The link between early childhood lower airway symptoms, airway hyperresponsiveness, and school-age lung function

BACKGROUND

The role of early airway hyperresponsiveness (AHR) in the lung function of school-age children is currently unclear.

OBJECTIVE

To conduct a prospective follow-up study of lung function in schoolchildren with a history of lower airway symptoms and AHR to methacholine in early childhood and to compare the findings to schoolchildren with no previous or current lung diseases. We also explored symptoms and markers of type 2 inflammation.

METHODS

In 2004 to 2011, data on atopic markers, lung function, and AHR to methacholine were obtained from 193 symptomatic children under 3 years old. In 2016 to 2018, a follow-up sample of 84 children (median age, 11 years; IQR, 11-12) underwent measurements of atopic parameters, lung function, and AHR to methacholine. Moreover, in 2017 to 2018, 40 controls (median age, 11 years; IQR, 9-12) participated in the study.

RESULTS

Schoolchildren with early childhood lower airway symptoms and increased AHR had more frequent blood eosinophilia than their peers without increased AHR and lower prebronchodilator forced expiratory volume in 1 second (FEV1) and FEV1/forced vital capacity Z-scores than those without increased AHR and controls. Post-bronchodilator values were not significantly different between the two AHR groups. Atopy in early childhood (defined as atopic eczema and at least 1 positive skin prick test result) was associated with subsequent lung function and atopic markers, but not AHR.

CONCLUSION

In symptomatic young children, increased AHR was associated with subsequent obstructive lung function, which appeared reversible by bronchodilation, and blood eosinophilia, indicative of type 2 inflammation.

Subtypes of Adult-Onset Asthma at the Time of Diagnosis: A Latent Class Analysis

INTRODUCTION

Only a few previous studies have investigated the subtypes of adult-onset asthma. No previous study has assessed whether these subtypes are different between men and women, or whether these subtypes have different risk factors.

METHODS

We applied latent class analyses to the Finnish Environment and Asthma Study population, including 520 new cases of adult-onset asthma. We formed subtypes separately between women and men and analyzed the following determinants as potential predictors for these subtypes: age, body mass index, smoking, and parental asthma.

RESULTS

Among women, the subtypes identified were: 1. Moderate asthma, 2. Cough-variant asthma, 3. Eosinophilic asthma, 4. Allergic asthma, and 5. Difficult asthma. Among men, the subtypes were: 1. Mild asthma, 2. Moderate asthma, 3. Allergic asthma, and 4. Difficult asthma. Three of the subtypes were similar among women and men: Moderate, Allergic, and Difficult asthma. In addition, women had two distinct subtypes: Cough-variant asthma, and Eosinophilic asthma. These subtypes had different risk factor profiles, e.g., heredity was important for Eosinophilic and Allergic asthma (RR for Both parents having asthma in Eosinophilic 3.55 (1.09 to 11.62)). Furthermore, smoking increased the risk of Moderate asthma among women (RR for former smoking 2.21 (1.19 to 4.11)) and Difficult asthma among men but had little influence on Allergic or Cough-variant asthma. Conclusion: This is an original investigation of the subtypes of adult-onset asthma identified at the time of diagnosis. These subtypes differ between women and men, and these subtypes have different risk factor profiles. These findings have both clinical and public health importance for the etiology, prognosis, and treatment of adult-onset asthma.

The continuous laryngoscopy exercise test in severe or in difficult-to-treat asthma in adults: a systematic review

OBJECTIVE

A systematic review was performed to determine if the continuous laryngoscopy exercise test (CLE) has been used in the diagnostics of exercise dyspnea in adults with asthma, and whether inducible laryngeal obstruction (ILO) is found in those with asthma or with severe or difficult-to-treat asthma.

DATA SOURCES

We used Scopus and PubMed databases. The articles published up to 13 August 2019 were considered.

STUDY SELECTIONS

We excluded manuscripts that did not contain information about adult patients with asthma. We included six studies from 59 search results in Scopus and none from the 17 search results in PubMed.

RESULTS

The articles included 455 study individuals. Of these, 229 (50.3%) had diagnosed asthma or were treated with asthma medication. Altogether 31/229 (13.5%) subjects with diagnosis of asthma or previous asthma treatment had exercise-induced laryngeal obstruction (EILO) as comorbidity. The CLE test was performed on 229 patients with asthma. The method was used only for differential diagnosis of exercise-induced dyspnea to confirm EILO. At least 10/455 (2.2%) out of the 455 subjects experienced adverse events.

CONCLUSIONS

This systematic review revealed that only a small proportion of patients with asthma had undergone the CLE test to assess exercise-induced dyspnea. None of the selected manuscripts reported severity of asthma. Whether CLE provides a valuable diagnostic tool for patients with severe or difficult-to-treat asthma cannot be determined according to this review.

Intermittent Tiotropium Bromide for Episodic Wheezing: A Randomized Trial

BACKGROUND AND OBJECTIVES

Options to treat and prevent episodic wheezing in children are scarce. Our objective was to assess the efficacy of intermittent tiotropium bromide treatment in early childhood episodic wheezing.

METHODS

This 48-week, randomized, open-label, controlled, parallel-group trial was conducted at 4 hospitals in Finland. Children aged 6 to 35 months with 2 to 4 physician-confirmed episodes of wheeze and/or shortness of breath were considered eligible. Study participants were randomly allocated to receive 1 of 3 treatments: once-daily tiotropium bromide 5 µg for 7 to 14 days during respiratory tract infections and as-needed albuterol sulfate 0.2 mg (n = 27), twice-daily fluticasone propionate 125 µg for 7 to 14 days during respiratory tract infections and as-needed albuterol sulfate 0.2 mg (n = 25), or as-needed albuterol sulfate 0.2 mg alone (n = 28). The primary outcome was efficacy, assessed as intention-to-treat by comparing the proportion of episode-free days (the days lacking symptoms or treatments) between the treatment groups.

RESULTS

The proportion of episode-free days was higher in those receiving intermittent tiotropium bromide (median 97% [interquartile range, 93% to 99%]) than in those receiving intermittent fluticasone propionate (87% [78% to 93%], P = .002), or with as-needed albuterol sulfate alone (88% [79% to 95%], P = .003). Adjustment with allergic sensitization, the baseline number of physician-confirmed episodes of wheeze and/or shortness of breath, or short-course glucocorticoid treatment in the 2 weeks before the enrollment, did not affect the result. Intervention-related adverse events were not seen.

CONCLUSIONS

Intermittent tiotropium bromide treatment may be an effective alternative to current therapies for episodic wheezing. Before implementation of use, further research on safety and efficacy is indicated.

Overweight and exercise-induced bronchoconstriction - Is there a link?

BACKGROUND

The objective of this study was to evaluate the role of body mass index with regard to exercise performance, exercise-induced bronchoconstriction (EIB), and respiratory symptoms in 7- to 16-year-old children.

METHODS

A total of 1120 outdoor running exercise challenge test results of 7- to 16-year-old children were retrospectively reviewed. Lung function was evaluated with spirometry, and exercise performance was assessed by calculating distance per 6 minutes from the running time and distance. Respiratory symptoms in the exercise challenge test were recorded, and body mass index modified for children (ISO-BMI) was calculated for each child from height, weight, age, and gender according to the national growth references.

RESULTS

Greater ISO-BMI and overweight were associated with poorer exercise performance (P < .001). In addition, greater ISO-BMI was independently associated with cough (P = .002) and shortness of breath (P = .012) in the exercise challenge. However, there was no association between ISO-BMI and EIB or with wheeze during the exercise challenge.

CONCLUSION

Greater ISO-BMI may have a role in poorer exercise performance and appearance of respiratory symptoms during exercise, but not in EIB in 7- to 16-year-old children.

Patients with asthma or chronic obstructive pulmonary disease (COPD) can generate sufficient inspiratory flows via Easyhaler® dry powder inhaler: a pooled analysis of two randomized controlled trials

Background

To evaluate whether patients of varying ages and lung function with asthma or those with chronic obstructive pulmonary disease (COPD) can achieve sufficient inspiratory flows for effective use of the fixed-dose combination of salmeterol-fluticasone propionate and budesonide-formoterol dispensed with the Easyhaler^® (EH) device-metered, multi-dose dry powder inhaler (DPI).

Methods

A pooled analysis of two randomized, multicenter, crossover, open-label studies (NCT01424137; NCT009849061) was conducted to characterize inspiratory flow parameters across the EH, Seretide Diskus (DI) and Symbicort Turbuhaler (TH) inhalers in patients with asthma and/or COPD of varying severity. The primary endpoint was peak inspiratory flow (PIF) rate through the EH.

Results

The intent-to-treat population comprised 397 patients; 383 patients were included in the per-protocol (PP) population. The mean PIF (standard deviation) values through the EH in patients <18 and ≥18 years of age with asthma and in those with COPD, were similar: 61.4 (11.5), 69.7 (13.5), and 61.9 (13.2) L/min, respectively. These flow rates correspond to pressure drops of 5.05 (1.80), 6.52 (2.34) and 5.19 (2.07) kPa, respectively. In total, 380 (99.2%) of patients in the PP population were able to generate a PIF rate through the EH of ≥30 L/min, which is required to enable consistent dose delivery from the DPI; there was a moderate direct association between age and PIF in younger patients with asthma, but this was inverse and less apparent in adult patients with asthma and/or those with COPD. Height and weight were also moderately correlated with PIF. Stronger associations with PIF were observed for some lung function parameters, particularly native PIF and forced inspiratory vital capacity.

Conclusions

Over 99% of patients with asthma and/or COPD were able to inhale through the EH with an adequate PIF rate, irrespective of age, or severity of airway obstruction. This confirms that patients with asthma and/or COPD can achieve inspiratory flows via the EH DPI that are sufficient for its effective use.

Expiratory variability index is associated with asthma risk, wheeze and lung function in infants with recurrent respiratory symptoms

Analysis of tidal breathing flow–volume (TBFV) curves is a convenient method to assess lung function in infants. We have shown that impedance pneumography (IP) is a valid method to assess overnight TBFV profiles in young children [1] and infants [2] and that certain specific curve shapes are related to symptom presentation and asthma risk [3]. We have also shown that the reduced variability of TBFV curves may be an indicator of airway obstruction in children [4–6]. However, in infants, it is unknown whether overnight TBFV variability is associated with respiratory symptoms or asthma risk.

Impedance pneumography enables the measurement of the expiratory variability index (EVI) at home during a night's sleep in infants with recurrent respiratory symptoms. EVI is associated with asthma risk, symptoms and lung function.https://bit.ly/2PF2cx8

Smoking and lung function among adults with newly onset asthma

Introduction

Smoking increases the risk of asthma and reduces lung function among subjects with and without asthma. We assessed the effects of smoking on lung function reflecting both central and small airways among adults with newly onset asthma.

Methods

In a population-based study, 521 (response rate 86%) working-aged adults with clinically defined newly diagnosed asthma answered a questionnaire on personal smoking and other factors potentially influencing lung function, and performed spirometry. We applied multiple linear regression analysis to estimate the relations between smoking and lung function adjusting for confounding.

Results

Among asthmatics, FEV₁ level was reduced significantly, on average 208 mL, related to regular smoking (adjusted effect estimate −0.208, 95% CI −0.355 to −0.061) and 245 mL in relation to former smoking, that is, among those who quit less than a year ago (−0.245, 95% CI −0.485 to −0.004). In contrast, FEV₁ was not significantly related to occasional smoking or former smoking among those who quit over a year ago. Forced expiratory flow (FEF) levels (L/s) were also significantly reduced among regular smokers (FEF_25–75%: −0.372, 95% CI −0.607 to −0.137; FEF_50%: −0.476, 95% CI −0.750 to −0.202). An exposure–response pattern related to both daily smoking rate and lifetime cumulative smoking was seen both among men and women.

Conclusions

This study provides new evidence that among working-aged adults with new asthma, regular smoking and former smoking reduce lung function levels with a dose–response pattern. The lung function parameters applied as outcomes reflect both larger and smaller airways.

Airway hyperresponsiveness in young children with respiratory symptoms: A five-year follow-up

BACKGROUND

Recurrent wheezing in early life is transient in most children. The significance of airway hyperresponsiveness (AHR) in persistence of respiratory symptoms from infancy to early childhood is controversial.

OBJECTIVE

We evaluated whether AHR in wheezy infants predicts doctor-diagnosed asthma (DDA) or AHR at the age of 6 years.

METHODS

Sixty-one wheezy infants (age 6-24 months) were followed up to the median age of 6 years. Lung function and AHR with methacholine challenge test were assessed at infancy and 6 years. The exercise challenge test was performed at the age of 6 years. Atopy was assessed with skin prick tests.

RESULTS

At 6 years, 21 (34%) of the children had DDA. Children with DDA had higher logarithmic transformed dose-response slope (LOGDRS) to methacholine in infancy than children without DDA (0.047 vs 0.025; P = .033). Furthermore, AHR to methacholine in infancy and at 6 years were associated with each other (r = 0.324, P = .011). Children with exercise-induced bronchoconstriction (EIB) at 6 years were more reactive to methacholine in infancy than those without EIB (P = .019).

CONCLUSION

Increased AHR in symptomatic infants was associated with increased AHR, DDA, and EIB at median the age of 6 years, suggesting early establishment of AHR.

Tidal breathing flow volume profiles during sleep in wheezing infants measured by impedance pneumography

Overnight analysis of tidal breathing flow volume (TBFV) loops, recorded by impedance pneumography (IP), has been successfully applied in the home monitoring of children with wheezing disorders. However, little is known on how sleep physiology modifies the relationship between TBFV profiles and wheeze. We studied such interactions in wheezing infants. Forty-three infants recruited because of recurrent lower airway symptoms were divided into three groups based on their risk of asthma: high (HR), intermediate (IR), or low (LR). Sedated patients underwent infant lung function testing including assessment of airway responsiveness to methacholine at the hospital and a full-night recording of TBFV profiles at home with IP during natural sleep. Overnight TBFV indexes were estimated from periods of higher and lower respiration variability, presumably belonging to active [rapid eye movement (REM)] and quiet [non-REM (NREM)] sleep, respectively. From 35 valid recordings, absolute time indexes showed intrasubject sleep phase differences. Peak flow relative to time and volume was lower in HR compared with LR only during REM, suggesting altered expiratory control. Indexes estimating the concavity/convexity of flow decrease during exhalation suggested limited flow during passive exhale in HR compared with IR and LR, similarly during NREM and REM. Moreover, during REM convexity was negatively correlated with maximal flow at functional residual capacity and methacholine responsiveness. We conclude that TBFV profiles determined from overnight IP recordings vary because of sleep phase and asthma risk. Physiological changes during REM, most likely decrease in respiratory muscle tone, accentuate the changes in TBFV profiles caused by airway obstruction. NEW & NOTEWORTHY Impedance pneumography was used to investigate overnight tidal breathing flow volume (TBFV) indexes and their interactions with sleep phase [rapid eye movement (REM) vs. non-REM] at home in wheezing infants. The study shows that TBFV indexes vary significantly because of sleep phase and asthma risk of the infant and that during REM the changes in TBFV indexes caused by airway obstruction are accentuated and better associated with lung function of the infant.

Influence of mouthwashes on extended exhaled nitric oxide (FENO) analysis

Fractional exhaled nitric oxide (F_ENO) is used to assess eosinophilic inflammation of the airways. F_ENO values are influenced by the expiratory flow rate and orally produced NO. We measured F_ENO at four different expiratory flow levels after two different mouthwashes: tap water and carbonated water. Further, we compared the alveolar NO concentration (C_ANO), maximum airway NO flux (J'_awNO) and airway NO diffusion (D_awNO) after these two mouthwashes. F_ENO was measured in 30 volunteers (healthy or asthmatic) with a chemiluminescence NO-analyser at flow rates of 30, 50, 100 and 300 mL/s. A mouthwash was performed before the measurement at every flow rate. The carbonated water mouthwash significantly reduced F_ENO compared to the tap water mouthwash at all expiratory flows: 50 mL/s (p < .001), 30 mL/s (p = .001), 100 mL/s (p < .001) and 300 mL/s (p = .004). J'_awNO was also significantly reduced (p = .017), however, there were no significant differences in C_ANO and D_awNO. In conclusion, a carbonated water mouthwash can significantly reduce oropharyngeal NO compared to a tap water mouthwash at expiratory flows of 30-300 mL/s without affecting the C_ANO and D_awNO. Therefore, mouthwashes need to be taken into account when comparing F_ENO results.

Abnormal lung function at preschool age asthma in adolescence?

BACKGROUND

Asthma often begins early in childhood. However, the risk for persistence is challenging to evaluate.

OBJECTIVE

This longitudinal study relates lung function assessed with impulse oscillometry (IOS) in preschool children to asthma in adolescence.

METHODS

Lung function was measured with IOS in 255 children with asthma-like symptoms aged 4-7 years. Baseline measurements were followed by exercise challenge and bronchodilation tests. At age 12-16 years, 121 children participated in the follow-up visit, when lung function was assessed with spirometry, followed by a bronchodilation test. Asthma symptoms and medication were recorded by a questionnaire and atopy defined by skin prick tests.

RESULTS

Abnormal baseline values in preschool IOS were significantly associated with low lung function, the need for asthma medication, and asthma symptoms in adolescence. Preschool abnormal R5 at baseline (z-score ≥1.645 SD) showed 9.2 odds ratio (95%CI 2.7;31.7) for abnormal FEV1/FVC, use of asthma medication in adolescence, and 9.9 odds ratio (95%CI 2.9;34.4) for asthma symptoms. Positive exercise challenge and modified asthma-predictive index at preschool age predicted asthma symptoms and the need for asthma medication, but not abnormal lung function at teenage.

CONCLUSION

Abnormal preschool IOS is associated with asthma and poor lung function in adolescence and might be utilised for identification of asthma persistence.

Nocturnal Heart Rate Variability Spectrum Characterization in Preschool Children With Asthmatic Symptoms

Asthma is a chronic lung disease that usually develops during childhood. Despite that symptoms can almost be controlled with medication, early diagnosis is desirable in order to reduce permanent airway obstruction risk. It has been suggested that abnormal parasympathetic nervous system (PSNS) activity might be closely related with the pathogenesis of asthma, and that this PSNS activity could be reflected in cardiac vagal control. In this work, an index to characterize the spectral distribution of the high frequency (HF) component of heart rate variability (HRV), named peakness ($\wp$), is proposed. Three different implementations of $\wp$, based on electrocardiogram (ECG) recordings, impedance pneumography (IP) recordings and a combination of both, were employed in the characterization of a group of preschool children classified attending to their risk of developing asthma. Peakier components were observed in the HF band of those children classified as high-risk ( $p < 0.005$), who also presented reduced sympathvoagal balance. Results suggest that high-risk of developing asthma might be related with a lack of adaptability of PSNS.

Sensitivity of newly defined impulse oscillometry indices in preschool children

INTRODUCTION

Early origins of chronic obstructive pulmonary disease have been recognized. Impulse oscillometry (IOS) is suitable for assessment of lung function also in preschool children, and some novel indices have been connected to assessment of small airway function. However, limited data exist on the sensitivity of these new indices to detect lung function deficits in young symptomatic children.

METHODS

IOS measurements of 103 healthy preschool children were evaluated to establish reference equations for the difference between respiratory resistance at 5 and 20 Hz (R5-20), the relative difference of R5-20 (R5-20%), and area under the reactance curve (AX). Thereafter, IOS results of children with late-onset troublesome lung symptoms (n = 20), a history of early wheeze (n = 37), or a history of bronchopulmonary dysplasia (BPD, n = 8) were compared to healthy children.

RESULTS

None of the patient groups differed from healthy regarding respiratory resistance at 5 Hz (R5), and only children with a history of BPD differed from healthy regarding respiratory reactance at 5 Hz (X5). In contrast, z-scores of R5-20, R5-20%, and AX were significantly higher in all patient groups than in healthy children (P < 0.001), showing improved sensitivity (20-55%) compared to R5 and X5 (5-6%).

CONCLUSION

R5-20, R5-20%, and AX are superior to conventional IOS parameters in distinguishing children with current or past lower respiratory tract symptoms from healthy, and may prove valuable for screening early lung function deficits. Pediatr Pulmonol. 2017;52:598-605. © 2016 Wiley Periodicals, Inc.

Tidal flow variability measured by impedance pneumography relates to childhood asthma risk

Lung function variability is a fundamental feature of asthma but has been difficult to quantify in children due to methodological limitations. We assessed the feasibility and clinical implications of overnight flow variability measurement at home using impedance pneumography in young children.44 children aged 3-7 years with recurrent or persistent lower airway symptoms were recruited. Patients were divided into high- or lower-risk groups (HR and LR groups) based on their risk of asthma (modified Asthma Predictive Index), and a third group was formed of children who had a history of wheeze and who were treated with inhaled corticosteroids (ICS group). Tidal volume and the derived flow were recorded through skin electrodes using impedance pneumography at home during sleep. Quantities describing overnight change in expiratory flow-volume minimum curve shape correlation (CSRmin) and respiratory chaoticity (minimum noise limit (NLmin)) were derived.Recordings were successful in 34 children. CSRmin differed between the HR and LR groups (p=0.002) and between the HR and ICS groups (p=0.003), indicating a stronger change in flow profile shape in the HR group. NLmin differed between the HR and LR groups (p=0.014), indicating momentarily lowered chaoticity in the HR group.Impedance pneumography was found feasible for quantifying nocturnal lung function variability and the measured variability was associated with risk of asthma in young children.

Preschool oscillometry and lung function at adolescence in asthmatic children

INTRODUCTION

Reduced lung function in early childhood is associated with persistent symptoms and low lung function later in life. Impulse oscillometry (IOS) is feasible for assessing lung function also in preschool children, and some of the parameters, such as respiratory resistance at 5 Hz (Rrs5) and the frequency dependence of resistance (dRrs/df), have been suggested to reflect small airway dysfunction. Whether changes in preschool IOS predict later lung function remains unknown.

METHODS

The medical data of 154 asthmatic children with IOS performed at 2-7 years and spirometry at 12-18 years were analyzed. IOS and post-bronchodilator spirometry parameters were compared, and the association was estimated in a multivariate model.

RESULTS

Measured at preschool age, particularly Rrs5 and dRrs/df were significantly correlated with post-bronchodilator forced expiratory volume in 1 sec (FEV1) at adolescence (Rrs5: r = -0.223, P = 0.005; dRrs/df: r = 0.234, P = 0.004). Although the number of children with decreased FEV1 was low, associations of increased Rrs5 (odds ratio (OR) 5.9, 95% confidence interval (CI) 1.7; 20.9) and decreased dRrs/df (OR 8.2, 95% CI 1.7; 39.6) with decreased FEV1 remained significant in multivariate analyses. Similar findings were observed also with other spirometric parameters.

CONCLUSION

In asthmatic children, preschool IOS is associated with spirometric lung function at adolescence, but the scatter is wide. Normal preschool IOS seems to indicate favourable lung function outcome, whereas in some individuals IOS could potentially be of clinical use, at a younger age than spirometry, to screen lung function deficits and increased risk for later lung function impairment.

Lung function, airway remodeling, and inflammation in infants: outcome at 8 years

BACKGROUND

Associations between early deficits of lung function, infant airway disease, and outcome at school age in symptomatic infants are still unclear.

OBJECTIVE

To report follow-up data on a unique cohort of children investigated invasively in infancy to determine predictive value of airway disease for school-aged respiratory outcomes.

METHODS

Fifty-three infants previously studied using bronchoscopy and airway conductance were approached at 8 years of age. Symptoms, lung volumes, and airway responsiveness were reassessed. Data on lifetime purchase of asthma medication were obtained. Lung function was compared with that of 63 healthy nonasthmatic children.

RESULTS

Forty-seven children were reevaluated. Physician-diagnosed asthma was present in 39 children (83%). Twenty-five children (53%) had current and 14 children (30%) had past asthma. No pathologic feature in infancy correlated with any outcome parameter. As expected, study children had significantly reduced lung function and increased airway responsiveness compared with healthy controls, and very early symptoms were risk factors for reduced lung function. Current asthma was associated with reduced infant lung function and parental asthma. Reduced lung function in infancy was associated with purchase of inhaled corticosteroids when 6 to 8 and 0 to 8 years of age.

CONCLUSION

The lack of predictive value of any pathologic measure in infancy, reported here for the first time to our knowledge, demonstrates that pathologic processes determining the inception of asthma, which are as yet undescribed, are different from the eosinophilic inflammation associated with ongoing disease.

Bronchoalveolar lavage in infants with recurrent lower respiratory symptoms

BACKGROUND

Few data are available about the inflammatory cytokine profile of bronchoalveolar lavage (BAL) from young children with frequent wheeze. The first aim was to investigate the BAL cellular and cytokine profiles in infants with recurrent lower respiratory symptoms in whom bronchoscopy was indicated for clinical symptom evaluation. The second aim was to relate the BAL results with the histological findings of the endobronchial carina biopsies.

METHODS

Thirty-nine infants (median age 0.9 years) underwent lung function testing by whole-body plethysmography prior to the bronchoscopy. The BAL differential cell counts and cytokine levels were quantified. These findings were compared with the histological findings of the endobronchial carina biopsies.

RESULTS

The differential cytology reflected mainly that described for healthy infants with lymphocyte counts at the upper range level. A positive association between BAL CD8+ lymphocytes and neutrophils and endobronchial reticular basement membrane was found. Detectable levels of pro-inflammatory cytokine proteins IL-1β, IL-17A, IL-18, IL-23, and IL-33 were found, whereas levels of Th2-type cytokine proteins were low. Frequent wheeze was the only clinical characteristic significantly related to detectable combined pro-inflammatory cytokine profile. Lung function did not correlate with any cytokine.

CONCLUSIONS

A positive association between BAL CD8+ lymphocytes and neutrophils and endobronchial reticular basement thickness was found. Detectable production of pro-inflammatory cytokines associated positively with frequent wheeze.

Evaluation of in vitro and in vivo flow rate dependency of budesonide/formoterol Easyhaler(®)

BACKGROUND

The Easyhaler(®) (EH) device-metered dry powder inhaler containing budesonide and formoterol is being developed for asthma and chronic obstructive pulmonary disease (COPD). As a part of product optimization, a series of in vitro and in vivo studies on flow rate dependency were carried out.

METHODS

Inspiratory flow parameters via EH and Symbicort(®) Turbuhaler(®) (TH) inhalers were evaluated in 187 patients with asthma and COPD. The 10(th), 50(th), and 90(th) percentile flow rates achieved by patients were utilized to study in vitro flow rate dependency of budesonide/formoterol EH and Symbicort TH. In addition, an exploratory pharmacokinetic study on pulmonary deposition of active substances for budesonide/formoterol EH in healthy volunteers was performed.

RESULTS

Mean inspiratory flow rates through EH were 64 and 56 L/min in asthmatics and COPD patients, and through TH 79 and 72 L/min, respectively. Children with asthma had marginally lower PIF values than the adults. The inspiratory volumes were similar in all groups between the inhalers. Using weighted 10(th), 50(th), and 90(th) percentile flows the in vitro delivered doses (DDs) and fine particle doses (FPDs) for EH were rather independent of flow as 98% of the median flow DDs and 89%-93% of FPDs were delivered already at 10(th) percentile air flow. Using±15% limits, EH and TH had similar flow rate dependency profiles between 10(th) and 90(th) percentile flows. The pharmacokinetic study with budesonide/formoterol EH in healthy subjects (n=16) revealed a trend for a flow-dependent increase in lung deposition for both budesonide and formoterol.

CONCLUSIONS

Comparable in vitro flow rate dependency between budesonide/formoterol EH and Symbicort TH was found using the range of clinically relevant flow rates. The results of the pharmacokinetic study were in accordance with the in vitro results showing only a trend of flow rate-dependant increase in lung deposition of active substances with EH.

Assessing direct and indirect airway hyperresponsiveness in children using impulse oscillometry

BACKGROUND

Airway hyperresponsiveness (AHR) is a hallmark of asthma but its assessment is usually restricted to older children who are capable of performing the maneuvers involved in spirometry. In younger children, a feasible option to perform the lung function measurement is impulse oscillometry (IOS), which requires less cooperation.

OBJECTIVE

To evaluate whether assessment of AHR by IOS could differentiate children with various obstructive symptoms from one another.

METHODS

One hundred twenty-one children (median age 6.0 years, range 3.7-8.1 years) were examined: 31 with probable asthma characterized by current troublesome lung symptoms, 61 with a history of early wheezing disorder (recurrent wheezing ≤24 months of age), 15 with a history of bronchopulmonary dysplasia, and 14 healthy controls. Indirect AHR was assessed by exercise and mannitol challenge tests, and direct AHR was assessed with methacholine using IOS. AHR to exercise was defined as an increase of at least 40% in respiratory resistance at 5 Hz. In the mannitol and methacholine challenges, the dose causing an increase of 40% in respiratory resistance at 5 Hz was calculated.

RESULTS

AHR to exercise was good at differentiating children with current troublesome lung symptoms from those in the other groups (P < .001). AHR to methacholine separated children with current troublesome lung symptoms, early wheezing disorder, and bronchopulmonary dysplasia from the controls (P < .001), whereas the mannitol test did not distinguish among the study groups (P = .209).

CONCLUSION

The methacholine and exercise challenge tests with IOS identify children with probable asthma characterized by troublesome lung symptoms and therefore may represent a practical aid in the evaluation of AHR in young children.

Tidal breathing flow measurement in awake young children by using impedance pneumography

Characteristics of tidal breathing (TB) relate to lung function and may be assessed even in young children. Thus far, the accuracy of impedance pneumography (IP) in recording TB flows in young children with or without bronchial obstruction has not been evaluated. The aim of this study was to evaluate the agreement between IP and direct flow measurement with pneumotachograph (PNT) in assessing TB flow and flow-derived indices relating to airway obstruction in young children. Tidal flow was recorded for 1 min simultaneously with IP and PNT during different phases of a bronchial challenge test with methacholine in 21 wheezy children aged 3 to 7 years. The agreement of IP with PNT was found to be excellent in direct flow signal comparison, the mean deviation from linearity ranging from 2.4 to 3.1% of tidal peak inspiratory flow. Methacholine-induced bronchoconstriction or consecutive bronchodilation induced only minor changes in the agreement. Between IP and PNT, the obstruction-related tidal flow indices were equally repeatable, and agreement was found to be high, with intraclass correlation coefficients for T PTEF/T E, V PTEF/V E, and parameter S being 0.94, 0.91, and 0.68, respectively. Methacholine-induced changes in tidal flow indices showed significant associations with changes in mechanical impedance of the respiratory system assessed by the oscillometric technique, with the highest correlation found in V PTEF/V E (r = -0.54; P < 0.005 and r = -0.55; P < 0.005 by using IP or PNT, respectively). The results indicate that IP can be considered as a valid method for recording tidal airflow profiles in young children with wheezing disorders.

Very low birth weight and respiratory outcome: association between airway inflammation and hyperresponsiveness

BACKGROUND

The respiratory outcomes after preterm birth have changed, and it is unclear whether increased airway hyperresponsiveness (AHR) later in childhood is associated with airway inflammation.

OBJECTIVE

To investigate the association between AHR and fractional exhaled nitric oxide (FeNO), including the alveolar concentration of nitric oxide, in school-age children with very low birth weight (VLBW).

METHODS

Twenty-nine children with VLBW, 33 children with a history of early wheeze, and 60 healthy controls underwent a FeNO measurement and bronchial challenge test with histamine. Atopy was assessed with skin prick tests.

RESULTS

Children with VLBW had well-preserved baseline lung function but significantly increased AHR, expressed as the dose response slope (P < .001). Geometric mean FeNO levels were similar between VLBW children and healthy controls, and a history of bronchopulmonary dysplasia had no effect. In the VLBW and early wheeze groups, AHR was associated with FeNO (r = 0.47, P = .01, and r = 0.43, P = .013, respectively), but in a stratified analysis, this association was significant only in atopic individuals. By using the multiple flow FeNO technique, the bronchial nitric oxide flux rather than alveolar nitric oxide concentrations were associated with AHR in both children with early wheeze and VLBW.

CONCLUSION

We conclude that in VLBW children AHR is related to FeNO but only in atopic individuals. Similar to children with early wheeze, this association is dependent on bronchial flux rather than alveolar nitric oxide concentration. It is likely that AHR is modified by atopic inflammation rather than by inflammatory process due to prematurity.

Maternal smoking affects lung function and airway inflammation in young children with multiple-trigger wheeze

BACKGROUND

Exposure to tobacco smoke is a well-known risk factor for childhood asthma and reduced lung function, but the effect on airway inflammation in preschool-aged children is unclear.

OBJECTIVE

To examine the effect of parental smoking on lung function and fractional concentration of exhaled nitric oxide (Feno) in relation to both parental reports and children's urine cotinine concentrations in preschool-aged children with multiple-trigger wheeze.

METHODS

A total of 105 3- to 7-year-old children with multiple-trigger wheeze and lung function abnormalities were recruited. Lung function was assessed by impulse oscillometry, and Feno measurements were performed. Exposure to tobacco smoke was determined by parental reports and measurement of children's urinary cotinine concentrations.

RESULTS

Forty-three percent of the children were exposed to environmental tobacco smoke according to parental reports. The Feno level was significantly higher in children with a smoking mother (n = 27) than in children with a nonsmoking mother (23.4 vs 12.5 ppb, P = .006). The Feno level expressed as z score and the cotinine level correlated significantly (P = .03). Respiratory resistance at 5 Hz was higher in children exposed to maternal smoking than in others (0.99 vs 0.88 kPas/L, P = .005). Urinary cotinine concentrations reflected well parental reports on their daily smoking and increased relative to the number of cigarettes smoked in the family (P < .01). Atopy was found in 75% of the children, but it was not associated with the Feno value (P = .65).

CONCLUSION

Maternal smoking was associated with increased Feno value and poorer lung function in steroid-naive preschool children with multiple-trigger wheeze. Larger controlled trials are needed to generalize the results.

Neuroendocrine cell hyperplasia of infancy: a prospective follow-up of nine children

Neuroendocrine cell hyperplasia of infancy (NEHI) has recently been described as an obstructive airway disease that affects infants aged 1-24 months, and presents typically with tachypnoea, crackles and hypoxia. The pathogenesis of the disease is unknown. We describe the clinical course of nine infants with radiologically and histologically confirmed NEHI. Host or environmental factors were not associated with the disease development. All infants with lung function tests demonstrated findings consistent with severe irreversible peripheral airway obstruction, assessed with whole body plethysmography (6/6) or the rapid thoracoabdominal compression technique (5/5). While the symptoms abated in all infants, six infants developed a non-atopic asthma during the follow-up. Systemic or inhaled corticosteroid treatment did not affect the duration of the symptoms. NEHI may mimic severe asthma and thus this entity should be taken into account when evaluating infants with chronic respiratory symptoms.

The effect of montelukast on respiratory symptoms and lung function in wheezy infants

Our aim was to investigate the effectiveness of montelukast in recurrently wheezy infants. We randomised 113, 6-24-month-old children with recurrent wheezing to receive either placebo or montelukast daily for an 8-week period. The primary end-point was symptom-free days. The secondary aims were to evaluate the effect of montelukast on rescue medication, on lung function, airway responsiveness and exhaled nitric oxide fraction (FeNO). Clinical response and FeNO were determined, the functional residual capacity (FRC) and specific airway conductance (sGaw) were measured using an infant whole-body plethysmograph, the maximal flow at functional residual capacity (V'max,FRC) was recorded using the squeeze technique and airway responsiveness was evaluated by performing a dosimetric methacholine challenge test. There was no significant difference in changes in weekly symptom-free days between the montelukast and the placebo group (3.1-3.7 days versus 2.7-3.1 days, p = 0.965). No significant differences were detected in the secondary end-points, i.e. use of rescue medication, FRC, sGaw, V'max,FRC, FeNO or airway responsiveness between groups. Montelukast therapy did not influence the number of symptom-free days, use of rescue medication, lung function, airway responsiveness or airway inflammation in recurrently wheezy, very young children.

Factors associated with elevated exhaled nitric oxide fraction in infants with recurrent respiratory symptoms

Exhaled nitric oxide fraction (F(eNO)) has been proposed as a noninvasive marker of eosinophilic bronchial inflammation in active asthma, and supposed to reflect responsiveness to corticosteroid therapy. There are several factors influencing F(eNO), and its role in early childhood respiratory disorders needs to be established. Between 2004 and 2008, 444 children aged <3 yrs with recurrent lower respiratory tract symptoms were referred to a tertiary centre for further investigation. 136 full-term, steroid-free, infection-free infants, median age of 16.4 months (range 4.0-26.7 months), successfully underwent measurement of F(eNO), lung function tests, and a dosimetric methacholine challenge test. The median level of F(eNO) was 19.3 ppb (interquartile range 12.3-26.9 ppb). Elevated F(eNO) (≥ 27 ppb, the highest quartile) was associated with maternal history of asthma (adjusted OR 3.2, 95% CI 1.3-8.1; p=0.012), and increased airway responsiveness (the provocative dose of methacholine causing a 40% fall in maximal expiratory flow at functional residual capacity ≤ 0.30 mg) (adjusted OR 4.1, 95% CI 1.4-12.7; p=0.012). Atopy, blood eosinophilia and lung function were not associated with elevated F(eNO). In conclusion, maternal history of asthma, and increased airway responsiveness are associated with elevated F(eNO) in infants with recurrent lower respiratory tract symptoms.

Salmeterol and fluticasone in young children with multiple-trigger wheeze

BACKGROUND

Treatment guidelines recommend using an inhaled corticosteroid (ICS) plus a long-acting β(2)-agonist (LABA) for childhood asthma when the symptoms are not controlled by ICS alone, but the appropriate use of LABAs in children continues to be debated.

OBJECTIVE

To compare the efficacy of an inhaled salmeterol and fluticasone propionate combination, 50/100 μg twice daily, with fluticasone propionate, 100 μg twice daily, or salmeterol, 50 μg twice daily, in children with multiple-trigger wheeze.

METHODS

A total of 105 children 4 to 7 years of age with multiple-trigger wheezing based on respiratory symptoms and bronchodilator responsiveness and/or exercise-induced bronchoconstriction without a viral cold were randomized to salmeterol-fluticasone, fluticasone propionate alone, or salmeterol alone via a metered-dose inhaler and a spacer device for 8 weeks. The primary efficacy outcome was exhaled nitric oxide level. Secondary outcomes were lung function measurements via impulse oscillometry, respiratory symptoms, and rescue medication use.

RESULTS

The exhaled nitric oxide levels decreased after all treatments, significantly more so after salmeterol-fluticasone and fluticasone than with salmeterol (adjusted geometric means at 8 weeks: salmeterol-fluticasone, 9.4 ppb; fluticasone, 9.3 ppb; salmeterol, 13.9 ppb; salmeterol-fluticasone vs salmeterol, P = .02; fluticasone vs salmeterol, P = .01). No treatment differences were found with respect to respiratory symptoms or median rescue use. Salmeterol-fluticasone resulted in a small but statistically significant improvement in baseline lung function compared with fluticasone. All treatments were equally well tolerated.

CONCLUSION

The effects of salmeterol-fluticasone and fluticasone were comparable, although lung function improvement was better with salmeterol-fluticasone than with fluticasone alone. There is no obvious benefit in initiation therapy with salmeterol-fluticasone rather than fluticasone alone in the treatment of steroid-naive children with multiple-trigger wheeze.

TRIAL REGISTRATION

Pathway of clinical trial registry of Helsinki University:http://www.hus.fi/?Path=1;28;2530;9899;9900;23618;23903;33578.

Methacholine-induced lung function changes measured with infant body plethysmography

Several techniques have been applied to measure airway responsiveness (AR) in infants, but there are limited data on lung function changes measured by body plethysmography during induced bronchoconstriction. The aim of this study was to compare changes in maximum forced expiratory flow measured at functional residual capacity (V'(maxFRC)) by rapid thoracoabdominal compression (RTC) technique with plethysmographic measurements of specific airway conductance (sG(aw) ), and to investigate whether changes in functional residual capacity (FRC) occur during methacholine-induced bronchoconstriction in infants. We examined 94 infants with recurrent airway symptoms using methacholine airway challenge test including RTC and plethysmographic measurements. A significant association between changes in V'(maxFRC) and sG(aw) (r = 0.30; P = 0.004) was observed, but after adjustments with baseline variability the changes in V'(maxFRC) were greater and showed a closer association with changes in oxygen saturation. At the point of maximal airway obstruction, there was a poor agreement between V'(maxFRC) and sG(aw) to indicate a significant methacholine-induced bronchoconstriction. Airway challenge was also associated with a significant increase in FRC (P < 0.001), with decreasing V'(maxFRC). We conclude that in infants undergoing airway challenge with methacholine, plethysmographic measurements of sG(aw) correlate with the changes in V(maxFRC), but the agreement is poor and the methods cannot be used interchangeably. V(maxFRC) is also more sensitive to detect airway obstruction than sG(aw). However, methacholine-induced bronchoconstriction was associated with significant increases in FRC, which may affect the validity of V(maxFRC) measurements during the test.

Cow's milk allergy as a predictor of bronchial hyperresponsiveness and airway inflammation at school age

BACKGROUND

Cow's milk allergy (CMA) has been found to be associated with an increased incidence of asthma at school age. However, prospective population-based studies of CMA and the development of airway inflammation and bronchial hyperresponsivess (BHR) are lacking.

OBJECTIVE

The aims of this study was to evaluate CMA as a risk factor for BHR and airway inflammation presented later in childhood.

METHODS

We followed prospectively 118 children with CMA and invited them to a clinical visit at a mean age of 8.6 years including the measurement of exhaled nitric oxide (FE(NO) ) and bronchial challenge with histamine. Ninety-four patients and 80 control subjects from the same cohort participated.

RESULTS

At school age, children with a history of CMA had higher FE(NO) levels (P=0.0009) and more pronounced responsiveness to histamine (P=0.027) than their controls. Stratified analysis showed a significant difference only in IgE-positive CMA. Multinomial logistic regression analysis showed that IgE-positive CMA [odds ratio (OR) 3.51; 95% confidence intervals (CI) 1.56-7.90; P=0.002] and a history of wheeze during the first year of life (OR 2.81; 95% CI 1.16-6.84; P=0.023) were independent explanatory factors for increased FE(NO) , and IgE-positive CMA (OR 3.37; 95% CI 1.03-10.97; P=0.044) and parental smoking (OR 3.41; 95% CI 1.14-10.22; P=0.028) for increased BHR, whereas for IgE-negative CMA, no associations with FE(NO) or BHR were found. In the CMA group, those exposed to CM very early at the maternity hospital, had less BHR (P=0.002).

CONCLUSIONS

Compared with their controls, children with a history of IgE-positive CMA show signs of airway inflammation, expressed as higher FE(NO) , and more pronounced bronchial responsiveness to histamine at school age. In contrast to IgE-negative CMA, IgE-positive CMA is a significant predictor of increased FE(NO) and BHR at school age. Very early exposure to CM was associated with less BHR.

Lung function, airway remodelling and inflammation in symptomatic infants: outcome at 3 years

BACKGROUND

Relationships between early deficits of lung function, infant airway pathology and outcome in symptomatic infants are unclear. A study was undertaken to determine the associations between early lung function, airway histology and inflammation in symptomatic infants with the continuance of respiratory symptoms, lung function and subsequent use of inhaled asthma medication at the age of 3 years.

METHODS

53 children who underwent lung function measurements and bronchoscopy following referral to a specialist children's hospital for recurrent lower respiratory symptoms at a mean age of 1 year were followed up at 3 years of age. Assessments were made of respiratory symptoms during the previous year, lung function by oscillometry and atopy by skin prick testing. Individual data on the purchase of asthma medications were obtained from the Social Insurance Institution for the 12 months preceding the follow-up visit.

RESULTS

50 children (94%) were re-evaluated, of whom 40 had ongoing airway symptoms. 11/39 (28%) who underwent successful oscillometry had reduced lung function, 31/50 (62%) used inhaled corticosteroids (ICS) regularly and 12/50 (24%) used ICS intermittently. Abnormal lung function at infancy was associated with ongoing airway symptoms (p<0.001) and with the purchase of ICS (p=0.009) and β agonists (p=0.002). Reticular basement membrane thickness in infancy and the numbers of mucosal mast cells, but not eosinophils, correlated significantly with the amount of ICS purchased at 3 years (p=0.003 and p=0.018, respectively).

CONCLUSIONS

Reduced lung function, thickening of the reticular basement membrane and increased density of mucosal mast cells in infancy are associated with respiratory morbidity and treatment needs at age 3 years in this highly selected group of children.

Inspiratory flows through dry powder inhaler in chronic obstructive pulmonary disease: age and gender rather than severity matters

BACKGROUND

Dry powder inhalers (DPIs) are inspiratory flow driven and hence flow dependent. Most patients with chronic obstructive pulmonary disease (COPD) are elderly and have poor lung function. The factors affecting their inspiratory flows through inhalers are unclear.

OBJECTIVE

To study peak inspiratory flows (PIFs) and their determinants through a DPI in COPD patients of varying age and severity.

METHODS

Flow-volume spirometry was performed in 93 COPD patients. Maximum PIF rates were recorded through an empty Easyhaler (PIF(EH); Orion Corporation, Espoo, Finland), a DPI that provides consistent dose delivery at inhalation rates through the inhaler of 28 L/min or higher.

RESULTS

The mean PIF(EH) was 54 L/min (range 26-95 L/min) with a coefficient of variation of 7%. All but two patients were able to generate a flow of > or = 28 L/min. In a general linear model, the independent determinants for PIF(EH) were age (P = 0.02) and gender (P = 0.01), and forced expiratory volume in 1 s (FEV(1)) expressed as percent predicted was not a significant factor. The regression model accounted only for 18% of the variation in PIF(EH).

CONCLUSION

In patients with COPD, age and gender are more important determinants of inspiratory flow through DPIs than the degree of expiratory airway obstruction. Most COPD patients with varying age and severity are able to generate inspiratory flows through the test inhaler that is sufficient for optimal drug delivery to the lower airways.

Clinical findings associated with abnormal lung function in children aged 3-26 months with recurrent respiratory symptoms

AIM

To evaluate whether there are any associations between parentally reported symptoms, clinical findings and lung function in young children with recurrent lower respiratory tract symptoms.

METHODS

In 2000-2003, 148 children, aged 3-26 months, with recurrent lower respiratory tract symptoms underwent physical examination, investigation of a chest radiograph, whole body plethysmography and skin prick testing to common food and inhalant allergens.

RESULTS

Lung function was considered abnormal (i.e. functional residual capacity z-score of > or =1.65 and/or specific conductance z-score of < or =-1.65) in 83 (56%) children. Findings of increased work of breathing (p < 0.001) and nonspecific noisy breathing sounds (p < 0.001) in the physical examination, as well as an abnormal chest radiograph (p = 0.028) were independently associated with abnormal lung function, explaining up to 34% of the variation in lung function. In contrast, parentally reported respiratory symptoms, environmental exposures or atopic trait were not associated with lung function abnormalities.

CONCLUSION

The results of this study emphasize the importance of the meticulous clinical examination in the evaluation of early childhood respiratory disorders. As physical examination alone cannot predict lung function abnormalities reliably in preschool children with troublesome respiratory symptoms, lung function testing may be considered in such patients to obtain additional objective information.

A 10-year open follow-up of eczema and respiratory symptoms in patients with atopic dermatitis treated with topical tacrolimus for the first 4 years

OBJECTIVES

To examine the 10-year outcome of affected body surface area (BSA), respiratory symptoms, and serum IgE in adult AD patients 6 years after a 4-year intervention with topical tacrolimus.

METHODS

Patients who 10 years ago participated in a 4-year, open tacrolimus study (n = 65) were contacted for assessment of affected BSA, bronchial hyper-reactivity (BHR), respiratory symptoms, skin prick tests and serum IgE.

RESULTS

Altogether, 50 (77%) patients attended the follow-up visit. The median affected BSA decreased from 19% to 1.6% during the 10-year follow-up (p < 0.0001). Patients with active asthma and rhinitis symptoms at baseline reported a significant decrease at the follow-up (p = 0.02 andp = 0.01). In patients with BHR at baseline, the provocative dose of inhaled histamine producing a 15% decrease in FEV(1) increased. Responders (>or= 60% improvement of affected BSA) to tacrolimus treatment at the 1-year visit had a significantly smaller affected BSA at the 4- and 10-year visits than non-responders (< 60% improvement). Responders also showed a significant decrease in serum IgE at the follow-up visit compared to baseline (p = 0.002).

CONCLUSIONS

The long-term, effective treatment of patients with AD may have a beneficial effect on affected BSA, respiratory symptoms, and serum IgE.

Thirteen-year follow-up of early intervention with an inhaled corticosteroid in patients with asthma

BACKGROUND

In a 3-year study, adult patients who recently developed asthma (symptoms for less than 1 year) were treated for 2 years with the inhaled corticosteroid (ICS) budesonide (early therapy) or terbutaline. During the third year of the study, terbutaline-treated patients received budesonide (delayed therapy). Differences in lung function and bronchial responsiveness to histamine were observed between the 2 groups.

OBJECTIVE

We compared the effects of early versus delayed budesonide therapy after a 10-year follow-up period (13 years after the study began) and current real-life data.

METHODS

Of the original 103 patients, 90 were re-examined 13 years after study initiation. After the third year of the study, all patients had their medications, including the dose of ICS, individually adjusted.

RESULTS

After the follow-up period, lung function was within the normal range for the entire group (all patients); bronchial responsiveness significantly improved compared with baseline data. No statistically significant differences in clinical or functional variables were found between patients given early or delayed budesonide therapy. However, the delayed therapy group had a higher neutrophil count and higher concentrations of eosinophilic cationic protein and myeloperoxidase in induced sputum. This group had also used more asthma medication and hospital days.

CONCLUSIONS

Patients with relatively mild asthma who received ICS within 12 months of their first asthma symptoms or after a 2-year delay achieved equally good functional control of asthma after 10 years of individualized therapy. However, the delayed therapy group exhibited slightly less optimal disease control and more signs of airway inflammation.

Exhaled nitric oxide and exercise-induced bronchoconstriction in young wheezy children - interactions with atopy

The association between exercise-induced bronchoconstriction (EIB) and exhaled nitric oxide (FE(NO)) has not been investigated in young children with atopic or non-atopic wheeze, two different phenotypes of asthma in the early childhood. Steroid naïve 3- to 7-yr-old children with recent wheeze (n = 84) and age-matched control subjects without respiratory symptoms (n = 71) underwent exercise challenge test, measurement of FE(NO) and skin prick testing (SPT). EIB was assessed by using impulse oscillometry, and FE(NO) by standard online technique. Although FE(NO) levels were highest in atopic patients with EIB, both atopic and non-atopic wheezy children with EIB showed higher FE(NO) than atopic and non-atopic control subjects, respectively. In atopic wheezy children, a significant relationship between FE(NO) and the severity of EIB was found (r = 0.44, p = 0.0004), and FE(NO) was significantly predictive of EIB. No clear association between FE(NO) and EIB or predictive value was found in non-atopic wheezy children. Both atopic and non-atopic young wheezy children with EIB show increased FE(NO) levels. However, the association between the severity of EIB and FE(NO) is present and FE(NO) significantly predictive of EIB only in atopic subjects, suggesting different interaction between bronchial responsiveness and airway inflammation in non-atopic wheeze.

Budesonide improves decreased airway conductance in infants with respiratory symptoms

OBJECTIVE

Inhaled corticosteroids (ICS) are commonly used to treat wheezing disorders in children, but few studies have investigated the effect of ICS on lung function in infants. We evaluated the efficacy of inhaled budesonide for decreased specific airway conductance (sGaw) as an indication of bronchial obstruction in very young children with recurrent cough and/or wheeze. PATIENTS, DESIGN AND INTERVENTIONS: Functional residual capacity (FRC) and sGaw of steroid-naive children aged 3-26 months with respiratory symptoms were measured using an infant whole-body plethysmograph. Clinically indicated bronchoscopy was performed in 79% of the patients to exclude anatomical abnormalities before randomisation. Children with abnormal lung function and respiratory symptoms were randomised into two treatment groups, receiving either inhaled budesonide (400 microg/day) or placebo with NebuChamber for 6 weeks. Inhaled terbutaline 0.25 mg/dose was used as a rescue medication. Lung function measurements were repeated after 6 weeks.

MAIN OUTCOME MEASURE

Lung function.

RESULTS

44 children with a median age of 11.3 months (range 3.7-25.9) completed the study. Median sGaw improved from a z score of -3.6 to -1.2 (p<0.001) in the budesonide group and from -3.2 to -2.6 (p = 0.033) in the placebo group; between group difference p = 0.014. Improvement in sGaw was more pronounced in children with atopy (p = 0.017). Symptom-free days increased in both the budesonide and placebo groups with no difference between groups.

CONCLUSION

Treatment with inhaled budesonide for 6 weeks improved sGaw in young children with chronic cough or wheeze and bronchial obstruction.

Effect of adenoidectomy on respiratory function: a randomised prospective study

OBJECTIVE

Risk of childhood asthma is increased in children with recurrent otitis media. This may be associated with recurrent respiratory tract infections in these children, but the role of adenoidectomy, a frequent operation during childhood, is unknown. Therefore, the role of adenoidectomy in the development of atopy and respiratory function changes characteristic of asthma was evaluated.

DESIGN

Randomised controlled study.

SETTING

Tertiary care centre.

PATIENTS

166 children aged 12-48 months who had recurrent or persistent otitis media and who were followed-up for 3 years after randomisation.

INTERVENTION

Randomisation to undergo insertion of tympanostomy tubes with or without adenoidectomy.

MAIN OUTCOME MEASURES

The primary outcome measure was exercise-induced bronchoconstriction as evaluated by impulse oscillometry. The secondary outcome measures were bronchial inflammation as evaluated by exhaled nitric oxide and atopy as evaluated by skin prick tests. During the 3-year follow-up period otitis media episodes were documented in patient diaries.

RESULTS

Adenoidectomy did not significantly influence baseline lung function, exercise-induced bronchoconstriction, exhaled nitric oxide concentration, the development of positive skin prick tests, or doctor-diagnosed asthma. Adenoidectomy did not significantly prevent otitis media. Recurrent otitis media (>or=4 episodes) during the first follow-up year was associated with an abnormal exercise-induced bronchoconstriction (OR 6.62, 95% CI 1.27 to 34) and an elevated exhaled nitric oxide concentration (OR 3.26, 95% CI 0.98 to 10.8) regardless of adenoidectomy.

CONCLUSIONS

Adenoidectomy did not promote asthma or allergy. Recurrent respiratory tract infections during early childhood are associated with the risk of bronchial hyper-reactivity.

Exercise-induced changes in respiratory impedance in young wheezy children and nonatopic controls

Exercise-induced bronchoconstriction (EIB) is a specific sign of active asthma, but its assessment in young children may be difficult with lung function techniques requiring active cooperation. The aim of the study was to assess the normal pattern of exercise-induced responses of respiratory impedance by using impulse oscillometry (IOS), and to investigate how these responses discriminate wheezy children from control subjects. IOS measurements were performed in a consecutive sample of wheezy children aged 3-7 years (n = 130) and in an aged matched control group of nonatopic children without respiratory symptoms (n = 79) before and after a free running test. After exercise, wheezy children showed significantly larger responses in respiratory resistance (Rrs5), reactance (Xrs5), and the resonance frequency (Fr) than the control subjects. In the control group, the upper 95% confidence limit of the maximal change was 32.5% for Rrs5, 85.7% for Xrs5, and 53.1% for Fr. By using analysis of receiver operating characteristics, the change in Rrs5 distinguished the wheezy children from the control subjects more effectively than change in Xrs5 or Fr. In wheezy children, the response was significantly effected by the outdoor temperature and exercise intensity in terms of maximum heart rate. In conclusion, an increase of 35% in Rrs5 after a free running test can be regarded as an abnormal response. Wheezy children show an enhanced airway response, which is clearly distinguishable from the control subjects. IOS is a feasible method to detect EIB in young children.

Bronchial response pattern of antigen presenting cells and regulatory T cells in children less than 2 years of age

BACKGROUND

In early childhood, the ability to mount protective immune responses in the airways is impaired, with increased risk of allergic sensitisation to inhaled allergens. Antigen presenting cells (APC) and regulatory T cells (Treg) are important modifiers of T cell immunity but little is known about their distribution in bronchial mucosa at this age. Here the subset distribution of APC and the appearance of Foxp3(+) Treg and bronchus associated lymphoid tissue (BALT) were examined immunohistochemically in children less than 2 years of age with chronic asthma-like symptoms of the lower airways.

METHODS

Immunophenotyping was performed in situ on bronchial biopsy specimens obtained from 45 infants, 4-23 months of age, under investigation for airway disease.

RESULTS

A well developed HLA-DR(+) network of APC was present in all samples, approximately 50% of the cells being CD68(+) macrophages and the remainder various subsets of dendritic cells. The density of HLA-DR(+) cells increased significantly with age but was not related to atopy, clinical symptoms or lung function. Comparing the density of APC subsets and clinical parameters, only the number of intraepithelial CD1a(+) dendritic cells was significantly increased in infants who had recently suffered a respiratory infection. BALT structures were identified in 22 children, with no relation to lung function, atopic status or human rhinovirus positivity. Plasmacytoid dendritic cells and Foxp3(+) Treg were located primarily within these isolated lymphoid follicles.

CONCLUSION

A bronchial network of dendritic cells and macrophages develops quite rapidly after birth, apparently independent of clinical symptoms or atopy. The high frequency of BALT structures containing putative tolerogenic dendritic cells and Treg suggests that these lymphoid follicles play an important role in bronchial immune homeostasis during infancy.

Airway responsiveness: associated features in infants with recurrent respiratory symptoms

Increased airway responsiveness (AR) is one of the main pathophysiological manifestations of asthma. The present study aimed to define the clinical features associated with increased AR in infants with recurrent lower respiratory tract symptoms. AR was evaluated by performing a novel dosimetric methacholine challenge test. Increased AR to methacholine, defined as a methacholine dose of < or =0.90 mg producing a 40% fall (PD(40)) in the maximal flow at functional residual capacity (V'(max,FRC)), was associated with atopy (odds ratio (OR) 4.1; 95% confidence interval (CI) 1.3-13.3), a history of physician-confirmed wheezing with respiratory syncytial virus (OR 32.9; 95% CI 2.5-428.8) or of a nonspecified aetiology (OR 4.9; 95% CI 1.1-22.5), functional residual capacity z-score > or =2 (OR 36.8; 95% CI 2.9-472.6), and V'(max,FRC) z-score (OR 0.5; 95% CI 0.2-0.9) at baseline, when compared with infants with only mild or no responsiveness to methacholine (PD(40) V'(max,FRC) >0.90 mg). In conclusion, in recurrently symptomatic infants, increased airway responsiveness is associated with reduced baseline lung function, an atopic trait of the child, a history of physician-confirmed wheeze and viral aetiology of wheeze. Future intervention studies are needed to confirm the role of airway responsiveness in respiratory morbidity during infancy.

Formoterol as needed with or without budesonide in patients with intermittent asthma and raised NO levels in exhaled air: A SOMA study

Patients with mild intermittent asthma sometimes show signs of inflammation, and guidelines suggesting bronchodilator therapy alone as needed may be questioned. The current study compared as-needed use of a rapid-acting beta2-agonist with as-needed use of a beta2-agonist and corticosteroid combination as the only medication in asthma patients with intermittent symptoms. A total of 92 nonsmoking asthma patients (of 187 screened) using only an inhaled beta2-agonist as needed (28 males, 64 females; mean age 37 yrs; mean forced expiratory volume in one second (FEV1) 101% predicted, mean reversibility 6.5% pred and fractional exhaled nitric oxide (FeNO) > or =20 parts per billion (ppb)) were randomised to treatment with formoterol (Oxis Turbuhaler) 4.5 microg as needed (n = 47) or budesonide/formoterol (Symbicort Turbuhaler) 160/4.5 microg as needed (n = 45) in a double-blind, parallel-group 24-week study. The primary variable of efficacy was change in FeNO. Baseline FeNO was 60 ppb and 59 ppb in the budesonide/formoterol and formoterol groups, respectively. Mean reductions in FeNO in the budesonide/formoterol and formoterol groups were 18.2 ppb and 2.8 ppb, respectively (95% confidence interval (CI) 7.5-23.5 ppb). The reduction in the budesonide/formoterol group occurred during the first 4 weeks of treatment and remained at this low level. Mean FEV1 increased by 1.8% pred normal value in the budesonide/formoterol group and decreased by 0.9% pred normal value in the formoterol group (95% CI -4.7- -0.7). In the budesonide/formoterol group, use of > or =4 inhalations x day(-1) of study medication was seen on 21 treatment days compared with 74 in the formoterol group. In conclusion, as-needed use of an inhaled corticosteroid together with a rapid-acting bronchodilator may be more beneficial than a beta2-agonist alone in patients with intermittent asthma and signs of airway inflammation. The long-term benefits are unknown.

Reference values for respiratory system impedance by using impulse oscillometry in children aged 2-11 years

The forced oscillation technique makes it possible to evaluate the mechanical properties of the respiratory system with a minimum of cooperation. The method is therefore especially useful in children. Impulse oscillometry (IOS) is a commercially available version of this technique. There is, as yet, limited information on reference values for IOS in children. The aim of this study was to extend the reference values for IOS variables and to study their correlation with height, weight and age in healthy children. A sample (n = 360) of children (age 2.1-11.1 years) was measured by using impulse oscillometry (IOS; Jaeger, Würzburg, Germany). The sample was based on children attending kindergarten in Finland and children attending primary school in Sweden. Measurements of respiratory resistance (Rrs) and reactance (Xrs) at 5, 10, 15 and 20 Hz, total respiratory impedance (Zrs) and the resonance frequency (Fr) were made. All variables were related to body height. Most of them were also weakly related to weight. Reference equations for children (height 90-160 cm) are presented.

Exhaled nitric oxide in healthy nonatopic school-age children: determinants and height-adjusted reference values

Exhaled nitric oxide (FENO) was proposed as a marker of airway inflammation, but data about FENO in healthy children measured with standardized methods are so far limited. In order to assess the determinants of FENO in healthy children, we investigated a population-based sample of school-age children (n = 276) with a questionnaire, skin-prick tests, spirometry, and the measurement of FENO. The FENO of 114 nonatopic and nonsmoking children considered healthy were analyzed with stepwise multiple regression analysis, which showed significant associations with age, standing height, weight, and body surface area, but not with gender. Height was found to be the best independent variable for the regression equation for FENO, which on average showed an increase in the height range of 120-180 cm from 7 to 14 ppb. In the random sample of children, increased FENO was associated with atopy (odds ratio, 9.0; 95% confidence interval, 3.9-21.1; P < 0.0001), and significantly with allergic rhinitis and atopic dermatitis, but not with asthma. Respiratory symptom-free children with skin-prick test positivity had significantly higher FENO than healthy nonatopic subjects. We conclude that height is the best determinant of FENO in healthy children. Due to the strong effect of atopy, FENO data should not be interpreted without knowing the atopic status of the child. The present reference values of FENO may serve in clinical assessments for measuring airway inflammation in children.

Human rhinovirus in bronchial epithelium of infants with recurrent respiratory symptoms

BACKGROUND

Human rhinoviruses (HRVs) are a common cause of upper respiratory tract infections. There is growing evidence that HRVs are also important in lower respiratory tract infections and often induce asthma exacerbations.

OBJECTIVE

We evaluated the presence of HRV in the lower respiratory tract by obtaining bronchial biopsies from infants with recurrent asthmalike respiratory symptoms.

METHODS

A total of 201 steroid-naive infants age 3 to 26 months with recurrent respiratory symptoms for at least 4 weeks within the preceding 2 months were studied for lung function using body plethysmography. Bronchoscopy was performed in 68 children, and bronchial biopsies were available from 59 infants for HRV detection with in situ hybridization.

RESULTS

Human rhinovirus was detected in 21 of 47 (45%) specimens. Abnormal lung function (decreased airways conductance) was found in 18 of 21 (86%) HRV(+) infants and in 15 of 26 (58%) HRV(-) infants (P = .037). Occurrence of a respiratory infection in the 6 weeks preceding bronchoscopy correlated with HRV positivity (P = .036).

CONCLUSION

Human rhinovirus is frequently found in the lower airways in infants with recurrent respiratory symptoms, and the majority of these HRV(+) infants also showed increased airway resistance.

CLINICAL IMPLICATIONS

Human rhinovirus is a common pathogen causing upper and lower respiratory symptoms. Follow-up of these infants will reveal whether the presence of HRV in the bronchial biopsy and abnormal lung function with recurrent respiratory symptoms predicts subsequent asthma.

Airway Remodeling and Inflammation in Symptomatic Infants with Reversible Airflow Obstruction

RATIONALE

We hypothesized that the epithelial reticular basement membrane (RBM) thickening and eosinophilic inflammation characteristic of asthma would be present in symptomatic infants with reversible airflow obstruction.

METHODS

RBM thickness and numbers of inflammatory cells were determined in ultrathin sections of endobronchial biopsies obtained from 53 infants during clinical bronchoscopy for severe wheeze and/or cough. Group A: 16 infants with a median age of 12 months (range 3.4-26 months), with decreased specific airway conductance (sGaw) and bronchodilator reversibility; Group B: 22 infants with a median age of 12.4 months (5.1-25.9 months), with decreased sGaw but without bronchodilator reversibility; and Group C: 15 infants with a median age of 11.5 months (3.4-24.3 months) with normal sGaw. Additional comparisons were made with the following groups. Group D: 17 children, median age 10.3 years (6-16 years), with difficult asthma; Group E: 10 pediatric control subjects without asthma, median age 10 years (6-16 years); and Group F: nine adult normal, healthy control subjects, median age 27 years (21-42 years).

MAIN RESULTS

There were no significant differences in RBM thickness or inflammatory cell number between the infant groups. RBM thickness was similar in the infants and Groups E and F. However, the RBM in all infant groups (Group A: median 4.3 microm [range 2.8-9.2 microm]; Group B: median 4.15 microm [range 2.7-5.8 microm]; Group C: median 3.8 microm [range 2.7-5.5 microm]) was significantly less thick than that in the older children with asthma (Group D: median 8.3 microm [range 5.3-12.7 microm]; p < 0.001).

CONCLUSION

RBM thickening and the eosinophilic inflammation characteristic of asthma in older children and adults are not present in symptomatic infants with reversible airflow obstruction, even in the presence of atopy.