Dataset Information

Association of elevated fractional exhaled nitric oxide concentration and blood eosinophil count with severe asthma exacerbations.

ABSTRACT:

Background

Blood eosinophil count (BEC) and fractional exhaled nitric oxide (FeNO) concentration are established biomarkers in asthma, associated particularly with the risk of exacerbations. We evaluated the relationship of BEC and FeNO as complementary and independent biomarkers of severe asthma exacerbations.

Methods

This observational study included data from the Optimum Patient Care Research Database. Asthma patients (18-80 years) with valid continuous data for 1 year before FeNO reading,???1 inhaled corticosteroid prescription, and BEC recorded???5 years before FeNO reading were separated into cohorts. Categorisation 1 was based on the American Thoracic Society criteria for elevated FeNO concentration (high:???50 ppb; non-high:?9 cells/L; non-high:?9 cells/L). Categorisation 2 (FeNO concentration, high:???35 ppb; non-high:?ResultsIn categorisation 1, patients with either high FeNO or high BEC (n?=?200) had a numerically greater exacerbation rate (unadjusted rate ratio, 1.31 [95% confidence interval: 0.97, 1.76]) compared with patients in the reference group. Combination of high FeNO and high BEC (n?=?27) resulted in a significantly greater exacerbation rate (3.67 [1.49, 9.04]). Similarly, for categorisation 2, when both biomarkers were raised (n?=?53), a significantly greater exacerbation rate was observed (1.72 [1.00, 2.93]).

Conclusion

The combination of high FeNO and high BEC was associated with significantly increased severe exacerbation rates in the year preceding FeNO reading, suggesting that combining FeNO and BEC measurements in primary care may identify asthma patients at risk of exacerbations.

SUBMITTER: Price DB

PROVIDER: S-EPMC6702739 | biostudies-literature | 2019

REPOSITORIES: biostudies-literature

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Publications

Association of elevated fractional exhaled nitric oxide concentration and blood eosinophil count with severe asthma exacerbations.

Price David B DB Bosnic-Anticevich Sinthia S Pavord Ian D ID Roche Nicolas N Halpin David M G DMG Bjermer Leif L Usmani Omar S OS Brusselle Guy G Ming Simon Wan Yau SWY Rastogi Sarang S

Clinical and translational allergy 20190821

<h4>Background</h4>Blood eosinophil count (BEC) and fractional exhaled nitric oxide (FeNO) concentration are established biomarkers in asthma, associated particularly with the risk of exacerbations. We evaluated the relationship of BEC and FeNO as complementary and independent biomarkers of severe asthma exacerbations.<h4>Methods</h4>This observational study included data from the Optimum Patient Care Research Database. Asthma patients (18-80 years) with valid continuous data for 1 year before F ...[more]

PMID: 31452870

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Project description:BackgroundTests to identify reversible airflow limitation are important in asthma diagnosis, but they are time-consuming and it may be difficult for patients to cooperate. We aimed to evaluate whether the combination of fractional exhaled nitric oxide (FeNO) and blood eosinophil (B-Eos) can be used to distinguish some asthma patients who could avoid objective tests.MethodsWe conducted a retrospective cohort study on 7463 suspected asthma cases between January 2014 and December 2019 in Chongqing, China, and identified 2349 patients with complete FeNO, B-Eos count, and spirometry data. Asthma was diagnosed by clinicians by the criteria of recurrent respiratory symptoms and a positive bronchial-provocation or bronchodilation test (BPT, BPD). We evaluated the diagnostic accuracy of FeNO or B-Eos alone or both in combination for asthma using receiver operating characteristic (ROC) curve analysis.ResultsIn this study, 824 patients were diagnosed with asthma. When FeNO and B-Eos counts were used in combination, the area under the ROC curve (AUC) for diagnosing asthma increased slightly (0.768 vs. 0.745 [FeNO] or 0.728 [B-Eos]; both P < 0.001). The odds ratio for having asthma increased progressively with a gradual increase in FeNO or B-Eos count (both P < 0.001; assessed using the Cochran-Armitage trend test). Further analysis of in-series combinations of different threshold values for these biomarkers indicated that moderately elevated biomarker levels (FeNO > 40 ppb and B-Eos > 300 cells/μl) support a diagnosis of asthma because diagnostic specificity was > 95% and the positive likelihood ratio (PLR) was > 10. This conclusion was verified when selecting the 2017-2019 data as the internal validation dataset.ConclusionFeNO or B-Eos count alone is insufficient to accurately diagnose asthma. Patients with moderately elevated biomarkers (FeNO > 40 ppb and B-Eos > 300 cells/μl) could be diagnosed with asthma and avoid objective tests when such tests are not feasible.

Project description:BackgroundAlthough the efficacy of corticosteroid treatment in controlling asthma is widely accepted, its effectiveness is undermined by poor adherence. However, the optimal method for measuring adherence to asthma therapy remains unclear.ObjectiveTo perform a review of the literature reporting biological, objective methods for assessing adherence to inhaled or oral corticosteroids in asthma; we included studies reporting direct measurement of exogenous corticosteroids in blood, or the effect of adherence on exhaled nitric oxide.DesignWe searched three databases MEDLINE (using both PubMed and Ovid), the Cumulative Index of Nursing and Allied Health Literature (CINAHL) and Web of Science for articles published between January 1975 and July 2020. Quality of the studies was assessed using the National Institute of Health checklist.ResultsFrom 2850 screened articles, 26 fulfilled the inclusion criteria. Measurement of blood prednisolone with or without cortisol was used in eight studies as a measure of oral corticosteroid adherence, and fractional exhaled nitric oxide (FeNO) in 17 studies for inhaled corticosteroid adherence. Inhaled corticosteroids were measured directly in the blood in one study. By direct measurement of drug levels in the blood, adherence rates to oral corticosteroids ranged from 47% to 92%, although the performance and timing of the test were often not known, making interpretation of findings and serum prednisolone concentrations difficult. FeNO is generally lower in adherent than non-adherent patients, but no absolute cut-off can be proposed based on the available data. However, a fall in FeNO following supervised inhaled corticosteroid dosing could indicate previous poor adherence.Conclusions and clinical relevanceDespite prednisolone and cortisol levels commonly being used as adherence markers in clinical practice, further work is required to assess the influence of the dose and timing on blood levels. The promising findings of FeNO suppression testing should be explored in further prospective studies.

Project description:INTRODUCTION:Fractional exhaled nitric oxide (FENO) is a biomarker of airway inflammation in asthma. The measurement of FENO is utilized to assist in the diagnosis and treatment of children with asthma, especially for those treated with inhaled corticosteroids. OBJECTIVES:The aims of this study were to evaluate the correlations between FENO and atopic status, blood eosinophil levels, FCER2 mutation, and asthma control in Vietnamese children. SUBJECTS AND METHODS:This was a prospective and descriptive study approved by the local Ethical Board. All children with uncontrolled asthma, seen in the National Hospital of Pediatrics (Hanoi, Vietnam), were included. Exhaled breath FENO, blood eosinophils, skin prick test, total IgE, asthma control test (ACT), and FCER2 gene polymorphism were performed at inclusion. They were followed up at 3 months to evaluate clinical status, FENO levels, and ACT. RESULTS:Forty-two children with uncontrolled asthma with a mean age of 10±3 years (6-16 years) were included. The male/female ratio was 2.5/1. The mean FENO levels were 26±25 ppb. FENO was significantly higher in patients with a positive skin prick test for respiratory allergens (P<0.05). FENO was significantly correlated with blood eosinophil levels (r=0.5217; P=0.0004). Five of the 32 subjects (15.6%) had a mutation of FCER2 gene (rs28364072 SNP). In this group, the levels of FENO were highest (37±10 ppb; P<0.05). The levels of FENO were significantly decreased after 3 months of treatment (17±8 ppb vs 26±25 ppb; P<0.05). Significant correlations between inhaled corticosteroid doses and FENO levels occurred at 1 and 3 months (r=0.415, P=0.007; r=0.396, P=0.010; respectively). There were no correlations between FENO levels, ACT, and daily use of salbutamol. After 3 months, asthma remained uncontrolled in 22.2% of children. CONCLUSION:The measurement of FENO levels is a useful and feasible tool to predict clinical, biological, and asthma control in Vietnamese children.

Dataset Information

Association of elevated fractional exhaled nitric oxide concentration and blood eosinophil count with severe asthma exacerbations.

Background

Methods

Conclusion

Publications

Association of elevated fractional exhaled nitric oxide concentration and blood eosinophil count with severe asthma exacerbations.

Similar Datasets

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