Anne Kotaniemi-Syrjänen

The prognosis of wheat hypersensitivity in children.

Kotaniemi‐Syrjänen A, Palosuo K, Jartti T, Kuitunen M, Pelkonen AS, Mäkelä MJ. The prognosis of wheat hypersensitivity in children.u2028Pediatr Allergy Immunol 2010: 21: e421–e428.u2028© 2009 John Wiley & Sons A/S

Wheat allergy in children – new tools for diagnostics

The detection of wheat‐specific IgE in children often leads to a suspicion of wheat allergy, but little information is available on the most reliable wheat allergens for predicting clinical reactivity.

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 ≤0.90u2005mg producing a 40% fall (PD40) 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 ≥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 (PD40 V′max,FRC >0.90u2005mg). 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.

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

Exhaled nitric oxide fraction (FeNO) 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 FeNO, 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 FeNO, lung function tests, and a dosimetric methacholine challenge test. The median level of FeNO was 19.3 ppb (interquartile range 12.3–26.9 ppb). Elevated FeNO (≥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 FeNO. In conclusion, maternal history of asthma, and increased airway responsiveness are associated with elevated FeNO in infants with recurrent lower respiratory tract symptoms.

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.

Preschool oscillometry and lung function at adolescence in asthmatic children

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 5u2009Hz (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.

Does tidal exhaled nitric oxide reflect mucosal airway inflammation in infants

Exhaled nitric oxide (FENO) has been proposed as a surrogate of airway inflammation in asthma. The measurement of FENO may be important to distinguish conditions characterised by eosinophilic inflammation from those which are non-eosinophilic, the former being more likely to respond to steroid treatment. Studies in adults and school-aged children have shown that FENO levels correlate to some extent with airway mucosal eosinophilia quantified in endobronchial biopsies.1 2 However, no such studies exist in infants. In this observational study, we assessed whether infants with recurrent respiratory symptoms, in whom bronchoscopy had been undertaken for clinical evaluation, showed evidence of a relationship between mucosal airway inflammation quantified in endobronchial biopsies and levels of FENO measured during tidal breathing.nnThe study consisted of 36 infants, aged between 3.4 and 25.9u2005months, referred for clinical evaluation of …

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 20u2009Hz (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 (nu2009=u200920), a history of early wheeze (nu2009=u200937), or a history of bronchopulmonary dysplasia (BPD, nu2009=u20098) were compared to healthy children. Results: None of the patient groups differed from healthy regarding respiratory resistance at 5u2009Hz (R5), and only children with a history of BPD differed from healthy regarding respiratory reactance at 5u2009Hz (X5). In contrast, z‐scores of R5‐20, R5‐20%, and AX were significantly higher in all patient groups than in healthy children (Pu2009<u20090.001), 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.

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 3–7u2005years 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. Impedance pneumography enables home monitoring of lung function variability relating to risk of asthma in children http://ow.ly/XFWtD

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 (VmaxFRC) by rapid thoracoabdominal compression (RTC) technique with plethysmographic measurements of specific airway conductance (sGaw), 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 VmaxFRC and sGaw (ru2009=u20090.30; Pu2009=u20090.004) was observed, but after adjustments with baseline variability the changes in VmaxFRC 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 VmaxFRC and sGaw to indicate a significant methacholine‐induced bronchoconstriction. Airway challenge was also associated with a significant increase in FRC (Pu2009<u20090.001), with decreasing VmaxFRC. We conclude that in infants undergoing airway challenge with methacholine, plethysmographic measurements of sGaw correlate with the changes in VmaxFRC, but the agreement is poor and the methods cannot be used interchangeably. VmaxFRC is also more sensitive to detect airway obstruction than sGaw. However, methacholine‐induced bronchoconstriction was associated with significant increases in FRC, which may affect the validity of VmaxFRC measurements during the test. Pediatr Pulmonol. 2011; 46:362–368.