Lung function and biomarkers of airway inflammation during and after hospitalization for acute exacerbations of childhood asthma associated with viral respiratory symptoms

Lung Function of Children Following an Intensive Care Unit Admission for Asthma

Background: To determine the lung function of children admitted to the intensive care unit (ICU) for a severe asthma exacerbation in the medium- to long-term following hospital discharge. Methods: We performed a retrospective chart review of children ≥6 years of age admitted to the ICU for a severe asthma exacerbation at a tertiary care center from January 1, 2000, to December 31, 2013. Lung function was ascertained during outpatient follow-up visits at 3-12 months and 12-24 months postdischarge. A total of 72 subjects met the inclusion criteria. Results: Subjects were predominantly boys (56.9%) and had a mean (standard deviation [SD]) age at admission of 10.3 years (3.4 years). The median (interquartile range) length of stay in the ICU was 1 day (1-3 days). Thirty-eight and 28 subjects performed pulmonary function tests with acceptable technique at the 3-12 months and 12-24 months postdischarge visits, respectively. At 3-12 months, the mean (SD) predicted forced expiratory volume in 1 s (FEV₁) and forced expiratory flow between 25% and 75% of vital capacity (FEF_25-75) percent were 95.9 (16.7) and 76.7 (25.8), respectively, and 97.4 (17.6) and 70.5 (24.9), respectively, at 12-24 months. FEV₁/forced vital capacity (FEV₁/FVC) was 81.7 (8.3) at 3-12 months and 79.3 (7.7) at 12-24 months. A paired t-test on 20 subjects who performed acceptable spirometry at both visits showed a significant intraindividual decrease in FEV₁ (P = 0.008), FEF_25-75 (P = 0.02), and FEV₁/FVC (P = 0.01) between the 2 time points. Conclusion: Although prospective studies are required to confirm our findings, our study suggests that children admitted to the ICU for severe asthma exacerbations may be at risk for declining pulmonary function in the medium- to long-term postdischarge.

Exhaled Breath Condensate in Childhood Asthma: A Review and Current Perspective

Exhaled breath condensate (EBC) was introduced more than two decades ago as a novel, non-invasive tool to assess airway inflammation. This review summarizes the latest literature on the various markers in EBC to predict asthma in children. Despite many recommendations and two comprehensive Task Force reports, there is still large heterogeneity in published data. The biggest issue remains a lack of standardization regarding EBC collection, preservation, processing, and analysis. As a result, published studies show mixed or conflicting results, questioning the reproducibility of findings. A joint, multicenter research study is urgently needed to address the necessary methodological standardization.

Biomarkers in inflammometry pediatric asthma: utility in daily clinical practice

Asthma is a common disease in both high and lower income countries that starts early and persists often for life. A correct and accurate diagnosis, treatment and follow-up during childhood are essential for a better understanding of adult asthma and avoiding over- or under-treatment. Th2 inflammation in children with asthma symptoms is usually assessed by measuring with serum total IgE, blood eosinophilia and FeNO levels that may help to predict asthma, particularly in those infants and young children in whom lung function tests are difficult to perform. FeNO measurement, compared to intra-individual levels, may be useful also for ascertaining treatment adherence. Nevertheless, an isolated measurement may be insufficient and only the combination of these markers improves the diagnosis, phenotyping and follow-up of an asthmatic child.

Exhaled breath condensate analysis from intubated newborns by nano-HPLC coupled to high resolution MS

Invasiveness of examination and therapy methods is a serious problem for intensive care and nursing of premature infants. Exhaled breath condensate (EBC) is the most attractive biofluid for non-invasive methods development in neonatology for monitoring the status of intubated infants. The aim of the study was to propose an approach for EBC sampling and analysis from mechanically ventilated neonates. EBC collection system with good reproducibility of sampling was demonstrated. Discovery-based proteomic and metabolomic studies were performed using nano-HPLC coupled to high resolution MS. Label-free semi-quantitative data were compared for intubated neonates with congenital pneumonia (12 infants) and left-sided congenital diaphragmatic hernia (12 infants) in order to define disease-specific features. Totally 119 proteins and 164 metabolites were found. A number of proteins and metabolites that can act as potential biomarkers of respiratory diseases were proposed and require further validation.

Airway hyperreactivity is frequent in non-asthmatic children with sickle cell disease

BACKGROUND

Asthma is associated with poorer outcomes in sickle cell disease (SCD). Whether AHR can exist in SCD as a distinct entity, separate and independent of asthma, is unknown.

AIMS

Our goal was to elucidate the prevalence of AHR, as measured by a methacholine challenge test (MCT), in children with SCD who did not have concomitant asthma or any recent history of acute chest syndrome (ACS). To determine if AHR was associated with asthma-like symptoms, we compared the results of the MCT to a validated asthma questionnaire. We also examined if a correlation between AHR and inflammatory markers exists.

METHODS

AHR was identified with a positive MCT defined as a provocation concentration (PC20 ) < 4 mg/ml. The children and/or their parents completed the ISAAC (International Study of Asthma and Allergies in Children) questionnaire. We obtained blood, urine, and exhaled breath condensate samples. We measured cysteinyl leukotriene levels in urine and exhaled breath condensate via enzyme immunoassay.

RESULTS

Twenty-nine of forty children (72.5%) had a positive MCT. Nine (31.0%) also reported asthma-like symptoms on questionnaire. Inflammatory markers did not correlate with AHR. Among MCT positive subjects, those on hydroxyurea had significantly less severe AHR as quantified by PC20 (P = 0.014).

CONCLUSIONS

In children with SCD, there is a high prevalence of AHR that is not associated with asthma-like symptoms. AHR may be a distinct entity in children with SCD, existing in the absence of concomitant asthma. Hydroxyurea therapy might lessen the severity of AHR in affected individuals. Pediatr Pulmonol. 2016; 51:950-957. © 2015 Wiley Periodicals, Inc.

Factors Affecting Recovery Time of Pulmonary Function in Hospitalized Patients With Acute Asthma Exacerbations

Purpose

Prolonged recovery time of pulmonary function after an asthma exacerbation is a significant burden on asthmatics, and management of these patients needs to be improved. The aim of this study was to evaluate factors associated with a longer recovery time of pulmonary function among asthmatic patients hospitalized due to a severe asthma exacerbation.

Methods

We retrospectively reviewed the medical records of 89 patients who were admitted for the management of acute asthma exacerbations. The recovery time of pulmonary function was defined as the time from the date each patient initially received treatment for asthma exacerbations to the date the patient reached his or her previous best FEV1% value. We investigated the influence of various clinical and laboratory factors on the recovery time.

Results

The median recovery time of the patients was 1.7 weeks. Multiple linear regression analysis revealed that using regular inhaled corticosteroids (ICS) before an acute exacerbation of asthma and concurrent with viral infection at admission were associated with the prolonged recovery time of pulmonary function.

Conclusions

The prolonged recovery time of pulmonary function after a severe asthma exacerbation was not shown to be directly associated with poor adherence to ICS. Therefore the results indicate that an unknown subtype of asthma may be associated with the prolonged recovery of pulmonary function time after an acute exacerbation of asthma despite regular ICS use. Further prospective studies to investigate factors affecting the recovery time of pulmonary function after an asthma exacerbation are warranted.

YKL-40 expression in chronic obstructive pulmonary disease: relation to acute exacerbations and airway remodeling

BACKGROUND

Recent studies suggest that YKL-40, also called chitinase-3-like-1 protein, has been implicated in the pathogenesis of various inflammatory diseases. It is currently unknown, however, whether YKL-40 plays a role in acute exacerbations of chronic obstructive pulmonary disease (AECOPD) and airway remodeling.

METHODS

We evaluated serum YKL-40 levels in patients with AECOPD (n = 37) and stable COPD (n = 44), as well as in controls (n = 47). The association between YKL-40 expression and airway remodeling was analyzed. The effects of YKL-40 on collagen synthesis of primary human lung fibroblasts were also evaluated.

RESULTS

Serum YKL-40 levels were elevated at AECOPD onset as compared to stable disease (median [interquartile range], 78.6 [52.3-122.2] ng/ml versus 46.7 [31.2-75.5] ng/ml; p = 0.0005). The ideal cutoff point for distinguishing patients with AECOPD from those with stable COPD was 64.7 ng/ml (AUC: 0.71; 95%CI: 0.596 to 0.823). YKL-40 expression correlated with airflow obstruction, C-reactive protein, and collagen deposition. Stimulation with YKL-40 promoted collagen production in lung fibroblasts through ERK- and p38-dependent mechanisms.

CONCLUSIONS

YKL-40 expression is up-regulated in patients with COPD and correlates with exacerbation attacks and may contribute to airway remodeling by acting on lung fibroblasts. The current data may provide insight into the underlying pathogenesis of COPD, in which YKL-40 has an important pathogenic role.

TRIAL REGISTRATION

ChiCTR-OCC-13003567.

The analysis of volatile organic compounds in exhaled breath and biomarkers in exhaled breath condensate in children - clinical tools or scientific toys?

Current monitoring strategies for respiratory diseases are mainly based on clinical features, lung function and imaging. As airway inflammation is the hallmark of many respiratory diseases in childhood, noninvasive methods to assess the presence and severity of airway inflammation might be helpful in both diagnosing and monitoring paediatric respiratory diseases. At present, the measurement of fractional exhaled nitric oxide is the only noninvasive method available to assess eosinophilic airway inflammation in clinical practice. We aimed to evaluate whether the analysis of volatile organic compounds (VOCs) in exhaled breath (EB) and biomarkers in exhaled breath condensate (EBC) is helpful in diagnosing and monitoring respiratory diseases in children. An extensive literature search was conducted in Medline, Embase and PubMed on the analysis and applications of VOCs in EB and EBC in children. We retrieved 1165 papers, of which nine contained original data on VOCs in EB and 84 on biomarkers in EBC. These were included in this review. We give an overview of the clinical applications in childhood and summarize the methodological issues. Several VOCs in EB and biomarkers in EBC have the potential to distinguish patients from healthy controls and to monitor treatment responses. Lack of standardization of collection methods and analysis techniques hampers the introduction in clinical practice. The measurement of metabolomic profiles may have important advantages over detecting single markers. There is a lack of longitudinal studies and external validation to reveal whether EB and EBC analysis have added value in the diagnostic process and follow-up of children with respiratory diseases. In conclusion, the use of VOCs in EB and biomarkers in EBC as markers of inflammatory airway diseases in children is still a research tool and not validated for clinical use.

Prediction of asthma exacerbations in children by innovative exhaled inflammatory markers: results of a longitudinal study

BACKGROUND

In asthma management guidelines the primary goal of treatment is asthma control. To date, asthma control, guided by symptoms and lung function, is not optimal in many children and adults. Direct monitoring of airway inflammation in exhaled breath may improve asthma control and reduce the number of exacerbations.

AIM

1) To study the use of fractional exhaled nitric oxide (FeNO) and inflammatory markers in exhaled breath condensate (EBC), in the prediction of asthma exacerbations in a pediatric population. 2) To study the predictive power of these exhaled inflammatory markers combined with clinical parameters.

METHODS

96 asthmatic children were included in this one-year prospective observational study, with clinical visits every 2 months. Between visits, daily symptom scores and lung function were recorded using a home monitor. During clinical visits, asthma control and FeNO were assessed. Furthermore, lung function measurements were performed and EBC was collected. Statistical analysis was performed using a test dataset and validation dataset for 1) conditionally specified models, receiver operating characteristic-curves (ROC-curves); 2) k-nearest neighbors algorithm.

RESULTS

Three conditionally specified predictive models were constructed. Model 1 included inflammatory markers in EBC alone, model 2 included FeNO plus clinical characteristics and the ACQ score, and model 3 included all the predictors used in model 1 and 2. The area under the ROC-curves was estimated as 47%, 54% and 59% for models 1, 2 and 3 respectively. The k-nearest neighbors predictive algorithm, using the information of all the variables in model 3, produced correct predictions for 52% of the exacerbations in the validation dataset.

CONCLUSION

The predictive power of FeNO and inflammatory markers in EBC for prediction of an asthma exacerbation was low, even when combined with clinical characteristics and symptoms. Qualitative improvement of the chemical analysis of EBC may lead to a better non-invasive prediction of asthma exacerbations.

Allergic rhinitis may impact the recovery of pulmonary function tests after moderate/severe asthma exacerbation in children

BACKGROUND

During an asthma exacerbation, pulmonary function test parameters (PFTs) return to their baseline values within a few weeks. Factors affecting the recovery of PFTs other than the severity of exacerbation are not well known.

OBJECTIVE

The primary aim of the study was to determine the risk factors for recovery of PFTs > 7 days after a moderate to severe asthma exacerbation in children.

METHODS

Children who had moderate to severe asthma exacerbation performed serial prebronchodilator PFTs on days 1, 3, 7 of the exacerbation and then once weekly until their PFTs reached a plateau. All children received systemic corticosteroid for 3 days and inhaled salbutamol as long as they needed.

RESULTS

Fifty-seven children were recruited. When all PFTs were considered, 42% and 74% of children recovered within 7 and 14 days, respectively. The last recovered PFT parameter was FEF25-75 . Allergic rhinitis (AR) (P = 0.016), persistent AR (P = 0.005), and severe asthma exacerbation (P = 0.009) were significantly higher in children whose PFTs recover >7 days; only severe asthma exacerbation was different for recovery >14 days (P = 0.048). Logistic regression analysis revealed that AR and severe asthma exacerbation increase the recovery of PFTs > 7 days by 4.3 (95% CI: 1.29-14.67) and 8.1 (95% CI: 1.51-44.43), respectively.

CONCLUSIONS

Recovery of PFTs during a moderate/severe asthma exacerbation may take up to 4 weeks. Apart from severity of the exacerbation, AR is a significant factor affecting the recovery time of PFTs and therefore may impact asthma management. This issue reinforces the combined treatment of AR and asthma.

Role of biomarkers in understanding and treating children with asthma: towards personalized care

Asthma is one of the most common chronic diseases affecting children. Despite publicized expert panels on asthma management and the availability of high-potency inhaled corticosteroids, asthma continues to pose an enormous burden on quality of life for children. Research into the genetic and molecular origins of asthma are starting to show how distinct disease entities exist within the syndrome of "asthma". Biomarkers can be used to diagnose underlying molecular mechanisms that can predict the natural course of disease or likely response to drug treatment. The progress of personalized medicine in the care of children with asthma is still in its infancy. We are not yet able to apply stratified asthma treatments based on molecular phenotypes, although that time may be fast approaching. This review discusses some of the recent advances in asthma genetics and the use of current biomarkers that can help guide improved treatment. For example, the fraction of expired nitric oxide and serum Immunoglobulin E (IgE) (including allergen-specific IgE), when evaluated in the context of recurrent asthma symptoms, are general predictors of allergic airway inflammation. Biomarker assays for secondhand tobacco smoke exposure and cysteinyl leukotrienes are both promising areas of study that can help personalize management, not just for pharmacologic management, but also education and prevention efforts.