Diffuse alveolar haemorrhage in children: an international multicentre study

Background

Paediatric diffuse alveolar haemorrhage (DAH) is a rare heterogeneous condition with limited knowledge on clinical presentation, treatment and outcome.

Methods

A retrospective, descriptive multicentre follow-up study initiated from the European network for translational research in children's and adult interstitial lung disease (Cost Action CA16125) and chILD-EU CRC (the European Research Collaboration for Children's Interstitial Lung Disease). Inclusion criteria were DAH of any cause diagnosed before the age of 18 years.

Results

Data of 124 patients from 26 centres (15 counties) were submitted, of whom 117 patients fulfilled the inclusion criteria. Diagnoses were idiopathic pulmonary haemosiderosis (n=35), DAH associated with autoimmune features (n=20), systemic and collagen disorders (n=18), immuno-allergic conditions (n=10), other childhood interstitial lung diseases (chILD) (n=5), autoinflammatory diseases (n=3), DAH secondary to other conditions (n=21) and nonspecified DAH (n=5). Median (IQR) age at onset was 5 (2.0-12.9) years. Most frequent clinical presentations were anaemia (87%), haemoptysis (42%), dyspnoea (35%) and cough (32%). Respiratory symptoms were absent in 23%. The most frequent medical treatment was systemic corticosteroids (93%), hydroxychloroquine (35%) and azathioprine (27%). Overall mortality was 13%. Long-term data demonstrated persistent abnormal radiology and a limited improvement in lung function.

Conclusions

Paediatric DAH is highly heterogeneous regarding underlying causes and clinical presentation. The high mortality rate and number of patients with ongoing treatment years after onset of disease underline that DAH is a severe and often chronic condition. This large international study paves the way for further prospective clinical trials that will in the long term allow evidence-based treatment and follow-up recommendations to be determined.

Long-term evolution of neuroendocrine cell hyperplasia of infancy: the FRENCHI findings

Only few studies report long-term evolution of patients with neuroendocrine cell hyperplasia of infancy (NEHI). We report data from a 54-patient cohort followed up in the French network for rare respiratory diseases (RespiRare). Demographic characteristics and respiratory and nutritional evolution were collected at the time of the patient's last scheduled visit. The mean duration of follow-up was 68 months (5 months to 18 years). Fifteen patients (27.8%) were considered clinically cured. During follow-up, hospitalizations for wheezy exacerbations were reported in 35 patients (55%), and asthma diagnosed in 20 (37%). Chest CT scan improvement was noted in 25/44 (56.8%). Spirometry showed a persistent obstructive syndrome in 8/27 (29.6%). A sleep disorder was rare (2/36, 5.5%). Oxygen weaning occurred in 28 of the 45 patients initially treated (62.2%) and was age-dependent (35.7% under 2 years, 70.5% between 2 and 6 years, and 100% after 7 years). Oxygen duration was linked to a biopsy-proven diagnosis (p = 0.02) and to the use of a nutritional support (p = 0.003). Corticosteroids were largely prescribed at diagnosis, with no evident respiratory or nutritional effect during follow-up. Among 23 patients with an initial failure to thrive, 12 (52.2%) had no weight recovery. Initial enteral feeding (17/54, 31.5%) was stopped at a mean age of 43 months (3 to 120), with no effect on cure and oxygen liberation at the last visit.  Conclusion: Our results show that NEHI has a globally positive, but unequal, improvement over time. Further prospective studies are needed to better clarify the different trajectories of patients with NEHI. What is Known: • Neuroendocrine cell hyperplasia of infancy (NEHI) is an interstitial lung disease whose long-term outcome is considered positive from very few studies including heterogeneous populations. What is New: • The 68-month follow-up of our 54-patient cohort showed respiratory/nutritional symptom persistence in 72.2%, oxygen requiring in 34%, and asthma in 37%. When controlled, radiological or functional improvement was noted in 56.8 and 40.7%. Further prospective studies are needed to better clarify the different trajectories of patients with NEHI.

Gas puff imaging on the TCV tokamak

We present the design and operation of a suite of Gas Puff Imaging (GPI) diagnostic systems installed on the Tokamak à Configuration Variable (TCV) for the study of turbulence in the plasma edge and Scrape-Off-Layer (SOL). These systems provide the unique ability to simultaneously collect poloidal 2D images of plasma dynamics at the outboard midplane, around the X-point, in both the High-Field Side (HFS) and Low-Field Side (LFS) SOL, and in the divertor region. We describe and characterize an innovative control system for deuterium and helium gas injection, which is becoming the default standard for the other gas injections at TCV. Extensive pre-design studies and the different detection systems are presented, including an array of avalanche photodiodes and a high-speed CMOS camera. First results with spatial and time resolutions of up to ≈2 mm and 0.5 µs, respectively, are described, and future upgrades of the GPI diagnostics for TCV are discussed.

French national cohort of neuroendocrine cell hyperplasia of infancy (FRENCHI) study: diagnosis and initial management

Early diagnosis of neuroendocrine cell hyperplasia of infancy (NEHI) is crucial as, conversely to the other causes of intersititial lung disease, corticosteroids are not recommended. Diagnosis is historically based on lung biopsy (NEHI), but in current practice, a clinical and radiological approach is more and more preferred (NEHI syndrome). This national study aimed to address diagnosis and initial management of patients followed up for a NEHI pattern in pediatric centers for rare lung diseases (RespiRare, France). Data on neonatal and familial events, symptoms at diagnosis, explorations performed and results, and therapeutic management were collected by questionnaire. Fifty-four children were included (boys 63%). The mean onset of symptoms was 3.8 ± 2.6 months. The most frequent symptoms at diagnosis were tachypnea (100%), retraction (79.6%), crackles (66.7%), and hypoxemia (59.3%). The mean NEHI clinical score, evocative when ≥ 7/10, was 7.9 ± 1.4 (76% with a score ≥ 7). All chest CT-scans showed ground glass opacities evolving at least the middle lobe and the lingula. Lung biopsy was performed in 38.9% of the cases and was typical of NEHI in only 52.4%, even when the clinical presentation was typical. Initial treatments were oxygen (83.6%) and more curiously intravenous pulses of steroids (83.3%) and azithromycin (70.2%).

CONCLUSION

This national cohort of patients underlines diagnosis difficulties of NEHI. A composite clinical and radiological score should help clinicians for limiting the use of anti-inflammatory drugs.

WHAT IS KNOWN

•Neuroendocrine cell hyperplasia of infancy (NEHI) is an interstitial lung disease whose diagnosis is essential to limit corticosteroids therapy.

WHAT IS NEW

•In this national cohort of 54 patients with a NEHI pattern, diagnosis is mainly based on clinical symptoms and chest CT-scan results. The newly proposed clinical score and, when performed, the lung biopsies are faulted in 25 and 50% of the cases, respectively. •Corticosteroids are widely used. Such results plead for a new composite score to formally diagnose NEHI.

Genotype-Phenotype Relationships in Inheritable Idiopathic Pulmonary Fibrosis: A Greek National Cohort Study

BACKGROUND

Monogenic and polygenic inheritances are evidenced for idiopathic pulmonary fibrosis (IPF). Pathogenic variations in surfactant protein-related genes, telomere-related genes (TRGs), and a single-nucleotide polymorphism in the promoter of MUC5B gene encoding mucin 5B (rs35705950 T risk allele) are reported. This French-Greek collaborative study, Gen-Phen-Re-GreekS in inheritable IPF (iIPF), aimed to investigate genetic components and patients' characteristics in the Greek national IPF cohort with suspected heritability.

PATIENTS AND METHODS

150 patients with familial PF, personal-family extrapulmonary disease suggesting short telomere syndrome, and/or young age IPF were analyzed.

RESULTS

MUC5B rs35705950 T risk allele was detected in 103 patients (90 heterozygous, 13 homozygous, allelic frequency of 39%), monoallelic TRG pathogenic variations in 19 patients (8 TERT, 5 TERC, 2 RTEL1, 2 PARN, 1 NOP10, and 1 NHP2), and biallelic ABCA3 pathogenic variations in 3. Overlapping MUC5B rs35705950 T risk allele and TRG pathogenic variations were shown in 11 patients (5 TERT, 3 TERC, 1 PARN, 1 NOP10, and 1 NHP2), MUC5B rs35705950 T risk allele, and biallelic ABCA3 pathogenic variations in 2. In 38 patients, neither MUC5B rs35705950 T risk allele nor TRG pathogenic variations were detectable. Kaplan-Meier curves showed differences in time-to-death (p = 0.025) where patients with MUC5B rs35705950 T risk allele alone or in combination with TRG pathogenic variations presented better prognosis.

CONCLUSION

The Gen-Phen-Re-GreekS in iIPF identified multiple and overlapping genetic components including the rarest, underlying disease's genetic "richesse," complexity and heterogeneity. Time-to-death differences may relate to diverse IPF pathogenetic mechanisms implicating "personalized" medical care driven by genotypes in the near future.

RaDiCo, the French national research program on rare disease cohorts

BACKGROUND

Rare diseases (RDs) affect nearly 3 million people in France and at least 26-30 million people in Europe. These diseases, which represent a major medical concern, are mainly of genetic origin, often chronic, progressive, degenerative, life threatening and disabling, accounting for more than one third of all deaths occurring during infancy. In this context, there are needs for coordinated information on RDs at national/international levels, based on high quality, interoperable and sharable data. The main objective of the RaDiCo (Rare Disease Cohorts) program, coordinated by Inserm, was the development of RD e-cohorts via a national platform. The cohort projects were selected through a national call in 2014. The e-cohorts are supported by an interoperable platform, equivalent to an infrastructure, constructed on the "cloud computing" principle and in compliance with the European General Data Protection Regulation. It is dedicated to allow a continuous monitoring of data quality and consistency, in line with the French Health Data Hub.

RESULTS

Depending on cohorts, the objectives are to describe the natural history of the studied RD(s), identify the underlying disease genes, establish phenotype-genotype correlations, decipher their pathophysiology, assess their societal and medico-economic impact, and/or identify patients eligible for new therapeutic approaches. Inclusion of prevalent and incident cases started at the end of 2016. As of April 2021, 5558 patients have been included within 13 RD e-cohorts covering 67 diseases integrated in 10 European Reference Networks and contributing to the European Joint Program on RDs. Several original results have been obtained in relation with the secondary objectives of the RaDiCo cohorts. They deal with discovery of new disease genes, assessment of treatment management, deciphering the underlying pathophysiological mechanisms, diagnostic approaches, genotype-phenotype relationships, development and validation of questionnaires relative to disease burden, or methodological aspects.

CONCLUSION

RaDiCo currently hosts 13 RD e-cohorts on a sharable and interoperable platform constructed on the "cloud computing" principle. New RD e-cohorts at the European and international levels are targeted.

Exposure to inorganic particles in paediatric sarcoidosis: the PEDIASARC study

Inorganic antigens may contribute to paediatric sarcoidosis. Thirty-six patients matched with 36 healthy controls as well as a group of 21 sickle-cell disease (SCD) controls answered an environmental questionnaire. Patients' indirect exposure to inorganic particles, through coresidents' occupations, was higher than in healthy and SCD controls (median score: 2.5 (0.5-7) vs 0.5 (0-2), p=0.003 and 1 (0-2), p=0.012, respectively), especially for construction, exposures to metal dust, talc, abrasive reagents and scouring products. Wood or fossil energies heating were also linked to paediatric sarcoidosis. This study supports a link between mineral environmental exposure due to adult coresident occupations and paediatric sarcoidosis.

Impact of Gender on the Characteristics of Patients with Idiopathic Pulmonary Fibrosis Included in the RaDiCo-ILD Cohort

BACKGROUND

There is growing evidence of gender-specific phenotypic differences among patients with idiopathic pulmonary fibrosis (IPF), which may affect patient outcomes.

OBJECTIVES

We present the characteristics of patients with IPF at inclusion in the French Rare Disease Cohort - Interstitial Lung Disease (RaDiCo-ILD) with the aim of characterizing gender-specific phenotypic differences.

METHODS

Patients with IPF who were enrolled in the national, multicentre RaDiCo-ILD cohort were included. Demographic characteristics, comorbidities, health-related quality of life (HRQoL) scores, pulmonary function, chest imaging, and IPF treatment were collected at inclusion and described by gender.

RESULTS

The cohort included 724 patients with IPF (54% of RaDiCo-ILD cohort), of whom 82.9% were male. The proportion of male and female patients with a prior history of smoking was 75.0% and 26.8%, respectively. Emphysema was present in 17.0% (95% confidence interval [CI]: 10.0, 24.0) of men and 5.4% (95% CI: 1.2, 9.6) of women. At inclusion, females had poorer HRQoL than males based on St. George's Respiratory Questionnaire scores (48.5 [95% CI: 43.9, 53.0] and 41.5 [39.4, 43.6], respectively). The mean forced vital capacity per cent predicted was 77.7% (95% CI: 76.2, 79.3) and 87.4% (83.4, 91.4) for males and females, respectively. Honeycombing on high-resolution computed tomography (HRCT) was present in 70.8% (95% CI: 61.0, 80.6) of males and 45.8% (95% CI: 35.1, 56.5) of females.

CONCLUSIONS

This analysis of patients with IPF at inclusion in the RaDiCo-ILD cohort provides evidence that comorbid emphysema, lung volume reduction, and honeycombing on HRCT are more common characteristics of males than females.

Study design of a randomised, placebo-controlled trial of nintedanib in children and adolescents with fibrosing interstitial lung disease

Childhood interstitial lung disease (chILD) comprises >200 rare respiratory disorders, with no currently approved therapies and variable prognosis. Nintedanib reduces the rate of forced vital capacity (FVC) decline in adults with progressive fibrosing interstitial lung diseases (ILDs). We present the design of a multicentre, prospective, double-blind, randomised, placebo-controlled clinical trial of nintedanib in patients with fibrosing chILD (1199-0337 or InPedILD; ClinicalTrials.gov: NCT04093024).

Male or female children and adolescents aged 6–17 years (≥30; including ≥20 adolescents aged 12–17 years) with clinically significant fibrosing ILD will be randomised 2:1 to receive oral nintedanib or placebo on top of standard of care for 24 weeks (double-blind), followed by variable-duration nintedanib (open-label). Nintedanib dosing will be based on body weight-dependent allometric scaling, with single-step dose reductions permitted to manage adverse events. Eligible patients will have evidence of fibrosis on high-resolution computed tomography (within 12 months of their first screening visit), FVC ≥25% predicted, and clinically significant disease (Fan score of ≥3 or evidence of clinical progression over time). Patients with underlying chronic liver disease, significant pulmonary arterial hypertension, cardiovascular disease, or increased bleeding risk are ineligible. The primary endpoints are pharmacokinetics and the proportion of patients with treatment-emergent adverse events at week 24. Secondary endpoints include change in FVC% predicted from baseline, Pediatric Quality of Life Questionnaire, oxygen saturation, and 6-min walk distance at weeks 24 and 52. Additional efficacy and safety endpoints will be collected to explore long-term effects.

We describe the design of #InPedILD, a study of 24 weeks’ nintedanib or placebo on top of standard of care, followed by variable-duration open-label nintedanib in children with interstitial lung disease (ClinicalTrials.gov NCT04093024) #PedILDhttps://bit.ly/3tC1a7P

Functional assessment and phenotypic heterogeneity of SFTPA1 and SFTPA2 mutations in interstitial lung diseases and lung cancer

INTRODUCTION

Interstitial lung diseases (ILDs) can be caused by mutations in the SFTPA1 and SFTPA2 genes, which encode the surfactant protein (SP) complex SP-A. Only 11 SFTPA1 or SFTPA2 mutations have so far been reported worldwide, of which five have been functionally assessed. In the framework of ILD molecular diagnosis, we identified 14 independent patients with pathogenic SFTPA1 or SFTPA2 mutations. The present study aimed to functionally assess the 11 different mutations identified and to accurately describe the disease phenotype of the patients and their affected relatives.

METHODS

The consequences of the 11 SFTPA1 or SFTPA2 mutations were analysed both in vitro, by studying the production and secretion of the corresponding mutated proteins and ex vivo, by analysing SP-A expression in lung tissue samples. The associated disease phenotypes were documented.

RESULTS

For the 11 identified mutations, protein production was preserved but secretion was abolished. The expression pattern of lung SP-A available in six patients was altered and the family history reported ILD and/or lung adenocarcinoma in 13 out of 14 families (93%). Among the 28 SFTPA1 or SFTPA2 mutation carriers, the mean age at ILD onset was 45 years (range 0.6-65 years) and 48% underwent lung transplantation (mean age 51 years). Seven carriers were asymptomatic.

DISCUSSION

This study, which expands the molecular and clinical spectrum of SP-A disorders, shows that pathogenic SFTPA1 or SFTPA2 mutations share similar consequences for SP-A secretion in cell models and in lung tissue immunostaining, whereas they are associated with a highly variable phenotypic expression of disease, ranging from severe forms requiring lung transplantation to incomplete penetrance.

Interstitial lung diseases in children

Interstitial lung disease (ILD) in children (chILD) is a heterogeneous group of rare respiratory disorders that are mostly chronic and associated with high morbidity and mortality. The pathogenesis of the various chILD is complex and the diseases share common features of inflammatory and fibrotic changes of the lung parenchyma that impair gas exchanges. The etiologies of chILD are numerous. In this review, we chose to classify them as ILD related to exposure/environment insults, ILD related to systemic and immunological diseases, ILD related to primary lung parenchyma dysfunctions and ILD specific to infancy. A growing part of the etiologic spectrum of chILD is being attributed to molecular defects. Currently, the main genetic mutations associated with chILD are identified in the surfactant genes SFTPA1, SFTPA2, SFTPB, SFTPC, ABCA3 and NKX2-1. Other genetic contributors include mutations in MARS, CSF2RA and CSF2RB in pulmonary alveolar proteinosis, and mutations in TMEM173 and COPA in specific auto-inflammatory forms of chILD. However, only few genotype-phenotype correlations could be identified so far. Herein, information is provided about the clinical presentation and the diagnosis approach of chILD. Despite improvements in patient management, the therapeutic strategies are still relying mostly on corticosteroids although specific therapies are emerging. Larger longitudinal cohorts of patients are being gathered through ongoing international collaborations to improve disease knowledge and targeted therapies. Thus, it is expected that children with ILD will be able to reach the adulthood transition in a better condition.

Efficacy and tolerability on melasma of a topical cosmetic product acting on melanocytes, fibroblasts and endothelial cells: a randomized comparative trial against 4% hydroquinone

Background

Recent data demonstrated that an altered basal membrane, activated melanocytes and secreted factors from keratinocytes but also fibroblasts and endothelial cells are involved in the pathophysiology of melasma.

Objectives

To evaluate the efficacy and tolerability on melasma of a new topical skin‐lightening cosmetic product combination (CCP) targeting several factors identified to be involved in melasma pathogenesis compared to 4% hydroquinone (HQ).

Methods

Forty‐three women with melasma were enrolled in a 12‐week double‐blind, randomized, parallel‐group trial and treated with CCP or 4% HQ cream. Efficacy was evaluated with the modified Melasma Area Severity Index (mMASI) score and colorimetric change. Cutaneous tolerability and patient satisfaction were also investigated.

Results

The mMASI score decreased for both products from baseline and over the study period. At week 12, 90% of the subjects who received the combination products had an improvement in pigmentation vs. 79% with HQ. Similarly, both products significantly increased Individual Typological Angle parameters. For both measures, no statistically significant difference was observed between CCP and HQ in terms of change from baseline. CPP was very well tolerated.

Conclusions

Cosmetic product combination is as effective as HQ in the management of facial dyspigmentation and represents a safe alternative.

P186 In search of lost time

Arrhythmogenic right ventricular dysplasia (ARVD) is one of the most difficult to diagnose and manage of the cardiomyopathies. Physical exercise can be a contributing factor and may accelerate the progression of the disease.

We present the case of a 49-year-old, a former professional football player, with a history of cardiac arrest in 2011 by ventricular tachycardia (VT) (normal coronary arteries). Between 2011 and 2019 the patient didn"t present for reevaluation and resumed endurance sports activity in spite of doctor recommendation. In 2019 he was directed to our clinic for a syncope followed by constrictive anterior chest pain and palpitations, the clinical expression of a VT with LBBB morphology and inferior axis, most likely originated in the RVOT, for which cardioversion was required. Upon admission, the patient was hemodynamically and respiratory stable, at sinus rhythm 60/min with left anterior hemiblock and negative T waves in V1-V2. Biologically, myocardial and hepatic cytolysis enzymes were within normal limits, with mild hypokalemia. Echocardiography showed significant dilatation of RV and RVOT with RV dysfunction (TAPSE 16 mm, FAC 20%, s" 8.6 cm/s). LV was nondilated, with normal systolic function and kinetic, but with trabeculation of the apex. To confirm the diagnosis of ARVD, cardiac MRI was performed and confirmed fat infiltration in the RV free wall with biventricular involvement. Given the high arrhythmic risk (two resuscitated VT episodes, syncope), a two-chamber ICD was implanted, without immediate post-procedural complications.

In the second postprocedural day, the patient suddenly installed important epigastric pain with thoracic irradiation. The ECG showed sensing and pacing malfunction and radioscopy showed evidence of ventricular probe displacement. The echocardiography confirmed the myocardial perforation. Emergency surgery by median thoracotomy was performed, with successful extraction of the electrode and myocardial suture. Postoperative progression was favorable under treatment with beta-blocker and amiodarone. A subcutaneous ICD will be implanted as soon as available.

In conclusion, this case is a very particular one. First of all, we’ve documented two distinct phases in the evolution of the ARVD (electrical phase – 2011 and structural phase - 2019). Moreover, by resuming endurance sports activity and in concordance with the literature data, we can only assume that the progression of the disease was accelerated and the arrhythmic risk was greater. Complications related to probe stability are common in this population, but myocardial perforation is a very rare and dangerous one. The therapeutic management of patients with ARVD has evolved over the years and continues to be an important challenge. To further improve risk stratification and treatment of patients, more information is needed on the natural history, long-term prognosis, and risk assessment.

Abstract P186 Figure. Echocardiografic and MRI aspect

Use of ruxolitinib in COPA syndrome manifesting as life-threatening alveolar haemorrhage

COPA (coatomer subunit α) syndrome is a newly recognised cause of interstitial lung disease in children and adults, frequently associated with arthritis and renal dysfunction. We report a 11-year-old girl with disease limited to major pulmonary haemosiderosis manifesting at the age of 2 years, due to a heterozygous p.(Arg233His) mutation in COPA Her interferon (IFN) signature was elevated (10.312 and 12.429, healthy <2.466), as was the level of serum IFNα (211 fg/mL, healthy <10 fg/mL). STAT1 phosphorylation in T lymphocytes and monocytes was increased as compared with healthy controls. Based on these results she was treated with the JAK1/2 inhibitor ruxolitinib, which resulted in reduction in IFN signalling and appeared to be associated with partial though incomplete decrease in the severity of her pulmonary disease. Patients with alveolar haemorrhage of unknown origin should be considered for COPA screening. Functional tests can help to personalise patient therapy.

Pilot experience of multidisciplinary team discussion dedicated to inherited pulmonary fibrosis

Background

Genetic testing is proposed for suspected cases of monogenic pulmonary fibrosis, but clinicians and patients need specific information and recommendation about the related diagnosis and management issues. Because multidisciplinary discussion (MDD) has been shown to improve accuracy of interstitial lung disease (ILD) diagnosis, we evaluated the feasibility of a genetic MDD (geneMDD) dedicated to the indication for and interpretation of genetic testing. The geneMDD group met monthly and included pediatric and adult lung specialists with ILD expertise, molecular and clinical geneticists, and one radiologist. Hematologists, rheumatologists, dermatologists, hepatologists, and pathologists were also invited to attend.

Results

Since 2016, physicians from 34 different centers in 7 countries have participated in the geneMDD. The medical files of 95 patients (53 males) have been discussed. The median age of patients was 43 years [range 0–77], 10 were ≤ 15 years old, and 6 were deceased at the time of the discussion. Among 85 analyses available, the geneMDD considered the rare gene variants pathogenic for 61: 37 variants in telomere-related genes, 23 variants in surfactant-related genes and 1 variant in MARS. Genetic counseling was offered for relatives of these patients. The geneMDD therapeutic proposals were as follows: antifibrotic drugs (n = 25), steroids or immunomodulatory therapy (n = 18), organ transplantation (n = 21), watch and wait (n = 21), or best supportive care (n = 4).

Conclusion

Our experience shows that a dedicated geneMDD is feasible regardless of a patient’s age and provides a unique opportunity to adapt patient management and therapy in this very rare condition.

Deep phenotyping, including quantitative ciliary beating parameters, and extensive genotyping in primary ciliary dyskinesia

Background

Primary ciliary dyskinesia (PCD) is a rare genetic disorder resulting in abnormal ciliary motility/structure, extremely heterogeneous at genetic and ultrastructural levels. We aimed, in light of extensive genotyping, to identify specific and quantitative ciliary beating anomalies, according to the ultrastructural phenotype.

Methods

We prospectively included 75 patients with PCD exhibiting the main five ultrastructural phenotypes (n=15/group), screened all corresponding PCD genes and measured quantitative beating parameters by high-speed video-microscopy (HSV).

Results

Sixty-eight (91%) patients carried biallelic mutations. Combined outer/inner dynein arms (ODA/IDA) defect induces total ciliary immotility, regardless of the gene involved. ODA defect induces a residual beating with dramatically low ciliary beat frequency (CBF) related to increased recovery stroke and pause durations, especially in case of DNAI1 mutations. IDA defect with microtubular disorganisation induces a low percentage of beating cilia with decreased beating angle and, in case of CCDC39 mutations, a relatively conserved mean CBF with a high maximal CBF. Central complex defect induces nearly normal beating parameters, regardless of the gene involved, and a gyrating motion in a minority of ciliated edges, especially in case of RSPH1 mutations. PCD with normal ultrastructure exhibits heterogeneous HSV values, but mostly an increased CBF with an extremely high maximal CBF.

Conclusion

Quantitative HSV analysis in PCD objectives beating anomalies associated with specific ciliary ultrastructures and genotypes. It represents a promising approach to guide the molecular analyses towards the best candidate gene(s) to be analysed or to assess the pathogenicity of the numerous sequence variants identified by next-generation-sequencing.

One-year outcomes in a multicentre cohort study of incident rare diffuse parenchymal lung disease in children (ChILD)

We performed a prospective, observational, cohort study of children newly diagnosed with children's interstitial lung disease (ChILD), with structured follow-up at 4, 8, 12 weeks and 6 and 12 months. 127 children, median age 0.9 (IQR 0.3-7.9) years had dyspnoea (68%, 69/102), tachypnoea (75%, 77/103) and low oxygen saturation (SpO₂) median 92% (IQR 88-96). Death (n=20, 16%) was the most common in those <6 months of age with SpO₂<94% and developmental/surfactant disorders. We report for the first time that ChILD survivors improved multiple clinical parameters within 8-12 weeks of diagnosis. These data can inform family discussions and support clinical trial measurements.

Bi-allelic missense ABCA3 mutations in a patient with childhood ILD who reached adulthood

The adenosine triphosphate (ATP)-binding cassette subfamily A member 3 (ABCA3) is a transmembrane glycoprotein that uses energy of ATP hydrolysis to transport phospholipids into the lamellar bodies of type 2 alveolar epithelial cells (AEC) and regulates lung surfactant homeostasis. More than 200 mutations have already been described in ABCA3, located on chromosome 16 [1, 2]. Patients present with a great heterogeneity of phenotypes, from lethal neonatal respiratory distress syndrome (RDS) to childhood and rarely adult interstitial lung disease (ILD) [3, 4]. ABCA3 mutations-related lung disease inheritance is autosomal recessive, as it requires two disease-causing (bi-allelic) mutations, one from each parent.

Children with ABCA3 mutations may survive beyond infancy and reach adulthood. Genetic mechanisms should always be examined in adult patients with childhood onset ILD and molecular analysis should be performed accordingly in specialised referral centres.http://bit.ly/2LzMNOE

Health-related quality of life in infants and children with interstitial lung disease

INTRODUCTION

Interstitial lung disease in children (chILD) is a highly heterogeneous group of rare and severe respiratory disorders. The disease by itself, the burden of the treatments (oxygen therapy, corticosteroid pulses, nutritional support) and recurrent hospitalizations may impair the quality of life (QoL) of these children. The aim of the study was to compare the health-related QoL (HR-QoL) in chILD compared to a healthy population and to find out the predictive factors of an altered QoL.

METHODS

Patients aged 1 month to 18 years with ILD of known or unknown etiology were prospectively included. Parents and children over 8 years old were asked to fill the PedsQL 4.0 Generic Core Scale ranging from 0 to 100 points.

RESULTS

A total of 78 children were recruited in 13 French pediatric centers. Total scores were 11.94 points (P = 0.0003) less for child self-report and 14.08 points ( P < 0.0001) less for parent proxy-report with respect to the healthy population. The clinical factors associated with a lower total score were: extrapulmonary expression of the disease, higher Fan severity score, long-term oxygen therapy, nutritional support, and a number of oral treatments.

CONCLUSION

Using a validated quality of life (QoL) scale, we showed that health-related-QoL is significantly impaired in chILD compared with a healthy population. Factors altering QoL score are easy to recognize and could help identify children at a heightened risk of low QoL.

Cystic Fibrosis Liver Disease: Outcomes and Risk Factors in a Large Cohort of French Patients

Cystic fibrosis (CF)-related liver disease (CFLD) is a common symptom in patients with CF. However, its prevalence, risk factors, and evolution are unclear. We analyzed a large database of patients with CF to investigate the incidence of CFLD, its related risk factors, and the use and effect of ursodeoxycholic acid (UDCA) treatment. We retrospectively analyzed 3,328 CF patients with pancreatic insufficiency born after 1985 and recruited into the French CF Modifier Gene Study since 2004. We determined liver status, age at CFLD and severe CFLD onset, sex, CFTR genotype, history of meconium ileus, treatment with UDCA, and respiratory and nutritional status. The incidence of CFLD increased by approximately 1% every year, reaching 32.2% by age 25. The incidence of severe CFLD increased only after the age of 5, reaching 10% by age 30. Risk factors for CFLD and severe CFLD were male sex, CFTR F508del homozygosity, and history of meconium ileus. Increasingly precocious initiation of UDCA treatment did not change the incidence of severe CFLD. Finally, patients with severe CFLD had worse lung function and nutritional status than other CF patients. Conclusion: CFLD occurs not only during childhood but also later in the lifetime of patients with CF; male sex, CFTR F508del homozygosity, and history of meconium ileus are independent risk factors for CFLD development; earlier use of UDCA over the last 20 years has not changed the incidence of severe CFLD, leading to questions about the use of this treatment in young children given its possible adverse effects.

Paediatric sarcoidosis

Paediatric sarcoidosis is an extremely rare disease characterized by a granulomatous inflammation. The estimated incidence is 0.6-1.02/100,000 children, but in the absence of international registers, the disease is probably under-reported. Its pathophysiologic basis is not clearly understood but the current hypothesis is a combination of a genetic predisposition and an environmental exposure that could be either organic or mineral. Contrary to adult forms of the disease, general symptoms are often at the forefront at diagnosis. In its most frequent form, paediatric sarcoidosis is a multi-organ disorder affecting preferentially the lungs, the lymphatic system and the liver, but all organs can be affected. This review aims to provide an overview of current knowledge on sarcoidosis in children, providing a summary of the data available from cohort studies on the presentation, the management and the evolution of the disease in this specific population.

Chronic interstitial lung diseases in children: diagnosis approaches

Introduction: Children interstitial lung disease (chILD) is a heterogeneous group of rare respiratory disorders characterized by inflammatory and fibrotic changes of the lung parenchyma. They include ILD related to exposure/environment insults, ILD related to systemic diseases processes, ILD related to primary lung parenchyma dysfunctions and ILD specific to infancy. Areas covered: This review provides an update on chILD pathophysiology and diagnosis approaches in immunocompetent children. It includes current information on genetic causes. Expert commentary: ChILD covers a large spectrum of entities with heterogeneous disease expression. Various classifications have been reported, but none of them seems completely satisfactory. Recently, progress in molecular genetics has allowed identifying some genetic contributors, with, so far, a lack of correlations between gene disorders and disease expression. Despite improvements in patient management, chILD prognosis is still burdened by significant morbidity and mortality. Ongoing international collaborations will allow gathering larger longitudinal cohorts of patients to improve disease knowledge and personalized care. The overall goal is to help the children with ILD to reach the adulthood transition in a better condition, and to structure genetic counseling for their family.

Pulmonary hemosiderosis in children with Down syndrome: a national experience

BACKGROUND

Pulmonary hemosiderosis is a rare and complex disease in children. A previous study from the French RespiRare® network led to two important findings: 20% of the children presented with both pulmonary hemosiderosis and Down syndrome (DS), and at least one tested autoantibody was found positive in 50%. This study investigates the relationships between pulmonary hemosiderosis and DS.

METHODS

Patients younger than 20 years old and followed for pulmonary hemosiderosis were retrieved from the RespiRare® database. Clinical, biological, functional, and radiological findings were collected, and DS and non-DS patients' data were compared.

RESULTS

A total of 34 patients (22 girls and 12 boys) were included, among whom nine (26%) presented with DS. The mean age at diagnosis was 4.1 ± 3.27 years old for non-DS and 2.9 ± 3.45 years old for DS patients. DS patients tended to present a more severe form of the disease with an earlier onset, more dyspnoea at diagnosis, more frequent secondary pulmonary hypertension, and an increased risk of fatal evolution.

CONCLUSIONS

DS patients have a higher risk of developing pulmonary hemosiderosis, and the disease seems to be more severe in this population. This could be due to the combination of an abnormal lung capillary bed with fragile vessels, a higher susceptibility to autoimmune lesions, and a higher risk of evolution toward pulmonary hypertension. A better screening for pulmonary hemosiderosis and a better prevention of hypoxia in DS paediatric patients may prevent a severe evolution of the disease.

Stenotrophomonas maltophilia: A marker of lung disease severity

BACKGROUND

While the prevalence of Stenotrophomonas maltophilia lung infection in cystic fibrosis (CF) patients has increased in the last decades, its pathogenicity remains controversial. The aim of this study was to investigate the effects of S. maltophilia initial infection on the progression of lung disease in CF children.

METHODS

This case-control retrospective study took place in a pediatric CF center. A total of 23 cases defined by at least one sputum culture positive for S. maltophilia, were matched for age, sex, and CFTR mutations to 23 never infected CF controls. The clinical data were collected for 2 years before and after S. maltophilia initial infection and comprised lung function analyses, rates of exacerbations and of antibiotic courses.

RESULTS

Compared with controls, cases had lower lung function (P = 0.05), more frequent pulmonary exacerbations (P = 0.01), hospitalizations (P = 0.02), and intravenous antibiotic courses (P = 0.04) before S. maltophilia acquisition. In the year following S. maltophilia initial infection, lung function decline was similar in cases and controls but cases remained more severe, with more frequent pulmonary exacerbations (P = 0.01), hospitalizations (P = 0.02) and intravenous antibiotic courses (P = 0.02).

CONCLUSIONS

S. maltophilia seems to be a marker of CF lung disease severity and international recommendations to reduce lung infection by this pathogen should rapidly emerge.

Whole exome sequencing in three families segregating a pediatric case of sarcoidosis

BACKGROUND

Sarcoidosis (OMIM 181000) is a multi-systemic granulomatous disorder of unknown origin. Despite multiple genome-wide association (GWAS) studies, no major pathogenic pathways have been identified to date. To find out relevant sarcoidosis predisposing genes, we searched for de novo and recessive mutations in 3 young probands with sarcoidosis and their healthy parents using a whole-exome sequencing (WES) methodology.

METHODS

From the SARCFAM project based on a national network collecting familial cases of sarcoidosis, we selected three families (trios) in which a child, despite healthy parents, develop the disease before age 15 yr. Each trio was genotyped by WES (Illumina HiSEQ 2500) and we selected the gene variants segregating as 1) new mutations only occurring in affected children and 2) as recessive traits transmitted from each parents. The identified coding variants were compared between the three families. Allelic frequencies and in silico functional results were analyzed using ExAC, SIFT and Polyphenv2 databases. The clinical and genetic studies were registered by the ClinicalTrials.gov - Protocol Registration and Results System (PRS) ( https://clinicaltrials.gov ) receipt under the reference NCT02829853 and has been approved by the ethical committee (CPP LYON SUD EST - 2 - REF IRB 00009118 - September 21, 2016).

RESULTS

We identified 37 genes sharing coding variants occurring either as recessive mutations in at least 2 trios or de novo mutations in one of the three affected children. The genes were classified according to their potential roles in immunity related pathways: 9 to autophagy and intracellular trafficking, 6 to G-proteins regulation, 4 to T-cell activation, 4 to cell cycle and immune synapse, 2 to innate immunity. Ten of the 37 genes were studied in a bibliographic way to evaluate the functional link with sarcoidosis.

CONCLUSIONS

Whole exome analysis of case-parent trios is useful for the identification of genes predisposing to complex genetic diseases as sarcoidosis. Our data identified 37 genes that could be putatively linked to a pediatric form of sarcoidosis in three trios. Our in-depth focus on 10 of these 37 genes may suggest that the formation of the characteristic lesion in sarcoidosis, granuloma, results from combined deficits in autophagy and intracellular trafficking (ex: Sec16A, AP5B1 and RREB1), G-proteins regulation (ex: OBSCN, CTTND2 and DNAH11), T-cell activation (ex: IDO2, IGSF3), mitosis and/or immune synapse (ex: SPICE1 and KNL1). The significance of these findings needs to be confirmed by functional tests on selected gene variants.

Stochastic approach for radionuclides quantification

Gamma spectrometry is a passive non-destructive assay used to quantify radionuclides present in more or less complex objects. Basic methods using empirical calibration with a standard in order to quantify the activity of nuclear materials by determining the calibration coefficient are useless on non-reproducible, complex and single nuclear objects such as waste packages. Package specifications as composition or geometry change from one package to another and involve a high variability of objects. Current quantification process uses numerical modelling of the measured scene with few available data such as geometry or composition. These data are density, material, screen, geometric shape, matrix composition, matrix and source distribution. Some of them are strongly dependent on package data knowledge and operator backgrounds. The French Commissariat à l’Energie Atomique (CEA) is developing a new methodology to quantify nuclear materials in waste packages and waste drums without operator adjustment and internal package configuration knowledge. This method suggests combining a global stochastic approach which uses, among others, surrogate models available to simulate the gamma attenuation behaviour, a Bayesian approach which considers conditional probability densities of problem inputs, and Markov Chains Monte Carlo algorithms (MCMC) which solve inverse problems, with gamma ray emission radionuclide spectrum, and outside dimensions of interest objects. The methodology is testing to quantify actinide activity in different kind of matrix, composition, and configuration of sources standard in terms of actinide masses, locations and distributions. Activity uncertainties are taken into account by this adjustment methodology.

Growth and nutritional status, and their association with lung function: a study from the international Primary Ciliary Dyskinesia Cohort

Chronic respiratory disease can affect growth and nutrition, which can influence lung function. We investigated height, body mass index (BMI), and lung function in patients with primary ciliary dyskinesia (PCD).In this study, based on the international PCD (iPCD) Cohort, we calculated z-scores for height and BMI using World Health Organization (WHO) and national growth references, and assessed associations with age, sex, country, diagnostic certainty, age at diagnosis, organ laterality and lung function in multilevel regression models that accounted for repeated measurements.We analysed 6402 measurements from 1609 iPCD Cohort patients. Height was reduced compared to WHO (z-score -0.12, 95% CI -0.17 to -0.06) and national references (z-score -0.27, 95% CI -0.33 to -0.21) in male and female patients in all age groups, with variation between countries. Height and BMI were higher in patients diagnosed earlier in life (p=0.026 and p<0.001, respectively) and closely associated with forced expiratory volume in 1 s and forced vital capacity z-scores (p<0.001).Our study indicates that both growth and nutrition are affected adversely in PCD patients from early life and are both strongly associated with lung function. If supported by longitudinal studies, these findings suggest that early diagnosis with multidisciplinary management and nutritional advice could improve growth and delay disease progression and lung function impairment in PCD.

Omalizumab treatment for allergic bronchopulmonary aspergillosis in young patients with cystic fibrosis

BACKGROUND

Allergic bronchopulmonary aspergillosis (ABPA) is a severe lung disease complication caused by an Aspergillus fumigatus-induced hypersensitivity that affects 2-15% of patients with cystic fibrosis (CF). The mainstay treatment consists of a combination of corticosteroids and antifungals. However, repeated or long-term corticosteroid therapies can lead to serious side effects. The monoclonal anti-IgE antibody, omalizumab, has demonstrated its efficacy in allergic asthma. As ABPA results from a hypersensitivity to a specific allergen, omalizumab might benefit CF patients with ABPA. Therefore, we conducted a retrospective study to investigate the effects of omalizumab on ABPA in CF patients.

METHODS

We retrospectively analyzed the clinical records of young patients with CF treated with omalizumab for an ABPA in several French CF centers. The clinical data were collected 3 months before the start of omalizumab treatment, at initiation, and every 3 months up to 12 following initiation. These data comprised clinical, biological, nutritional, and functional parameters.

RESULTS

Eighteen patients were included (mean age: 17.1 ± 5.2 yrs). Under omalizumab was observed a stabilization of the lung function decline associated with a significant decrease in the corticosteroid daily dose (p = 0.0007) and an improvement in the nutritional status (p = 0.01). No serious side effect of omalizumab was reported.

CONCLUSIONS

This study suggests that omalizumab might be an interesting therapeutic strategy in ABPA, associated with less side effects compared to long-term corticosteroids. Further randomized-controlled trials are needed to ascertain the efficacy of omalizumab in CF patients with ABPA.

International management platform for children's interstitial lung disease (chILD-EU)

BACKGROUND

Children's interstitial lung diseases (chILD) cover many rare entities, frequently not diagnosed or studied in detail. There is a great need for specialised advice and for internationally agreed subclassification of entities collected in a register.Our objective was to implement an international management platform with independent multidisciplinary review of cases at presentation for long-term follow-up and to test if this would allow for more accurate diagnosis. Also, quality and reproducibility of a diagnostic subclassification system were assessed using a collection of 25 complex chILD cases.

METHODS

A web-based chILD management platform with a registry and biobank was successfully designed and implemented.

RESULTS

Over a 3-year period, 575 patients were included for observation spanning a wide spectrum of chILD. In 346 patients, multidisciplinary reviews were completed by teams at five international sites (Munich 51%, London 12%, Hannover 31%, Ankara 1% and Paris 5%). In 13%, the diagnosis reached by the referring team was not confirmed by peer review. Among these, the diagnosis initially given was wrong (27%), imprecise (50%) or significant information was added (23%).The ability of nine expert clinicians to subcategorise the final diagnosis into the chILD-EU register classification had an overall exact inter-rater agreement of 59% on first assessment and after training, 64%. Only 10% of the 'wrong' answers resulted in allocation to an incorrect category. Subcategorisation proved useful but training is needed for optimal implementation.

CONCLUSIONS

We have shown that chILD-EU has generated a platform to help the clinical assessment of chILD.

TRIAL REGISTRATION NUMBER

Results, NCT02852928.

The international primary ciliary dyskinesia cohort (iPCD Cohort): methods and first results

Data on primary ciliary dyskinesia (PCD) epidemiology is scarce and published studies are characterised by low numbers. In the framework of the European Union project BESTCILIA we aimed to combine all available datasets in a retrospective international PCD cohort (iPCD Cohort).

We identified eligible datasets by performing a systematic review of published studies containing clinical information on PCD, and by contacting members of past and current European Respiratory Society Task Forces on PCD. We compared the contents of the datasets, clarified definitions and pooled them in a standardised format.

As of April 2016 the iPCD Cohort includes data on 3013 patients from 18 countries. It includes data on diagnostic evaluations, symptoms, lung function, growth and treatments. Longitudinal data are currently available for 542 patients. The extent of clinical details per patient varies between centres. More than 50% of patients have a definite PCD diagnosis based on recent guidelines. Children aged 10–19 years are the largest age group, followed by younger children (≤9 years) and young adults (20–29 years).

This is the largest observational PCD dataset available to date. It will allow us to answer pertinent questions on clinical phenotype, disease severity, prognosis and effect of treatments, and to investigate genotype–phenotype correlations.

The iPCD Cohort offers a unique opportunity to study PCD in an international retrospective cohort of >3000 patientshttp://ow.ly/rn0m304Jgsu

Effectiveness of palivizumab in children with childhood interstitial lung disease: The French experience

INTRODUCTION

There is a lack of evidence concerning the effectiveness of immunoprophylaxis with palivizumab in children with childhood interstitial lung disease (chILD). In this retrospective study, we evaluated the effectiveness of palivizumab for decreasing the rate of RSV-related hospitalizations in children under the age of 24 months with chILD treated with corticosteroids.

METHODS

A retrospective national study was conducted in France. Patients born between 2007 and 2013, diagnosed with chILD and on corticosteroid treatment were identified through the French online database for pediatric interstitial lung disease (Respirare(®) ). Data were collected for the etiology and severity of chILD, risk factors and preventive measures for bronchiolitis, palivizumab immunoprophylaxis, and hospitalizations for bronchiolitis and RSV-bronchiolitis.

RESULTS

We included and evaluated 24 children during their first two RSV seasons, corresponding to 36 patient-seasons. The observed rate of RSV-related hospitalization (305/1000 patient-seasons), and the median length of stay (7 days), were higher than those for the general population. RSV-related hospitalization rates did not differ significantly between children with and without palivizumab prophylaxis (5/16 vs. 4/18, respectively, P = 0.70).

CONCLUSION

Children with chILD on corticosteroid treatment are at high risk of hospitalization for RSV-bronchiolitis, which tends to be more severe in these children than in the general population. The effectiveness of palivizumab prophylaxis in this population remains to be demonstrated. Pediatr Pulmonol. 2016;51:688-695. © 2015 Wiley Periodicals, Inc.

Mutations in GAS8, a Gene Encoding a Nexin-Dynein Regulatory Complex Subunit, Cause Primary Ciliary Dyskinesia with Axonemal Disorganization

Primary ciliary dyskinesia (PCD) is an autosomal recessive disease characterized by chronic respiratory infections of the upper and lower airways, hypofertility, and, in approximately half of the cases, situs inversus. This complex phenotype results from defects in motile cilia and sperm flagella. Among the numerous genes involved in PCD, very few-including CCDC39 and CCDC40-carry mutations that lead to a disorganization of ciliary axonemes with microtubule misalignment. Focusing on this particular phenotype, we identified bi-allelic loss-of-function mutations in GAS8, a gene that encodes a subunit of the nexin-dynein regulatory complex (N-DRC) orthologous to DRC4 of the flagellated alga Chlamydomonas reinhardtii. Unlike the majority of PCD patients, individuals with GAS8 mutations have motile cilia, which, as documented by high-speed videomicroscopy, display a subtle beating pattern defect characterized by slightly reduced bending amplitude. Immunofluorescence studies performed on patients' respiratory cilia revealed that GAS8 is not required for the proper expression of CCDC39 and CCDC40. Rather, mutations in GAS8 affect the subcellular localization of another N-DRC subunit called DRC3. Overall, this study, which identifies GAS8 as a PCD gene, unveils the key importance of the corresponding protein in N-DRC integrity and in the proper alignment of axonemal microtubules in humans.

Biomarkers in Interstitial lung diseases

Interstitial lung diseases (ILD)s represent a heterogeneous group of rare respiratory disorders, mostly chronic and associated with high morbidity and mortality. They are complex diseases that remain, in children, largely underdiagnosed and difficult to manage. Therefore, identification of biomarkers, which could be used for ILD diagnosis, measurements of disease severity and progression, and responsiveness to treatments, is a major challenge for clinical practice and for translational research. The present review focuses on blood biomarkers and provides an overview on the current information on molecular parameters of interest for ILD patient management.

RSPH3 Mutations Cause Primary Ciliary Dyskinesia with Central-Complex Defects and a Near Absence of Radial Spokes

Primary ciliary dyskinesia (PCD) is a rare autosomal-recessive condition resulting from structural and/or functional defects of the axoneme in motile cilia and sperm flagella. The great majority of mutations identified so far involve genes whose defects result in dynein-arm anomalies. By contrast, PCD due to CC/RS defects (those in the central complex [CC] and radial spokes [RSs]), which might be difficult to diagnose, remains mostly unexplained. We identified non-ambiguous RSPH3 mutations in 5 of 48 independent families affected by CC/RS defects. RSPH3, whose ortholog in the flagellated alga Chlamydomonas reinhardtii encodes a RS-stalk protein, is mainly expressed in respiratory and testicular cells. Its protein product, which localizes within the cilia of respiratory epithelial cells, was undetectable in airway cells from an individual with RSPH3 mutations and in whom RSPH23 (a RS-neck protein) and RSPH1 and RSPH4A (RS-head proteins) were found to be still present within cilia. In the case of RSPH3 mutations, high-speed-videomicroscopy analyses revealed the coexistence of immotile cilia and motile cilia with movements of reduced amplitude. A striking feature of the ultrastructural phenotype associated with RSPH3 mutations is the near absence of detectable RSs in all cilia in combination with a variable proportion of cilia with CC defects. Overall, this study shows that RSPH3 mutations contribute to disease in more than 10% of PCD-affected individuals with CC/RS defects, thereby allowing an accurate diagnosis to be made in such cases. It also unveils the key role of RSPH3 in the proper building of RSs and the CC in humans.