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Multiple-breath nitrogen washout (MBNW) and its clinical parameter lung clearance index (LCI) are gaining increasing attention for the assessment of small airway function. Measurement of LCI relies on accurate assessment of functional residual capacity (FRC). The EasyOne Pro LAB (ndd) and Exhalyzer D (EM) are two commercially available MBNW devices. The aim of the study was to compare these two devices in vitro and in vivo in healthy subjects with regard to FRC, LCI and secondary outcome parameters and to relate FRC MBNW to FRC measured by body plethysmography (pleth) and helium dilution technique. MBNW measurements were performed using a lung model (FRC between 500 and 4000 mL) in vitro and in 38 subjects aged 6-65 years followed by helium dilution and pleth in vivo using fixed and relaxed breathing techniques. In vitro accuracy within 5% of lung model FRC was 67.3% for ndd, FRC was >5% higher for EM in all tests. In vivo , FRC pleth ranged from 1.2 to 5.6 L. Mean differences (limits of agreement) between FRC pleth and FRC MBNW were -7.0%, (-23.2 to 9.2%) and 5.7% (-11.2 to 22.6%) using ndd and EM, respectively. FRC ndd was consistently lower than FRC EM (-11.8% (-25.6 to 2%)). LCI was comparable between the two devices (-1.3% (-21.9 to 19.3%)). There was a difference of >10 % in LCI in 12 of 38 subjects. Using the most recent software updates, both devices show relevant deviations in FRC measurement both in vitro and in vivo and individual differences in LCI in a significant proportion of subjects. The devices are therefore not interchangeable., Competing Interests: Conflict of interest: A.M. Zwitserloot reports a grant from Stichting Astma Bestrijding and that ndd Medical Technologies provided the EasyOne Pro LAB MBNW device and lung model setup for this study; and money to her institution for an advisory board for GSK outside the submitted work. Conflict of interest: E.J. van den Berg has nothing to disclose. Conflict of interest: L.H.A. Raaijmakers has nothing to disclose. Conflict of interest: W.E. Stalman has nothing to disclose. Conflict of interest: M. van Smaalen has nothing to disclose. Conflict of interest: M. van den Berge reports research grants to his university from GlaxoSmithKline, TEVA, Chiesi and Novartis, outside the submitted work. Conflict of interest: M. Gappa has nothing to disclose. Conflict of interest: G.H. Koppelman reports grants from the Lung Foundation of the Netherlands during the conduct of the study, TETRI Foundation, UBBO EMMIUS Foundation, TEVA the Netherlands, VERTEX and GSK, and that he has participated in an advisory board for GSK, outside the submitted work. Conflict of interest: B.W.M. Willemse has nothing to disclose., (Copyright ©ERS 2020.)

Background: Severe asthma affects less than 5% of asthmatics, but is associated with high costs and increased mortality. The aim of this study was to assess age- and sex-dependent differences in this patient group., Methods: Retrospective analysis of 1317 children and adults with severe asthma who are included in the German Asthma Net registry., Results: There were more adults than children in the registry and patients' mean age was 52. Apart from children <18 years, there were more women (57%) than men. The age of first diagnosis ranged from 0 to 76 years. 38% of patients had a positive bronchial reversibility after short acting bronchodilators. Quality of life, FEV1 and MEF 25 decreased with older age whereas treatment with oral steroids and monoclonal antibodies increased. An anti-eosinophil treatment was most frequently used in patients aged around 57 years, while an anti-IgE treatment was used in all age-groups including children. There were sex-dependent differences with lower values in men for FEV1, FVC, MEF 25 and DLCO. Yet, women were more frequently unable to work than men due to the disease., Conclusion: In patients with severe asthma, clinical characteristics, but also treatments differed between age groups and between the sexes, reflecting different phenotypes of the disease., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

The development of new asthma biologics and receptor blockers for the treatment of paediatric severe asthma raises challenges. It is unclear whether there are sufficient children in Europe to recruit into randomised placebo-controlled trials to establish efficacy and safety in this age group. In February 2016, the European Respiratory Society funded a clinical research collaboration entitled "Severe Paediatric Asthma Collaborative in Europe" (SPACE). We now report the SPACE protocol for a prospective pan-European observational study of paediatric severe asthma. Inclusion criteria are: 1) age 6-17 years, 2) severe asthma managed at a specialised centre for ≥6 months, 3)clinical and spirometry evidence of asthma, and 4) reaching a pre-defined treatment threshold. The exclusion criterion is the presence of conditions which mimic asthma symptoms. Eligible children will be prospectively recruited into a registry, recording demographics, comorbidities, quality of life, family history, neonatal history, smoking history, asthma background, investigations, and treatment. Follow-up will provide longitudinal data on asthma control and treatment changes. The SPACE registry, by identifying well-phenotyped children eligible for clinical trials, and the amount of overlap in eligibility criteria, will inform the design of European trials in paediatric severe asthma, and facilitate observational research where data from single centres are limited., Competing Interests: Conflict of interest: N.M. Liu has nothing to disclose. Conflict of interest: W. van Aalderen has nothing to disclose. Conflict of interest: K.C.L. Carlsen has received financial support from governmental and other bodies for studies not related to the present project, andhas no conflict of interest to declare. Conflict of interest: C. Coleman is an employee of the European Lung Foundation. Conflict of interest: J.D. Chalmers reports grants and personal fees from Glaxosmithkline (research grants for COPD), Boehringer-Ingelheim (research grants for COPD studies), Pfizer (research grants for COPD), Bayer Healthcare (research into bronchiectasis) and Grifols (research into bronchiectasis); grants from AstraZeneca (research grants for COPD); personal fees from Napp (for consulting), outside the submitted work. Conflict of interest: S. Cunningham has nothing to disclose. Conflict of interest: R.M. Fernandes has nothing to disclose. Conflict of interest: L.J. Fleming reports other from Novartis (lecture fees and advisory board fees paid to her institution), Vectura (consultancy fees, paid to her institution), Boehringer Ingelheim (advisory board fees, paid to her institution) and AstraZeneca (lecture fees paid to her institution), outside the submitted work. Conflict of interest: M. Gappa reports personal fees from GSK (advisory board), Boehringer (advisory board and speaker honorarium) and Novartis (advisory board and speaker honorarium), outside the submitted work. Conflict of interest: B. Karadag has nothing to disclose. Conflict of interest: F. Midulla has nothing to disclose. Conflict of interest: M.W.H. Pijnenburg has nothing to disclose. Conflict of interest: N.W. Rutjes has nothing to disclose. Conflict of interest: F.Rusconi has nothing to disclose. Conflict of interest: J. Grigg reports personal fees (honorarium for advisory board) from GSK and Vifor Pharmaceuticals, outside the submitted work.

Background: Obstructive airway disease is nonuniformly distributed throughout the bronchial tree, although the extent to which this occurs can vary among conditions. The multiple-breath washout (MBW) test offers important insights into pediatric lung disease, not available through spirometry or resistance measurements. The European Respiratory Society/American Thoracic Society inert gas washout consensus statement led to the emergence of validated commercial equipment for the age group 6 years and above; specific recommendations for preschool children were beyond the scope of the document. Subsequently, the focus has shifted to MBW applications within preschool subjects (aged 2-6 yr), where a "window of opportunity" exists for early diagnosis of obstructive lung disease and intervention., Methods: This preschool-specific technical standards document was developed by an international group of experts, with expertise in both custom-built and commercial MBW equipment. A comprehensive review of published evidence was performed., Results: Recommendations were devised across areas that place specific age-related demands on MBW systems. Citing evidence where available in the literature, recommendations are made regarding procedures that should be used to achieve robust MBW results in the preschool age range. The present work also highlights the important unanswered questions that need to be addressed in future work., Conclusions: Consensus recommendations are outlined to direct interested groups of manufacturers, researchers, and clinicians in preschool device design, test performance, and data analysis for the MBW technique.

Competing Interests: Disclosure The authors report no conflicts of interest in this work.

The present study aimed to evaluate the possible relationship between the changes in hydrogen peroxide (H 2 O 2 ) and nitric oxide (NO) content and the course of growth and reproductive processes of the cell cycle of Chlamydomonas reinhardtii. The peak of H 2 O 2 observed at the beginning of the cell cycle was found to originate from Fe-SOD and Mn-SOD chl. activity and result from the alternation in the photosynthetic processes caused by the dark-to-light transition of daughter cells. A rapid increase in NO concentration, observed before the light-to-dark cell transition, originated from NR and NIR activity and was followed by a photosynthesis-independent, Mn-SOD chl. -mediated increases in H 2 O 2 production. This H 2 O 2 peak overlapped the beginning of Chlamydomonas cell division, which was indicated by a profile of CYCs and CDKs characteristic of cells' passage through the G1/S and S/M checkpoints. Taken together, our results show that there is a clear relationship between the course of the Chlamydomonas cell cycle and typical changes in the H 2 O 2 /NO ratio, as well as changes in expression and activity of enzymes involved in generation and scavenging of these signaling molecules., (Copyright © 2016 Elsevier GmbH. All rights reserved.)

A hallmark of the newly published GLI (Global Lungs Initiative) spirometric reference values is their "all-age" (3-95yr) predictive power, accomplished by incorporating non-linear age dependencies into modelling parameters. This modelling strategy is especially promising for the age range of puberty; however, the performance of GLI-values for adolescents is currently unknown. We calculated GLI-based z-scores for children/adolescents without apparent respiratory diseases from two different German studies, LUNOKID (N = 1943, 4-19 years) and GINIplus (N = 1042, 15 years) and determined the goodness of fit for specific age groups. We defined fit sufficient if the absolute mean of z-scores was <0.5. For children (<10yr) the mean GLI-based z-scores for FEV1 and FVC reached a good fit with mean z-scores for FEV1 between -0.11 and 0.01 and mean z-scores for FVC between 0.01 and 0.16, but larger deviations were observed in adolescents, especially boys (mean z-score -0.58 for FEV1 and -0.57 for FVC in GINIplus). The fit for FEV1/FVC was sufficient. GLI reference values provided reasonable estimates for the individuals enrolled in our studies, which span the age range of lung growth and development. However, we found that GLI-predictions overestimated lung volumes, especially those for German adolescent boys, which may, left unrecognised, lead to erroneous diagnosis of lung disease. Caution should be taken when applying these reference values to epidemiologic studies.

Patients with alpha-1-antitrypsin deficiency (AATD) and a PI-ZZ genotype are at high risk to develop severe emphysema during adulthood. However, little is known about early stages of emphysema and disease manifestation in other PI-types. Spirometry is commonly used for monitoring although early manifestation of emphysema is suspected within the peripheral airways that are not accessible by forced expiratory manoeuvres. We hypothesized that the Lung Clearance Index (LCI) derived from multiple breath nitrogen-washout (N2-washout) is useful to bridge this diagnostic gap. Patients from age 4 years onward and different PI-types performed N2-washout and spirometry. Results were compared to controls. 193 patients (4-79 years, 75% PI-ZZ) and 33 controls (8-60 years) were included. Mean (SD) LCI in patients was 9.1 (3.1) and 6.3 (0.6) in controls (p ≤ 0.001). 47% of adult patients with other than PI-ZZ genotypes and 39% of all patients with normal spirometry had abnormal LCIs. The LCI measured by N2-washout discriminates between patients with AATD and controls, reflects AATD related lung disease in all stages and appears to identify early peripheral lung changes in younger age than spirometry. We conclude that a normal spirometry does not exclude presence of AATD related lung disease even in genotypes other than PI-ZZ., (Copyright © 2016. Published by Elsevier Ltd.)

HERMES: European accreditation of training centres in paediatric respiratory medicine http://ow.ly/ZBmUg.

Background: Specific IgE measurement predicts the outcome of oral food challenges with considerable uncertainty when evaluating food allergy., Objective: Our aim was to assess whether accounting for the ratio of component- or allergen-specific to total IgE can improve this prediction., Methods: This multicenter study collected blood samples from children with suspected peanut or hazelnut allergy referred to allergy specialist clinics for food challenges. Specific IgE to peanuts, hazelnuts, and their components (Ara h 1, Ara h 2, Ara h 3, Ara h 8, Cor a 1, Cor a 8, Cor a 9, and Cor a 14) and total IgE levels were determined by using the ImmunoCAP-FEIA. Specific to total IgE ratios were compared with raw IgE levels in terms of discrimination and prediction., Results: Eighty-eight (43%) of 207 children with suspected peanut allergy and 44 (31%) of 142 children with suspected hazelnut allergy had symptoms during food challenge. Discrimination was similar for raw and ratio measures: areas under the curve of 0.93 for Ara h 2-specific IgE versus 0.92 for the Ara h 2-specific/total IgE ratio and 0.89 for Cor a 14-specific IgE versus 0.87 for the Cor a 14-specific/total IgE ratio. The probability for a positive peanut challenge with 0.35 kU/L Ara h 2-specific IgE was 16% when the total IgE level was greater than 500 kU/L compared with 51%/48% for low/medium total IgE levels (<100/100-500 kU/L). A positive hazelnut challenge with 0.35 kU/L Cor a 14-specific IgE was estimated in 7% when total IgE levels were high compared with 34%/32% with low/medium total IgE levels., Conclusions: Raw Ara h 2- and Cor a 14-specific IgE levels were the best single predictors for pediatric peanut and hazelnut allergies, suggesting the omission of challenges at very high levels. Calculating ratio measures did not improve prediction in this population. However, estimation of individual probabilities for challenge outcomes could be supported by total IgE levels because high levels might indicate lower probabilities at a given component-specific IgE level., (Copyright © 2016 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.)

To assess whether long-term inhalation with hypertonic saline is able to halt the progression of mild CF lung disease, we analysed longitudinal data of lung clearance index (LCI) and spirometry. A total of 34 patients with mild lung disease (FEV1 ≥ 70% of predicted) had at least one LCI result before and ≥2 LCI measurements after start of hypertonic saline (HS) therapy. After a mean follow-up of 39.7 (SD 7.4) months after starting HS, LCI improved significantly from 7.89 (SD 1.35) at baseline to 6.96 (SD 1.03), and 19/34 patients had a normal LCI value at the last measurement. No decrease in mean FEV1 was observed. Thus, ventilation inhomogeneity can improve in patients with mild lung disease., (Copyright © 2015 European Cystic Fibrosis Society. Published by Elsevier B.V. All rights reserved.)

The current standard for monitoring lung function in children with asthma is spirometry. In Europe, results of these lung function tests have been related to Zapletal reference values published in 1977. Recently, the Global Lung Function Initiative (GLI) published predicted values of spirometry for 5 ethnic groups, valid over an age range from 3 to 95 years. These reference values have been approved by many international lung societies, and the algorithms are increasingly being implemented globally. This report describes the consequences of the transition from Zapletal reference values to GLI reference values for 2 pediatric asthma patients, which include unexpected declines in lung function and the ability to take advantage of newly approved reimbursement for advanced therapy. The Zapletal and GLI reference values cannot be used interchangeably, and transition to the GLI values might lead to better treatment in the future., (Copyright © 2016 by the American Academy of Pediatrics.)

Introduction: Continuous or episodic allergen exposure is a major risk factor of frequent symptoms and exacerbations for patients with allergic asthma. It has been shown that temperature-controlled laminar airflow (TLA) significantly reduced allergen exposure and airway inflammation and improved quality of life of patients with poorly controlled allergic asthma., Objective: The objective was to evaluate the effects of nighttime TLA when used during real-life conditions for 12 consecutive months in addition to the patients' regular medication., Methods: This multicenter, pre- and postretrospective observational study included patients with inadequately controlled moderate-to-severe allergic asthma who received add-on treatment with TLA for 12 consecutive months. Data on medication use, asthma control, asthma symptoms, lung function, use of hospital resources, and exacerbations were collected after 4 and 12 months and compared with corresponding data collected retrospectively from medical records during the year prior to inclusion in the study., Results: Data from 30 patients (mean age 28; range 8-70) completing 4 months and 27 patients completing 12 months of TLA use are presented. The mean number of exacerbations was reduced from 3.6 to 1.3 (p<0.0001), and the ratio of asthma-related emergency room visits or hospitalizations diminished from 72.4 to 23.3% (p=0.001) or from 44.8 to 20.0% (p<0.05), respectively, after 12 months of TLA use. The Asthma Control Test index increased from 14.1 to 18.5 (p<0.0001). After 4 months of TLA use, clear improvements can be shown for most variables in line with the data collected after 12 months., Conclusions: The addition of TLA to the patients' regular medication significantly reduced exacerbations, asthma symptoms, and the utilization of hospital resources. The data support that TLA may be an important new non-pharmacological approach in the management of poorly controlled allergic asthma.

Patients with interstitial lung disease due to surfactant protein C (SFTPC) mutations are rare and not well characterised. We report on all subjects collected over a 15-year period in the kids-lung register with interstitial lung disease and a proven SFTPC mutation. We analysed clinical courses, interventions and outcomes, as well as histopathological and radiological interrelations. 17 patients (seven male) were followed over a median of 3 years (range 0.3-19). All patients were heterozygous carriers of autosomal dominant SFTPC mutations. Three mutations (p.L101P, p.E191 K and p.E191*) have not been described before in the context of surfactant protein C deficiency. Patients with alterations in the BRICHOS domain of the protein (amino acids 94-197) presented earlier. At follow-up, one patient was healthy (2 years), six patients were "sick-better" (2.8 years, range 0.8-19), seven patients were "sick-same" (6.5 years, 1.3-15.8) and three patients were "sick-worse" (0.3 years, 0.3-16.9). Radiological findings changed from ground-glass to increasing signs of fibrosis and cyst formation with increasing age. Empiric treatments had variable effects, also in patients with the same genotype. Prospective studies with randomised interventions are urgently needed and can best be performed in the framework of international registers., (Copyright ©ERS 2015.)

Spirometry is a simple test and considered the gold standard in lung function. An obstructive ventilatory defect is a disproportionate reduction of maximal airflow from the lung in relation to the maximal volume that can be displaced from the lung. It implies airway narrowing and is defined by a reduced FEV1/FVC ratio below the 5th percentile of the predicted value (lower limit of normal, LLN). A restrictive disorder may be suspected when vital capacity (FVC) is reduced and FEV1/FVC is normal. It is definitely proven, however, only by a decrease in TLC below the 5th percentile of predicted value (LLN). The measurement of TLC by body plethysmography is necessary to confirm or exclude a restrictive defect or hyperinflation of the lung when FVC is below the LLN. 2012 a task force of the ERS published new reference values based on 74,187 records from healthy non-smoking males and females from 26 countries. The new reference equations for the 3-95 age range are now available that include appropriate age-dependent mean values and lower limits of normal (LLN). This presentation aims at providing the reader with recommendations dealing with standardization and interpretation of spirometry., (© Georg Thieme Verlag KG Stuttgart · New York.)

Inhaled medications are the cornerstone of treatment in early childhood wheezing and paediatric asthma. A match between patient and device and a correct inhalation technique are crucial for good asthma control. The aim of this paper is to propose an inhaler strategy that will facilitate an inhaler choice most likely to benefit different groups of children. The main focus will be on pressurised metered dose inhalers and dry powder inhalers. In this paper we will discuss (1) practical difficulties with the devices and with inhaled therapy and (2) the optimal location for deposition of medicines in the lungs, and (3) we will propose a practical and easy way to make the best match between the inhaler device and the individual patient. We hope that this paper will contribute to an increased likelihood of treatment success and improved adherence to therapy.

Background: Juvenile pulmonary alveolar proteinosis (PAP) due to CSF2RA mutations is a rare disorder with only a few cases described worldwide., Methods: We identified nine children with severe diffuse interstitial lung disease due to CSF2RA mutations. Clinical course, diagnostic findings and treatment were evaluated and correlated to the genotype. Functional impairment of the intracellular JAK/pStat5 signaling pathway was assessed using flow-cytometry of peripheral mononuclear cells (PBMC) and granulocytes., Results: We identified six individuals with homozygous missense/nonsense/frameshift mutations and three individuals homozygous for a deletion of the complete CSF2RA gene locus. Overall, four novel mutations (c.1125 + 1G > A, duplication exon 8, deletion exons 2-13, Xp22.3/Yp11.3) were found. Reduced STAT5 phosphorylation in PBMC and granulocytes was seen in all cases examined (n = 6). Pulmonary symptoms varied from respiratory distress to clinically silent. Early disease onset was associated with a more severe clinical phenotype (p = 0.0092). No association was seen between severity of phenotype at presentation and future clinical course or extent of genetic damage. The clinical course was favorable in all subjects undergoing whole lung lavage (WLL) treatment., Conclusions: Our cohort broadens the spectrum of knowledge about the clinical variability and genotype-phenotype correlations of juvenile PAP, and illustrates the favorable outcome of WLL treatment in severely affected patients.

Introduction: Children with asthma often have normal spirometry despite significant disease. The pathology of the small airways in asthma may be assessed using Multiple Breath Washout (MBW) and calculating the Lung Clearance Index (LCI). There are only few studies using MBW in children with asthma and existing data regarding bronchodilator effect are contradictory. The aim of the present pilot study was to compare LCI in asthma and controls and assess the effect of salbutamol in children with asthma on the LCI., Methods: Unselected patients with a diagnosis of asthma visiting the outpatient department of our hospital between 04-2010 and 03-2011 were recruited and compared to a healthy control group. MBW was performed as inert gas MBW using sulfurhexafluorid (SF6) as the tracer gas. Clinical data were documented and spirometry and MBW (EasyOne Pro, MBW module, NDD Switzerland) were performed before and after the use of salbutamol (200-400 μg). Healthy controls performed baseline MBW only., Results: 32 children diagnosed with asthma (4.7-17.4 years) and 42 controls (5.3-20.8) were included in the analysis. LCI differed between patients and controls, with a mean LCI (SD) of 6.48 (0.48) and 6.21 (0.38) (P = 0.008). Use of salbutamol had no significant effect on LCI for the group., Conclusion: These pilot data show that clinically stable asthma patients and controls both have a LCI in the normal range. However, in patients the LCI is significantly higher indicating that MBW may have a role in assessing small airways disease in asthma., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

Introduction: Lung disease remains the main cause of morbidity and mortality in patients with Cystic Fibrosis (CF). To detect lung disease before clinical symptoms become apparent, sensitive tools are essential. Spirometry is used for monitoring, but the FEV1 remains frequently normal throughout childhood. The Lung Clearance Index (LCI) calculated from Multiple Breath Washout (MBW) was introduced at the CF centre Innsbruck in 2007 for assessing ventilation inhomogeneity in patients with mild lung disease. We hypothesized that LCIs in 2007 are of prognostic value for the presence or absence of structural lung changes in later years., Methods: Between 2007 and 2010 MBW, spirometry and ultra-low-dose HR-CT were prospectively tracked in 36 patients (6-53 years) with a mean FEV1 ≥ 80% predicted in 2007., Results: At study start the majority of patients had abnormal CT scores and LCI results. While CT and spirometry remained largely stable throughout the study, LCI results slightly improved but still correlated with CT scores in 2010. LCI results in 2007 correlated with CT scores in 2010 while FEV1 did not. In 86% the LCI value in 2007 was indicative for the presence or absence of structural lung changes in 2010., Conclusion: The LCI is a sensitive tool for detecting and tracking pulmonary changes. Extended structural changes are unlikely if the LCI is normal. The LCI has the potential to be used for monitoring the progression of early CF lung disease and assessing the effect of treatment in both clinical care and research settings., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

The gold standard for assessing quality of forced expiratory manoeuvres is visual inspection by an expert. American Thoracic Society/European Respiratory Society numerical quality criteria (NQC) include back-extrapolated volume (BEV), repeatability and forced expiratory time (FET). Equipment currently available provides feedback tempting the investigator to use NQC as pass-fail criterion. To investigate whether using NQC instead of visual acceptability is a valid option, we analysed data from a multicentre national reference study in Germany of children aged 4-18 years. Spirometry was performed under field conditions. Receiver operating characteristic analysis was used to assess performance of BEV, repeatability, FET and a combination thereof in relation to visual acceptability. We included data from 3133 healthy Caucasians in the analyses; 72% delivered at least two visually acceptable manoeuvres. Of these, 59% would have been rejected based on combined NQC, mainly because the FET criterion was not feasible. Specificity of the NQC was generally low (BEV 10%, repeatability 30% and FET 50%). Receiver operating characteristic analysis showed that a combination of the three measures could reach at best a sensitivity of 90% and specificity of 56%. We conclude that visual control is mandatory and NQC may help obtain the best possible results, but a fixed cut-off for FET should be abandoned.

Background: Volumetric capnography reflecting the course of CO2-exhalation is used to assess ventilation inhomogeneity. Calculation of the slope of expiratory phase 3 and the capnographic index (KPIv) from expirograms allows quantification of extent and severity of small airway impairment. However, technical limitations have hampered more widespread use of this technique. Using expiratory molar mass-volume-curves sampled with a handheld ultrasonic flow sensor during tidal breathing is a novel approach to extract similar information from expirograms in a simpler manner possibly qualifying as a screening tool for clinical routine. The aim of the present study was to evaluate calculation of the KPIv based on molar mass-volume-curves sampled with an ultrasonic flow sensor in patients with CF and controls by assessing feasibility, reproducibility and comparability with the Lung Clearance Index (LCI) derived from multiple breath washout (MBW) used as the reference method., Methods: Measurements were performed in patients with CF and healthy controls during a single test occasion using the EasyOne Pro, MBW Module (ndd Medical Technologies, Switzerland)., Results: Capnography and MBW were performed in 87/96 patients with CF and 38/42 controls, with a success rate of 90.6% for capnography. Mean age (range) was 12.1 (4-25) years. Mean (SD) KPIv was 6.94 (3.08) in CF and 5.10 (2.06) in controls (p=0.001). Mean LCI (SD) was 8.0 (1.4) in CF and 6.2 (0.4) in controls (p=<0.001) and correlated significantly with the KPIv (p=<0.001)., Conclusion: Calculation of the KPIv based on molar mass-volume-curves is feasible. KPIv is significantly different between patients with CF and controls and correlates with the LCI. However, individual data revealed a relevant overlap between patients and controls requiring further evaluation, before this method can be recommended for clinical use., (Copyright © 2012 European Cystic Fibrosis Society. Published by Elsevier B.V. All rights reserved.)

Although pulmonary function testing plays a key role in the diagnosis and management of chronic pulmonary conditions in children under 6 years of age, objective physiologic assessment is limited in the clinical care of infants and children less than 6 years old, due to the challenges of measuring lung function in this age range. Ongoing research in lung function testing in infants, toddlers, and preschoolers has resulted in techniques that show promise as safe, feasible, and potentially clinically useful tests. Official American Thoracic Society workshops were convened in 2009 and 2010 to review six lung function tests based on a comprehensive review of the literature (infant raised-volume rapid thoracic compression and plethysmography, preschool spirometry, specific airway resistance, forced oscillation, the interrupter technique, and multiple-breath washout). In these proceedings, the current state of the art for each of these tests is reviewed as it applies to the clinical management of infants and children under 6 years of age with cystic fibrosis, bronchopulmonary dysplasia, and recurrent wheeze, using a standardized format that allows easy comparison between the measures. Although insufficient evidence exists to recommend incorporation of these tests into the routine diagnostic evaluation and clinical monitoring of infants and young children with cystic fibrosis, bronchopulmonary dysplasia, or recurrent wheeze, they may be valuable tools with which to address specific concerns, such as ongoing symptoms or monitoring response to treatment, and as outcome measures in clinical research studies.

Background: Omalizumab has been successfully established as add-on therapy to improve asthma control in adults and children aged 6 years and older with uncontrolled severe persistent allergic asthma (GINA 2009 step 5)., Patients and Methods: 15 patients between 12 and 20 years of age with severe allergic asthma, which was inadequately controlled despite intensive antiasthmatic therapy according to NVL step 4 /5, received treatment with omalizumab for 6 - 69 months. After 12 months of treatment the effect was evaluated by means of objective parameters., Results: Significant improvements were found for the asthma-exacerbation rate and emergency treatment as well as for most of the lung function parameters. Systemic steroids could be discontinued in 10 of 11 patients. Asthma control has improved in all patients according to the ACT. Omalizumab was well tolerated by 13 patients. Adverse effects occurred in two patients in the first two and after 5 months, respectively. Only in one of them omalizumab had to be discontinued after 6 months due to the development of serum disease., Conclusions: Omalizumab can be considered a valuable add-on therapy in adolescent patients with severe allergic asthma that is inadequately controlled despite GINA step 5 treatment. A significant effect on clinical and functional parameters was shown over 12 months., (© Georg Thieme Verlag KG Stuttgart · New York.)

Background: Comparing children's lung function with reference values is important for diagnosing respiratory diseases. The values by Zapletal et al., commonly used nowadays, are not appropriate for the current stage of children's development. We have now developed new reference values and a lower limit of normal (LLN) for children in Germany, divided into small-range age and height categories., Material and Methods: We examined 4- to 18-year-old children in 3 German communities under field conditions. 1943 children were healthy and had a visually acceptable lung function which also fulfilled international quality criteria. We used the regression model LMS, which was introduced by Stanojevic and Quanjer in this context., Results: There were significant differences between the measured lung function and the predicted values according to Zapletal et al. The lung function did not only depend on the child's height, but also in a non-linear way on the age. The variation coefficient did not depend on age., Conclusions: To avoid diagnostic errors, the currently often used reference values according to Zapletal et al. should no longer be used. The non-linear dependence on age corresponds to the recently published results by Stanojevic and Quanjer., (© Georg Thieme Verlag KG Stuttgart · New York.)

Inert gas washout tests, performed using the single- or multiple-breath washout technique, were first described over 60 years ago. As measures of ventilation distribution inhomogeneity, they offer complementary information to standard lung function tests, such as spirometry, as well as improved feasibility across wider age ranges and improved sensitivity in the detection of early lung damage. These benefits have led to a resurgence of interest in these techniques from manufacturers, clinicians and researchers, yet detailed guidelines for washout equipment specifications, test performance and analysis are lacking. This manuscript provides recommendations about these aspects, applicable to both the paediatric and adult testing environment, whilst outlining the important principles that are essential for the reader to understand. These recommendations are evidence based, where possible, but in many places represent expert opinion from a working group with a large collective experience in the techniques discussed. Finally, the important issues that remain unanswered are highlighted. By addressing these important issues and directing future research, the hope is to facilitate the incorporation of these promising tests into routine clinical practice.

The Lung Clearance Index (LCI) is superior to spirometry in detecting early lung disease in cystic fibrosis (CF) and correlates with structural lung changes seen on CT scans. The LCI has the potential to become a novel outcome parameter for clinical and research purposes. However longitudinal studies are required to further prove its prognostic value. Multi-center design is likely to facilitate realization of such studies. Therefore the aim of the present study was to assess multi-center feasibility and inter-center variability of LCI measurements in healthy children and adolescents. Comparative measurements were performed in unselected patients with CF to confirm previous single-center results. LCI measurements were performed in eight centers using the EasyOne Pro, MBW Module (ndd Medical Technologies, Zurich, Switzerland). The overall success rate for LCI measurements was 75.5%, leaving 102/151 measurements in healthy volunteers and 139/183 measurements in patients with CF for final analysis. Age ranged between 4 and 24 years. Mean LCI (range of means among centers) was 6.3 (6.0-6.5) in healthy volunteers and thus normal. Inter-center variability of center means was 2.9%, ANOVA including Schffé procedure demonstrated no significant inter-center differences (P > 0.05). Mean LCI (range of means among centers) was 8.2 (7.4-8.9) in CF and thus abnormal. Our study demonstrates good multi-center feasibility and low inter-center variability of the LCI in healthy volunteers when measured with the EasyOne Pro MBW module. Our data confirm published LCI data in CF. However, central coordination, quality control, regular training, and supervision during the entire study appear essential for successfully performing multi-center trials., (Copyright © 2011 Wiley Periodicals, Inc.)

Objectives: Methotrexate may cause severe adverse pulmonary side-effects in adults with rheumatoid arthritis. Our aim was to examine the long-term effect of MTX on lung function in patients with juvenile idiopathic arthritis (JIA)., Methods: We retrospectively reviewed the charts of all 68 patients with JIA treated with MTX at our centre over a 14-year period. Results of annual pulmonary function tests (PFT) were compared using paired t-tests adjusted by Bonferroni correction and by linear regression analysis., Results: The patients in our study had taken MTX for a median of 6.7 years with a median cumulative dose of 3219 mg. In a subgroup of 37 patients PFT had been performed before the onset of MTX. In this subgroup there was a significant decrease of mean mid-expiratory flow (MMEF) after 3 years (-14.0%, p<0.001) of MTX. Diffusion capacity of the lung for carbon monoxide (DLCO) was reduced after the third year (-12.4%, p=0.001). In the total group there was a decrease in MMEF between years 3 and 4 after MTX onset (-13.5%, p=0.001). Forced expiratory volume (FEV1) showed a slight rise between years 4 and 5 (+5.5%, p=0.003). All other parameters remained without significant changes. There was no correlation of PFT results and cumulative MTX dose or JIA subtype. None of our patients developed clinically relevant lung disease., Conclusions: In summary we found some declines of MMEF and DLCO during long-term treatment with MTX. Overall our data confirm the relative safety of long-term MTX treatment in patients with JIA. We conclude that further data on the development of pulmonary function in patients receiving MTX therapy would be helpful.

Multiple breath washout (MBW) has been demonstrated to be sensitive for assessing ventilation inhomogeneity (VI). VI is supposed to reflect changes in peripheral airways which are not apparent using spirometry. The lung clearance index (LCI) is the most robust parameter to quantify VI, and is largely independent of age; therefore, it potentially qualifies as a surrogate outcome parameter for clinical and research purposes, particularly during childhood. This review summarizes the current evidence regarding the clinical value of measuring LCI in children. Feasibility, reproducibility and diagnostic accuracy have been demonstrated; available data confirm that LCI is superior to spirometry in detecting small air way disease. However, there is little information regarding the value in the individual patient, and sparse longitudinal data looking at its prognostic value. Currently, only in patients with Cystic Fibrosis, it appears likely that knowledge of LCI will be useful for routine clinical management., (Copyright © 2011 Elsevier Ltd. All rights reserved.)

It is widely accepted that CF lung disease starts before clinical symptoms become apparent or spirometry deteriorates. Computed chest tomography (CT) is the reference method for identifying structural changes in CF; however, radiation exposure limits its use as a monitoring tool. It has been suggested that the Lung Clearance Index (LCI) measured by Multiple Breath Washout (MBW) for assessing ventilation inhomogeneity is a more sensitive surrogate marker than spirometry allowing non-invasive monitoring of CF lung disease. The aim of this study was to prospectively investigate the diagnostic accuracy of the LCI in comparison to CT in CF patients with early lung disease and normal FEV(1) (>80% pred.). MBW and ultra-low-dose CT were performed in 34 patients (6-26 years). LCI was abnormal in 76.5% subjects. LCI and CT correlated significantly in 82.3%. LCI was related to presence and extent of structural lung changes observed on CT with a sensitivity of 88%. Diagnostic accuracy of the LCI for detecting CF lung disease in patients with normal FEV(1) was good when compared to CT. Results indicate that structural changes are unlikely if a normal LCI is measured. We speculate that serial measurements of the LCI for assessing ventilation inhomogeneity may help to identify early structural lung disease and help to reduce the individual cumulative radiation dose. The LCI may be a suitable surrogate marker for monitoring progression of CF lung disease and effect of treatment in both, clinical care and research settings., (Copyright © 2010 Elsevier Ltd. All rights reserved.)

Multiple breath washout (MBW) for measuring the lung clearance index (LCI) has been proposed as a non-invasive tool for detecting early cystic fibrosis (CF) lung disease. The LCI is highly repeatable and reproducible in healthy subjects. In patients with CF, within-test variability is low. However, application of physiotherapy (PT) immediately preceding MBW may affect LCI variability in CF patients and thus interpretation of repeat measurements and treatment effects. Therefore, the aim of the present study was to prospectively assess the short-term effect of PT on LCI in CF patients in order to address the question whether or not standardized timing of PT and MBW has to be considered when introducing MBW into clinical CF management. Twenty-seven out of 32 patients (5.7-15.9 years) with CF successfully performed two technically acceptable MBW tests with the EasyOne Pro, MBW Module (ndd, Switzerland) at intervals of 1(1/2) hr. Sixteen out of 27 received 30 min PT in between, whereas 11/27 did not.Repeatability expressed as intraindividual coefficient of variation (CV) was 6.1% pre-PT and 6.5% post-PT. Mean difference (95% CI) of LCI between the two tests was -0.20 (-0.51; 0.11). Reproducibility (SD) was 4.6% (3.1). Repeatability was 4.2% and 7.1% without intervention. Mean difference (95% CI) of LCI between 1st and 2nd test was 0.07 (-0.22; 0.35). Reproducibility (SD) was 2.6% (2.1).In conclusion, PT does not have a consistent effect on the LCI. Repeatability was slightly poorer than published for healthy subjects possibly reflecting variable mucus plugging, and, thus, variable trapped air in patients with CF. Reproducibility was good and independent on intervention. From our data, we conclude that timing of PT in relation to MBW can be ignored when designing study protocols or when interpreting longitudinal data and treatment effects.

Although Pediatric Respiratory Medicine as a subspecialty has a long tradition and is well established in some countries, there is a wide variation across different regions of the world with regard to e.g. recognition of the discipline, training requirements, training facilities and clinical needs. This review summarizes the situation in North America (US and Canada), South America, Asia, Australia, Israel and Europe with the aim to highlight commonalities and differences and, ultimately, to further support continuous development of paediatric Respiratory Medicine Worldwide., ((c) 2009 Wiley-Liss, Inc.)

There is increasing interest in using the Multiple Breath Washout technique and the lung clearance index (LCI) for detecting early pulmonary changes, for example, in cystic fibrosis lung disease. However, there are still limited data regarding equipment specific reference ranges, repeatability and reproducibility. The aim of this prospective study was to assess within-test repeatability, short term reproducibility and long term reproducibility, and to establish normal values for the LCI in healthy children and adolescents using the sidestream ultrasonic flow sensor (EasyOne Pro, MBW Module, ndd Medical Technologies, Switzerland). Fourty-four volunteers (5.3-20.3 years) were recruited for the 1st test. Twenty-two out of 44 were measured on a 2nd test occasion after an interval of 1 hr (2nd test). Thirty-four out of 44 agreed to come back for a follow up test 6-15 months later (3rd test). Mean LCI (SD) was 6.2 (0.4), 6.3 (0.4), and 6.0 (0.4) at the 1st, 2nd, and 3rd test. The upper limit of normal was 7.0 for all subjects. Within-test repeatability was 5.1%. Short-term reproducibility (1st test vs. 2nd test) was 4.2% with a mean difference of -0.13 (95% CI -0.350; 0.087). Long-term reproducibility (1st test vs. 3rd test) was 5.1%, with a mean difference of 0.017 (95% CI -0.016; 0.348). With this low variability of the LCI for both, within and between tests, our study demonstrates reliability and robustness of equipment, protocol and analysis and the reliability of the MBW technique in general. The present data will help to interpret the effect of therapeutic interventions and interpretation of longitudinal data in patients with pulmonary diseases.

Rationale: In asthmatic children whose symptoms are uncontrolled on standard doses of inhaled corticosteroids (ICS), guidelines recommend to either increase the ICS dose or to add further controller medication, e.g. a long acting ss2-agonist (LABA). The aim of this study was to compare the efficacy and safety of doubling the dose of ICS (fluticasone proprionate FP 200 microg twice daily) with adding a long-acting beta-2 agonist to the ICS (SFC, salmeterol 50 microg/ FP 100 microg twice daily) in children with uncontrolled asthma., Methods: Children between 4 and 16 years of age were eligible for this multicenter, randomized, double blind, double dummy, parallel-group study. During a 14-day run-in phase, all children inhaled FP 100 microg b.i.d. Patients with persistent symptoms on > or =7 of 14 days were randomized to 8 weeks treatment with a Diskus(R) containing either SFC 50 microg/100 microg b.i.d. or FP 200 microg b.i.d.. The primary endpoint was the mean change in morning (a.m.) PEF from baseline. The initial statistical hypothesis of non-inferiority of SFC vs. FP was confirmed in an adaptive interim analysis, so that the study was terminated prematurely., Results: 441 patients from 39 centers entered the run-in phase, and 64% of these were randomized to treatment (N = 138 to SFC and N = 145 to FP). After 8 weeks, patients on SFC had significantly better results for primary and secondary endpoints: The mean increase in morning PEF was 30.4 +/- 34.1 L/min in the SFC group and 16.7 +/- 35.8 L/min in the fluticasone group, and the mean (95% CI) improvement from baseline a.m. PEF in the ITT group was significantly larger after SFC (+8.6 L/min, CI: [1.3; infinity]). Patients in the SFC group experienced 8.7% (CI: [1.2;16.3]) more days without asthma symptoms and 8.0% (CI: [0.6;15.3]) more days without salbutamol than patients receiving FP. Good asthma control was achieved for a longer period in the SFC (3.4 +/- 2.7 weeks) group than in the FP group (2.7 +/- 2.7, P = 0.02). Both treatments were generally well tolerated. Asthma exacerbations were recorded in 3 and 6 and SAEs in 2 and 1 patients from the SFC and FP groups, respectively., Conclusions: In children with persistent asthma inadequately controlled on low dose ICS alone, adding a long acting beta-2-agonist to ICS in a single inhaler was more effective than doubling the ICS dose. These results support recommendations of adding LABA to low-dose ICS as the preferred controller option for children older than 4 years with symptomatic asthma.

Lung biopsy is necessary for establishing the diagnosis in patients with otherwise unclassified diffuse or localized parenchymal lung disease. This study aimed to assess the safety and accuracy of video-assisted thoracoscopic (VATS) lung biopsy in children with diffuse parenchymal lung disease (DPLD). In addition we aimed to evaluate the value of this technique with respect to the spectrum of diseases encountered, correlating histological diagnosis with treatment decisions and subsequent clinical outcome. Data from all patients (n = 21) who underwent surgical lung biopsy for suspected DPLD between March 2001 and August 2006 were collected prospectively. Median age was 3 years, 8 months (range 11 days to 15 years, 2 months). All lung biopsies were performed by VATS under general anesthesia. Median operative time was 45 min (range 25-100 min). Conversion to minithoracotomy due to cardiorespiratory difficulties was necessary in two young infants. There were no further intraoperative complications. In 8/21 children, a chest tube was inserted postoperatively for a median of 2 days (range 1-5 days). In one patient, prolonged air-leakage was managed thoracoscopically on postoperative day 9. There were no other postoperative complications. The specimens were of adequate volume and quality and a histopathological diagnosis was obtained for all patients. There was a broad spectrum of different diagnoses which led to specific therapeutic decisions. Subsequent medical treatment was beneficial in the majority of the patients. In conclusion, VATS is a safe and effective procedure for diagnosis of children with suspected DPLD. Diagnostic accuracy is high, morbidity rates are low, and patients may benefit from avoiding thoracotomy., ((c) 2008 Wiley-Liss, Inc.)

Objective: Inert gas multiple breath washout (MBW) for measuring Lung Clearance Index using mass spectrometry and 4% sulfur hexafluoride (SF(6)) as the tracer gas has been shown to be sensitive for detecting early Cystic Fibrosis (CF) lung disease. However, mass spectrometry requires bulky equipment and is expensive to buy and maintain. A novel sidestream ultrasonic device may overcome this problem. The aims of this study were to assess the feasibility and clinical validity of measuring lung volume (functional residual capacity, FRC) and the LCI using the sidestream ultrasonic flow sensor in children and adolescents with CF in relation to spirometry and plain chest radiographs., Patients and Methods: MBW using the sidestream ultrasonic device and conventional spirometry were performed in 26 patients with CF and 22 healthy controls., Results: In the controls (4.7-17.7 years) LCI was similar to that reported using mass spectrometry (mean (SD) 6.7 (0.5)). LCI was elevated in 77% of the CF children (6.8-18.9 years), whereas spirometry was abnormal in only 38.5%, 61.5%, and 26.9% for FEV(1), MEF(25), and FEV(1)/FVC, respectively. This was more marked in children <10 years. LCI correlated with the Crispin-Norman score, whereas FEV(1) did not., Conclusions: Sidestream ultrasonic MBW is a valid and simple alternative to mass spectrometry for assessing ventilation homogeneity in children., ((c) 2008 Wiley-Liss, Inc.)

The case is reported of a 6 year old girl whose mother had multidrug resistant tuberculosis (MDR TB). The diagnostic algorithm and the pros and cons of treatment of MDR TB in a child are discussed.

Over recent years, there has been renewed interest in the multiple breath wash-out (MBW) technique for assessing ventilation inhomogeneity (VI) as a measure of early lung disease in children. While currently considered the gold standard, use of mass spectrometry (MS) to measure MBW is not commercially available, thereby limiting widespread application of this technique. A mainstream ultrasonic flow sensor was marketed for MBW a few years ago, but its use was limited to infants. We have recently undertaken intensive modifications of both hardware and software for the ultrasonic system to extend its use for older children. The aim of the current in vivo study was to compare simultaneous measurements of end-tidal tracer gas concentrations and lung clearance index (LCI) from this modified ultrasonic device with those from a mass spectrometer. Paired measurements of three MBW, using 4% sulfur hexafluoride (SF(6)) as the tracer gas and the two systems in series, were obtained in nine healthy adult volunteers. End-tidal tracer gas concentrations (n = 675 paired values) demonstrated close agreement (95% CI of difference -0.23; -0.17%, r(2) = 1). FRC was slightly higher from the MS (95%CI 0.08;0.17 L), but there was no difference in LCI (95%CI -0.10; 0.3). We conclude, that this ultrasonic prototype system measures end-tidal tracer gas concentration accurately and may therefore be a valid tool for MBW beyond early childhood. This prototype system could be the basis for a commercial device allowing more widespread application of MBW in the near future.

This is the fifth paper in a review series that summarizes available data and critically discusses the potential role of lung function testing in infants and young children with acute neonatal respiratory disorders and chronic lung disease of infancy (CLDI). This review focuses on respiratory mechanics, including chest-wall and tissue mechanics, obtained in the intensive care setting and in infants during unassisted breathing. Following orientation of the reader to the subject area, we focused comments on areas of enquiry proposed in the introductory paper to this series. The quality of the published literature is reviewed critically with respect to relevant methods, equipment and study design, limitations and strengths of different techniques, and availability and appropriateness of reference data. Recommendations to guide future investigations in this field are provided. Numerous different methods have been used to assess respiratory mechanics with the aims of describing pulmonary status in preterm infants and assessing the effect of therapeutic interventions such as surfactant treatment, antenatal or postnatal steroids, or bronchodilator treatment. Interpretation of many of these studies is limited because lung volume was not measured simultaneously. In addition, populations are not comparable, and the number of infants studied has generally been small. Nevertheless, results appear to support the pathophysiological concept that immaturity of the lung leads to impaired lung function, which may improve with growth and development, irrespective of the diagnosis of chronic lung disease. To fully understand the impact of immaturity on the developing lung, it is unlikely that a single parameter such as respiratory compliance or resistance will accurately describe underlying changes. Assessment of respiratory mechanics will have to be supplemented by assessment of lung volume and airway function. New methods such as the low-frequency forced oscillation technique, which differentiate the tissue and airway components of respiratory mechanics, are likely to require further development before they can be of clinical significance., (2006 Wiley-Liss, Inc.)

Compared with those born at term, preterm newborns are at an increased risk of short term disorders of the lung (bronchopulmonary dysplasia; BPD) and the brain (white matter damage; WMD), and of long term developmental and pulmonary dysfunctions. Although all of these adverse outcomes are associated with low gestational age, brain, but not lung, damage appears to be associated with the prematurity subgroup [spontaneous preterm labour and/or preterm prelabour rupture of membranes (PPROM) vs pregnancy-induced hypertension (PIH)]. Part of the association between brain damage and prematurity subgroup might be due to a differential exposure of members of these subgroups to perinatal infection/inflammation. There is a lack of studies evaluating the association of antenatal and perinatal risk factors with late childhood pulmonary dysfunction among those born during the second trimester. In this paper we discuss the complexities that paediatricians, perinatologists and perinatal epidemiologists face as they try to understand the contributions of factors associated with preterm birth to neonatal and childhood disorders.

Regular anti-inflammatory treatment is essential in treating persistent asthma. Most commonly, inhaled corticosteroids (ICS) are used. However, especially in children, there is concern about the long-term safety of ICS such that doses should be kept to a minimum. The use of theophylline has decreased because of frequent side-effects in therapeutic doses. In adults, there have been reports about an immunomodulatory effect of low-dose theophylline. To study the clinical and immunomodulatory effect in children, 36 patients (mean age 12.5 SD 2.4 years) with moderate, persistent asthma on regular ICS were recruited into a placebo-controlled, double-blind study. After a 6-week run-in period, patients received either theophylline 10 mg/kg bodyweight or placebo for 12 weeks. Diary cards, lung function, peripheral blood lymphocyte subpopulations and serum eosinophil cationic protein (sECP) were assessed. In the treatment group, mean serum theophylline was 7.1 mg/l. There was no change in symptoms or use of rescue medication. Mean (SD) peak expiratory flow (PEF) increased from 86% (24) to 95% (18) predicted. sECP decreased from 43.2 microg/l (32.5) to 26.5 microg/l (16.9) (p = 0.02). Lymphocyte subpopulations did not change. The study failed to show a beneficial clinical or an immunomodulatory effect of theophylline when used in low doses. These results do not support a more important role of theophylline in the long-term treatment of moderate childhood asthma.