ASSOCIATION BETWEEN FRACTION OF EXHALED NITRIC OXIDE AND SPIROMETRY DATA AND CLINICAL CONTROL OF ASTHMA IN CHILDREN AND ADOLESCENTS

Functional analysis of airway remodeling is related with fibrotic mediators in asthmatic children

BACKGROUND

Asthmatic children present variable degrees of airway inflammation, remodeling, and resistance, which correlate with disease control and severity. The chronic inflammatory process of the airway triggers airway remodeling, which reflects the degree of airway resistance. Pro-inflammatory and pro-fibrotic mediators are centrally involved in this process.

OBJECTIVE

To investigate whether the levels of pulmonary and systemic pro-inflammatory and pro-fibrotic mediators present a correlation with the resistance of the respiratory system and of the proximal and distal airways.

METHODS

39 Asthmatic children (persistent mild and moderate) and 39 non-asthmatic children (both between 6 and 13 years old) were evaluated for anthropometric characteristics, lung function and mechanics, and pulmonary and systemic immune responses.

RESULTS

Asthmatic children showed an increased number of blood eosinophils (p < 0.04), basophils (p < 0.04), monocytes (p < 0.002) and lymphocytes (p < 0.03). In addition, asthmatic children showed impaired lung function, as demonstrated by FEV1 (p < 0.0005) and FEV1/FVC (p < 0.004), decreased total resistance of the respiratory system (R5Hz; p < 0.009), increased resistance of the proximal airways (R20Hz; p < 0.02), increased elastance (Z5Hz; p < 0.02) and increased reactance (X5Hz; p < 0.002) compared to non-asthmatic children. Moreover, the following inflammatory factors were significantly higher in asthmatic than non-asthmatic children: GM-CSF in the breath condensate (BC) (p < 0.0001) and in the serum (p < 0.0001); TGF-beta in the BC (p < 0.0001) and in the serum (p < 0.004); IL-5 in the BC (p < 0.02) and in the serum (p < 0.01); IL-4 in the serum (p < 0.0002).

CONCLUSIONS

Impulse oscillometry is a sensitive method to detect airway resistance in persistent mild and moderate asthmatic children, an event followed by increased levels of pro-inflammatory and pro-fibrotic mediators.

Childhood severe asthma: relationship among asthma control scores, FeNO, spirometry and impulse oscillometry

INTRODUCTION

The evaluation of the asthmatic patient is usually based on clinical and functional parameters that do not necessarily evidence the degree of airway inflammation. The aim of this study was to analyze whether clinical scores (CS) correlate with spirometry (S), impulse oscillometry (IO) and FeNO, in severe asthmatic children.

MATERIAL AND METHODS

A multicentric, prospective, cross-sectional study was conducted over a 12-month period. All SA patients (6-18 years old) followed-up in the Pulmonology Department were recruited. CS, FeNO measurements, IO and S were consecutively performed on the same day. Asthma control was ascertained using ACT and GINAq. A cut-off value of ≥ 25 parts per billion (ppb) was used to define airway inflammation.

RESULTS

Eighty-one patients were included. ACT: 75% (n 61) were controlled; GINAq: 44.5% (n 36) were controlled; 39.5% (n 32) were partly controlled, and 16% (n 13) were uncontrolled. FeNO had a median value of 24 ppb (IQR 14-41); FeNO ≥ 25 ppb was observed in 49% of patients (n 39). ROC AUC for FeNO vs. ACT was 0.71 (95%CI 0.57-0.86), PPV 0.47, NPV 0.87, SE 0.61, SP 0.80; FeNO vs. GINAq was ROC AUC 0.69 (95%CI 0.54-0.85), PPV 0.34, NPV 0.91, SE 0.62, SP 0.77; Youden cut-off FeNO > 39 ppb for both CS.

CONCLUSION

In severe asthmatic children, current symptoms control as evidenced by ACT and GINA correlates with low FeNO values. Clinical scores showed good correlation with airway inflammation.

Doxofylline as a steroid-sparing treatment in Mexican children with asthma

OBJECTIVE

The aim of this pilot study was to assess the efficacy of doxofylline as an ICS-sparing agent in the treatment of Mexican children with asthma.

METHODS

10-week, open-label, crossover, pilot study, we examined the steroid-sparing effect of doxofylline in Mexican children with asthma. Patients aged 6-16 years treated with inhaled corticosteroids (ICS) for at least 8 wk before enrollment were divided randomly into two groups at the baseline visit. Group A (n = 31) received doxofylline (18 mg/kg/day) plus standard-dose budesonide (D + SDB) for the first 4-week period followed by doxofylline plus reduced-dose budesonide (D + RDB) for the second 4-week period. Group B (n = 30) received D + RDB followed by D + SDB. Clinical outcomes assessed included lung function (forced expiratory volume; in 1 s, FEV1), fractional exhaled nitric oxide (FeNO), asthma control, number of exacerbations and use of rescue medication (salbutamol).

RESULTS

It was shown that combined use of doxofylline and ICS may allow children with asthma to reduce their daily dose of ICS while maintaining lung function and improving asthma control (p = 0.008). There were few asthma exacerbations and only one patient required treatment with systemic corticosteroids. Rescue medication use decreased significantly in patients receiving D + SDB during the first 4-week period.

CONCLUSIONS

Our results suggest that doxofylline may be a steroid-sparing treatment in asthma, but longer-term, controlled studies are needed to confirm these observations.

A Longitudinal Study of a Selected Pediatric Asthmatic Population with Normal and Abnormal Spirometry at Baseline: An Emphasis on Treatment Outcomes

Purpose

It is still unclear whether considering abnormal spirometry as a marker for disease control can help physicians adjust asthma controllers in children because of the scarcity of pediatric studies. We aimed to investigate the prevalence of abnormal spirometry in a selected pediatric asthmatic population and its effect on longitudinal outcomes.

Patients and Methods

This retrospective cohort study was conducted at the Songklanagarind Hospital, Thailand. Children with asthma aged <18 years were recruited for review if they attended the clinic and underwent acceptable spirometry with bronchodilator responsiveness (BDR) tests after receiving asthma treatment for at least 3 months between January 2011 and June 2022. Differences in baseline characteristics, atopic factors, asthma treatment, and outcomes were analyzed between the normal and abnormal spirometry groups over a 12-month post-spirometry period.

Results

The mean age of the 203 enrolled patients was 10.9 ± 2.6 years. Abnormal spirometry, defined as airflow limitation or the presence of BDR, was observed in 58.1% of patients. No significant differences were observed in baseline characteristics, atopic factors, asthma treatment, or outcomes between the normal and abnormal spirometry groups. Further analysis of 107 patients with abnormal spirometry with symptom control revealed that physicians adjusted the asthma controller based on spirometry and symptoms in 84 and 23 patients, respectively. There was no significant difference in the loss of disease control over the 12-month post-spirometry period between the two groups.

Conclusion

Abnormal spirometry was found in 58.1% of treated school-aged patients with asthma. Abnormal spirometry results were not associated with poor asthma outcomes during the 12-month follow-up. Both symptom-based and spirometry-based adjustments of asthma controllers resulted in comparable symptom control over a 12-month follow-up period in the selected population.

Association of fractional exhaled nitric oxide with asthma morbidity in urban minority children

OBJECTIVE

Fractional exhaled nitric oxide (FeNO) is a well-established measure of allergic airway inflammation and possible useful adjunct disease management tool. We investigated the association of baseline and follow-up FeNO measurements with disease burden in minority children with persistent asthma.

METHODS

A retrospective chart review was conducted on 352 African American and Hispanic children seen at an urban Asthma Center in Bronx, NY. Demographic, clinical characteristics, and pulmonary function tests (PFTs) were compared between children with low, intermediate, and high baseline FeNO levels. Among 95 children with subsequent follow up visits, associations of change in FeNO with demographics, clinical characteristics, and PFTs were examined using mixed effects linear regression models.

RESULTS

A higher proportion of children with intermediate (54%) and high FeNO (58%) levels had lower airways obstruction compared to those with low FeNO levels (33%). Children with intermediate FeNO levels had more annual hospitalizations (2.8 ± 6.2) compared to those with low and high FeNO levels (1.3 ± 2.8 and 1.3 ± 2.5). These associations did not differ between ethnicities. An increase in FeNO over time was associated with higher BMI z-scores (β = 6.2, 95% CI: 1.0 to 11.4) and two or more hospitalizations in the past year (β = 16.1, 95% CI: 1.5 to 30.8).

CONCLUSIONS

Intermediate and high FeNO levels are associated with lower airways obstruction and hospitalizations. Initial and serial FeNO measurements can be a useful adjunctive tool in identifying asthma-related morbidity in urban African American and Hispanic children.

Comparison of fractional exhaled nitric oxide, spirometry, and Asthma Control Test, in predicting asthma exacerbations: A prospective cohort study

Context

Fractional exhaled nitric oxide (FeNO) is a noninvasive test for airway inflammation in asthma. The usefulness of FeNO in predicting exacerbations is uncertain.

Aims

The study aims to assess and compare the ability of FeNO, spirometry, and asthma control test (ACT) in predicting future exacerbations of asthma and their correlation with each other.

Settings and Design

This prospective, cohort study was conducted at the Department of Respiratory Medicine, Kasturba Medical College, Manipal.

Materials and Methods

Adult asthma patients of age 18-65 years were included. Patients with a smoking history of >10 pack-years and those in whom spirometry was contraindicated were excluded. Patients who consented underwent FeNO and spirometry. The control of asthma was assessed using the ACT questionnaire. We captured the number of exacerbations in the follow-up period of 4 months.

Statistical Analysis Used

Mann-Whitney test was used to compare the utility of FeNO, spirometry, ACT in predicting exacerbations and Spearman's correlation coefficient was used to ascertain the correlation among them.

Results

Of 154 study patients, 28% had exacerbations. We found that there was no significant difference in FeNO in patients with and without exacerbations. The median (interquartile range [IQR]) FEV1% in the patients with and without exacerbations were 68 (55-79) and 75 (65-88), respectively (P = 0.013). The median (IQR) ACT score in patients with exacerbations was 12 (10-16) which was significantly lower than in those without exacerbation in whom it was 16 (14-18) (P = 0.003). There was a negative correlation of ACT with FeNO (Correlation coefficient: -0.167, P = 0.038). The median (IQR) FeNO level (ppb) was lower in patients who were on inhaled corticosteroid (ICS) than in the other group values being 22 (14-38) and 30 (17-58), respectively (P = 0.05).

Conclusions

In our study, FEV1% and ACT score could predict exacerbations of asthma whereas FeNO could not. FeNO level correlated inversely with ACT score. FeNO level decreased with inhaled corticosteroid usage.

The relationship between serum vitamin D level and asthma

OBJECTIVE:

Several studies have established a relationship between low serum vitamin D levels and the onset of asthma in childhood. In this study, we aim to assess the relationship between vitamin D and asthma.

METHODS:

This study included 29 mild and 30 moderate persistent asthma and 38 healthy control group. Evaluation of the three groups was carried out in respect of serum vitamin D levels, Respiratory Function Test (RFT), and Exercise Provocation Test (EPT). The two asthma groups were also examined using the Asthma Control Test (ACT) and Nitric Oxide in Exhaled Breath (FeNO) level.

RESULTS:

The vitamin D levels of the mild and the moderate persistent asthma groups were determined to be lower than the vitamin D levels of the control group (p=0.007). A significant negative correlation was determined in all cases between the vitamin D levels and the broncho-reversibility percentage (p=0.0002). The negative correlation between the vitamin D levels and the broncho-reversibility percentage was more evident in the moderate persistent asthma group (p=0.0001). In the moderate persistent asthma group, a significant positive correlation was determined between the lowness of the maximum forced expiratory volume in EPT and a low vitamin D level (p=0.009). The ACT scores were lower, and the FeNO levels were higher in the moderate asthma group compared to the mild asthma group (p=0.0001).

CONCLUSION:

The findings showed that low serum vitamin D levels were observed more often in children with asthma, and there was a correlation with increased broncho-reversibility in the RFT and increased bronchial hyper-reactivity in the EPT.

Asthma control test reflects not only lung function but also airway inflammation in children with stable asthma

Objective: Various numerical asthma control tools have been developed to distinguish different levels of symptom control. We aimed to examine whether the asthma control test (ACT) is reflective of objective findings such as lung function, fractional exhaled nitric oxide (FeNO) and laboratory data in patients with stable asthma.Methods: We included patients who were enrolled in the Korean Childhood Asthma Study. ACT, spirometry, blood tests and FeNO were performed in patients after stabilization of their asthma. We examined differences among spirometry parameters, blood tests and FeNO according to control status as determined by ACT and investigated for any significant correlations.Results: The study population consisted of 441 subjects. Spirometry showed that forced expiratory volume in one second (FEV₁), forced expiratory flow between 25% and 75% of forced vital capacity and FEV₁/forced vital capacity were all significantly higher in the controlled asthma group. Likewise, FeNO and percent-change in FEV₁ were both significantly lower in the controlled asthma group. In blood tests, the eosinophil fraction was significantly lower in the controlled asthma group while white blood cell count was significantly higher in the controlled asthma group. Lastly, among the various factors analyzed, only provocative concentration of methacholine causing a 20% fall in FEV₁ significantly correlated with ACT score.Conclusion: ACT is useful as part of the routine evaluation of asthmatic children and should be used as a complement to existing tools such as spirometry and FeNO measurement.