ERS International Congress 2023: highlights from the Paediatrics Assembly.

Respiratory health in children is essential for general wellbeing and healthy development in the short and long term. It is well known that many respiratory diseases in adulthood have their origins in early life, and therefore research on prevention of respiratory diseases and management of children with respiratory diseases will benefit patients during the full life course. Scientific and clinical advances in the field of respiratory health are moving at a fast pace. This article summarises some of the highlights in paediatric respiratory medicine presented at the hybrid European Respiratory Society (ERS) International Congress 2023 which took place in Milan (Italy). Selected sessions are summarised by Early Career Members of the Paediatrics Assembly (Assembly 7) under the supervision of senior ERS officers, and cover a wide range of research areas in children, including respiratory physiology and sleep, asthma and allergy, cystic fibrosis, respiratory infection and immunology, neonatology and intensive care, respiratory epidemiology and bronchology.

Differences in the swallowing process of newborns and healthy preterm infants: first results with a non-invasive bioimpedance and electromyography measurement system.

PURPOSE: Preterm infants (PI) have difficulty coordinating sucking, swallowing and breathing, and there is a risk of aspiration. The causes of this are not yet sufficiently understood. The aim of this study was to test a novel measurement device to measure breathing and pharyngeal processes involved in swallowing externally in everyday life to identify possible differences in neonates (NB) and PI. METHODS: Forty healthy NB were studied at 4-8 weeks of age (mean: 6.7 weeks) and 20 healthy PI (mean gestational age 30.5 weeks) at postmenstrual age (PMA) 34/35 weeks (mean PMA 35.1 weeks) during a single feeding. Surface electrodes were used to measure bioimpedance and electromyography reflecting swallow-related changes in the pharynx and muscle activation of the tongue and submental muscles. A respiratory belt was combined with recording of the depth of chest movements and the occurrence of pauses in breathing. RESULTS: Velocity and extent of pharyngeal closure did not differ significantly across the feeding period (velocity: p=0.09, closure: p=0.17), but during the first two suck-swallow bursts PI had greater velocity (p<0.001*) and extent of pharyngeal closure (p=0.004*) than NB. The duration of swallowing phases was significantly longer in PIs (p<0.001*), their muscle activation decreased faster (p<0.001*), and they had more pauses in breathing than NBs. CONCLUSIONS: The novel measurement device allowed, for the first time in everyday life, the measurement of factors influencing swallowing and breath-swallow coordination in NBs and PIs. PIs showed differences from NBs most likely due to differences in muscle strength and condition.

ERS International Congress 2022: highlights from the Paediatrics Assembly.

This review has been prepared by the Early Career Members and Chairs of the European Respiratory Society (ERS) Assembly 7: Paediatrics. We here summarise the highlights of the advances in paediatric respiratory research presented at the ERS International Congress 2022. The eight scientific groups of this Assembly cover a wide range of research areas, including respiratory physiology and sleep, asthma and allergy, cystic fibrosis (CF), respiratory infection and immunology, neonatology and intensive care, respiratory epidemiology, bronchology, and lung and airway developmental biology. Specifically, we report on abstracts presented at the congress on the effect of high altitude on sleep, sleep disorders, the hypoxic challenge test, and measurements of ventilation inhomogeneity. We discuss prevention of preschool wheeze and asthma, and new asthma medications. In children with CF, we describe how to monitor the effect of CF transmembrane conductance regulator modulator therapy. We present respiratory manifestations and chronic lung disease associated with common variable immunodeficiency. Furthermore, we discuss how to monitor respiratory function in neonatal and paediatric intensive care units. In respiratory epidemiology, we present the latest news from population-based and clinical cohort studies. We also focus on innovative and interventional procedures for the paediatric airway, such as cryotherapy. Finally, we stress the importance of better understanding the molecular mechanisms underlying normal and abnormal lung development.

Preference matters: New aspects on how foreign bodies should and could be removed from a child's airway.

BACKGROUND: Foreign body aspiration in children is a potentially life-threatening event that can be diagnosed and treated by airway endoscopy. We aimed to analyze the influence of the examiner's experience and preference on the choice of the technique and the resulting complication rate. METHODS: In this international study, experts in the field documented their preferred and applied technique as well as the outcome of each case of foreign body removal. Personal data of the bronchoscopists and their medical center were collected via an online questionnaire separately from the case specifics. RESULTS: A total of 399 foreign body removals were performed by 64 examiners. A total of 279 removals were performed using rigid endoscopy, and 120 procedures were performed by flexible. When a difficulty was expected, flexible endoscopy was used significantly more often (χ2 (1) = 11.06, p < 0.001). Complications occurred significantly less often when the bronchoscopist used their preferred technique (χ2 (1) = 6.41, p = 0.011), had more than 5 years of experience (χ2 (1) = 5.13, p = 0.023) or performed more than 100 removals (χ2 (2) = 11.51, p = 0.003). In medical centers, complication rates significantly decreased if more than 200 bronchoscopies were performed in children, compared to the centers that perform 50-200 bronchoscopies per year (χ2 (1) = 24.56, p < 0.001). CONCLUSION: Preference and experience of a bronchoscopist and his/her medical center with flexible or rigid foreign body removal distinctively affect the outcome of the procedure and cannot be neglected in the discourse on the appropriate technique. This link also emphasizes the importance of a structured training program.

Safety, feasibility and diagnostic value of Clinical Swallow Examination and FEES in children between 0 and 24 months.

BACKGROUND: Clinical Swallowing Examination (CSE) and Fiberoptic Endoscopic Evaluation of Swallowing (FEES) are relevant diagnostic methods in pediatric dysphagia. Satisfactory and comprehensive healthcare is still not part of the standard diagnostic process. AIMS: The purpose of this article is to evaluate the safety, feasibility, and diagnostic value of CSE and FEES in children 0-24 months of age. STUDY DESIGN: A retrospective cross-sectional study which was conducted at the pediatric clinic of the University Hospital Düsseldorf, Germany, between 2013 and 2021. SUBJECTS: A total of 79 infants and toddlers with suspected dysphagia were included. OUTCOME MEASURES: Analyses of the cohort and FEES pathologies were performed. Dropout criterion, complications and change of diet were recorded. Chi-square identified associations between clinical symptoms and FEES results. RESULTS: All FEES examinations were performed without complications and with a completion rate of 93.7 %. Anatomical abnormalities in the laryngeal region were diagnosed in 33 children. Wet voice was significantly associated with premature spillage (p = .028). CONCLUSIONS: CSE and FEES are important and uncomplicated examinations for children with suspected dysphagia between 0 and 24 months. They are equally helpful for differential diagnosis of feeding disorders and anatomical abnormalities. The results underline the added value of combining both examinations and their importance for individual nutritional management. History taking and CSE are mandatory as they reflect the everyday eating situation. This study adds essential knowledge to the diagnostic work-up of dysphagic infants and toddlers. Standardizing the examinations and validating dysphagia scales are future tasks.

Complication rates in rigid vs. flexible endoscopic foreign body removal in children.

While foreign body aspiration remains a frequent and preventable cause of morbidity and mortality in children, recommendations on the appropriate removal technique do often not match the lived practice and expertise of the performing examiners. As there is a scarcity of data regarding success and complication rates of the procedure, the aim of this study was to set up a classification system for procedure-related complications, prospectively record and analyze them. Specialists in the field of foreign body removal contributed cases anonymously. Information regarding procedural details of the bronchoscopy, type, and severity of complications as well as patient characteristics were classified and recorded. Correlations were calculated using Pearson's Chi Square test. A total of 314 rigid and 178 flexible bronchoscopies were compared. Complications were categorized and their severity was defined by the anesthesiologist's assessment of whether to interrupt or terminate the procedure. The overall complication rate was similar in rigid vs. flexible bronchoscopy (19.1% vs. 24.2%, p = 0.232), while respiratory complications occurred significantly less frequent during rigid bronchoscopy (9.2% vs. 16.3%, p = 0.025). This is the largest pediatric case collection recording and comparing complications between rigid and flexible foreign body removal. The higher rate of respiratory complications in flexible bronchoscopy has been shown for the first time and validates some of the concerns about its use for foreign body removal. Flexible bronchoscopy is a safe procedure when extended respiratory monitoring and the possibility of an immediate switch to a secured airway are assured.

Cryotherapy in the paediatric airway: Indications, success and safety.

BACKGROUND AND OBJECTIVE: Cryotherapy in interventional bronchoscopy is a new treatment modality, which has recently been made available for the paediatric airway. Lack of experience and safety concerns have led to hesitant adaptation. The aim of this study was to assess indications, success rates and complications of airway cryotherapy in children. METHODS: Bronchoscopists from medical centre performing cryotherapy in patients between 0 and 18 years were invited to participate in a prospective study based on an online questionnaire. Patient and participant data were collected between June 2020 and June 2021. RESULTS: A total of 69 cryotherapy procedures were performed in 57 patients a for three main indications: Biopsy (30), restoration of airway patency (23) and foreign body aspiration (16). The overall success rate was 93%, the remaining 7% were performed for foreign body removal and required a switch of technique. Restoration of airway patency was successfully applied in various pathologies, including mucus plugs, bronchial casts and post traumatic stenosis. The diagnostic yield of transbronchial biopsies was 96%. No severe complications were encountered; one pneumothorax following a cryobiopsy required a chest drain for 48 h. No child was admitted to intensive care or died from a procedural complication. CONCLUSION: In this largest paediatric case collection to date, cryotherapy was safe and carried a high success rate. Cryobiopsy compares favourably to the widely used forceps biopsy and could replace it in the future. Paediatric bronchoscopists are encouraged to add cryotherapy to their armamentarium of airway interventions.

ERS International Congress 2021: highlights from the Paediatric Assembly.

In this review, Early Career Members of the European Respiratory Society (ERS) and the Chairs of the ERS Assembly 7: Paediatrics present the highlights in paediatric respiratory medicine from the ERS International Congress 2021. The eight scientific Groups of this Assembly cover respiratory physiology and sleep, asthma and allergy, cystic fibrosis (CF), respiratory infection and immunology, neonatology and intensive care, respiratory epidemiology, bronchology, and lung and airway development. We here describe new developments in lung function testing and sleep-disordered breathing diagnosis, early life exposures affecting pulmonary function in children and effect of COVID-19 on sleep and lung function. In paediatric asthma, we present the important role of the exposome in asthma development, and how biologics can provide better outcomes. We discuss new methods to assess distal airways in children with CF, as some details remain blind when using the lung clearance index. Moreover, we summarise the new ERS guidelines for bronchiectasis management in children and adolescents. We present interventions to reduce morbidity and monitor pulmonary function in newborns at risk of bronchopulmonary dysplasia and long-term chronic respiratory morbidity of this disease. In respiratory epidemiology, we characterise primary ciliary dyskinesia, identify early life determinants of respiratory health and describe the effect of COVID-19 preventive measures on respiratory symptoms. Also, we describe the epidemiology of interstitial lung diseases, possible consequences of tracheomalacia and a classification of diffuse alveolar haemorrhage in children. Finally, we highlight that the characterisation of genes and pathways involved in the development of a disease is essential to identify new biomarkers and therapeutic targets.

Pulmonary alveolar proteinosis due to heterozygous mutation in OAS1: Whole lung lavages for long-term bridging to hematopoietic stem cell transplantation.

INTRODUCTION: Pulmonary alveolar proteinosis (PAP) is defined by increased accumulation of surfactant in the alveolar space. PAP has been reported to be associated with a large number of clinical conditions and diseases. Whole lung lavages (WLLs) can be helpful to stabilize the clinical course of PAP until the underlying condition is identified, which may enable more specific treatment. Recently, heterozygous OAS1 gain-of-function variants were described as cause in patients with infantile-onset PAP combined with hypogammaglobulinemia. CASE PRESENTATION: At age 4 months, a female infant born to term was diagnosed with hypogammaglobulinemia and treated with monthly immunoglobulin injections. At age 15 months, the girl needed supplemental oxygen at night, and at age 18 months, also during the day. At age 2 years, PAP of unknown etiology was diagnosed by computed tomography scan and open lung biopsy. Subsequently, monthly WLLs were started, which stabilized the clinical course for over 2 years until a disease-causing OAS1 variant was diagnosed and the patient was successfully treated by hematopoietic stem cell transplantation (HSCT). CONCLUSION: Here, we describe the successful management of a female patient with severe PAP caused by a heterozygous OAS1 gain-of-function variant until a definitive diagnosis was made and cured by HSCT.

Laryngeal sensation and its association with aspiration and cough in children with neurological impairment.

BACKGROUND: Aspirations are frequent in children with neurological impairment. They significantly increase the risk for acute and chronic respiratory insufficiencies leading to high morbidity and mortality. Laryngeal sensation deficits have been linked to aspirations in adults and are a suspected cause for dysphagia in children. In a similar neurological circuit as swallowing, laryngeal receptors trigger coughing as a protective airway reflex. The aim of this study was to examine the association between impaired laryngeal sensation (ILS), aspiration, and coughing in neurologically impaired children. DESIGN AND METHODS: In a retrospective study, 110 children with suspected dysphagia underwent a clinical evaluation of swallowing and a flexible endoscopic evaluation of swallowing (FEES) between 2013 and 2019 in the children's university clinic Düsseldorf were analyzed. Laryngeal sensation was tested by the endoscopic touch method. Associations were computed using χ2 -test. RESULTS: Fifty-four patients (49.1%) had a neurological impairment, 56 patients (50.9%) had no or other comorbidities and served as a control cohort. Children with neurological impairment suffered from ILS significantly more often than children with no or other comorbidities (χ²(1) = 4.63, p = .031). ILS was associated with all other FEES variables but did not correlate with coughing. The symptom coughing correlated with aspiration in the group of neurologically impaired children and in children ILS. CONCLUSION: ILS is a potential cause of aspirations in children with neurological impairment. Physicians need to pay special attention to the occurrence of coughing in children with neurological impairment and/or ILS since it signals aspirations that took place.

Early-onset, fatal interstitial lung disease in STAT3 gain-of-function patients.

Gain-of-function variants in STAT3 are known to cause severe, multifaceted autoimmunity. Here we report three individuals with de-novo STAT3 GOF alleles and early-onset, severe interstitial lung disease manifesting during the first 3 years of life. Imaging and histology revealed different forms of interstitial pneumonia alongside fibrotic and cystic tissue destruction. Definitive diagnosis was established by postmortem whole exome sequencing and functional validation of two new STAT3 variants. Such lung-predominant forms of STAT3 GOF disease expand the phenotypic spectrum of diseases associated with activating STAT3 variants and add to our understanding of this life-threatening inborn error of immunity.

Pediatric Airway Endoscopy: Recommendations of the Society for Pediatric Pneumology.

For many decades, pediatric bronchoscopy has been an integral part of the diagnosis and treatment of acute and chronic pulmonary diseases in children. Rapid technical advances have continuously influenced the performance of the procedure. Over the years, the application of pediatric bronchoscopy has considerably expanded to a broad range of indications. In this comprehensive and up-to-date guideline, the Special Interest Group of the Society for Pediatric Pneumology reviewed the most recent literature on pediatric bronchoscopy and reached a consensus on a safe technical performance of the procedure.

ERS International Congress 2020: highlights from the Paediatric Assembly.

In this review, the Paediatric Assembly of the European Respiratory Society (ERS) presents a summary of the highlights and most relevant findings in the field of paediatric respiratory medicine presented at the virtual ERS International Congress 2020. Early Career Members of the ERS and Chairs of the different Groups comprising the Paediatric Assembly discuss a selection of the presented research. These cover a wide range of research areas, including respiratory physiology and sleep, asthma and allergy, cystic fibrosis, respiratory infection and immunology, neonatology and intensive care, epidemiology, bronchology and lung and airway development. Specifically, we describe the long-term effect in lung function of premature birth, mode of delivery and chronic respiratory conditions such as cystic fibrosis. In paediatric asthma, we present risk factors, phenotypes and their progression with age, and the challenges in diagnosis. We confirm the value of the lung clearance index to detect early lung changes in cystic fibrosis. For bronchiectasis treatment, we highlight the importance of identifying treatable traits. The use of biomarkers and genotypes to identify infants at risk of long-term respiratory morbidity is also discussed. We present the long-term impact on respiratory health of early life and fetal exposures to maternal obesity and intrauterine hypoxia, mechanical ventilation hyperoxia, aeroallergens, air pollution, vitamin A deficient intake and bronchitis. Moreover, we report on the use of metabolomics and genetic analysis to understand the effect of these exposures on lung growth and alveolar development. Finally, we stress the need to establish multidisciplinary teams to treat complex airway pathologies.

The use of pediatric flexible bronchoscopy in the COVID-19 pandemic era.

On March 11, 2020, the World Health Organization (WHO) declared the pandemic because of a novel coronavirus, called severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). In January 2020, the first transmission to healthcare workers (HCWs) was described. SARS-CoV-2 is transmitted between people because of contact, droplets, and airborne. Airborne transmission is caused by aerosols that remain infectious when suspended in air over long distances and time. In the clinical setting, airborne transmission may occur during aerosol generating procedures like flexible bronchoscopy. To date, although the role of children in the transmission of SARS-CoV-2 is not clear the execution of bronchoscopy is associated with a considerably increased risk of SARS-CoV-2 transmission to HCWs. The aim of this overview is to summarize available recommendations and to apply them to pediatric bronchoscopy. We performed systematic literature searches using the MEDLINE (accessed via PubMed) and Scopus databases. We reviewed major recommendations and position statements published at the moment by the American Association for Bronchology and Interventional Pulmonology, WHO, European Center for Disease Prevention and Control and expert groups on the management of patients with COVID-19 to limit transmission among HCWs. To date there is a lack of recommendations for safe bronchoscopy during the pandemic period. The main indications concern adults and little has been said about children. We have summarized available recommendations and we have applied them to pediatric bronchoscopy.

Glucose Tolerance in Patients with Cystic Fibrosis - Results from the German Cystic Fibrosis Registry.

BACKGROUND: Oral glucose tolerance (OGT) deteriorates progressively in cystic fibrosis (CF). Clinical registries provide a unique basis to study real-world data. PATIENTS & METHODS: OGT tests (OGTTs) documented in the German CF-registry in 2016 were classified according WHO, modified by ADA: normal glucose tolerance (NGT), indeterminate glycaemia (INDET), impaired fasting glucose (IFG), impaired glucose tolerance (IGT), IFG+IGT, diabetes mellitus (DM). To study the association with lung function, multivariable regression adjusted for age, sex, and CFTR mutation was performed. RESULTS: Overall, OGTT screening was done in 35% of CF patients ≧10 years. Of the 996 patients (46.4% females; median age (IQR): 19 (14-27) years) with evaluable OGTTs, 56.2% had either NGT or INDET, whereas 34% had a pre-diabetic OGTT (IFG; IGT; IFG+IGT) and 9.8% a diabetic OGTT. 7 patients had glucose tolerance abnormalities <10 years. DM was more common in females or patients with F508del homozygote mutation, whereas IFG was more frequent in males (all p<0.05). Nearly 75% of patients after transplantation and about half with enteral/parental nutrition and/or steroid use had either a pre-diabetic or diabetic glucose tolerance. In the adjusted model, age (p<0.001) and OGTT category (p=0.013) had both a significant impact on %FEV1. CONCLUSION: Our data of the German CF-registry highlights incidence of glucose tolerance abnormalities in second decade of life in CF patients. However, it also underlines the need for improvement of the documentation and/or performance of OGTT screening in real-world CF care. HINTERGRUND: Bei Mukoviszidose (zystischer Fibrose: CF) verschlechtert sich die orale Glukosetoleranz (OGT) im Krankheitsverlauf. PATIENTEN & METHODEN: OGT Tests (OGTTs), die 2016 im Deutschen CF-Register dokumentiert waren, wurden gemäß WHO (modifiziert nach ADA) kategorisiert: Normale Glukosetoleranz (NGT), intermittierende Glykämie (INDET), eingeschränkte Nüchternglukosetoleranz (IFG), gestörte Glukosetoleranz (IGT), IFG+IGT, Diabetes Mellitus (DM). Um den Zusammenhang mit der Lungenfunktion zu analysieren, wurde eine multivariable Regressionsanalyse adjustiert für Alter, Geschlecht und CFTR Mutation durchgeführt. ERGEBNISSE: Insgesamt wurden 35% der CF-Patienten ≥10 Jahre mittels OGTT gescreent. Von den 996 Patienten (46,4% weiblich, medianes Alter (IQR): 19 (14-27) Jahre) mit auswertbaren OGTTs hatten 56,2% entweder NGT oder INDET, wohingegen bei 34% ein prädiabetischer (IFG; IGT; IFG+IGT) und bei 9,8% ein diabetischer OGTT beobachtet wurde. Bei 7 Patienten zeigten sich vor dem 10. LJ Abnormalitäten im Glukosestoffwechsel. DM war häufiger bei Frauen und Patienten mit homozygoter F508del Mutation, wobei IFG öfters bei Männern vorlag (alle p<0,05). Ca. 75% der Patienten mit Transplantation und etwa die Hälfte der Patienten mit künstlicher Ernährung und/oder Steroidgabe hatten eine prädiabetische oder diabetische Glukosetoleranz. Das Alter (p<0,001) und die OGTT Kategorie (p=0,013) zeigten im adjustierten Modell eine signifikante Assoziation mit %FEV1. SCHLUSSFOLGERUNG: Unsere Daten unterstreichen das Auftreten von Abnormalitäten im Glukosestoffwechsel bei CF im 2. Lebensjahrzehnt. Jedoch weißt es auf die Notwendigkeit eines regelmäßigen Diabetesscreenings und/oder Dokumentation von OGTTs bei CF hin.

Postinfectious Bronchiolitis Obliterans in Children: Diagnostic Workup and Therapeutic Options: A Workshop Report.

Bronchiolitis obliterans (BO) is a rare, chronic form of obstructive lung disease, often initiated with injury of the bronchiolar epithelium followed by an inflammatory response and progressive fibrosis of small airways resulting in nonuniform luminal obliteration or narrowing. The term BO comprises a group of diseases with different underlying etiologies, courses, and characteristics. Among the better recognized inciting stimuli leading to BO are airway pathogens such as adenovirus and mycoplasma, which, in a small percentage of infected children, will result in progressive fixed airflow obstruction, an entity referred to as postinfectious bronchiolitis obliterans (PIBO). The present knowledge on BO in general is reasonably well developed, in part because of the relatively high incidence in patients who have undergone lung transplantation or bone marrow transplant recipients who have had graft-versus-host disease in the posttransplant period. The cellular and molecular pathways involved in PIBO, while assumed to be similar, have not been adequately elucidated. Since 2016, an international consortium of experts with an interest in PIBO assembles on a regular basis in Geisenheim, Germany, to discuss key areas in PIBO which include diagnostic workup, treatment strategies, and research fields.

Immediate and Sustained Effect of Neonatal Teaching in a Perinatal Setting in Urban Laos.

OBJECTIVE: This study aimed to quantify knowledge on neonatal topics among obstetricians and pediatricians participating in a perinatal teaching program aimed at reducing neonatal mortality in Laos. STUDY DESIGN: Obstetricians and pediatricians from Vientiane and the surrounding areas participated in a 1-week teaching program in obstetric and neonatal topics and responded to pre- and posttests questionnaires to quantify their knowledge. RESULTS: Although questions were predominantly related to neonatal topics, obstetricians performed significantly better than pediatricians during the pretest. Both groups increased their knowledge significantly as quantified by the results of the posttest. CONCLUSION: The teaching program was effective in improving knowledge on perinatal mortality related topics of the participants. These results may be related to the fact that most of the obstetricians had participated in a structured teaching program previously, whereas the pediatricians did not. We thus speculate that there is a sustained effect of even a 1-week teaching program in neonatology even several years after the initial teaching.

Higher Interleukin-7 serum concentrations in patients with cystic fibrosis correlate with impaired lung function.

BACKGROUND: Patients with cystic fibrosis (CF) are highly susceptible to infection and colonization of pulmonary epithelia. Repeated and chronic infections may affect disease course and efficacy of host immune protection. Higher Interleukin (IL)-7 serum levels, indicating impaired T-cell response to IL-7, have been described for chronic viral and mycobacterial infections. METHODS: Time course measures of IL-7 serum concentrations in patients with CF (n = 164; n = 78 for the second time point) and healthy controls (n = 60) were done. CF patients were characterized for disease severity parameters as well as infection status and association with IL-7 serum levels was determined. RESULTS: CF patients had significantly higher IL-7 serum concentrations as compared to healthy controls (9.79 pg/ml, IQR 6.76-13.6 versus 4.55 pg/ml, IQR 2.76-9.51, p < .001). IL-7 serum levels were negatively correlated with individual CF patient's BMI (r = -0.19, p = .021) and a tendency of increased IL-7 levels in Staphylococcus aureus infected CF patients was found. Linear regression of multiple parameters revealed significant negative correlation of FEV1%pred with IL-7 serum concentrations in patients with CF (ß-coefficient: -0.04, 95% confidence interval [-0.08; -0.003], p = .034). Time course analyses after 1 year +/- 6 months showed increased IL-7 serum levels (time point 1:9.26 pg/ml, IQR 6.94-13.12 time point 2:10.86 pg/ml, IQR 9.14-14.76, p = .016) that correlated negatively with decreased FEV1%pred during CF disease course. CONCLUSIONS: High IL-7 serum levels were found in CF patients and correlated with impaired lung function during CF disease course. As a candidate biomarker of T-cell dysfunction, higher IL-7 serum level may also indicate worsened immune competence of patients with CF.