Radiation-free and injection-free imaging of the paediatric chest using a magnetic resonance imaging protocol including zero time echo sequence (3D-ZTE).

Computed tomography (CT) is commonly used for paediatric thoracic diseases but involves radiation exposure and often requires intravenous contrast. We evaluated the performance of a magnetic resonance imaging (MRI) protocol including a 3D zero echo time (3D-ZTE) sequence for radiation-free and contrast-free imaging of the paediatric chest. In this prospective, single-centre study, children aged 6-16 years underwent chest CT and MRI within 48 h. CT and MRI exams were independently assessed by two paediatric radiologists. The primary outcome was the image quality of the 3D-ZTE sequence using a scoring system based on the acceptability of the images obtained and visibility of bronchial structures, vessels and fissures. Secondary outcomes included radiologists' ability to detect lung lesions on 3D-ZTE MRI images compared with CT images. Seventy-two children were included. Overall, the image quality achieved with the 3D-ZTE MRI sequence was inferior to that of CT for visualising pulmonary structures, with satisfactory lung image quality observed for 81.9% (59/72) and 100% (72/72) of patients, respectively. However, MRI sensitivity was excellent (above 90%) for the detection of certain lesions such as lung consolidation, proximal mucoid impactions, pulmonary cysts, ground glass opacities and honeycombing. Intermodality agreement (MRI versus CT) was consistently higher for the senior reader compared to the junior reader. CONCLUSION: Despite its overall lower image quality compared to CT, and the additional years of experience required for accurate interpretation, the 3D-ZTE MRI sequence demonstrated excellent sensitivity for several lesions, making it an appropriate imaging method in certain indications. WHAT IS KNOWN: • Chest radiography and CT are the main imaging modalities for paediatric thoracic diseases but involve radiation exposure and CT often requires IV contrast. • MRI is promising for radiation-free lung imaging in children but faces challenges of low signal-to-noise ratio and motion artefacts. WHAT IS NEW: • An MRI protocol including a 3D zero echo time (ZTE) sequence allows satisfactory visualisation of lung parenchyma in 82% of children. • Despite overall inferior image quality compared to CT, MRI demonstrated excellent sensitivity for several lesions, making it an appropriate imaging method in certain indications.

Late-onset pulmonary complications following allogeneic hematopoietic cell transplantation in pediatric patients: a prospective multicenter study.

The primary objective of our multicenter prospective study was to describe the incidence of late-onset non-infectious pulmonary complications (LONIPCs) in children undergoing hematopoietic cell transplantation (HCT) using sensitive criteria for pulmonary function test (PFT) abnormalities including the non-specific pattern of airflow obstruction. Secondary objectives were to assess the factors associated with LONIPC occurrence and the sensitivity of the 2014 NIH-Consensus Criteria of bronchiolitis obliterans syndrome (BOS). PFT and clinical assessment were performed prior to HCT and at 6, 12, 24, and 36 months post-HCT. LONIPC diagnosis was validated by an Adjudication Committee. The study comprised 292 children from 12 centers. Thirty-two individuals (11%, 95% CI: 8-15%) experienced 35 LONIPCs: 25 BOS, 4 interstitial lung diseases, 4 organizing pneumonia and 2 pulmonary veno-occlusive diseases. PFT abnormalities were obstructive defects (FEV1/FVC z-score < -1.645; n = 12), restrictive defects (TLC < 80% predicted, FEV1 and FVC z-scores < -1.645; n = 7) and non-specific pattern (FEV1 and FVC z-score< -1.645, FEV1/FVC z-score > -1.645, and TLC > 80% predicted; n = 8). HCT for malignant disease was the only factor associated with LONIPC (P = 0.04). The 2014 NIH-Consensus Criteria would only diagnose 8/25 participants (32%) as having BOS. In conclusion, 11% of children experienced a LONIPC in a prospective design. Clinical Trials.gov identifier (NCT number): NCT02032381.

Hyperventilation syndrome in children with asthma.

BACKGROUND: Hyperventilation syndrome (HVS) may be associated with asthma. In the absence of a gold standard diagnosis for children, its impact on asthma has been rarely assessed. OBJECTIVE: To assess the impact of HVS on the symptoms and lung function of children with asthma and determine the diagnostic value of the Nijmegen questionnaire in comparison to a hyperventilation test (HVT). METHODS: Data from asthmatic children followed in the department of Pediatric Pulmonology of Necker Hospital and explored for HVS were retrospectively analyzed. HVS was diagnosed by a positive HVT. Asthma exacerbations, control and lung function were assessed in children with or without a positive HVT. The sensitivity and specificity of the Nijmegen questionnaire were determined relative to the positivity of a HVT. The Nijmegen questionnaire threshold was ≥23. RESULTS: Data from 112 asthmatic children, median age 13.9 years [11.6-16], were analyzed. Twenty-eight children (25%) had mild or moderate asthma and 84 (75%) severe asthma. The HVT was performed on 108 children and was negative for 34 (31.5%) and positive for 74 (68.5%). The number of asthma exacerbations in the past 12 months, Asthma Control Test (ACT) score, and lung function did not differ between children with a positive HVT and a negative HVT. The Nijmegen questionnaire was administered to 103 children. Its sensitivity was 56.3% and specificity 56.3%. CONCLUSION: The symptoms and lung function of adolescents with asthma are not affected by the presence of HVS. The sensitivity and specificity of the Nijmegen questionnaire are low.

Proteomic profiling of sweat in patients with cystic fibrosis provides new insights into epidermal homoeostasis.

Background: A high proportion of patients with Cystic Fibrosis (CF) also present the rare skin disease aquagenic palmoplantar keratoderma. A possible link between this condition and absence of a functional CF Transmembrane conductance Regulator protein in the sweat acinus and collecting duct remains unknown. Methods: In-depth characterization of sweat proteome profiles was performed in 25 CF patients compared to 12 healthy controls. A 20 µL sweat sample was collected after pilocarpine iontophoresis and liquid chromatography tandem mass spectrometry (LC-MS/MS) proteomic analysis was performed. Results: Sweat proteome profile of CF patients was significantly different from that of healthy subjects with 57 differentially expressed proteins. Cystic Fibrosis sweat proteome was characterized by an increase in 25 proteins including proteases (Kallikrein 7 and 13, Phospholipase B domain containing 1, Cathepsin A L2 and B, Lysosomal Pro-X carboxypeptidase); proinflammatory proteins (Annexin A2, Chitinase-3-like protein 1); cytochrome c and transglutaminases. Thirty-two proteins were downregulated in CF sweat including proteases (Elastase 2), antioxidative protein FAM129 B; membrane-bound transporter SLC6A14 and regulator protein Sodium-hydrogen antiporter 3 regulator 1. Conclusion: This study is the first to report in-depth characterization of endogenous peptides in CF sweat and could help understand the complex physiology of the sweat gland. The proteome profile highlights the unbalanced proteolytic and proinflammatory activity of sweat in CF. These results also suggest a defect in pathways involved in skin barrier integrity in CF patients. Sweat proteome profile could prove to be a useful tool in the context of personalized medicine in CF.

High Nasal Nitric Oxide, Cilia Analyses, and Genotypes in a Retrospective Cohort of Children with Primary Ciliary Dyskinesia.

Rationale: Although children with primary ciliary dyskinesia (PCD) typically have low nasal nitric oxide (nNO), some children with indisputable PCD may have unexplained high nNO concentrations. Objectives: To look for relationships between nNO measures and genetic findings (and cilia motility or ultrastructure when available) in children with PCD with known genotypes. Methods: We retrospectively studied 73 children with PCD (median age, 9.5 [range, 2.1-18.2] yr). nNO was the mean value of a plateau reached while the velum was closed (nNO-VC; threshold, 77 nl ⋅ min-1) or was calculated as the average of five peaks obtained during tidal breathing (threshold, 40 nl ⋅ min-1). Ciliary beat was classified as either motile (including dyskinetic pattern) or immotile, depending on whether motility was present or absent in all cilia, or as a mixture of motile and immotile cilia. Genotypes were classified as pathogenic mutations in genes known to be associated with high nNO (mild genotype), biallelic truncating mutations in other genes (severe mutations), or putative hypomorphic pathogenic mutations (missense, single amino acid deletion, or moderate splicing mutations) in at least one allele believed to be possibly associated with residual production of a functional protein. Results: nNO was above the discriminant threshold in 16 of 73 (21.9%) children (11 nNO-VC and 5 nNO during tidal breathing). High nNO was less frequent in children with severe mutations (2 of 42) than in those with mild genotypes (7 of 10) or at least one hypomorphic mutation (7 of 21) (P < 0.0001). Median (interquartile range) nNO-VC values (n = 60) were significantly different in the three genotype groups: severe mutations, 18 (10-26) nl ⋅ min-1 (n = 36); possible residual functional protein production (putative hypomorphic mutations), 23 (16-68) nl ⋅ min-1 (n = 17); and mild genotypes, 139 (57-216) nl ⋅ min-1 (n = 7) (P = 0.0002). The higher the cilia motility, the higher the nNO-VC (16 [10-23], 23 [17-56], and 78 [45-93] nl ⋅ min-1 in patients with immotile, dyskinetic motile and immotile, and dyskinetic motile cilia, respectively; P < 0.0001), while nNO values were scattered across different ultrastructure defects (P = 0.07). Conclusions: In children with PCD, high nNO values were linked not only to specific genes but also to potentially hypomorphic mutations in other genes (with possible functional protein production). nNO values increased with the proportion of motile cilia.

Lumacaftor-ivacaftor effects on cystic fibrosis-related liver involvement in adolescents with homozygous F508 del-CFTR.

BACKGROUND: The effects of lumacaftor-ivacaftor on cystic fibrosis transmembrane conductance regulator (CFTR)-associated liver disease remain unclear. The objective of the study was to describe the effect of this treatment on features of liver involvement in a cystic fibrosis (CF) adolescent population homozygous for F508del. METHODS: Clinical characteristics, liver blood tests, abdominal ultrasonography (US), and pancreas and liver proton density fat fraction (PDFF) by magnetic resonance imaging, were obtained at treatment initiation and at 12 months for all patients. Biomarkers of CFTR activity (sweat chloride test, nasal potential difference, and intestinal current measurement) were assessed at initiation and at 6 months therapy. RESULTS: Of the 37 patients who started ivacaftor/lumacaftor treatment, 28 were eligible for analysis. In this group, before treatment initiation, 4 patients were diagnosed with multinodular liver and portal hypertension, 19 with other forms of CF liver involvement, and 5 with no signs of liver involvement. During treatment, no hepatic adverse reactions were documented, and no patient developed liver failure. Serum levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST) and gammaglutamyl transferase (GGT) decreased significantly following initiation of lumacaftor-ivacaftor, and remained so after 12 months treatment. This was not correlated with changes in clinical status, liver and pancreas US and PDFF, fecal elastase, or lumacaftor-ivacaftor serum levels. The most "responsive" patients demonstrated a significant increase in biomarkers of CFTR activity. CONCLUSIONS: These results may suggest a potential beneficial effect of CFTR modulators on CF liver disease and warrant further investigation in larger, prospective studies.

Real-world assessment of LCI following lumacaftor-ivacaftor initiation in adolescents and adults with cystic fibrosis.

Lung clearance index (LCI) is a biomarker of ventilation inhomogeneity. Data are scarce on its usefulness in daily practice for monitoring the effects of treatments in older children and adults with CF. In this French observational study of lumacaftor-ivacaftor, 63 of 845 patients (7.5%) had available LCI performed at baseline and at six (M6; n=34) or 12 months (M12; n=46) after lumacaftor-ivacaftor initiation. At inclusion, median [IQR] age was 16 years [13-17], ppFEV1 was 72.8 [59.6-80.7], and LCI was 12.3 [10.3-15.0]. At both M6 and M12, no statistically significant LCI increases of 0.13 units or 1.34% (95% CI: -4.85-7.53) and 0.6 units or 6.66% (95% CI: -0.03-13.5) were observed. Discordant results between LCI and ppFEV1 were observed in one-third of the patients. In daily practice, LCI monitoring in adolescents and young adults with moderate lung disease gives results that are more heterogenous than those reported in children with milder disease.

Chest physiotherapy enhances detection of Pseudomonas aeruginosa in nonexpectorating children with cystic fibrosis.

Lung damage in cystic fibrosis (CF) is strongly associated with lower airway infections. Early treatment of Pseudomonas aeruginosa is recommended. Pathogen detection requires sampling of lower airway secretions, which remains a challenge in nonexpectorating patients. Our hypothesis was that chest physiotherapy would improve the quality of airway secretion samples and increase the rates of pathogens detected in nonexpectorating patients. This prospective multicentre study compared three successive methods for sampling airway secretions applied through the same session: 1) an oropharyngeal swab (OP), 2) a chest physiotherapy session followed by a provoked cough to obtain sputum (CP-SP) and 3) a second oropharyngeal swab collected after chest physiotherapy (CP-OP). Haemophilus influenzae, Staphylococcus aureus and P. aeruginosa growth cultures were assessed. Accuracy tests and an equivalence test were performed to compare the three successive methods of collection. 300 nonexpectorating children with CF were included. P. aeruginosa was detected cumulatively in 56 (18.9%) children, and according to the different collection methods in 28 (9.8%), 37 (12.4%) and 44 (14.7%) children by using OP, CP-OP and CP-SP, respectively. Compared with OP, the increased detection rate was +22% for CP-OP (p=0.029) and +57% for CP-SP (p=0.003). CP-SP had the best positive predictive value (86.3%) and negative predictive value (96.0%) for P. aeruginosa compared with the overall detection. The results of this adequately powered study show differences in the rates of pathogens detected according to the sampling method used. Chest physiotherapy enhanced detection of P. aeruginosa in nonexpectorating children with CF.

The economic burden of severe asthma in children: a comprehensive study.

OBJECTIVE: The economic burden of severe asthma (SA) in children is poorly described. We aimed to determine the healthcare costs of SA in children for the French national health insurance (NHI). METHODS: Children (6-18 years of age) with physician-confirmed diagnoses of SA or non-SA (NSA) were identified. Direct and indirect expenditures related to asthma and associated co-morbidities in the previous six months were determined, based on a physician-guided parental questionnaire and confirmed by medical records. The costs for the French NHI were assessed per child over a six month period. RESULTS: Data from 74 children, including 48 with SA (22 requiring omalizumab) and 26 with NSA, were analyzed. The global cost of SA was €3,982 per child over a six-month period, including €3,821 direct costs and €161.9 indirect costs. The global cost was €6,716 (4,220) for those requiring omalizumab vs. €1,669 (3,108) for those who did not (p < 0.01). For children with SA, 65% of direct costs were attributed to medication. Among those on omalizumab, such treatment accounted for 93% of medication costs. The global cost was 10 times higher for children with SA than those with NSA (€3,982 (4,422) vs. €363.2 (352.6), p < 0.01), and 20 times higher for children with SA on omalizumab than those with NSA (p < 0.01). CONCLUSION: The economic burden of SA in children for the French NHI is substantial and mainly driven by the most severe children requiring biologics.

Geleophysic and acromicric dysplasias: natural history, genotype-phenotype correlations, and management guidelines from 38 cases.

PURPOSE: Geleophysic dysplasia (GD) and acromicric dysplasia (AD) are characterized by short stature, short extremities, and progressive joint limitation. In GD, cardiorespiratory involvement can result in poor prognosis. Dominant variants in the FBN1 and LTBP3 genes are responsible for AD or GD, whereas recessive variants in the ADAMTSL2 gene are responsible for GD only. The aim of this study was to define the natural history of these disorders and to establish genotype-phenotype correlations. METHODS: This monocentric retrospective study was conducted between January 2008 and December 2018 in a pediatric tertiary care center and included patients with AD or GD with identified variants (FBN1, LTBP3, or ADAMTSL2). RESULTS: Twenty-two patients with GD (12 ADAMTSL2, 8 FBN1, 2 LTBP3) and 16 patients with AD (15 FBN1, 1 LTBP3) were included. Early death occurred in eight GD and one AD. Among GD patients, 68% presented with heart valve disease and 25% developed upper airway obstruction. No AD patient developed life-threatening cardiorespiratory issues. A greater proportion of patients with either a FBN1 cysteine variant or ADAMTSL2 variants had a poor outcome. CONCLUSION: GD and AD are progressive multisystemic disorders with life-threatening complications associated with specific genotype. A careful multidisciplinary follow-up is needed.

Mycobacterium bolletii Lung Disease in Cystic Fibrosis.

BACKGROUND: The cystic fibrosis (CF) pathogen, Mycobacterium abscessus complex, covers three subspecies: M. abscessus, M. massiliense, and M. bolletii. There are no clinical outcome data concerning M. bolletii. Our aim was to characterize M. bolletii lung infections in patients with CF. METHODS: We included patients with M. bolletii lung infection recorded between 1994 and 2012 in France. Data were collected from the CF registry, medical records, and questionnaires submitted to the CF primary physician. Strains were typed by multilocus sequence typing analysis. RESULTS: Fifteen cases were identified in nine CF centers. Nine patients (60%) presented with nontuberculous mycobacterial pulmonary disease. Follow-up of 13 patients showed a trend to more rapid decline in FEV1 in the first year of colonization (-9.4%; SD 19.3) in comparison with noninfected control subjects (-2.3%; SD 12.1) (P = .16). Twelve patients were treated, and 11 received oral macrolides. Treatment-induced eradication occurred in five patients (41.7%). Four patients died (26.7%), including one patient with fatal nontuberculous mycobacterial pulmonary disease. Inducible macrolide resistance was demonstrated in all strains. Patients always harbored unique strains. CONCLUSIONS: Our study reports the largest study cohort of CF patients infected with M. bolletii. M. bolletii infection affects both children and young adults, is most often symptomatic, and may be fatal. Macrolide-based therapies have poor effectiveness. There is no evidence of patient-to-patient transmission.

Predictive factors for lumacaftor/ivacaftor clinical response.

BACKGROUND: Ivacaftor-lumacaftor combination therapy corrects the F508 del-CFTR mutated protein which causes Cystic Fibrosis. The clinical response of the patients treated with the combination therapy is highly variable. This study aimed to determine factors involved in the individual's response to lumacaftor-ivacaftor therapy. METHODS: Sweat test was assessed at baseline and after 6 months of ivacaftor-lumacaftor treatment in 41 homozygous F508del children and young adults. ß-adrenergic peak sweat secretion, nasal potential difference (NPD) and intestinal current measurements (ICM) were performed in patients accepting these tests. Seric level of lumacaftor and ivacaftor were determined and additional CFTR variant were searched. RESULTS: Sweat chloride concentration significantly decreased after treatment, whereas the ß-adrenergic peak sweat response did not vary in 9 patients who underwent these tests. The average level of F508del-CFTR activity rescue reached up to 15% of the normal level in intestinal epithelium, as studied by ICM in 12 patients (p = .03) and 20% of normal in the nasal epithelium in NPD tests performed in 21 patients (NS). There was no significant correlation between these changes and improvements in FEV1 at 6 months. Serum drug levels did not correlate with changes in FEV1, BMI-Zscore or other CFTR activity biomarkers. Additional exonic variants were identified in 4 patients. The F87L-I1027T-F508del-CFTR complex allele abolished the lumacaftor corrector effect. CONCLUSION: This observational study investigates a number of potential factors linked to the clinical response of F508del homozygous patients treated with lumacaftor-ivacaftor combination therapy. Lumacaftor and ivacaftor blood levels are not associated with the clinical response. Additional exonic variants may influence protein correction.

Early follow-up of lung disease in infants with cystic fibrosis using the raised volume rapid thoracic compression technique and computed tomography during quiet breathing.

BACKGROUND: Among the different techniques used to monitor lung disease progression in infants with CF diagnosed by Newborn screening (NBS), raised volume-rapid thoracic compression (RVRTC) remains a promising tool. However, the need of sedation and positive pressure ventilation considerably limits its clinical use. We recently described a semi-quantitative method to evaluate air trapping by chest tomography during quite breathing without sedation (CTqb score). This parameter is the radiological sign of airway obstruction and could be also used for lung disease follow-up in infants with CF. However, its discriminative power compared with RVRTC and correlation with lung function parameters are not known. OBJECTIVES: To compare the discriminative powers of the CTqb score and RVRTC parameters and to determine their correlation during the first year of life of infants with CF. METHODS: In this multicenter longitudinal study, infants with CF diagnosed by NBS underwent RVRTC and CT during quite breathing at 10 ± 4 weeks (n = 30) and then at 13 ± 1 months of age (n = 28). RESULTS: All RVRTC parameters and the CTqb score remained stable between evaluations. The CTqb score showed a higher discriminative power than forced expiratory volume in 0.5 s (FEV0.5 ; the main RVRTC parameter) at both visits (66% and 50% of abnormal values vs 30% and 28%, respectively). No correlation was found between CTqb score and, the different RVRTC parameters or the plethysmographic functional residual capacity, indicating that they evaluate different aspect of CF lung disease.

Changes of CFTR functional measurements and clinical improvements in cystic fibrosis patients with non p.Gly551Asp gating mutations treated with ivacaftor.

Ivacaftor, a CFTR potentiator, has been found to improve CFTR function and clinical outcomes in patients with cystic fibrosis (CF) gating mutations. We investigated the effects of ivacaftor on CFTR functional measurement in CF patients carrying gating mutations other than p.Gly551Asp. Two siblings aged 13 and 12 carrying the p.Ser549Asn mutation, two sisters (45 and 43years old) compound heterozygotes for p.Asp1152His and p.Gly1244Glu, a 37year old man homozygous for the p.Gly1244Glu mutation, and a 7year old girl with p.Arg352Gln and p.Gly1244Glu mutations commenced treatment with ivacaftor. NPD was performed in all the patients and approached normal for four patients who had also clinical improvement (p.Ser549Asn compound heterozygotes, and p.Asp1152His/p.Gly1244Glu siblings). Beta-adrenergic sweat chloride secretion performed in thep.Asp1152His/p.Gly1244Glu patients improved significantly. The p.Gly1244Glu mutation homozygous patient, who had undergone an ileal resection with ileostomy and enterocutaneous fistula, did not respond clinically to ivacaftor and did not modify his sweat test. These results highlight the importance of different CFTR activity measurements to explore CFTR modulator efficacy.

A simplified, semi-quantitative structural lung disease computed tomography outcome during quiet breathing in infants with cystic fibrosis.

Chest tomography (CT) using the controlled ventilation technique (CTCV) is a sensitive method to detect features of lung cystic fibrosis (CF) disease in infants with CF. However, this technique needs sedation and is not easily applied for the clinician who may need, in the follow-up, to evaluate more precisely lung disease in infants with CF. Thus, our study aims to evaluate if CT assessment of lung disease, without the need of sedation, during quiet breathing, using a semi-quantitative scoring system, is reproducible and may discriminate infants with CF from control infants at an early stage of the lung disease. 39 infants with CF underwent a first CT at 10.3 [9.4, 11.4] weeks of age. Among them, 33 underwent a second CT at 56.1 [53.1, 59.6] weeks of age. CF scoring images of the different scanner variables, i.e. bronchial wall thickening, bronchiectasis, mucus plugging and air trapping were compared to CT scoring obtained in 2 different groups of control infants of similar age without lung disease. Among all the constituents of the scoring, air trapping is the only parameter discriminating infants with CF from control infants at both ages in our study (p≤0.01). Moreover, air trapping explains 90% of the total score variability with r2=0.89 with a good concordance after re-scoring in blind, 6months apart, by the same operator for both infant populations: ICC=0.98 [0.97, 0.99]. In this study, we propose that CT during quiet breathing could be a useful clinical tool to evaluate the early presence of gas trapping in infants with CF.