[Pulmonary function test: The testing of children]. / Exploration fonctionnelle respiratoire : explorer l'enfant.

In paediatrics, the pulmonary function test (PFT) is most often performed to support the diagnosis or in follow-up of asthma patients. Whatever the pathology responsible for respiratory symptoms and/or functional impairment, repeated PFTs make it possible to establish a prognosis (pulmonary function trajectories…) and to orient preventive interventions. PFT can be performed routinely from the age of three years, provided that the following requirements are met: suitable techniques and equipment, staff trained to apply the techniques and to receive young children, reference values for each technique indicating the limits of normal values and of between-test significant variation. From the age of three, children can be subjected to tidal breathing measurement of: resistance of the respiratory system (oscillometry, Rrs; airflow interruption, Rint) or of airways specific resistance (sRaw) and functional residual capacity (by applying a dilution technique). With maturity, the child will become capable of mobilizing his or her slow vital capacity to measure total lung capacity (TLC), once again by applying a dilution technique, then later by breathing against a closed shutter (plethysmography TLC and Raw). Finally, the child will be able to carry out forced expiration (forced spirometry) along with all of the other PFTs. It is important to take into account the paediatric adaptations specified in the international recommendations regarding the performance, reproducibility and quality of PFTs targeting this population.

Guidelines for the clinical management and follow-up of infants with inconclusive cystic fibrosis diagnosis through newborn screening.

Neonatal screening for cystic fibrosis (CF) can detect infants with elevated immunoreactive trypsinogen (IRT) levels and inconclusive sweat tests and/or CFTR DNA results. These cases of uncertain diagnosis are defined by (1) either the presence of at most one CF-associated cystic fibrosis transmembrane conductance regulator (CFTR) mutation with sweat chloride values between 30 and 59mmol/L or (2) two CFTR mutations with at least one of unknown pathogenic potential and a sweat chloride concentration below 60mmol/L. This encompasses various clinical situations whose progression cannot be predicted. In these cases, a sweat chloride test has to be repeated at 12 months, and if possible at 6 and 24 months of life along with extended CFTR sequencing to detect rare mutations. When the diagnosis is not definite, CFTR functional explorations may provide a better understanding of CFTR dysfunction. The initial evaluation of these infants must be conducted in dedicated CF reference centers and should include bacteriological sputum analysis, chest radiology, and fecal elastase assay. The primary care physicians in charge of these patients should be familiar with the current management of CF and should work in collaboration with CF centers. A follow-up should be performed in a CF reference center at 3, 6, and 12 months of life and every year thereafter. Any symptom indicative of CF requires immediate reevaluation of the diagnosis. These guidelines were established by the "neonatal screening and difficult diagnoses" working group of the French CF society. Their objective is to standardize the management of infants with unclear diagnosis.

[Management of infants whose diagnosis is inconclusive at neonatal screening for cystic fibrosis]. / Recommandations pour la prise en charge et le suivi des nourrissons pour lesquels un diagnostic de mucoviscidose n'a pu être conclu après dépistage néonatal.

Neonatal screening for cystic fibrosis (CF) may detect infants with elevated immunoreactive trypsinogen (IRT) levels but with inconclusive sweat tests and/or DNA results. This includes cases associating (1) either the presence of at most one CF-causing mutation and sweat chloride values between 30 and 59mmol/L or (2) two CFTR mutations with at least one of unknown pathogenicity and a sweat chloride below 60mmol/L. This encompasses different clinical situations whose progression cannot be predicted. These cases require redoing the sweat test at 12 months and if possible at 6 and 24 months of life. This must be associated with extended genotyping. CFTR functional explorations can also help by investigating CFTR dysfunction. These infants must be initially evaluated in dedicated CF centers including bacteriological sputum analysis, chest radiology and fecal elastase dosage. A home practitioner must be informed of the specificity of follow-up. These infants will be reviewed in the CF center at 3, 6 and 12 months and every year. Any CF-related symptom requires reevaluation of the diagnosis. These guidelines were established by the "neonatal screening and difficult diagnoses" working group of the French CF Society. They aim to standardize management of infants with unclear diagnosis in French CF centers.

Bioelectrical impedance in young patients with cystic fibrosis: Validation of a specific equation and clinical relevance.

BACKGROUND: Body composition (BC) analysis based on bioelectrical impedance analysis (BIA) provides conflicting results. The purpose of the study was to validate an equation specific for young patients with cystic fibrosis (CF), describe their BC and investigate its association with lung function. METHODS: Fifty-four young CF patients were evaluated by BIA and dual X-ray absorptiometry (DXA). An empirically derived CF-specific equation for fat-free mass (FFM) estimation by BIA was elaborated after stepwise multivariate regression and the agreement between BIA and DXA was assessed by Bland-Altman plots. The association between BC and lung function was investigated by regression analysis. RESULTS: The mean difference between the BIA and DXA assessment was close to zero. A total of 22.5% of patients (n=9) presented a FFM z-score≤-2. They had a worse pulmonary function and diaphragmatic impairment. Among these 9 patients, 7 had a normal BMI z-score>-1. CONCLUSIONS: BIA, based on a CF-specific equation, is a reliable method for BC assessment and allows the identification of patients at risk of nutritional degradation and bad respiratory prognosis.

[Recommendations for the use of diagnostic testing in low respiratory infections in children older than three months]. / Recommandations sur l'utilisation des nouveaux outils diagnostiques étiologiques des infections respiratoires basses de l'enfant de plus de trois mois.

Recommendations for the use of diagnostic testing in low respiratory infection in children older than 3 months were produced by the Groupe de Recherche sur les Avancées en Pneumo-Pédiatrie (GRAPP) under the auspices of the French Paediatric Pulmonology and Allergology Society (SP(2)A). The Haute Autorité de santé (HAS) methodology, based on formalized consensus, was used. A first panel of experts analyzed the English and French literature to provide a second panel of experts with recommendations to validate. Only the recommendations are presented here, but the full text is available on the SP(2)A website.

Lung clearance index: evidence for use in clinical trials in cystic fibrosis.

The ECFS-CTN Standardisation Committee has undertaken this review of lung clearance index as part of the group's work on evaluation of clinical endpoints with regard to their use in multicentre clinical trials in CF. The aims were 1) to review the literature on reliability, validity and responsiveness of LCI in patients with CF, 2) to gain consensus of the group on feasibility of LCI and 3) to gain consensus on answers to key questions regarding the promotion of LCI to surrogate endpoint status. It was concluded that LCI has an attractive feasibility and clinimetric properties profile and is particularly indicated for multicentre trials in young children with CF and patients with early or mild CF lung disease. This is the first article to collate the literature in this manner and support the use of LCI in clinical trials in CF.

[The respiratory disease of cystic fibrosis, from infancy to childhood]. / Atteinte respiratoire de la mucoviscidose de l'enfance à l'âge adulte.

The respiratory disease of cystic fibrosis, which is secondary to bronchial inflammation and infection, appears from the youngest age and its evolution is made of exacerbations due to acute respiratory infections. In adulthood, complications such as hemoptysis and pneumothorax are more frequent and respiratory insufficiency is more severe, conditioning prognosis. Care is mainly based on physiotherapy and adapted antibiotics.

[Fungal infections in cystic fibrosis]. / Infections fongiques au cours de la mucoviscidose.

Fungal colonization in cystic fibrosis patient is frequent and dominated by Aspergillus fumigatus (A. fumigatus). Mycological analysis on specific media showed other filamentous species Scedosporium, Geosmithia argillacea. Prospective studies are necessary to appreciate prevalence and pathogenicity in this pathology. A. fumigatus causes the most frequently allergic bronchopulmonary aspergillosis (ABPA). Invasive infection is exceptional in this context. An early diagnosis is important to avoid bronchial deterioration but is very difficult despite international consensus. New more specific biological markers are evaluated. Oral corticotherapy is the cornerstone of therapy but adverse effects are more frequent in cystic fibrosis. Antifungal therapy has a corticosteroid-sparing effect. New therapeutic strategies have to be evaluated.

Allergy to betalactam antibiotics in children: results of a 20-year study based on clinical history, skin and challenge tests.

Studies based on skin and challenge tests have shown that 12-60% of children with suspected betalactam hypersensitivity were allergic to betalactams. Responses in skin and challenge tests were studied in 1865 children with suspected betalactam allergy (i) to confirm or rule out the suspected diagnosis; (ii) to evaluate diagnostic value of immediate and non-immediate responses in skin and challenge tests; (iii) to determine frequency of betalactam allergy in those children, and (iv) to determine potential risk factors for betalactam allergy. The work-up was completed in 1431 children, of whom 227 (15.9%) were diagnosed allergic to betalactams. Betalactam hypersensitivity was diagnosed in 50 of the 162 (30.9%) children reporting immediate reactions and in 177 of the 1087 (16.7%) children reporting non-immediate reactions (p<0.001). The likelihood of betalactam hypersensitivity was also significantly higher in children reporting anaphylaxis, serum sickness-like reactions, and (potentially) severe skin reactions such as acute generalized exanthematic pustulosis, Stevens-Johnson syndrome, and drug reaction with systemic symptoms than in other children (p<0.001). Skin tests diagnosed 86% of immediate and 31.6% of non-immediate sensitizations. Cross-reactivity and/or cosensitization among betalactams was diagnosed in 76% and 14.7% of the children with immediate and non-immediate hypersensitivity, respectively. The number of children diagnosed allergic to betalactams decreased with time between the reaction and the work-up, probably because the majority of children with severe and worrying reactions were referred for allergological work-up more promptly than the other children. Sex, age, and atopy were not risk factors for betalactam hypersensitivity. In conclusion, we confirm in numerous children that (i) only a few children with suspected betalactam hypersensitivity are allergic to betalactams; (ii) the likelihood of betalactam allergy increases with earliness and/or severity of the reactions; (iii) although non-immediate-reading skin tests (intradermal and patch tests) may diagnose non-immediate sensitizations in children with non-immediate reactions to betalactams (maculopapular rashes and potentially severe skin reactions especially), the diagnostic value of non-immediate-reading skin tests is far lower than the diagnostic value of immediate-reading skin tests, most non-immediate sensitizations to betalactams being diagnosed by means of challenge tests; (iv) cross-reactivity and/or cosensitizations among betalactams are much more frequent in children reporting immediate and/or anaphylactic reactions than in the other children; (v) age, sex and personal atopy are not significant risk factors for betalactam hypersensitivity; and (vi) the number of children with diagnosed allergy to betalactams (of the immediate-type hypersensitivity especially) decreases with time between the reaction and allergological work-up. Finally, based on our experience, we also propose a practical diagnostic approach in children with suspected betalactam hypersensitivity.

Multicentre trial evaluating alveolar NO fraction as a marker of asthma control and severity.

BACKGROUND: Exhaled NO can be partitioned in its bronchial and alveolar sources, and the latter may increase in the presence of recent asthmatic symptoms and in refractory asthma. The aim of this multicentre prospective study was to assess whether alveolar NO fraction and FE(NO) could be associated with the level of asthma control and severity both at the time of measurement and in the subsequent 3 months. METHODS: Asthma patients older than 10 years, nonsmokers, without recent exacerbation and under regular treatment, underwent exhaled NO measurement at multiple constant flows allowing its partition in alveolar (with correction for back-diffusion) and bronchial origins based on a two-compartment model of NO exchange; exhaled NO fraction at 50 ml/s (FE(NO,0.05)) was also recorded. On inclusion, severity was assessed using the four Global initiative for asthma (GINA) classes and control using Asthma Control Questionnaire (ACQ). Participants were followed-up for 12 weeks, control being assessed by short-ACQ on 1st, 4th, 8th and 12th week. RESULTS: Two-hundred patients [107 children and 93 adults, median age (25th; 75th percentile) 16 years (12; 38)], 165 receiving inhaled corticosteroid, were included in five centres. The two-compartment model was valid in 175/200 patients (87.5%). Alveolar NO and FE(NO,0.05) did not correlate to control on inclusion or follow-up (either with ACQ /short-ACQ values or their changes), nor was influenced by severity classes. Alveolar NO negatively correlated to MEF(25-75%) (rho = -0.22, P < 0.01). CONCLUSION: Alveolar and exhaled NO fractions are not indexes of control or severity in asthmatic children and adults under treatment.

New surfactant protein C gene mutations associated with diffuse lung disease.

BACKGROUND: Mutations in the surfactant protein C gene (SFTPC) have been recently associated with the development of diffuse lung disease, particularly sporadic and familial interstitial lung disease (ILD). OBJECTIVE: We have investigated the prevalence and the spectrum of SFTPC mutations in a large cohort of infants and children with diffuse lung disease and suspected with surfactant dysfunction. METHOD AND RESULTS: 121 children were first screened for the common SFTPC mutation, p.Ile73Thr (I73T). Ten unrelated patients were shown to carry this mutation. The I73T mutation was inherited in six cases, and appeared de novo in four. The 111 patients without the I73T mutation were screened for the entire coding sequence of SFTPC. Of these, eight (seven unrelated) subjects were shown to carry a novel mutant allele of SFTPC. All these seven new mutations are located in the BRICHOS domain except the p.Val39Ala (V39A) mutation, which is in the surfactant protein C (SP-C) mature peptide. CONCLUSIONS: Our results confirm that SFTPC mutations are a frequent cause of diffuse lung disease, and that I73T is the most frequent SFTPC mutation associated with diffuse lung disease.

[Influenza vaccination coverage in asthmatic children in France in 2006-2007]. / Couverture vaccinale contre la grippe chez les enfants asthmatiques en France en 2006-2007.

In France, an annual seasonal influenza vaccination has been recommended since 2000 for patients suffering from chronic respiratory diseases, including asthma. Each year, a free influenza vaccination voucher is sent by the French Public Health Insurance authorities to patients with chronic respiratory disease, including severe asthma. In November 2006, this measure was extended to all asthmatic patients, irrespective of asthma severity. The present paper examines the 2006-2007 influenza vaccination coverage rate in 433 asthmatic children aged six to 17 years (mean age: 9.5 years; male: 61%) who consulted a pediatric pulmonologist between March and September 2007 in eight hospitals throughout France. The influenza vaccination coverage rate was 15.7% for the 2006-2007 season (13.9% for the 2005-2006 season and 10.9% for the 2004-2005 season). General practitioners vaccinated 72.1% of the children. Lack of information (42%) was the most frequently reported reason for non-vaccination. Free vouchers (received by 39.6% of the children) significantly increased the vaccination coverage rate (31% versus 5.9%; p < 0.001). In France, in 2006-2007, the influenza vaccination coverage rate in asthmatic children was far below the national public health objective to achieve for the year 2008 (at least 75%). Concerted action is needed to improve the influenza vaccination coverage rate in asthmatic children.

Low influenza vaccination coverage in asthmatic children in France in 2006-7.

In France, annual seasonal influenza vaccination has been recommended since 2000 for patients suffering from chronic respiratory diseases, including asthma. Since 1988, each year from September to December, a free influenza vaccination voucher is sent by the French Public Health Insurance authorities to patients with chronic respiratory disease, including severe asthma. In November 2006, this measure was extended to all asthmatic patients, irrespective of asthma severity. The present paper examines the 2006-7 influenza vaccination coverage rate (VCR) in 433 asthmatic children aged 6 to 17 years (mean age: 9.5 years; male: 61%) who consulted a paediatric pulmonologist between March and September 2007 in eight hospitals throughout France. The influenza VCR was 15.7% for the 2006-7 season (13.9% for the 2005-6 season and 10.9% for the 2004-5 season). General practitioners vaccinated 72.1% of the children. "Lack of information" (42%) was the most frequently reported reason for non-vaccination. Vouchers (received by 39.6% of the children) significantly increased the VCR (31% versus 5.9%; p<0.001). In France, in 2006-7, the influenza VCR in asthmatic children was far below the national public health objective (at least 75% for the year 2008). Concerted action is needed to improve the influenza VCR in asthmatic children.

[Exercise alveolar hypoventilation in long-term survivors of bronchopulmonary dysplasia]. / Hypoventilation alvéolaire à l'exercice chez des enfants avec dysplasie bronchopulmonaire.

BACKGROUND: We aimed to confirm that children who have survived bronchopulmonary dysplasia (BPD) display lower ventilation during exercise than healthy children, and to determine whether alveolar hypoventilation associated with exercise-induced hypoxemia occurred in these children. METHODS: Twenty children with BPD (birth weight 1441+/-523 g [mean +/- SD], gestational age 31+2.3 weeks), aged 7 to 14 years, and 18 matched healthy children, born at term, performed resting pulmonary function and cardiopulmonary incremental exercise tests. Arterialized capillary blood gases were measured at rest and at maximal exercise in the BPD group. RESULTS: The BPD group showed moderate expiratory airflow limitation and hyperinflation. Maximal oxygen uptake and ventilatory threshold were similar in the two groups. The BPD group displayed ventilatory limitation on exercise, with greater use of the ventilatory reserve (p<0.01), lower maximal ventilation (p<0.01), tidal volume (p=0.01). Changes in ventilation (p<0.0001) and tidal volume (p=0.003) during exercise were significantly smaller in the BPD group than in controls, at similar submaximal workloads. At peak exercise, we observed hypoxemia in 12 BPD children (60%). In the subgroup with hypoxemia, a significant increase in PaCO2 (p=0.01) was measured at peak exercise, showing alveolar hypoventilation sustained by the lower tidal volume. CONCLUSIONS: Despite normal maximal aerobic performance, BPD children showed ventilatory limitation on exercise, frequently with hypoxemia and alveolar hypoventilation. Despite an improvement in their pulmonary condition, continued follow-up by cardiopulmonary exercise testing, is strongly recommended.

Incidence rate and factors related to post-bronchoalveolar lavage fever in children.

BACKGROUND: Post-bronchoscopy and bronchoalveolar lavage (BAL) fever in children has been described by several authors. OBJECTIVES: This study aimed at assessing the occurrence of fever after these examinations and associated risk factors. METHODS: The study was performed in the Bronchoscopy Unit of Hôpital Necker-Enfants Malades, Paris, France, from June 2004 to July 2005. 148 children who underwent fiberoptic bronchoscopy and BAL, and remained in the Unit for 24 h, were included. RESULTS: 37.8% of the patients presented post-BAL fever. In the multivariate analysis of the selected factors (age, immunodeficiency, general or local anesthesia, mucosal biopsy, inflammation and suppuration at the moment of the examination, abnormal bronchoalveolar fluid cellularity and infection), only age <2 years and presence of infection remained associated with fever. CONCLUSIONS: The occurrence of fever is a frequent event in children who underwent BAL. In order to reduce post-BAL fever, antibiotic strategies should be devised based on prospective studies assessing identification of predictive air-way infection criteria and/or rapid bacteriological result analysis.