Serum interleukin-33 combined with FEF75% z-score and FeNO improves the diagnostic accuracy of asthma in children

Abstract Objective To investigate the diagnostic efficacy of serum IL-33 single indicator and combined indicators for asthma in children. Methods 132 children were initially diagnosed with asthma during acute exacerbation and 100 healthy children were included. Serum IL-33 concentration differences were compared between asthmatic and normal children. Correlations between IL-33 with pulmonary function parameters, FeNO, peripheral blood EOS counts and serum total IgE were analyzed in asthmatic children. ROC curves were used to assess IL-33 diagnostic efficacy and its combined indicators. To prevent overfitting of the predictive model, the hold-out cross-validation method was used. Results (1) Serum IL-33 concentrations were significantly higher in children with asthma than in normal children (p < 0.001). (2) IL-33 concentration was negatively correlated with FVC z-score, FEV1 z-score and FEF75% z-score in asthmatic children (p < 0.05). (3) The area under the ROC curve of IL-33 was 0.821, which was higher than those of FeNO, FVC z-score, and FEV1 z-score. (4) Cross-validation of the combined indicators showed that IL-33 significantly improved asthma diagnostic efficacy. The combination of IL-33, FEF75% z-score, and FeNO showed the highest diagnostic efficacy, with the AUC, sensitivity, and specificity of the combined indicator being 0.954, 90.1%, and 89. 0%, respectively, and good extrapolation of the predictive model. Conclusion Serum IL-33 is higher in children with asthma and increases with the severity of pulmonary ventilation obstruction. A single indicator of serum IL-33 demonstrates moderate diagnostic accuracy, and its combination with FEF75% z-score and FeNO significantly improves the diagnostic accuracy in childhood asthma.

Helicobacter pylori Infection Do Not Influence the Determination of Fractional Exhaled Nitric Oxide / 胃肠病学

Background: Helicobacter pylori (Hp) infection induces inflammation in gastric mucosa, and the production of nitric oxide (NO) may increase in response to the inflammation. However, the correlations between NO concentration in exhaled air and the severity of gastric inflammation and Hp infection are not clear. Aims: To explore the influence of Hp infection on fractional exhaled nitric oxide (FeNO), an indicator of airway inflammation, and the relationship between FeNO and severity of gastric inflammation. Methods: Adult patients who accepted

Progress in application of alveolar exhaled nitric oxide in pediatric lung diseases / 国际儿科学杂志

As a biomarker of airway inflammation, alveolar exhaled nitric oxide(CaNO), which represents small airway inflammation, is increasingly used in respiratory diseases.CaNO not only can be applied to children bronchial asthma severity evaluation, the selection of treatment and treatment effect of the dynamic monitoring, can also be applied to the early diagnosis of interstitial lung disease and assessment of the severity of lung damage for other diseases such as tuberculosis, pulmonary hypertension diagnosis.This paper reviews the diagnostic and therapeutic value of CaNO in pediatric respiratory diseases, and discusses the role of CaNO in the diagnosis and therapeutic evaluation in pediatric lung diseases.

The level of fractional exhaled nitric oxide and its influencing factors in chronic obstructive pulmonary disease / 中国医师杂志

Objective:To analyze the level of fractional exhaled nitric oxide (FeNO) and its influencing factors in patients with chronic obstructive pulmonary disease (COPD).Methods:678 patients with stable COPD(COPD group), 281 patients with asthma-COPD overlap(COPD with asthma group) and 120 healthy nonsmoker controls (healthy control group) were recruited from the outpatient clinics of Xiangya Second Hospital of Central South University and the 1st People′s Hospital of Huaihua from November 2016 to December 2021. The gender, smoking status, age, height, weight, body mass index (BMI), FEV 1% predicted value (FEV 1% pred), forced expiratory volume in 1 second/forced vital capacity (FEV 1/FVC%), and FeNO value among the three groups were compared. Multiple linear regression analysis was performed to analyze the influencing factors of FeNO levels in COPD patients. Results:There was no significant difference in gender, smoking status, age, height, weight and BMI among the three groups (all P>0.05). The FEV 1% and FEV 1/FVC% in COPD group were lower than those in healthy group and COPD combined with asthma group (all P<0.05). The FeNO in COPD group was lower than that in COPD and asthma group, but higher than that in healthy group (all P<0.05). Univariate analysis showed that FeNO levels in COPD patients were associated with height, BMI, Global Initiative for Chronic Obstructive Pulmonary Disease (GOLD) classification, and Chronic Obstructive Pulmonary Disease Assessment Test (CAT) score (all P<0.05). Multiple linear regression analysis showed that FeNO level was positively correlated with height ( β=0.094, P=0.014), CAT score ( β=0.129, P=0.001), and negatively correlated with BMI ( β=-0.093, P=0.016). There was no significant correlation between GOLD grading and FeNO level ( P>0.05). Conclusions:The level of FeNO in patients with COPD is higher than that in healthy subjects, which is related to height, BMI and CAT.

Application of fractional exhaled nitric oxide and nasal nitric oxide in control evaluation of bronchial asthma and diagnosis of allergic rhinitis in children / 中国当代儿科杂志

OBJECTIVES@#To study the association of fractional exhaled nitric oxide (FeNO) and nasal nitric oxide (nNO) with asthma control and their value in the diagnosis of allergic rhinitis in children.@*METHODS@#A total of 186 children aged 5-12 years, who attended the outpatient service of the Department of Respiration, Shanghai Children's Hospital due to bronchial asthma and/or allergic rhinitis or who underwent physical examination, were enrolled as subjects, with 52 children in the asthma group, 60 children in the asthma+allergic rhinitis group, 36 children in the allergic rhinitis group, and 38 children in the control group. FeNO, nNO, and pulmonary function were compared between groups.@*RESULTS@#The asthma+allergic rhinitis, asthma, and allergic rhinitis groups had a significantly higher level of FeNO than the control group (P<0.05). The asthma+allergic rhinitis and allergic rhinitis groups had a significantly higher level of nNO than the asthma and control groups (P<0.05). The uncontrolled asthma and partially controlled asthma groups had significantly higher levels of FeNO and nNO than the completely controlled asthma group (P<0.05). The receiver operating characteristic (ROC) curve analysis showed that nNO had an area under the ROC curve of 0.91, with a sensitivity of 80.0% and a specificity of 89.5% in the diagnosis of allergic rhinitis in children with asthma (P<0.05).@*CONCLUSIONS@#The combined measurement of nNO and FeNO can be used to evaluate the control of asthma, and the measurement of nNO can help with the diagnosis of allergic rhinitis in children with bronchial asthma.

Offline exhaled nitric oxide in children: chemiluminescence vs. electrochemical devices / Óxido nítrico exhalado «fuera de línea¼ en niños: comparación entre equipos de quimioluminiscencia y electroquímicos

Abstract Background: Exhaled nitric oxide (eNO) is a noninvasive marker of airway inflammation that has been used in children, using the "offline" technique. To the extent of our knowledge, no article reported in literature compares the concordance and correlation between the two different technologies used to measure eNO at tidal volume offline. This study aimed to report the concordance and correlation of the eNO measured "offline" at tidal volume, using chemioluminiscence (cl) vs electrochemical devices (eq). Methods: A cross-sectional, observational, and prospective study was conducted in the National Institute of Respiratory Diseases (Instituto Nacional de Enfermedades Respiratorias), Mexico City. Healthy children and those with a lung disease between 1 and 11 years of age were included. The exhaled air sample at tidal volume was obtained by attaching a mask connected to a Mylar® bag. Results: We studied 36 children. The mean ± standard deviation (SD) age of the study population was 6 ± 2.6 years; 25% of the subjects included were healthy, and the rest had a lung disease. The concordance correlation coefficient between the two measuring devices was 0.98 (p < 0.001), with a mean difference of 1.46 ± 3.5 ppb and 95% limits of agreement from -5.3 ppb to 8.3 ppb. The linear regression model equation for the estimation of eNO was eNOcl = (eNOeq·1.0718) - 0.1343 (r2 = 0.97). Conclusions: The measurement of eNO at tidal volume by the offline method can be analyzed by electrochemical devices, and the results are interchangeable with those analyzed by chemiluminescence technology.

Resumen Introducción: El óxido nítrico exhalado (eNO) es un marcador no invasivo de inflamación de la vía aérea que se ha utilizado en niños mediante técnica «fuera de línea¼. Por lo que sabemos, en la literatura no existen reportes que comparen la concordancia y la correlación entre dos técnicas diferentes a volumen corriente. El objetivo de este trabajo es informar la concordancia y la correlación del eNO obtenido por la técnica fuera de línea a volumen corriente en los equipos de quimioluminiscencia (cl) y electroquímico (eq). Métodos: Se realizó un estudio transversal, observacional y prospectivo en el Instituto Nacional de Enfermedades Respiratorias, en Ciudad de México. Se incluyeron niños sanos y con enfermedad pulmonar de 1-11 años de edad. La muestra de aire exhalado se obtuvo a volumen corriente mediante una máscara con conexión a una bolsa de Mylar®. Resultados: Se estudiaron 36 niños. La edad promedio con su desviación estándar de la población de estudio fue de 6 ± 2.6 años. El 25% de los sujetos incluidos estaban sanos y el resto tenían alguna enfermedad pulmonar. El coeficiente de correlación de concordancia entre los dos equipos fue de 0.98 (p < 0.001), con una diferencia media de 1.46 ± 3.5 ppb y unos límites de concordancia del 95% de −5.3 a 8.3 ppb. La ecuación del modelo de regresión lineal del eNO fue eNOcl = (eNOeq·1,0718) − 0.1343 (r2 = 0.97). Conclusiones: La medición del eNO por el método fuera de línea a volumen corriente puede analizarse en dispositivos electroquímicos. Los resultados son intercambiables con los de quimioluminiscencia.

Research progress in the application of impulse oscillometry and fractional exhaled nitric oxide in idiopathic pulmonary fibrosis / 中国医师杂志

Impulse oscillometry (IOS) and exhaled nitric oxide fraction determination (FeNO) are two detection methods to evaluate lung function, which can provide important functional information not captured in standardized lung function tests. These two methods may be promising disease assessment and detection tools for idiopathic pulmonary fibrosis (IPF). Therefore, it is necessary to standardize IOS and FeNO methods. This paper reviews the research progress of IOS and FeNO in IPF, and discusses the limitations of these two detection methods and their application value in IPF.

Progress on detection of exhaled nitric oxide in diagnosis and treatment of asthma in children / 国际儿科学杂志

Asthma is a common chronic airway inflammatory disease in children.In recent decades, the global prevalence of asthma in children has been increasing significantly.As a heterogeneous disease, asthma presents multiple phenotypes, with the type 2(eosinophilic)airway inflammation predominating in children.Currently, fractional exhaled nitric oxide(FeNO)is an internationally recognized marker of eosinophilic airway inflammation, and its value in the diagnosis and treatment of asthma in children has been gradually recognized.This article reviews the sources, detection methods, possible influencing factors of FeNO and its role in the diagnosis and treatment of asthma in children.

Rol de la fracción espirada de oxido nítrico en el niño con diagnóstico de asma bronquial / Role of the exhaled fraction of nitric oxide in children with diagnosis of bronchial asthma

El asma es la enfermedad respiratoria crónica pediátrica más frecuente. En la mayoría de los niños se caracteriza por inflamación de la vía aérea de tipo eosinofílica alérgica. La fracción espirada de óxido nítrico (FENO) es un biomarcador de inflamación eosinofílica de vía aérea, su medición es no invasiva y fácil de realizar y ha sido evaluado en los últimos años para su aplicación clínica en el diagnóstico y tratamiento del asma en niños y adultos. Esta revisión abordará el origen anatómico y bioquímico del FENO, aspectos prácticos de su medición, valores de referencia y su aplicación clínica en el diagnóstico y tratamiento del asma pediátrico.

Asthma is the most common pediatric chronic disease characterized in most children by allergic eosinophilic airway inflammation. The exhaled fraction of nitric oxide (FENO) is a biomarker of eosinophilic airway inflammation, constituting a non-invasive and easy-to-perform test that has been evaluated in recent years for its clinical application in the diagnosis and treatment of asthma in children and adults. This review will address the anatomical and biochemical origin of FENO, practical aspects of its measurement, reference values and its clinical application in the diagnosis and treatment of pediatric asthma.

Exhaled Nitric Oxide in Patients with Stable Chronic Obstructive Pulmonary Disease: Clinical Implications of the Use of Inhaled Corticosteroids / 결핵

Fractional exhaled nitric oxide and forced expiratory volume in 1 second/forced vital capacity have predictive value of asthma exacerbation in Korean school children

BACKGROUND: The incidence of asthma exacerbation (AE) and the predictive value of spirometry and fractional exhaled nitric oxide (FeNO) in school children have not been evaluated.OBJECTIVE: We sought to evaluate the efficacy of spirometry measurement and FeNO monitoring for predicting AE in school children in the Cheongju area in Korea.METHODS: With parental agreement, we studied 170 students aged 7–12 years. Children were evaluated by an asthma specialist using baseline spirometry, skin prick test, seasonal FeNO measurement, and asthma control test. The study participants underwent a physical examination and their medical history was also evaluated by the specialist. They were assessed for asthma control status during regular doctor visits for 1 year.RESULTS: In total, 160 children (94.1%) completed follow-up and FeNO monitoring. Of which, 26 children (16.3%) had AE. AE was associated with male children and children with allergic rhinitis (p < 0.05). While, children with AE tended to have higher FeNO than those without AE, no significant difference was found. The maximum value of FeNO ≥35 ppb was associated with AE (p < 0.05). Children with AE had a significantly decreased baseline forced expiratory volume in 1 second/forced vital capacity (FEV₁/FVC), %predicted, forced expiratory flow at 25%–75% of FVC (FEF(25%–75%)). FEV₁/FVC < 80% was associated with AE in children regardless of inhalant allergen sensitization (all p < 0.05).CONCLUSION: Baseline spirometry had a predictive value of AE in school children. Sensitive spirometric parameters such as FEV₁/FVC and FEF(25%–75%) can be used as prognostic factors to predict future childhood AE. FeNO value ≥ 35 ppb during monitoring was associated with AE in school children.

Serum levels of interleukin-18, interleukin-33 and fractional exhaled nitric oxide in children with acute respiratory syncytial virus bronchiolitis / 中国医师进修杂志

Objective To observe the changes of interleukin-18 (IL-18),interleukin-33 (IL-33) and fractional exhaled nitric oxide (FeNO) in children with acute respiratory syncytial virus (RSV) bronchiolitis,and explore the potential mechanism of the transformation from acute RSV bronchiolitis to recurrent wheezing.Methods Fifty-three children with RSV bronchiolitis (RSV bronchiolitis group),32 children with repeated wheeze (repeated wheeze group) and 30 children receiving regular physical examination (healthy control group) from January 2016 to January 2017 in Cangzhou People's Hospital of Hebei Province were selected.The serum IL-18 and IL-33 at the time of inclusion and 2,3 months after inclusion were detected by enzyme linked immunosorbent assay,the FeNO at the same time was detected by multiple breathing technique,and the indexes were compared.The correlation between FeNO and IL-33,IL-18 was analyzed by Spearman method.Results The IL-18 at the time of inclusion and 2,3 months after inclusion in RSV bronchiolitis group and repeated asthmatic group were significantly higher than those in healthy control group:(10.89 ± 1.54) and (14.86 ± 5.54) ng/L vs.(7.26 ± 3.25) ng/L,(13.74 ± 4.16) and (15.45 ± 5.75) ng/L vs.(7.28 ± 3.56) ng/L,(11.38 ± 6.21) and (14.86 ± 5.28) ng/L vs.(7.18 ± 3.41) ng/L,those in repeated asthmatic group were significantly higher than those in RSV bronchiolitis group,and there were statistical differences (P＜0.05).The IL-33 levels at the time of inclusion and 2,3 months after inclusion in RSV bronchiolitis group and repeated asthmatic group were significantly higher than those in healthy control group:(17.68 ± 5.25) and (13.14 ± 5.01) ng/L vs.(3.69 ± 1.61) ng/L,(15.68 ± 4.16) and (15.11 ± 5.24) ng/L vs.(3.28 ± 1.56) ng/L,(13.87 ± 6.21) and (14.11 ± 5.14) ng/L vs.(3.18 ± 1.41) ng/L,IL-33 levels at the time of inclusion in RSV bronchiolitis group were significantly higher than those in repeated asthmatic group,and there were statistical differences (P＜0.05).The FeNO levels at the time of inclusion and 2,3 months after inclusion in repeated asthmatic group were significantly higher than those in RSV bronchiolitis group and healthy control group:(13.14 ± 4.47) ppb vs.(1.89 ± 1.54) and (7.26 ± 4.25) ppb,(14.75 ± 5.15) ppb vs.(7.74 ± 4.16) and (7.28 ± 4.12) ppb,(13.68 ± 5.62) ppb vs.(11.38 ± 6.21) and (7.18 ± 3.41) ppb;compared with that in healthy control group,FeNO at the time of inclusion in RSV bronchiolitis group was significantly decreased,and at 3 months was significantly increased,and there were statistical differences (P＜0.05).Correlation analysis result showed that FeNO at 2 and 3 months after inclusion in RSV bronchiolitis group had positive correlation with IL-18 level at the time of inclusion and 2,3 months after inclusion (P＜0.05),and negative correlation with IL-33 (P＜0.05);FeNO at 2 and 3 months after inclusion in repeated asthmatic group showed positive correlation with IL-18 at the same time (P＜0.05),and was negatively correlated with IL-33 level (P＜0.05);there was no correlation between FeNO and IL-18,IL-33 in healthy control group (P＞0.05).Conclusions IL-18 and IL-33 may be involved in the pathogenesis of acute RSV bronchiolitis and recurrent wheezing,and the concentration of IL-18 and IL-33 is correlated with the level of FeNO.Its potential mechanism needs further study.

The predictive value of serum EOS ％ and FeNO in stable phase of COPD for the therapeutic effect of glucocorticoids / 中国医师杂志

Objective To investigate the predictive value of peripheral blood eosinophil percentage (EOS％) and exhaled nitric oxide (FeNO) on the efficacy of inhaled corticosteroids (ICS) in patients with chronic obstructive pulmonary disease (COPD) at stable stage.Methods A total of 78 patients with stable COPD during the outpatient clinic from January 2017 to December 2018 were enrolled.EOS％,FeNO,and pulmonary function indicators [forced vital capacity (FVC),forced expiratory volume in 1 sec (FEV1),peak expiratory flow (PEF)] were measured after ICS-free elution.The questionnaire was used to assess the severity of the symptoms.The above indicators were reviewed after 4 weeks of ICS treatment.According to the improvement of pulmonary function and chronic obstructive pulmonary disease assessment (CAT) improvement,the patients were divided into effective and ineffective groups.Pearson correlation analysis and receiver operating characteristic (ROC) curve were used to analyze the predictive value of EOS％ and FeNO for ICS.Results After ICS treatment,EOS％ and FeNO were lower,FVC,FEV1,and PEF were higher than before,and CAT score was lower than before (P ＜ 0.05).There was a positive correlation between EOS％ and FeNO levels before treatment and the FEV1 improvement (r =0.412,0.397,P ＜ 0.05),and no correlation with the improvement of FVC,PEF and CAT scores (P ＞ 0.05).The FeNO level in the effective group was higher than that in the ineffective group before and after ICS treatment,with statistically significant difference (P ＜ 0.05).The pre-treatment EOS％ level and post-treatment EOS％were not significantly different between the two groups (P ＞ 0.05);the area under the ROC curve for EOS％ prediction of ICS efficacy before treatment was 0.531 (P ＞0.05),with critical value 3.13％,the sensitivity 57.1％ and specificity 52.4％,respectively.The area under the ROC curve of FeNO for ICS treatment before treatment was 0.628 (P ＜ 0.05),with critical value 30.00％,sensitivity and specificity (64.6％ and 91.0％) respectively.Conclusions For patients with stable COPD,EOS％ and FeNO levels are positively correlated with the improvement of FEV1 after ICS treatment.Both of them can predict the efficacy of ICS to a certain extent,and FeNO has higher predictive value than EOS％,which can be applied to clinical practice.

Monitoring metrics for short-term exposure to ambient ozone and pulmonary function and airway inflammation in healthy young adults / 北京大学学报(医学版)

OBJECTIVE@#To assess the associations of different monitoring metrics for short-term exposure to ambient ozone (O3) with pulmonary function and airway inflammation in healthy young adults.@*METHODS@#A total of 97 healthy young college students were recruited and followed in a panel study conducted from December 2017 to June 2018. Each participant underwent 3 follow-up visits, and lung function and fractional exhaled nitric oxide (FeNO) were measured at each visit. Ambient air pollutant concentrations were obtained from the environment monitoring station of Beijing closest to the participant residences, and meteorological data were collected from China Meteorological Data Service Center. Linear mixed-effect models were applied to assess the associations between different monitoring metrics for ambient O3 short-term exposure with pulmonary function or airway inflammation in the healthy young adults.@*RESULTS@#During the study period, the P50 (P25, P75) values for ambient O3 concentration expressed as daily 1-hour maximum (O3-1 h max), daily maximum 8-hour average (O3-8 h max) and 24-hour average (O3-24 h avg) were 102.5 (76.8, 163.0) μg/m3, 91.1 (68.3, 154.3) μg/m3 and 61.6 (36.9, 81.7) μg/m3, respectively. The different monitoring metrics for short-term exposure to ambient O3 were significantly associated with reduced forced expiratory volume in the first second (FEV1) and increased FeNO. An interquartile range (IQR) increase in 6-d moving average of O3-1 h max (IQR=71.5 μg/m3) was associated with a 6.2% (95%CI: －11.8%, －0.5%) decrease in FEV1 and a 63.3% (95%CI: 13.8%, 134.3%) increase in FeNO. An IQR increase in 7-d moving average of O3-8 h max (IQR=62.0 μg/m3) was associated with a 6.2% (95%CI: －11.6%, －0.7%) decrease in FEV1and a 75.5% (95%CI: 19.3%, 158.0%) increase in FeNO. An IQR increase in 5-d moving average of O3-24 h avg (IQR=32.9 μg/m3) was associated with a 3.7% (95%CI: －7.1%, －0.2%) decrease in FEV1and a 25.3% (95%CI: 3.6%, 51.6%) increase in FeNO. There was no significant association between the three monitoring metrics for O3 exposure and peak expiratory flow (PEF).@*CONCLUSION@#Short-term exposure to ambient O3 was associated with decreased lung function and increased airway inflammation among the healthy young adults, and daily 1-hour maximum was more sensitively to the respiratory effects of O3.

Current status of asthma control and influencing factors of occupational sensitizer-induced asthma / 中国职业医学

OBJECTIVE: To investigate the asthma control status of occupational sensitizer-induced asthma(OSIA) and explore the influencing factors. METHODS: A total of 50 OSIA patients were selected as study subjects by judgment sampling method. Asthma Control Test(ACT) and Asthma Quality of Life Questionnaire were used to investigate the asthma control status and the quality of life of patients. The fractional exhaled nitric oxide(FeNO) level, pulmonary function, peripheral blood eosinophil ratio(EOS%)and serum total immunoglobulin E(IgE) level of the patients were measured. RESULTS: Among the 50 cases of OSIA patients, 27(54.0%) cases were well controlled, and 23(46.0%) cases were non-fully controlled. The patients with allergic rhinitis, with no inhaled corticosteroids treatment and with poor compliance were risk factors of the non-fully controlled OSIA(all P<0.05). The scores of ACT and the quality of life, and the percentage of the first second forced expiratory volume(FEV_1%) decreased(all P<0.05), while the level of FeNO increased(P<0.05) in the non-fully controlled group compare with the well-controlled group. There was no statistical significance in EOS% and serum total IgE level between the two groups(both P>0.05).CONCLUSION: Allergic rhinitis, lack of inhaled corticosteroids treatment and poor compliance are the influencing factors that affect the control of OSIA. The combinational scores of ACT and quality of life, FeNO, FEV_1% and other indicators can reflect the status of OSIA and assess the level of asthma control, and help guiding OSIA diagnosis and treatment plans.

Effects of Indoor Air Purifiers on Children with Asthma

PURPOSE: To evaluate the effects of air purifiers on the concentrations of indoor air pollutants and on asthma control in children.MATERIALS AND METHODS: In this randomized crossover trial, daily use of an air purifier filter was compared with a matched placebo with the filter off. Thirty elementary school students who had asthma were enrolled and randomly allocated to one of two groups. The primary endpoints were changes in indoor air quality, asthma severity, lung function, airway inflammatory, urine microbiome, and phthalate after the installation of air purifiers. PM(2.5) and CO₂ were measured as indoor air pollutants. Asthma severity was assessed in terms of both symptom and medication scores acquired using a daily questionnaire. The higher the score, the better the symptom or the less frequent the use of medication. Peak expiratory flow rate and fractional exhaled nitric oxide were also measured.RESULTS: The mean age of the enrolled patients was 9.2±1.98 years. The mean concentration of PM2.5 was 17.0 µg/m³ in the filter-off condition, but significantly lower at 9.26 µg/m³ in the filter-on condition. Medication scores were 6.9 for the filter-off and 7.12 for the filter-on conditions, reflecting a statistically significant decrease in the frequency of medications used during air purifier operation. Bacterial richness, as determined using the Chao 1 index, was markedly lower in the filter-on than the filter-off condition.CONCLUSION: This study suggests that air purifiers benefit medication burden in children with asthma by reducing PM(2.5) levels.

Usefulness of bronchodilator response as an index of asthma control in children

PURPOSE: Assessing asthma control is important for proper management, and various indices for objective assessment of asthma control, such as fractional exhaled nitric oxide (FeNO) and asthma control test (ACT) score have been proposed. Recently, bronchodilator response (BDR) was reported as a marker of poor asthma control in adults. This study aimed to assess the usefulness of BDR as a biomarker for childhood asthma. METHODS: A total of 305 children diagnosed with asthma were included. Spirometry with bronchodilator test was done at the time of diagnosis and about 14 months after asthma treatment. All children were evaluated by childhood asthma control test (c-ACT) and FeNO after asthma treatment. The patients were divided into 2 groups according to BDR results: the positive and negative BDR groups. Various biomarkers for asthma control, such as c-ACT, FeNO and changes of forced expiratory volume in 1 second (FEV1), were compared between the 2 groups. RESULTS: Of the 305 patients, 143 (46.9%) were positive and 162 (53.1%) were negative for BDR. The BDR-positive group showed lower FEV1. In the BDR positive group, FEV1 was significantly increased after asthma treatment, especially in children with airflow limitation which was defined as below 80% of FEV1 or atopy. In atopic children, BDR showed a significant negative correlation with c-ACT and a positive correlation with FeNO. CONCLUSION: In asthmatic children with airflow limitation at the time of diagnosis, BDR can be a useful index for predicting improvement in lung function by asthma maintenance treatment. BDR could be a reliable marker for the assessment of asthma control in atopic children.

Best time for detecting experiment of fractional exhaled nitric oxide in young wheezing children / 中华实用儿科临床杂志

Objective To study the correlation between fractional exhaled nitric oxide (FeNO) and lung function in young children for acute attack of wheezing,and to compare the FeNO in different stages in order to explore the best suitable time for the experiment of FeNO in young children by the method of on-line tidal breathing.Methods Recurrent wheezing children aged 1-5 year old were selected who were underwent the test at lung function laboratory from January 2016 to March 2018,at Guangzhou Women and Children's Medical Center.The children aged less than 5 years old were detected for FeNO in both stages of acute exacerbation and 2 weeks after treatment,and the children aged less than 3 years were also detected for the tidal lung function in the acute exacerbation stage.According to time ratio of reaching tidal peak flow to total expiratory time(TPTEF/TE) and ratio of volume at tidal peak flow to total tidal volume (VPEF/VE),the children aged less than 3 years were divided into 4 groups (normal group,mild group,moderate group and severe group).Results The FeNO of the normal group [9.85 (5.17,19.62) ppb] and mild group[13.00 (7.00,23.30) ppb] were significantly higher than that of the severe group [3.10 (2.20,5.25)ppb],and the differences were statistically significant (all P ＜ 0.05).And there was a positive correlation between TPTEF/TE and FeNO(r =0.304,P ＜ 0.05),VPEF/VE and FeNO(r =0.320,P ＜ 0.05),tidal volume per kilogram (VT/kG) and FeNO(r =0.293,P ＜ 0.05)and a negative correlation between respiration rate(RR) and FeNO (r =-0.449,P ＜ 0.05).The FeNO in the stage of acute exacerbation was significantly lower than that in the stage of 2 weeks after treatment[(10.49± 8.49) ppb vs.(20.41 ± 9.13) ppb],and there was a significant difference among them(t =-5.79,P ＜ 0.01).Conclusions If researchers want to use the method of on-line breathing to test FeNO in young children with wheezing,they should choose the time of 2 weeks after treatment,and analyze the results combined with the lung function.

Study on lung function and inflammatory indicators among infants with high_risk asthma / 中华实用儿科临床杂志

Objective To analyze the changes in lung function and inflammatory indicators such as eosino-phils(EOS),Creola bodies and exhaled nitric oxide(FeNO),and to explore their value in early diagnosing asthma. Methods One hundred and thirty-five infants with high-risk asthma were selected as an observation group who were admitted to Department of Respiratory,Childrenˊs Hospital of Soochow University from April 2016 to August 2017 due to asthmatic bronchitis and asthmatic bronchopneumonia,and a total of 200 non -asthmatic and non -allergic healthy children who were screened and followed up at the Department of Cardiology in the same period were selected as a healthy control group for the measurement of moist respiratory lung function and FeNO. In the observation group,the bronchial dilation test(BDT),EOS and Creola bodies were performed simultaneously. Classification of lung function:23%≤time to peak ratio(TPTEF/Te)<28% had mild obstruction,15%≤TPTEF/Te<23% had moderate obstruc-tion,and TPTEF/Te<15% showed severe obstruction. Results The TPTEF/Te[17. 20%(8. 10%)],volume to peak ratio(VPEF/Ve)[21. 20%(6. 20%)],tidal volume per kilogram of body weight(VT/kg)[7. 80(3. 70)]and ratio of tidal expiratory flow 25% to peak tidal expiratory flow(25/PF)[0. 54(0. 20)]in the observation group were signifi-cantly lower than those in the healthy control group[22. 30%(9. 22%),27. 15%(7. 10%),8. 90(3. 17),0. 60 (0. 18)],and the differences were statistically significant(Z＝ -6. 81,-9. 35,-3. 16,-3. 52,all P<0. 05). BDT positive rate in the mild obstruction group was 20. 00%(3/15 cases),BDT positive rate in the moderate obstruction group was 26. 56%(17/64 cases),and BDT positive rate in the severe obstruction group was 48. 72%(19/39 cases). The higher the degree of obstruction,the higher the value of BDT positive diagnosis(F＝6. 353,P<0. 05). BDT of VPEF/Ve,25/PF and TPTEF/Te were consistent and statistically significant(Kappa＝0. 78,0. 49,all P<0. 001). Ti-dal expiratory flow 50% -remaining(TEF50% -r)[(117. 86 ± 42. 16)mL/s],tidal expiratory flow 25% -remai- ning(TEF25% -r)[(82. 82 ± 35. 44)mL/s]in the second wheezing group were higher than those in the first whee-zing group[(92. 81 ± 28. 40)mL/s,(65. 22 ± 24. 93)mL/s],and the differences were statistically significant( t＝3. 34,2. 77,all P <0. 05). There was no statistically significant difference in sputum EOS,FeNO and Creola body scores among wheezing children between the first and second groups(all P>0. 05). FeNO in the observation group [3. 80(5. 43)μg/L]was significantly lower than that in the healthy control group[9. 60(11. 3)μg/L],and the diffe-rence was statistically significant(Z＝14. 56,P<0. 05). Sputum EOS had a positive correlation with blood EOS and Creola bodies(r＝0. 20,0. 21,all P<0. 05);there was no correlation between lung function parameters and inflamma-tory indices(all P>0. 05). Conclusions In the acute phase of infant asthma attack,the pulmonary function presents different degrees of obstructive ventilation dysfunction,the higher the degree of obstruction,the higher the diagnostic value of BDT. The value of single FeNO measurement is limited,and continuous dynamic monitoring may be more mea-ningful in predicting the occurrence of asthma. Detection of Creola bodies may be helpful in predicting asthma.

Diagnostic value study of fractional exhaled nitric oxide (FeNO) in infants with recurrent wheezing / 国际儿科学杂志

Objective To analyze the correlation between the fractional exhaled nitric oxide (FeNO) levels and blood eosinophil (EOS) count and the frequency of wheeze in infants with recurrent wheezing.Methods From February 2015 to August 2016 in the General Hospital of Northern War Zone,outpatient department of Pediatrics treatment and hospitalization of age less than or equal to 3 year old children with recurrent wheezing,101 cases were induded as the research object.On the basis of asthma predictive index (API) score were divided into API positive group (n =55) and API negative group (n =46),according to the wheeze frequency of the two groups children were divided into 3 ～ 4 times wheezing groups and more than 5 times.Select 37 cases of healthy children as control group.The concentration of FeNO and blood EOS count are detected in all the children.The correlation between the three groups of children with FeNO concentration,the correlation between FeNO and blood EOS count,the correlation between the the frequency of wheeze and FeNO in experimental groups were analyzed.Results (1) API positive group mean FeNO (19.3 ± 6.2) ppb was significantly higher than API negative group (7.7 ± 2.9) ppb,there was no difference (P ＞ 0.05).API negative group mean FeNO (7.7 ± 2.9) ppb is lower than the normal control group (9.5 ± 2.0) ppb,there was no difference (P ＞0.05).(2) API positive group mean EOS count (124.7 ± 1.6) x 106/L is higher than API negative group (86.1 ± 1.9) x 106/L,there was significant difference (P ＜ 0.01);(3) There was a correlation between FeNO level and blood EOS count in API positive group,there was no correlation between FeNO level and blood EOS count in API negative group and con~ol group.(4) No statistical differences were found in ≤4 times wheezing groups and more than 5 times of the mean FeNO.Conclusion There is no significant difference in the mean value of FeNO between different times of wheezing in children with recurrent wheezing.The combination of medical history,EOS,FeNO and API might be used to predict the wheezing episode of infants.