of patients with suspected asthma. In the USA, American Thoracic Society (ATS) guidelines recommend F _eNO as part of the initial diagnosis of asthma and for monitoring of airway inflammation. F _eNO has also been shown to be a predictive factor for asthma exacerbations, with higher levels being associated with a greater number of exacerbations. In addition, higher levels of F _eNO have been shown to be associated with a decline in lung function. F _eNO testing is a cost-effective procedure and has been shown to improve patient management when combined with standard assessment methods. Recent evidence suggests that F _eNO may also be useful as a surrogate biomarker for the assessment and management of severe asthma and to predict responsiveness to some biological therapies.

Asthma and Corticosteroid Responses in Childhood and Adult Asthma

Corticosteroids are the most effective treatment for asthma; inhaled corticosteroids (ICSs) are the first-line treatment for children and adults with persistent symptoms. ICSs are associated with significant improvements in lung function. The anti-inflammatory effects of corticosteroids are mediated by both genomic and nongenomic factors. Variation in the response to corticosteroids has been observed. Patient characteristics, biomarkers, and genetic features may be used to predict response to ICSs. The existence of multiple mechanisms underlying glucocorticoid insensitivity raises the possibility that this might indeed reflect different diseases with a common phenotype.

Priorities for future research into asthma diagnostic tools: A PAN-EU consensus exercise from the European asthma research innovation partnership (EARIP)

The diagnosis of asthma is currently based on clinical history, physical examination and lung function, and to date, there are no accurate objective tests either to confirm the diagnosis or to discriminate between different types of asthma. This consensus exercise reviews the state of the art in asthma diagnosis to identify opportunities for future investment based on the likelihood of their successful development, potential for widespread adoption and their perceived impact on asthma patients. Using a two-stage e-Delphi process and a summarizing workshop, a group of European asthma experts including health professionals, researchers, people with asthma and industry representatives ranked the potential impact of research investment in each technique or tool for asthma diagnosis and monitoring. After a systematic review of the literature, 21 statements were extracted and were subject of the two-stage Delphi process. Eleven statements were scored 3 or more and were further discussed and ranked in a face-to-face workshop. The three most important diagnostic/predictive tools ranked were as follows: "New biological markers of asthma (eg genomics, proteomics and metabolomics) as a tool for diagnosis and/or monitoring," "Prediction of future asthma in preschool children with reasonable accuracy" and "Tools to measure volatile organic compounds (VOCs) in exhaled breath."

Exhaled nitric oxide in chronic cough: A good tool in a multi-step approach

INTRODUCTION

The impact of fractional exhaled nitric oxide (FENO) on the management of chronic cough (CC) is still inconclusive. The aim of the present study was to assess whether FENO is a good tool to predict the response to inhaled corticosteroids (ICS) in patients with CC.

METHODS

Patients, referred for investigation of CC, had a FENO measurement determined as part of their first-line assessment. A methacholine test was performed as part of a second-line assessement. Patients were assigned to two groups according to their FENO values: a high FENO level group (Ⱕ25 ppb) and a normal FENO level group (<25 ppb).

RESULTS

One hundred patients were included in the study. High FENO levels were found in 25 patients (25%). The proportion of patients who responded to ICS was significantly greater in the high FENO group compared to the normal FENO level group (86.4% vs 46.3%, P<0.05). FENO is a good tool to predict ICS response in patients with high FENO levels but a response to ICS cannot be ruled out in patients with normal FENO levels. In patients with normal FENO values, a methacholine test could be an interesting tool for a second-line assessment. Among the 13 patients with a positive methacholine test result, 11 responded to ICS whilst 2 did not. Of the patients with a negative methacholine test result, 3 responded to ICS whilst 13 did not.

CONCLUSION

FENO may be a more reliable predictor of ICS response when used as part of a multi-step assessment procedure.

Correlation Between Fractional Exhaled Nitric Oxide Levels and Efficacy of Inhaled Corticosteroids in Children With Bronchial Asthma

To investigate correlation between fractional exhaled nitric oxide (FeNO) levels and efficacy of inhaled corticosteroids in children with bronchial asthma. Between October 2013 and December 2014, 133 cases of children with bronchial asthma were randomly divided into the glucocorticoid group (n = 67; inhaled with Seretide/Pulmicort) and the nonglucocorticoid group (n = 66; inhaled with short-acting β2 receptor agonist if needed); and alternatively 72 cases of healthy children were regarded as the control group. FeNO, forced expiratory volume in 1 second to predicted value, forced expiratory volume in 1 second/forced vital capacity, induced sputum eosinophils (EOS)%, and total serum immunoglobulin (Ig) E and serum EOS% were detected and childhood asthma control test (C-ACT) scale was investigated pretreatment and 3 and 6 months posttreatment, respectively. FeNO levels, induced sputum EOS%, total serum IgE, and serum EOS% were significantly lower, whereas forced expiratory volume in 1 second to predicted value, forced expiratory volume in 1 second/forced vital capacity, and C-ACT scores were obviously improved in the glucocorticoid group 6 months posttreatment compared with those of pretreatment (all P < 0.05). FeNO levels, induced sputum EOS%, and total serum IgE were significantly lower, whereas C-ACT scores were significantly higher in the glucocorticoid group compared with those of the nonglucocorticoid group (all P < 0.05). In the glucocorticoid group, induced sputum EOS% and total serum IgE showed significantly positive correlations with FeNO levels (r = 0.73, P < 0.01; r = 0.56, P < 0.01), whereas C-ACT scores were negatively correlated with FeNO levels (r = -0.67, P < 0.01). FeNO levels might be correlated with efficacy of inhaled corticosteroids in children with bronchial asthma.

Efficacy and safety of AZD7594, an inhaled non-steroidal selective glucocorticoid receptor modulator, in patients with asthma: a phase 2a randomized, double blind, placebo-controlled crossover trial

Background

Inhaled corticosteroids reduce inflammation in asthma but chronic use may cause adverse effects. AZD7594, an inhaled non-steroidal selective glucocorticoid receptor modulator, has the potential of an improved risk-benefit profile. We investigated the safety and efficacy of AZD7594 in asthma.

Methods

This phase 2a multi-center, randomized, double-blind, placebo-controlled crossover study enrolled adults with asthma aged 18 to 75 years. Patients were treated with budesonide 200 μg twice daily for 2–3 3 weeks (run in part one). If controlled, as demonstrated by an asthma control questionnaire-5 score of < 1.5, patients entered a three-week run-in (part two) where they received a short acting bronchodilator alone. Thereafter, patients with a fractional exhaled nitric oxide (F_ENO) ≥25 ppb and pre-dose FEV₁ 40 to 90% predicted were randomized to one of nine treatment sequences. Each patient received placebo and two of three dose levels of AZD7594 (58, 250, 800 μg) once daily via inhalation, in 14-day treatment periods, separated by three-week washout periods. The primary endpoint was the change from baseline in morning trough FEV₁ versus placebo on day 15. Secondary endpoints included measures of airway inflammation and asthma control.

Results

Fifty-four patients were randomized and received at least 1 dose of treatment, 48 patients completed the study. Overall 52 patients received placebo, 34 received AZD7594 58 μg, 34 received AZD7594 250 μg, and 34 received AZD7594 800 μg. AZD7594 800 μg demonstrated a significant improvement in Day 15 morning trough FEV₁versus placebo (LS means difference 0.148 L 95% CI 0.035–0.261, p = 0.011), with a dose-dependent response seen in the 250 μg (0.076 L -0·036–0·188, p = 0.183) and 58 μg (0·027 L -0·086–0·140, p = 0.683). All secondary endpoints showed statistically significant improvement at the 800 μg dose. All doses demonstrated a significant reduction in F_ENO at day 15 p < 0.01. No statistically significant difference in plasma cortisol level was observed between AZD7594 and placebo at any dose. AZD7594 was considered safe and well tolerated.

Conclusions

Two-week treatment with AZD7594 demonstrated a favorable risk-benefit profile in patients with mild to moderate asthma. Further clinical studies are needed to fully characterize AZD7594.

Trial registration

ClinicalTrials.gov number NCT02479412.

Electronic supplementary material

The online version of this article (10.1186/s12931-019-1000-7) contains supplementary material, which is available to authorized users.

The Fraction Exhaled Nitric Oxide as a Biomarker of Asthma Control

INTRODUCTION AND OBJECTIVE

The main goal of asthma treatment is to achieve and maintain clinical control of the disease. The exhaled fraction nitric oxide (FeNO) level is a biomarker of T-helper cell type 2 (Th2) inflammation of the airways. Our objective was to determine whether the FeNO level can be used to discriminate between patients with controlled, partially controlled, and uncontrolled asthma.

MATERIALS AND METHODS

The FeNO level and asthma control were evaluated in a retrospective and analytic cross-sectional study through data collected from asthmatic patients who were assessed by clinical history, asthma control, physical examination, spirometry, and FeNO level. Asthma control was determined by the criteria of the Global Initiative for Asthma and classified as controlled asthma, partially controlled asthma, and uncontrolled asthma. The FeNO values were classified as low (<25 ppb) or intermediate/high (⩾25 ppb) based on the American Thoracic Society recommendations.

RESULTS

The symptoms of 81 asthmatic patients were classified as controlled (34 [42%] patients), partially controlled (27 [33.3%] patients), and uncontrolled (20 [24.7%] patients). The FeNO level discriminated between the uncontrolled and controlled groups (P = .01) and between the uncontrolled and partially controlled groups (P = .01), but not between the controlled and partially controlled groups (P = .98). An FeNO level >30 ppb was associated with uncontrolled asthma (P = .0001) with an area under the receiver operating characteristic curve of 0.78 (95% confidence interval = 0.65-0.89).

CONCLUSIONS

FeNO level could be helpful in determining asthma control as >30 ppb was associated with uncontrolled asthma.

Measurement of fractional exhaled nitric oxide in real-world clinical practice alters asthma treatment decisions

BACKGROUND

Assessment of asthma using clinical measures alone often fails to detect underlying airway inflammation. Fractional exhaled nitric oxide (FeNO) is a recognized biomarker of type 2 airway inflammation in asthma. Measurement of FeNO is instrumental in the assessment and management of patients with corticosteroid-sensitive asthma.

OBJECTIVE

To determine the impact of measuring FeNO on asthma management in real-world clinical practices.

METHODS

Clinicians from 337 US practices performed a clinical assessment and recorded treatment plans before and after measuring FeNO in 7,901 patients with asthma. Airway inflammation was classified as low, intermediate, or high according to the clinician's usual procedures, including clinical examination, spirometry, and symptoms. Clinicians recorded asthma medication plans, indicating medications to be initiated, continued, or stopped. FeNO measurement was performed, followed by documentation of any change(s) in the treatment plans based on the FeNO value (eg, initiating new medications or changing the dose of or discontinuing existing medications).

RESULTS

Clinical assessment was concordant with FeNO measurement in only 56% of cases, matching FeNO more frequently in patients with low inflammation (64%) vs high inflammation (34%). After FeNO measurement, clinicians modified their treatment plan in 31% and altered prescriptions for inhaled corticosteroids in 90% of cases. Inhaled corticosteroids were initiated or their dose increased in 66% of patients with high inflammation but discontinued or their dose decreased in only 9% of patients with low inflammation.

CONCLUSION

Measurement of FeNO enabled clinicians to assess underlying airway inflammation, leading to a significant revision of their treatment plans compared with real-world clinical assessment of asthma alone.

Is aging a "comorbidity" of asthma?

The aging population is growing at an unparalleled rate. Asthma is common in the elderly (age over 65 years) and can be more severe with little chance for remission. Asthma in older individuals is often under-diagnosed, misdiagnosed and frequently under-treated. Concomitant medical and psychosocial conditions are more prevalent in the elderly and can obfuscate the presentation of asthma and make it more difficult to assess and manage. While these comorbidities are important in understanding elderly asthma, aging itself can be considered a "comorbidity" since it impacts structural and functional changes in the lung. Structural changes of the aging lung may worsen physiologic function in asthma. The immune system also changes with age, with increased vulnerability to pathogens and differences in airway inflammation, leading to variability in how asthma manifests and responds to treatment. The fact that aging can influence the severity and presentation of asthma along with its diagnosis and management is important for the treating physician to understand. This article will discuss the multitude of factors that justify considering aging as a comorbidity of asthma.

Race and ethnicity have significant influence on fractional exhaled nitric oxide

BACKGROUND

Race and ethnicity have been shown to influence fractional exhaled nitric oxide (FeNO). There is a need to investigate cutoff points for different races and ethnicities to improve clinical application.

OBJECTIVE

To investigate cutoff points for different races and ethnicities by analyzing the FeNO data collected by the National Health and Nutrition Examination Survey from 2007 to 2012.

METHODS

This study included 23,433 participants. After excluding participants with confounding factors, 11,084 participants were eligible for data analysis. Based on age and the probability of having allergic airway inflammation, participants were divided into 4 groups. The geometric mean and 5th, 50th, and 95th percentiles of FeNO in Hispanic, white, black, and other races were analyzed in all groups.

RESULTS

Compared with white participants, the geometric mean for FeNO in black participants was 36% to 41% higher in children and 5% to 8% higher in adults. Hispanic children had significantly higher FeNO values (14% to 19%) compared with non-Hispanic white children; however, those differences were not significant in adults. Other races had significantly higher FeNO values in children (24-54%) and adults (9-29%) compared with white participants. Further, for normal healthy black children, the 95th percentile was 40.2 parts per billion (ppb), which is significantly higher than the cutoff point recommended by current guidelines.

CONCLUSION

Although there are significant differences in FeNO values among races and ethnicities, the current cutoff point at 50 ppb is sufficient to separate healthy from asthmatic populations in adults. However, for black children, we suggest increasing the cutoff point from 35 to 40 ppb to avoid unnecessary diagnosis and treatment.

The use of fractional exhaled nitric oxide is valuable in select asthmatic patients

PURPOSE OF REVIEW

Clinical management of asthma is challenging and measuring fractional exhaled nitric oxide (FeNO) can be another tool to assist in meeting this challenge.

RECENT FINDINGS

Asthma is a heterogeneous condition. There are many different phenotypes. FeNO can help the physician identify which patients have eosinophilic inflammation and would potentially respond to corticosteroid therapy.

SUMMARY

FeNO is a complement to standard asthma care. FeNO can be used in the initial diagnosis of asthma and aid in stratification of which patients would be steroid responsive but also for assessment of disease severity, response to treatment, and compliance.

A randomised pragmatic trial of corticosteroid optimization in severe asthma using a composite biomarker algorithm to adjust corticosteroid dose versus standard care: study protocol for a randomised trial

Background

Patients with difficult-to-control asthma consume 50–60% of healthcare costs attributed to asthma and cost approximately five-times more than patients with mild stable disease. Recent evidence demonstrates that not all patients with asthma have a typical type 2 (T2)-driven eosinophilic inflammation. These asthmatics have been called ‘T2-low asthma’ and have a minimal response to corticosteroid therapy. Adjustment of corticosteroid treatment using sputum eosinophil counts from induced sputum has demonstrated reduced severe exacerbation rates and optimized corticosteroid dose. However, it has been challenging to move induced sputum into the clinical setting. There is therefore a need to examine novel algorithms to target appropriate levels of corticosteroid treatment in difficult asthma, particularly in T2-low asthmatics. This study examines whether a composite non-invasive biomarker algorithm predicts exacerbation risk in patients with asthma on high-dose inhaled corticosteroids (ICS) (± long-acting beta agonist) treatment, and evaluates the utility of this composite score to facilitate personalized biomarker-specific titration of corticosteroid therapy.

Methods/design

Patients recruited to this pragmatic, multi-centre, single-blinded randomised controlled trial are randomly allocated into either a biomarker controlled treatment advisory algorithm or usual care group in a ratio of 4:1. The primary outcome measure is the proportion of patients with any reduction in ICS or oral corticosteroid dose from baseline to week 48. Secondary outcomes include the rate of protocol-defined severe exacerbations per patient per year, time to first severe exacerbation from randomisation, dose of inhaled steroid at the end of the study, cumulative dose of inhaled corticosteroid during the study, proportion of patients on oral corticosteroids at the end of the study, proportion of patients who decline to progress to oral corticosteroids despite composite biomarker score of 2, frequency of hospital admission for asthma, change in the 7-item Asthma Control Questionnaire (ACQ-7), Asthma Quality of Life Questionnaire (AQLQ), forced expiratory volume in 1 s (FEV1), exhaled nitric oxide, blood eosinophil count, and periostin levels from baseline to week 48. Blood will also be taken for whole blood gene expression; serum, plasma, and urine will be stored for validation of additional biomarkers.

Discussion

Multi-centre trials present numerous logistical issues that have been addressed to ensure minimal bias and robustness of study conduct.

Trial registration

ClinicalTrials.gov, NCT02717689. Registered on 16 March 2016.

Electronic supplementary material

The online version of this article (doi:10.1186/s13063-017-2384-7) contains supplementary material, which is available to authorized users.

Increased serum amyloid A in nasal polyps is associated with systemic corticosteroid insensitivity in patients with chronic rhinosinusitis with nasal polyps: a pilot study

BACKGROUND

Serum amyloid A (SAA) was involved in the pathogenesis of glucocorticoid resistance in lung diseases. However, their association with systemic corticosteroid insensitivity in chronic rhinosinusitis with nasal polyps (CRSwNP) patients remains to be assessed.

METHODS

This study enrolled 32 CRSwNP patients to evaluate the association between SAA expression in NP and corticosteroid insensitivity, and the value of polyp SAA level for predicting the response to oral corticosteroids in CRSwNP patients. All patients were given a course of oral prednisone (30 mg daily for 2 weeks) and subdivided into glucocorticoid(GC)-sensitive and -insensitive subgroup according to the change in polyp size scores. The polyp specimens were obtained before and after corticosteroid treatment. SAA levels in polyp tissues were evaluated by enzyme-linked immunosorbent assay and quantitative reverse transcription polymerase chain reaction. Regression analysis was performed to analyze the association between SAA protein levels and corticosteroid insensitivity.

RESULTS

13/32 (40.62%) CRSwNP patients were insensitive to the oral corticosteroid therapy. SAA mRNA and protein levels were significantly increased in GC-insensitive NP compared to those in GC-sensitive NP. Tissue SAA protein levels were positively correlated with tissue neutrophil numbers. Regression analysis revealed tissue SAA levels were significantly correlated with corticosteroid insensitivity (P < 0.01). ROC curves indicated that the area under the curve was 0.87. When the polyp SAA protein level was 122.2 ng/ml or higher, the sensitivity and specificity were 76.92 and 73.68%, respectively.

CONCLUSIONS

Our findings suggest that increased SAA in NP is associated with reduced response to oral corticosteroids in CRSwNP. SAA levels in NP may have potential value in predicting corticosteroid insensitivity in CRSwNP patients.

Precision medicine in airway diseases: moving to clinical practice

On February 21, 2017, a European Respiratory Society research seminar held in Barcelona discussed how to best apply precision medicine to chronic airway diseases such as asthma and chronic obstructive pulmonary disease. It is now clear that both are complex and heterogeneous diseases, that often overlap and that both require individualised assessment and treatment. This paper summarises the presentations and discussions that took place during the seminar. Specifically, we discussed the need for a new taxonomy of human diseases, the role of different players in this scenario (exposome, genes, endotypes, phenotypes, biomarkers and treatable traits) and a number of unanswered key questions in the field. We also addressed how to deploy airway precision medicine in clinical practice today, both in primary and specialised care. Finally, we debated the type of research needed to move the field forward.

Asthma in the Elderly

The older population has seen the greatest increase in the prevalence of current asthma in recent years. Asthma may begin at any age and when it occurs at an advanced as opposed to a young age, it is often nonatopic, severe, and unremitting. Unfortunately, geriatric-specific guidelines are not available for the diagnosis and treatment of asthma. However, with objective monitoring, avoidance of asthma triggers, appropriate pharmacotherapy, and patient education, the disease can be managed successfully.

Prevalence of high fractional exhaled nitric oxide among US youth with asthma

BACKGROUND

High fractional exhaled nitric oxide (FeNO) is an indicator of poor asthma control and has been proposed as a non-invasive assessment tool to guide asthma management.

OBJECTIVE

We aimed to describe the prevalence of and factors associated with high FeNO among US youth with asthma.

METHODS

Data from 716 children and adolescents with asthma ages 6-19 years who participated in the 2007-2012 National Health and Nutrition Examination Survey were analyzed. Using American Thoracic Society guidelines, high FeNO was defined as >50 ppb for ages 12-19 years and >35 ppb for ages 6-11 years. Multivariate logistic regression examined associations between high FeNO and age, sex, race/Hispanic origin, income status, weight status, tobacco smoke exposure, and other factors associated with asthma control (recent use of inhaled corticosteroids, recent respiratory illness, asthma-related respiratory signs/symptoms, and spirometry).

RESULTS

About 16.5% of youth with asthma had high FeNO. The prevalence of high FeNO was higher among non-Hispanic black (27%, P < 0.001) and Hispanic (20.2%, P = 0.002) youth than non-Hispanic white (9.7%) youth. Differences in high FeNO prevalence by sex (girls < boys), weight status (obese < normal weight), tobacco smoke exposure (smokers < home exposure < no exposure), and FEV1/FVC (normal < abnormal) were also observed. No differences were noted between categories for the remaining covariates.

CONCLUSION

High FeNO was observed to be associated with sex, race/Hispanic origin, weight status, tobacco smoke exposure, and abnormal FEV1/FVC, but was not associated with asthma-related respiratory symptoms. These findings may help inform future research and clinical practice guidelines on the use of high FeNO in the assessment of asthma control.

Exhaled nitric oxide in a middle-aged Icelandic population cohort

The prevalence of atopy and asthma is relatively low in Iceland. The purpose of this study was to describe exhaled nitric oxide (FeNO) levels in the general population in correlation with demographic characteristics, smoking status, asthma, rhinitis, atopic status and lung function tests. Altogether 403 subjects, from the European Community Respiratory Health Survey (ECRHS) III who answered the main questionnaire and were checked by FeNO measurements, lung function testing, skin prick testing and measurement of total IgE and specific IgE were included. The geometric mean (95% CI) of FeNO was 16.2 ppb (15.2-17.1) and the prevalence of higher FeNO (⩾25 ppb) was 19.5% in the random sample. Subjects with higher FeNO levels were less likely to be current smokers and more likely to have asthma and rhinitis. Having higher FeNO values was also associated with higher total IgE, having specific IgE to at least one allergen and being skin prick test positive. Current smokers had significantly lower levels of FeNO, geometric mean (95% CI) 9.6 ppb (8.4-11.0), than ex-smokers 18.2 ppb (16.6-20.0) and never smokers 17.3 ppb (16.1-18.5). In multivariable models, having asthma (OR (95% CI) 2.10 (1.20-3.67)), having a specific IgE (OR 2.30 (1.25-4.23)) and being skin prick test positive (OR 2.06 (1.18-3.60)) were independently positively associated with a higher FeNO (⩾25) whereas current smoking was independently negatively associated with a higher FeNO (OR 0.19 (0.06-0.63)). Higher levels of FeNO (⩾25 ppb) were found in one out of five Icelanders; FeNO was positively associated with asthma and allergy and negatively with smoking.

Could Fractional Exhaled Nitric Oxide Test be Useful in Predicting Inhaled Corticosteroid Responsiveness in Chronic Cough? A Systematic Review

BACKGROUND

Fractional exhaled nitric oxide (Feno) is a safe and convenient test for assessing T_H2 airway inflammation, which is potentially useful in the management of patients with chronic cough.

OBJECTIVE

To summarize the current evidence on the diagnostic usefulness of Feno for predicting inhaled corticosteroid (ICS) responsiveness in patients with chronic cough.

METHODS

A systematic literature review was conducted to identify articles published in peer-reviewed journals up to February 2015, without language restriction. We included studies that reported the usefulness of Feno (index test) for predicting ICS responsiveness (reference standard) in patients with chronic cough (target condition). The data were extracted to construct a 2 × 2 accuracy table. Study quality was assessed with Quality Assessment of Diagnostic Accuracy Studies 2.

RESULTS

We identified 5 original studies (2 prospective and 3 retrospective studies). We identified considerable heterogeneities in study design and outcome definitions, and thus were unable to perform a meta-analysis. The proportion of ICS responders ranged from 44% to 59%. Sensitivity and specificity ranged from 53% to 90%, and from 63% to 97%, respectively. The reported area under the curve ranged from about 0.60 to 0.87; however, studies with a prospective design and a lower prevalence of asthma had lower area under the curve values. None measured placebo effects or objective cough frequency.

CONCLUSIONS

We did not find strong evidence to support the use of Feno tests for predicting ICS responsiveness in chronic cough. Further studies need to have a randomized, placebo-controlled design, and should use validated measurement tools for cough. Standardization would facilitate the development of clinical evidence.

Evaluation of exhaled nitric oxide's ability to predict methacholine challenge in adults with nonobstructive spirometry

BACKGROUND

Compared with methacholine challenge, exhaled nitric oxide is less expensive, is performed as a simpler point-of-care maneuver, and may provide treatment guiding information.

OBJECTIVE

To determine whether exhaled nitric oxide levels can predict the outcome of methacholine challenge in patients without obvious baseline obstruction.

METHODS

This retrospective database and medical record review included adults presenting to a tertiary care center from November 1, 2009, through August 31, 2013, who underwent methacholine challenge and exhaled nitric oxide measurement within 2 weeks of each other. Database extraction identified age, sex, body mass index, baseline corticosteroid use, testing indication, forced expiratory volume in 1 second (FEV₁), and testing results. Individuals taking corticosteroid-containing medication or who had an FEV₁ less than the lower limit of normal at baseline were excluded.

RESULTS

A total of 1,322 individuals were identified, with 774 meeting the eligibility criteria. A total of 123 methacholine challenges (16%) had positive results. Fractional exhaled nitric oxide was statistically higher in those with positive methacholine challenge results (mean [SD], 41.9 [54.5] ppb vs 25.2 [19.7] ppb; P < .01). Receiver operating characteristic curve revealed an area under the curve of 0.572 (P < .01), suggesting a poor correlation between exhaled nitric oxide level and methacholine challenge outcome. Fractional exhaled nitric oxide of greater than 50 ppb has a sensitivity, specificity, positive predictive value, and negative predictive value of 12%, 89%, 17%, and 84%, respectively, for a positive methacholine challenge result.

CONCLUSION

In this large, retrospective cohort of corticosteroid-naive pulmonary patients with normal FEV₁ on baseline spirometry, exhaled nitric oxide poorly predicts the outcome of a methacholine challenge.

Measurement of exhaled nitric oxide concentration in asthma: a systematic review and economic evaluation of NIOX MINO, NIOX VERO and NObreath

BACKGROUND

High fractions of exhaled nitric oxide (FeNO) in the breath of patients with symptoms of asthma are correlated with high levels of eosinophils and indicate that a patient is likely to respond to inhaled corticosteroids. This may have a role in the diagnosis and management of asthma.

OBJECTIVE

To assess the diagnostic accuracy, clinical effectiveness and cost-effectiveness of the hand-held electrochemical devices NIOX MINO(®) (Aerocrine, Solna, Sweden), NIOX VERO(®) (Aerocrine) and NObreath(®) (Bedfont Scientific, Maidstone, UK) for the diagnosis and management of asthma.

DATA SOURCES

Systematic searches were carried out between March 2013 and April 2013 from database inception. Databases searched included MEDLINE, EMBASE, the Cochrane Database of Systematic Reviews, the Database of Abstracts of Reviews of Effects, Science Citation Index Expanded and Conference Proceedings Citation Index - Science. Trial registers such as ClinicalTrials.gov and the metaRegister of Controlled Trials were also searched in March 2013. All searches were updated in September 2013.

REVIEW METHODS

A rapid review was conducted to assess the equivalence of hand-held and chemiluminescent FeNO monitors. Systematic reviews of diagnostic accuracy and management efficacy were conducted. A systematic review of economic analyses was also conducted and two de novo health economic models were developed. All three reviews were undertaken according to robust high-quality methodology.

RESULTS

The rapid review (27 studies) found varying levels of agreement between monitors (Bland-Altman 95% limits of agreement up to ±10 parts per billion), with better agreement at lower FeNO values. Correlation was good (generally r > 0.9). The diagnostic accuracy review identified 22 studies in adults (all ages) and four in children. No studies used NObreath or NIOX VERO and seven used NIOX MINO. Estimates of diagnostic accuracy varied widely. FeNO used in combination with another test altered diagnostic accuracy only slightly. High levels of heterogeneity precluded meta-analysis. Limited observations included that FeNO may be more reliable and useful as a rule-in than as a rule-out test; lower cut-off values in children and in smokers may be appropriate; and FeNO may be less reliable in the elderly. The management review identified five randomised controlled trials in adults, one in pregnant asthmatics and seven in children. Despite clinical heterogeneity, exacerbation rates were lower in all studies but not generally statistically significantly so. Effects on inhaled corticosteroid (ICS) use were inconsistent, possibly because of differences in management protocols, differential effectiveness in adults and children and differences in population severity. One UK diagnostic model and one management model were identified. Aerocrine also submitted diagnostic and management models. All had significant limitations including short time horizons and the selective use of efficacy evidence. The de novo diagnostic model suggested that the expected difference in quality-adjusted life-year (QALY) gains between diagnostic options is likely to be very small. Airway hyper-responsiveness by methacholine challenge test is expected to produce the greatest QALY gain but with an expected incremental cost-effectiveness ratio (ICER) compared with FeNO (NObreath) in combination with bronchodilator reversibility of £1.125M per QALY gained. All remaining options are expected to be dominated. The de novo management model indicates that the ICER of guidelines plus FeNO monitoring using NObreath compared with guidelines alone in children is expected to be approximately £45,200 per QALY gained. Within the adult subgroup, FeNO monitoring using NObreath compared with guidelines alone is expected to have an ICER of approximately £2100 per QALY gained. The results are particularly sensitive to assumptions regarding changes in ICS use over time, the number of nurse visits for FeNO monitoring and duration of effect.

CONCLUSIONS

Limitations of the evidence base impose considerable uncertainty on all analyses. Equivalence of devices was assumed but not assured. Evidence for diagnosis is difficult to interpret in the context of inserting FeNO monitoring into a diagnostic pathway. Evidence for management is also inconclusive, but largely consistent with FeNO monitoring resulting in fewer exacerbations, with a small or zero reduction in ICS use in adults and a possible increased ICS use in children or patients with more severe asthma. It is unclear which specific management protocol is likely to be most effective. The economic analysis indicates that FeNO monitoring could have value in diagnostic and management settings. The diagnostic model indicates that FeNO monitoring plus bronchodilator reversibility dominates many other diagnostic tests. FeNO-guided management has the potential to be cost-effective, although this is largely dependent on the duration of effect. The conclusions drawn from both models require strong technical value judgements with respect to several aspects of the decision problem in which little or no empirical evidence exists. There are many potential directions for further work, including investigations into which management protocol is best and long-term follow-up in both diagnosis and management studies.

STUDY REGISTRATION

This study is registered as PROSPERO CRD42013004149.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

Important non-disease-related determinants of exhaled nitric oxide levels in mild asthma - results from the Swedish GA(2) LEN study

BACKGROUND

Fractional exhaled nitric oxide (FeNO) has a potential clinical role in asthma management. Constitutive factors such as age, height and gender, as well as individual characteristics, such as IgE sensitization and smoking, affect the levels of FeNO in population-based studies. However, their effect on FeNO in subjects with asthma has been scarcely studied.

OBJECTIVE

To study the effects on FeNO of these commonly regarded determinants, as demonstrated in healthy subjects, as well as menarche age and parental smoking, in a population of asthmatics.

MATERIAL AND METHODS

Fractional exhaled nitric oxide was measured in 557 subjects with asthma from the Swedish GA(2) LEN study. Allergic sensitization was assessed by skin prick tests to most common aeroallergens. Upper airway comorbidities, smoking habits, smoking exposure during childhood and hormonal status (for women) were questionnaire-assessed.

RESULTS

Male gender (P < 0.001), greater height (P < 0.001) and sensitization to both perennial allergens and pollen (P < 0.001) are related to higher FeNO levels. Current smoking (P < 0.001) and having both parents smoking during childhood, vs. having neither (P < 0.001) or only one parent smoking (P = 0.002), are related to lower FeNO. Women with menarche between 9 and 11 years of age had lower FeNO than those with menarche between 12 and 14 years of age (P = 0.03) or 15 and 17 years of age (P = 0.003).

CONCLUSIONS AND CLINICAL RELEVANCE

Interpreting FeNO levels in clinical practice is complex, and constitutional determinants, as well as smoking and IgE sensitisation, are of importance in asthmatic subjects and should be accounted for when interpreting FeNO levels. Furthermore, menarche age and parental smoking during childhood and their effects on lowering FeNO deserve further studies.

A chemiluminescent platform for smartphone monitoring of H2O2 in human exhaled breath condensates

Noninvasive measurement of oxidative markers in clinical samples has the potential to rapidly provide information for disease management, but is limited by the need for expensive analytical instrumentation that precludes home monitoring or point-of-care applications. We have developed a simple to use diagnostic platform for airway hydrogen peroxide (H₂O₂) that combines optimized reaction-based chemiluminescent designs with an inexpensive home-built darkbox and readily available smartphone cameras. Specialized photography software applications and analysis of pixel intensity enables quantification of sample concentrations. Using this platform, sample H₂O₂ concentrations as low as 264nM can be detected. The platform has been used to measure H₂O₂ in the exhaled breath condensates of human subjects, showing good agreement with the standard Amplex Red assay.

Importance of fractional exhaled nitric oxide in diagnosis of bronchiectasis accompanied with bronchial asthma

BACKGROUND

Fractional exhaled nitric oxide (FeNO) measurement is a simple, rapid, highly reproducible, and noninvasive method of airway inflammation assessment. Therefore, FeNO is extensively used for the diagnosis and management of asthma. The feasibility of using FeNO as an alternative to conventional pulmonary function test to differentiate patients with bronchiectasis (BE) and bronchial asthma from those with BE only remains unclear.

METHODS

From February 2013 to February 2015, 99 patients diagnosed with BE through high-resolution computed tomography (HRCT) were subjected to FeNO measurement, bronchial challenge test (BCT), or bronchodilator test. Bronchial hyperreactivity and/or reversible airway obstruction was used to define asthma. The receiver operating characteristic (ROC) curves were obtained to elucidate the clinical functions of FeNO in the diagnosis of asthmatic patients with BE, and the optimal operating point was also determined.

RESULTS

Of 99 patients with BE, 20 patients presented asthma, and 12 of these patients received regular treatment, which were given with budesonide (200 µg, bid) for 12 weeks to evaluate changes in the concentration and assess the role of FeNO in the treatment. The area under the ROC curve was estimated as 0.832 for FeNO. Results also revealed a cut off value of >22.5 part per billion (ppb) FeNO for differentiating asthmatic from non-asthmatic (sensitivity, 90.0%; specificity, 62.5%) patients with BE. FeNO and forced expiratory volume for 1 second significantly improved after the treatment.

CONCLUSIONS

Clinical FeNO measurement is a simple, noninvasive, and rapid method used to differentiate asthmatic from nonasthmatic patients with BE. This technique exhibits potential for asthma management.

Fractional exhaled nitric oxide for the management of asthma in adults: a systematic review

The aim of this review was to evaluate the clinical effectiveness of fractional exhaled nitric oxide (FeNO) measured in a clinical setting for the management of asthma in adults.13 electronic databases were searched and studies were selected against predefined inclusion criteria. Quality assessment was conducted using QUADAS-2. Class effect meta-analyses were performed.Six studies were included. Despite high levels of heterogeneity in multiple study characteristics, exploratory class effect meta-analyses were conducted. Four studies reported a wider definition of exacerbation rates (major or severe exacerbation) with a pooled rate ratio of 0.80 (95% CI 0.63-1.02). Two studies reported rates of severe exacerbations (requiring oral corticosteroid use) with a pooled rate ratio of 0.89 (95% CI 0.43-1.72). Inhaled corticosteroid use was reported by four studies, with a pooled standardised mean difference of -0.24 (95% CI -0.56-0.07). No statistically significant differences for health-related quality of life or asthma control were found.FeNO guided management showed no statistically significant benefit in terms of severe exacerbations or inhaled corticosteroid use, but showed a statistically significant reduction in exacerbations of any severity. However, further research is warranted to clearly define which management protocols (including cut-off points) offer best efficacy and which patient groups would benefit the most.