Inefficient antiviral response in reconstituted small-airway epithelium from chronic obstructive pulmonary disease patients following human parainfluenza virus type 3 infection

Chronic obstructive pulmonary disease (COPD) affects over 250 million individuals globally and stands as the third leading cause of mortality. Respiratory viral infections serve as the primary drivers of acute exacerbations, hastening the decline in lung function and worsening the prognosis. Notably, Human Parainfluenza Virus type 3 (HPIV-3) is responsible for COPD exacerbations with a frequency comparable to that of Respiratory Syncytial Virus and Influenza viruses. However, the impact of HPIV-3 on respiratory epithelium within the context of COPD remains uncharacterized.In this study, we employed in vitro reconstitution of lower airway epithelia from lung tissues sourced from healthy donors (n = 4) and COPD patients (n = 5), maintained under air-liquid interface conditions. Through a next-generation sequencing-based transcriptome analysis, we compared the cellular response to HPIV-3 infection.Prior to infection, COPD respiratory epithelia exhibited a pro-inflammatory profile, notably enriched in canonical pathways linked to antiviral response, B cell signaling, IL-17 signaling, and epithelial-mesenchymal transition, in contrast to non-COPD epithelia. Intriguingly, post HPIV-3 infection, only non-COPD epithelia exhibited significant enrichment in interferon signaling, pattern recognition receptors of viruses and bacteria, and other pathways involved in antiviral responses. This deficiency could potentially hinder immune cell recruitment essential for controlling viral infections, thus fostering prolonged viral presence and persistent inflammation.

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.

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.

Diagnostic tests and subtypes of dysfunctional breathing in children with unexplained exertional dyspnea

BACKGROUND

Inappropriate hyperventilation during exercise may be a specific subtype of dysfunctional breathing (DB).

OBJECTIVE

To assess whether Nijmegen questionnaire and hyperventilation provocation test (HVPT) are able to differentiate inappropriate hyperventilation from other DB subtypes in children with unexplained exertional dyspnea, and normal spirometry and echocardiography.

METHODS

The results were compared between a subgroup of 25 children with inappropriate hyperventilation (increased V'E/V'CO₂ slope during a cardiopulmonary exercise test (CPET)) and an age and sex matched subgroup of 25 children with DB without hyperventilation (median age, 13.5 years; 36 girls). Anxiety was evaluated using State-Trait Anxiety Inventory for Children questionnaire.

RESULTS

All children were normocapnic (at rest and peak exercise) and the children with hyperventilation had lower tidal volume/vital capacity on peak exercise (shallow breathing). The Nijmegen score correlated positively with dyspnea during the CPET and the HVPT (p = 0.001 and 0.010, respectively) and with anxiety score (p = 0.022). The proportion of children with a positive Nijmegen score (≥19) did not differ between hyperventilation (13/25) and no hyperventilation (14/25) groups (p = 0.777). Fractional end-tidal CO₂ (FETCO₂ ) at 5-min recovery of the HVPT was < 90% baseline in all children (25/25) of both subgroups. Likewise, there was no significant difference between the two subgroups for other indices of HVPT (FETCO₂ at 3-min recovery and symptoms during the test).

CONCLUSION

The validity of the Nijmegen questionnaire and the HVPT to discriminate specific subtypes of dysfunctional breathing, as well as the relevance of the inappropriate hyperventilation subtype itself may both be questioned.

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.

Beneficial short-term effect of autogenic drainage on peripheral resistance in childhood cystic fibrosis disease

Background

Airway clearance techniques are supposed to be a necessary adjunct for the enhancement of impaired peripheral clearance in cystic fibrosis (CF). The objective was to assess the effect of one physiotherapy session (autogenic drainage: AD) on mucus clearance (sputum wet weight) and impulse oscillometry system (IOS) indices, including those obtained from extended Resistance-Inertance-Compliance (eRIC) modelling, considering the degree of bronchial congestion.

Methods

Thirty children with CF (median age: 12.7 years) in a stable condition prospectively underwent IOS measurements at baseline and after AD. They were divided in two groups: with (visual analog scale of bronchial congestion by the physiotherapist ≥ 5/10) and without (scale < 5/10) bronchial congestion. Paired-comparison of the effects of AD on airway resistance measurements was done with Wilcoxon test.

Results

The congestion scale correlated with the wet weight of sputum production during the session (Pearson test: p < 0.0001, R = 0.66). Ten children had bronchial congestion and 20 were without congestion. In the whole group, R5–20 Hz significantly decreased after AD (P = 0.049), which was related to a decrease in the children with congestion (P = 0.025), whereas it was not significantly modified in the children without congestion (P = 0.327). The eRIC model allowed the calculation of the peripheral resistance of the respiratory system, which also decreased in the children with congestion (P = 0.037), however, not modified in the children without congestion (P = 0.390).

Conclusion

One session of autogenic drainage has the ability to decrease peripheral resistance obtained from IOS measurements, more specifically in children with CF with moderate to severe bronchial congestion.

Trial registration

ClinicalTrials.gov Identifier: NCT04094441.

[Therapeutic adherence among asthma patients: Variations according to age groups. How can it be improved? The potential contributions of new technologies]

While asthma patients' treatment adherence (TA) generally leaves to be desired, few data exist on TA evolution from age group to another. During the meeting of a working group of pneumo-pediatricians and adult pulmonologists, we reviewed the literature on adherence according to age group, examined explanations for poor adherence, and explored ways of improving adherence via new technologies. Asthma is a chronic disease for which TA is particularly low, especially during adolescence, but also among adults. Inhaled medications are the least effectively taken. Several explanations have been put forward: cost and complexity of treatments, difficulties using inhalation devices, poor understanding of their benefits, erroneous beliefs and underestimation of the severity of a fluctuating disease, fear of side effects, neglect, and denial (especially among teenagers). Poor TA is associated with risks of needless treatment escalation, aggravated asthma with frequent exacerbations, increased school absenteeism, degraded quality of life, and excessive mortality. Better compliance is based on satisfactory relationships between caregivers and asthmatics, improved caregiver training, and more efficient transmission to patients of relevant information. The recent evolution of innovative digital technologies opens the way for enhanced communication, via networks and dedicated applications, and thanks to connected inhalation devices, forgetfulness can be limited. Clinical research will also help to ameliorate TA. Lastly, it bears mentioning that analysis of the existing literature is hampered by differences in terms of working definitions and means of TA measurement.

Cumulative Incidence and Risk Factors for Severe COVID-19 in French People with Cystic Fibrosis

Background

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections are closely monitored in people with cystic fibrosis (pwCF), with a special emphasis on severe cases. Previous studies used hospitalization rates as proxy for severity.

Methods

We evaluated data from coronavirus disease 2019 (COVID-19) cases diagnosed in French pwCF followed in one of the 47 French CF center over the first year of the pandemic.

Objective

criteria were applied for defining severity (e.g., respiratory failure and/or death). Data were compared to those from all French pwCF using the French CF Registry.

Results

As of April 30, 2021, 223 pwCF were diagnosed with COVID-19, with higher risks in adults (≥18 years, odds ratio [OR] = 2.52, 95% confidence interval [CI] = 1.82-3.48) and post-transplant individuals (OR = 2.68, 95% CI = 1.98-3.63). Sixty (26.9%) patients were hospitalized, with an increased risk in post-transplant individuals (OR = 4.74, 95% CI = 2.49-9.02). In 34 (15%) cases, COVID-19 was considered severe; 28/60 (46.7%) hospitalizations occurred in patients without objective criteria of severity. Severe cases occurred mostly in adults (85.3%) and post-transplant pwCF (61.8%, OR = 6.02, 95% CI = 2.77-13.06). In non-transplanted pwCF, risk factors for severity included low lung function (median ppFEV₁ 54.6% vs. 75.1%, OR = 1.04, 95% CI = 1.01-1.08) and CF-associated diabetes (OR = 3.26, 95% CI = 1.02-10.4). While most cases recovered without sequelae (n = 204, 91.5%), 16 (13%) were followed for possible sequelae, and three post-transplant females died.

Conclusions

Severe COVID-19 cases occurred infrequently during the first year of the pandemic in French pwCF. Non-transplanted adults with severe respiratory disease or diabetes and post-transplant individuals were at risk for severe COVID-19. Thus, specific preventive measures should be proposed.

Glucocorticoid induced adrenal insufficiency in children: Morning cortisol values to avoid LDSST

OBJECTIVES

Glucocorticoid-induced adrenal insufficiency (GI-AI) is a common side effect of glucocorticoid therapy. However, its diagnosis currently relies on the realization of a Low Dose Short Synacthen Test (LD-SST) that requires an outpatient hospital and several blood samples. Our goal was to evaluate whether morning cortisol values could predict the response to LD-SST, in children, to avoid useless dynamic tests and facilitate diagnosis of glucocorticoid induced adrenal insufficiency.

STUDY DESIGN

We recorded data of 91 pediatric patients who underwent a LD-SST in our center between 2016 and 2020 in a retrospective observational study. We selected LD-SST realized following administration of supra-physiologic doses of glucocorticoids during more than 3 weeks and performed at least four weeks after treatment was stopped. Adrenal deficiency was defined as a plasma cortisol concentration inferior to 500 nmol/l at LD-SST.

RESULTS

Glucocorticoid-induced adrenal insufficiency was diagnosed in 60% of our cohort. Morning cortisol values were predictive of the response to the LD-SST (AUC ROC 0.78). A plasma cortisol concentration of less than 144 nmol/l predicted glucocorticoid induced adrenal insufficiency with a specificity of 94% and a value over 317 nmol/l predicted recovery of the HPA axis with a sensitivity of 95%. We did not find any other predictive factor for glucocorticoid-induced adrenal insufficiency.

CONCLUSIONS

Morning cortisol values can safely assess recovery of the HPA axis in children treated chronically with glucocorticoids. Using these thresholds, more than 50% of LD-SST could be avoided in children.

Small airway dysfunction is an independent dimension of wheezing disease in preschool children

BACKGROUND

Whether small airway dysfunction (SAD), which is prevalent in asthma, helps to characterize wheezing phenotypes is undetermined. The objective was to assess whether SAD parameters obtained from impedance measurement and asthma probability are linked.

METHODS

One hundred and thirty-nine preschool children (mean age 4.7 years, 68% boys) suffering from recurrent wheezing underwent impulse oscillometry that allowed calculating peripheral resistance and compliance of the respiratory system (markers of SAD) using the extended RIC model (central and peripheral resistance, inertance, and peripheral compliance). Children were classified using the probability-based approach of GINA guidelines (few, some, and most having asthma). A principal component analysis (PCA) that determined the dimensions of wheezing disease evaluated the links between SAD and asthma probability.

RESULTS

Forty-seven children belonged to the few, 28 to the some, and 64 to the most having asthma groups. Whereas their anthropometrics and measured parameters were similar, the most having asthma group exhibited the lowest mean value of airway inertance after bronchodilator probably due to airway inhomogeneities. PCA characterized four independent dimensions including a peripheral resistance (constituted by baseline peripheral compliance, Frs, R5Hz, R5-20Hz, X5Hz, and AX), a central resistance (baseline central resistance, R20Hz), anthropometrics (age and height), and asthma probability (wheezing patterns and therapeutic steps). Thus, PCA showed that the SAD markers were independent from clinical dimensions and were unable to differentiate wheezing phenotypes.

CONCLUSIONS

Lung function parameters obtained from impulse oscillometry and asthma probability were belonging to independent dimensions of the wheezing disease.

Impulse oscillometry indices to detect an abnormal lung clearance index in childhood cystic fibrosis

The objective of our cross-sectional study was to assess the relationships between indices of multiple breath washout (MBW) and impulse oscillometry system (IOS) in cystic fibrosis in forty consecutive children (median age 8.1 years) in stable conditions and to evaluate whether cut-off values of IOS indices may help to avoid MBW, which is time-consuming. IOS measurements took a median duration of 3 min, while MBW measurements took a median duration of 49 min. Lung Clearance Index (LCI_2.5% ) depicted significant linear correlations with z-scores of R5Hz, R5-20Hz, X5Hz, AX, and Fres (r²  = 0.27 to 0.51). Receiver-operator characteristic curves were constructed and showed that the best compromise was obtained with the z-score of Fres, with a cut-off value of -1.37 that had a sensitivity of 0.966, a specificity of 0.636, and a negative predictive value of 0.875. This z-score is useful for excluding increased LCI_2.5% when below -1.37 using the reference set of Gochicoa et al. In conclusion, IOS measurement is easily and rapidly obtained in children and may be clinically useful for excluding increased LCI_2.5% , thus allowing the time-consuming MBW test to be avoided.

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.

Evaluation of prognostic scores for respiratory syncytial virus infection in a French multicentre cohort of allogeneic haematopoietic stem cell transplantation recipients

Haematopoietic stem cell transplantation (HSCT) recipients are at risk for severe respiratory syncytial virus (RSV) infection. Two prognostic scores have been proposed to predict the risk of progression from upper respiratory tract infection (URTI) to lower respiratory tract infection (LRTI) and death. This was a multicentre study of allogeneic HSCT recipients diagnosed with an RSV infection between 2010 and 2019 who were retrospectively stratified by the immunodeficiency scoring index (ISI) and the severe immunodeficiency (SID) score. Endpoints were overall survival, RSV-attributable mortality and progression to LRTI after URTI. Prognostic analyses were performed using Cox regression models. We included 147 consecutive patients, including 94 (63.9%) initially diagnosed with URTI and 53 (36.1%) with LRTI. At 90 days, 14 patients had died (survival rate, 90.5%; 95% CI: 85.9-95.3), and nine deaths were attributable to RSV (attributable mortality rate, 5.4%; 95% CI: 2.5-10.0). The cumulative 90-day incidence of LRTI after URTI was 13.8% (95% CI: 7.8-21.6). Neither score showed prognostic value for mortality, while the ISI allowed the prediction of progression to LRTI (p = 0.0008). Our results do not fully replicate the results previously reported in cohorts of HSCT recipients. This may reflect the recent epidemiology of RSV infections in this HSCT cohort.

Frequent lower respiratory tract disease in hematological patients with parainfluenza virus type 3 infection

Human parainfluenza virus type 3 (HPIV-3) may cause lower respiratory tract infection disease (LRTI-D) after hematopoietic stem cell transplantation (HSCT). Most previous have studies focused on recipients of HSCT whereas data on characteristics and outcomes in patients with hematological malignancies (HMs) compared to non-hematological patients are limited. The prognostic value of viral load in respiratory specimens remains elusive. In a 2-year retrospective study, we determined the frequencies of LRTI-D in HM, HSCT, and in non-hematological patients, and HPIV-3 levels in respiratory tract secretions. Among 98 patients with HPIV-3 infection, including 31 HSCT and 40 HM, 36 had a diagnosis of LRTI-D. LRTI-D was significantly more frequent in patients with HM or HSCT (n = 32, 45.1%) than in non-hematological patients (n = 4, 14.8%) (p = 0.006). The median HPIV-3 loads were high in upper respiratory tract secretions regardless of the presence or absence of LRTI-D (8.3 log₁₀ vs. 7.6 log₁₀ TCID₅₀ /10⁶ cells). HPIV-3 loads in respiratory tract samples in HM were not significantly higher than those found in HSCT but significantly higher than in non-hematological patients (p = 0.007). In conclusion, LRTI-D was frequent in HM patients who were diagnosed with HPIV-3 infection.

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.

Sputum collection after a chest physiotherapy session strongly enhances the detection of P. aeruginosa in nonexpectorating CF children compared with the commonly used oropharyngeal swab method. Oropharyngeal swab after physiotherapy may be an acceptable alternative.https://bit.ly/3757ewq

First Wave of COVID-19 in French Patients with Cystic Fibrosis

Viral infections are known to lead to serious respiratory complications in cystic fibrosis (CF) patients. Hypothesizing that CF patients were a population at high risk for severe respiratory complications from SARS-CoV-2 infection, we conducted a national study to describe the clinical expression of COVID-19 in French CF patients. This prospective observational study involves all 47 French CF centers caring for approximately 7500 CF patients. Between March 1st and June 30th 2020, 31 patients were diagnosed with COVID-19: 19 had positive SARS-CoV-2 RT-PCR in nasopharyngeal swabs; 1 had negative RT-PCR but typical COVID-19 signs on a CT scan; and 11 had positive SARS-CoV-2 serology. Fifteen were males, median (range) age was 31 (9-60) years, and 12 patients were living with a lung transplant. The majority of the patients had CF-related diabetes (n = 19, 61.3%), and a mild lung disease (n = 19, 65%, with percent-predicted forced expiratory volume in 1 s (ppFEV1) > 70). Three (10%) patients remained asymptomatic. For the 28 (90%) patients who displayed symptoms, most common symptoms at admission were fever (n = 22, 78.6%), fatigue (n = 14, 50%), and increased cough (n = 14, 50%). Nineteen were hospitalized (including 11 out of the 12 post-lung transplant patients), seven required oxygen therapy, and four (3 post-lung transplant patients) were admitted to an Intensive Care Unit (ICU). Ten developed complications (including acute respiratory distress syndrome in two post-lung transplant patients), but all recovered and were discharged home without noticeable short-term sequelae. Overall, French CF patients were rarely diagnosed with COVID-19. Further research should establish whether they were not infected or remained asymptomatic upon infection. In diagnosed cases, the short-term evolution was favorable with rare acute respiratory distress syndrome and no death. Post-lung transplant patients had more severe outcomes and should be monitored more closely.

[In Utero Exposure to Maternal Smoking: Impact on the Child from Birth to Adulthood - CNGOF-SFT Expert Report and Guidelines for Smoking Management during Pregnancy]

INTRODUCTION

Smoking during pregnancy leads to fetal passive smoking. It is associated with several obstetrical complications and is a major modifiable factor of maternal and fetal morbidity. Long-term consequences also exist but are less well known to health professionals and in the general population.

METHODS

Consultation of the Medline® database.

RESULTS

Maternal smoking during pregnancy is associated in the offspring with sudden infant death syndrome (NP2), impaired lung function (NP2), lower respiratory infections and asthma (NP2), overweight and obesity (NP2), cancers (NP3), risk of tobacco use, nicotine dependence and early smoking initiation (NP2). Unadjusted analyses show associations between in utero tobacco exposure and cognitive deficits (NP3), impaired school performance (NP3) and behavioral disorders in children (NP2), which are in a large part explained by environmental factors. There is a cross-generational effect of smoking during pregnancy. For example, an increased risk of asthma is observed in the grandchildren of smoking women (NP4). The respective roles of ante- and post-natal smoking remain difficult to assess.

CONCLUSION

These results highlight the importance of prevention measures against tobacco use in the general population, as well as screening measures and support for smoking cessation before or at the beginning of the pregnancy.

Cross-sectional phenotyping of small airway dysfunction in preschool asthma using the impulse oscillometry system

Objective. Asthma is a chronic inflammatory airway disorder known to induce small airways dysfunction (SAD). It is important to develop tools to assess the presence and extent of SAD in daily clinical practice. An Impulse Oscillometry System (IOS) might detect SAD, but the validity of the underlying model (serial Resistive airway and Compliant tissue model: RC model) in diseased lungs remains questionable.Methods. Our objective was to evaluate the usefulness of parameters obtained from six electrical circuit models that were fitted to the measurements of impedance obtained with IOS in asthmatic children characterized by an abnormal lung function defined by an increased baseline interrupter resistance (Rint, z-score > +1.645).Results. The six models were tested in 102 asthmatic children (median age: 5.5 years). Two models allowed the description of 92/102 (90%) children: 74 by the extended RIC model (central and peripheral Resistance, Inertance and peripheral airway Compliance) and 18 by the Mead₁₉₆₉ model (extended RIC plus lung compliance). Thus, peripheral airway compliance and resistance were essential to describe lung function abnormalities of these asthmatic children. Parenchyma impairment (increased lung compliance) which was responsive to salbutamol was present in 18% of asthmatic children. After salbutamol, peripheral airway resistance decreased while peripheral airway compliance increased, arguing for asthma-related SAD. R5-20Hz independently correlated with the two latter parameters but was increased in two thirds of children with increased Rint only.Conclusion. Additional modeling of IOS results can be a reliable tool to assess the presence and extent of SAD in young asthmatic children.

Usefulness of bronchoalveolar lavage in a French pediatric cohort with hypersensitivity pneumonitis

BACKGROUND

Hypersensitivity pneumonitis (HP) is a rare interstitial lung disease in children, and very little data are available on the frequency, diagnosis, and outcomes of HP. In a pediatric cohort with HP, the characteristics of the CD4/CD8 lymphocyte ratio are often described as nonspecific.

METHODS

We used the National French Database (RespiRare) to collect data from the last decade on HP. The diagnosis of HP was defined by the presence of a relevant exposure, clinical symptoms, and compatible lung imaging radiology and was usually defined by positive precipitins antibodies.

RESULTS

A total of 16 children with a mean age of 10 years (4-13) presented with HP. All children presented with dyspnea on exertion. Diffuse ground-glass opacity was present in all computed tomography (CT) scans. Research guided by a questionnaire and precipitins antibodies against the corresponding antigens showed that patients were positive for contact with birds with or without fungi. Bronchoalveolar lavage (BAL) was performed in 12 children. The total cell counts were elevated in BAL fluid, with a mean value of 36% lymphocytes. The CD4/CD8 lymphocyte ratio was below one for all children.

CONCLUSION

BAL in our pediatric cohort with HP had the same characteristics as that of adults with HP. An HP diagnosis must be considered when dyspnea on exertion and diffuse ground-glass opacity are observed. Carrying out BAL and serological tests can help diagnose and avoid lung biopsy.

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.

Mucosal-Associated Invariant T Cell Levels Are Reduced in the Peripheral Blood and Lungs of Children With Active Pulmonary Tuberculosis

Mucosal associated invariant T (MAIT) cells are unconventional, semi-invariant T lymphocytes that recognize microbial-derived vitamin B2 (riboflavin) biosynthesis precursor derivatives presented by the monomorphic MHC class 1-related (MR1) molecule. Upon microbial infection, MAIT cells rapidly produce cytokines and cytotoxic effectors, and are thus important players in anti-microbial defense. MAIT cells are protective in experimental models of infection and are decreased in the blood of adult patients with bacterial infections, including Mycobacterium tuberculosis (Mtb). In children, the risk of rapid progression to active tuberculosis (TB) following Mtb infection is higher than in adults. Whether MAIT cells influence the outcome of Mtb infection in children is therefore, an important issue. We analyzed MAIT cell numbers and phenotype in 115 children investigated for pulmonary TB and determined their potential correlation with disease progression. MAIT cells were reduced in numbers and activated in the peripheral blood of children with active TB as compared to those with latent TB infection (LTBI) and healthy children. Moreover, MAIT cells did not accumulate and did not proliferate in the lung of children with active TB. These results suggest that MAIT cells may be important in preventing progression of Mtb infection to active TB in children.

Pneumonia with pleural empyema caused by Salmonella Typhi in an immunocompetent child living in a non-endemic country

Extra-intestinal complications of Salmonella Typhi (S. Typhi) infections usually occur in endemic countries and in patients with underlying risk conditions. A 14-year-old immunocompetent girl was admitted with respiratory distress owing to S. Typhi pneumonia and pleural empyema. She was a native of Ivory Coast but had lived in France for 4 years and had not travelled abroad for several years. There were no gastro-intestinal symptoms and no S. Typhi carriage was detected in her family. She recovered completely with ceftriaxone and ciprofloxacin and pleural drainage was not required. An atypical presentation of S. Typhi should be considered even in settings where there are no risk factors.

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.

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.

Ontogeny of human mucosal-associated invariant T cells and related T cell subsets

There are very few human MAIT cells in cord blood. Ben Youssef et al. show that they slowly expand during childhood and point to a critical role of the TCRαβ repertoire in determining their unique ability to recognize MR1-restricted microbial antigens.

Mucosal-associated invariant T (MAIT) cells are semi-invariant Vα7.2⁺ CD161^highCD4⁻ T cells that recognize microbial riboflavin precursor derivatives such as 5-OP-RU presented by MR1. Human MAIT cells are abundant in adult blood, but there are very few in cord blood. We longitudinally studied Vα7.2⁺ CD161^high T cell and related subset levels in infancy and after cord blood transplantation. We show that Vα7.2⁺ and Vα7.2⁻ CD161^high T cells are generated early during gestation and likely share a common prenatal developmental program. Among cord blood Vα7.2⁺ CD161^high T cells, the minority recognizing MR1:5-OP-RU display a TRAV/TRBV repertoire very similar to adult MAIT cells. Within a few weeks of life, only the MR1:5-OP-RU reactive Vα7.2⁺ CD161^high T cells acquire a memory phenotype. Only these cells expand to form the adult MAIT pool, diluting out other Vα7.2⁺ CD161^high and Vα7.2⁻ CD161^high populations, in a process requiring at least 6 years to reach adult levels. Thus, the high clonal size of adult MAIT cells is antigen-driven and likely due to the fine specificity of the TCRαβ chains recognizing MR1-restricted microbial antigens.

Mucosal-Associated Invariant T Cell Interactions with Commensal and Pathogenic Bacteria: Potential Role in Antimicrobial Immunity in the Child

Mucosal-associated invariant T (MAIT) cells are unconventional CD3⁺CD161^high T lymphocytes that recognize vitamin B2 (riboflavin) biosynthesis precursor derivatives presented by the MHC-I related protein, MR1. In humans, their T cell receptor is composed of a Vα7.2-Jα33/20/12 chain, combined with a restricted set of Vβ chains. MAIT cells are very abundant in the liver (up to 40% of resident T cells) and in mucosal tissues, such as the lung and gut. In adult peripheral blood, they represent up to 10% of circulating T cells, whereas they are very few in cord blood. This large number of MAIT cells in the adult likely results from their gradual expansion with age following repeated encounters with riboflavin-producing microbes. Upon recognition of MR1 ligands, MAIT cells have the capacity to rapidly eliminate bacterially infected cells through the production of inflammatory cytokines (IFNγ, TNFα, and IL-17) and cytotoxic effector molecules (perforin and granzyme B). Thus, MAIT cells may play a crucial role in antimicrobial defense, in particular at mucosal sites. In addition, MAIT cells have been implicated in diseases of non-microbial etiology, including autoimmunity and other inflammatory diseases. Although their participation in various clinical settings has received increased attention in adults, data in children are scarce. Due to their innate-like characteristics, MAIT cells might be particularly important to control microbial infections in the young age, when long-term protective adaptive immunity is not fully developed. Herein, we review the data showing how MAIT cells may control microbial infections and how they discriminate pathogens from commensals, with a focus on models relevant for childhood infections.

[The lung microbiota. Review]

In the last 20years, culture-independent DNA-based techniques ("shotgun sequencing") demonstrated that complex microbial communities reside on most epithelial surfaces, including the lower airways. Until the amniotic sac ruptures, a fetus is considered to be essentially sterile. Many factors affect the composition of the lung microbiota: inheritance, mode of delivery, diet, and age-related changes in adults. It interacts with the digestive and oropharyngeal microbiotas. Animal models show that these interactions play a role in innate pulmonary immunity and modulation of the inflammatory response. The microbial composition of the airway microbiota differs between healthy children and those with chronic lung disease. The advances in the comprehension of microbiome changes have resulted in new approaches concerning the microbiota for treatment and prevention of disease.

Lung sarcoidosis in children: update on disease expression and management

BACKGROUND

Sarcoidosis is a rare lung disease in children. The aim of the present study was to provide update information on disease presentation and progression, patient management and prognosis factors in a cohort of children with lung sarcoidosis.

METHODS

With the network of the French Reference Centre for Rare Lung Diseases (RespiRare), we collected information on a large cohort of paediatric thoracic sarcoidosis to provide information on disease presentation, management and outcome.

RESULTS

Forty-one patients were included with a median age at diagnosis of 11.8  years (1.1-15.8), mostly from Afro-Caribbean and Sub-Saharan origin. At diagnosis, 85% presented with a multi-organic disease, and no major differences were found regarding disease severity between the patients diagnosed before or after 10 years old. Corticosteroids were the most used treatment, with more intravenous pulses in the youngest patients. The 18-month outcome showed that patients diagnosed before 10 years old were more likely to recover (50% vs 29%), and presented fewer relapses (29% vs 58%). At 4-5 years of follow-up, relapses were mostly observed for patients diagnosed after 10 years old.

DISCUSSION

In the included children, mostly of Afro-Caribbean and Sub-Saharan origin, sarcoidosis seems severe, with multi-organic involvement and foreground general symptoms. Common prognosis factors are not suitable in paediatric patients, and a young age at diagnosis does not seem to be associated with a poorer prognosis. The study is ongoing to provide further information on the very-long-term follow-up of paediatric sarcoidosis.

Lung manifestations in MPO-ANCA associated vasculitides in children

OBJECTIVE

To describe lung manifestations in MPO-ANCA associated vasculitides in children.

METHODS

We retrospectively reviewed the medical records of patients with MPO-ANCA associated vasculitis, who were followed in two pediatric nephrology departments from January 2000 to December 2010.

RESULTS

Twelve patients were identified with MPO-ANCA over the study period. Their median age (IQR) at diagnosis was 10.5 (6.3-12.0) years, and their median duration of follow-up was 4.8 (1.2-7.5) years. Only five of them had pulmonary involvement with diffuse alveolar hemorrhage. Lung involvement was inaugural for four of five children. One child with severe chronic respiratory disease and renal failure died after 6 years of disease progression. Pulmonary function tests were available for 10 children. They were within normal ranges in four of five patients without clinical lung manifestations, and no significant impairment was observed in children with pulmonary complications.

CONCLUSIONS

Diffuse alveolar hemorrhage complicates 40% of cases of MPO-ANCA associated vasculitides in children with renal involvement. After an acute potentially severe phase, a complete recovery without significant functional impairment was observed in four of five affected children.

Idiopathic eosinophilic pneumonia in children: the French experience

Background

Idiopathic eosinophilic pneumonia is extremely rare in children and adults. We present herein the first series describing the specificities of idiopathic chronic (ICEP) and acute (IAEP) eosinophilic pneumonia in children.

Methods

We retrospectively analyzed all cases of ICEP and IAEP in children that were retrieved from French Reference Centers for rare pediatric lung diseases.

Results

Five cases of pediatric ICEP were identified. Corticosteroid or immunosuppressive therapy dramatically improved the outcome in three cases. The remaining two cases had a persistent interstitial pattern with progressive development of cystic airspace lesions. Three cases of IAEP in adolescents were reported, with one requiring four days of extracorporeal membrane oxygenation.

Conclusion

ICEP is a rare disease with a polymorphic clinical presentation in children. We identified patients with persistent interstitial patterns progressing to cystic airspace regions, for which the boundaries with idiopathic interstitial pneumonias are difficult to establish. We therefore propose a specific pediatric definition and classification algorithm. IAEP in children remains an inflammatory reaction of the lung to an acute toxic exposure, mainly tobacco, as in adults. International studies are required to comprehensively assess the various clinical forms of the disease as well as the appropriate therapeutic regimens.

Loss-of-function mutations in RSPH1 cause primary ciliary dyskinesia with central-complex and radial-spoke defects

Primary ciliary dyskinesia (PCD) is a rare autosomal-recessive respiratory disorder resulting from defects of motile cilia. Various axonemal ultrastructural phenotypes have been observed, including one with so-called central-complex (CC) defects, whose molecular basis remains unexplained in most cases. To identify genes involved in this phenotype, whose diagnosis can be particularly difficult to establish, we combined homozygosity mapping and whole-exome sequencing in a consanguineous individual with CC defects. This identified a nonsense mutation in RSPH1, a gene whose ortholog in Chlamydomonas reinhardtii encodes a radial-spoke (RS)-head protein and is mainly expressed in respiratory and testis cells. Subsequent analyses of RSPH1 identified biallelic mutations in 10 of 48 independent families affected by CC defects. These mutations include splicing defects, as demonstrated by the study of RSPH1 transcripts obtained from airway cells of affected individuals. Wild-type RSPH1 localizes within cilia of airway cells, but we were unable to detect it in an individual with RSPH1 loss-of-function mutations. High-speed-videomicroscopy analyses revealed the coexistence of different ciliary beating patterns-cilia with a normal beat frequency but abnormal motion alongside immotile cilia or cilia with a slowed beat frequency-in each individual. This study shows that this gene is mutated in 20.8% of individuals with CC defects, whose diagnosis could now be improved by molecular screening. RSPH1 mutations thus appear as a major etiology for this PCD phenotype, which in fact includes RS defects, thereby unveiling the importance of RSPH1 in the proper building of CCs and RSs in humans.

A national internet-linked based database for pediatric interstitial lung diseases: the French network

BACKGROUND

Interstitial lung diseases (ILDs) in children represent a heterogeneous group of rare respiratory disorders that affect the lung parenchyma. After the launch of the French Reference Centre for Rare Lung Diseases (RespiRare®), we created a national network and a web-linked database to collect data on pediatric ILD.

METHODS

Since 2008, the database has been set up in all RespiRare® centres. After patient's parents' oral consent is obtained, physicians enter the data of children with ILD: identity, social data and environmental data; specific aetiological diagnosis of the ILD if known, genetics, patient visits to the centre, and all medical examinations and tests done for the diagnosis and/or during follow up. Each participating centre has a free access to his own patients' data only, and cross-centre studies require mutual agreement. Physicians may use the system as a daily aid for patient care through a web-linked medical file, backed on this database.

RESULTS

Data was collected for 205 cases of ILD. The M/F sex ratio was 0.9. Median age at diagnosis was 1.5 years old [0-16.9]. A specific aetiology was identified in 149 (72.7%) patients while 56 (27.3%) cases remain undiagnosed. Surfactant deficiencies and alveolar proteinosis, haemosiderosis, and sarcoidosis represent almost half of the diagnoses. Median length of follow-up is 2.9 years [0-17.2].

CONCLUSIONS

We introduce here the French network and the largest national database in pediatric ILDs. The diagnosis spectrum and the estimated incidence are consistent with other European databases. An important challenge will be to reduce the proportion of unclassified ILDs by a standardized diagnosis work-up. This database is a great opportunity to improve patient care and disease pathogenesis knowledge. A European network including physicians and European foundations is now emerging with the initial aim of devising a simplified European database/register as a first step to larger European studies.