Pediatric interstitial lung disease

Interstitial lung disease in children (chILD) is rare and encompasses more than 200 entities, with new especially genetic causes being discovered. Several classifications have been proposed, and there is considerable overlap with entities which present in adult life. Presentation may be shortly after birth with acute respiratory distress and in infancy and childhood either with a primary respiratory presentation or with systemic symptoms such as poor feeding and failure to thrive. Newborn acute presentations are usually due either to a mutation in one of the surfactant protein (Sp) genes or the alveolar capillary dysplasia (ACD)-congenital alveolar dysplasia (CAD) spectrum. The latter usually progress rapidly to extracorporeal membrane oxygenation, and early lung biopsy is advisable to prevent prolonged futile treatment being offered. Outside the newborn period, a staged protocol for investigation is proposed. This starts with a computed tomography scan, which confirms or otherwise the presence of chILD, and occasionally can lead to a specific diagnosis. In particular in settings where there is a high burden of infection, infective mimics of chILD need to be excluded. The next investigations aim to try to move from pattern recognition to specific diagnoses, both genetic and environmental. The speed of progression to lung biopsy will depend on the clinical state of the child, and the biopsy itself may suggest a hunt for a new underlying cause, such as immunodeficiency. Specific genetic causing chILD includes mutations in SpB and SpC and processing genes (thyroid transcription factor-1 [TTF-1] and adenosine triphosphate-binding cassette subfamily A) (the last three can present at any time in the life course); genes involved in Sp catabolism (granulocyte-macrophage colony factor receptor A and B genes), an increasing number implicated in the ACD-CAD spectrum, and other non-Sp related genes such as Filamin-A and integrin genes. Environmental causes are also important and vary across the world. Vaping has been implicated as causing a large number of chILDs, and a vaping history is essential in any young person with an unusual respiratory illness. Medications, both prescribed and over-the-counter such as oily laxatives, are also causes of chILD. There are important conditions of unknown cause presenting in early childhood. Neuroendocrine cell hyperplasia of infancy (NEHI) and pulmonary interstitial glycogenosis generally have a good prognosis, and are probably best considered as part of a spectrum of pulmonary dysmaturity syndromes, in some of which underlying gene mutations have been detected, for example, TTF-1 for NEHI. Pulmonary alveolar proteinosis is an example of an umbrella description, which may present at any age, and has a number of underlying causes with different specific treatments, underscoring the need to move from pattern recognition to specific diagnoses. chILDs have important implications for adult physicians; there may be late as yet poorly described sequelae of the disease or its treatment in adult life; there may be genetic implications for the wider family; and there may be late chILD relapses. Smooth transition to adult services is essential for all chILD survivors, with pediatric and adult chest physicians working closely together

Novel methods of detection and treatment of Pseudomonas aeruginosa infection in cystic fibrosis

Although advances in the management of cystic fibrosis (CF) have led to a significant extension of life expectancy, the disease remains life-limiting. Successive pulmonary infections are the primary cause of morbidity, leading eventually to respiratory failure. Pseudomonas aeruginosa (Pa) is the dominant respiratory pathogen but difficulties in detection and increasing failure of conventional treatments to combat established infection mean that an urgent need exists for non-invasive techniques that screen for Pa, particularly in non-expectorating patients, and for novel antimicrobial therapies. The first part of this thesis aimed to determine whether markers in exhaled breath, measured using selected ion-flow tube mass spectrometry (SIFT-MS), could distinguish between CF patients with and without chronic Pa infection. In what is the largest study to date of well-phenotyped CF patients, I demonstrated that a fingerprint that differentiates according to Pa status does appear to be present in exhaled breath, although the technique is not sufficiently sensitive at present to be used on an individual patient basis. The second part of this thesis studies the potential of using bacteriophage in the treatment of Pa infection. I have shown that novel bacteriophage cocktails are efficacious in vitro against laboratory and clinical Pa strains isolated from CF patients. In a murine model of acute infection, I demonstrate that bacteriophage not only hasten clearance of Pa from the lung but also diminish the associated inflammatory response under certain conditions. Efficacy was demonstrated when bacteriophage was given prophylactically and after established infection, indicating potential utility in a clinical scenario. That bacteriophage remain viable following nebulisation, the preferred route of administration for future human trials, was also ascertained. Whilst the results are promising, with potential to improve patient outcomes, both strands of work only demonstrate proof-of-concept for the studied strategies. A significant amount of additional work, some already underway, is necessary before either approach can be used in a clinical setting.Open Acces

Screening for sleep-disordered breathing with Pediatric Sleep Questionnaire in children with underlying conditions.

The Pediatric Sleep Questionnaire described by Chervin et al. (Sleep Medicine, 2000, 1, 21-32) was originally validated for children with obstructive sleep apnoea syndrome but without other disorders. The aim of our study was to check the applicability of this questionnaire in children with underlying chronic medical conditions. Children aged 2-18 years who underwent a diagnostic sleep study at Great Ormond Street Hospital were recruited over a 10-month period. The Pediatric Sleep Questionnaire completed by their parents and cardiorespiratory polygraphy were scored. Sensitivities and specificities of the Pediatric Sleep Questionnaire were calculated using a Pediatric Sleep Questionnaire score of 0.33 as being indicative of sleep-disordered breathing. A total of 561 patients were reviewed. Neuromuscular disorders (n = 108), craniofacial anomalies (n = 58) and the obstructive sleep apnea syndrome control group (n = 155) were best represented. The sensitivity for patients with isolated obstructive sleep apnoea syndrome was 76.5% when using an apnoea-hypopnoea index ≥ 5, but this was much lower when looking at specific sub-groups such as neuromuscular patients (25%) or patients with Trisomy 21 (36.7%). Sensitivities remained unchanged for patients with obstructive sleep apnoea syndrome (77.3%) when an apnoea-hypopnoea index of ≥ 1 was used, but improved for neuromuscular disorders sub-groups (36.7%) and Trisomy 21 (84%). In conclusion, the Pediatric Sleep Questionnaire is not a good screening tool for obstructive sleep apnoea syndrome in children with complex underlying disorders when a cut-off apnoea-hypopnoea index of ≥ 5 is used, and it cannot replace cardiorespiratory polygraphy recording

Pseudomonas aeruginosa infection in cystic fibrosis: pathophysiological mechanisms and therapeutic approaches

Pseudomonas aeruginosa is a remarkably versatile environmental bacterium with an extraordinary capacity to infect the cystic fibrosis (CF) lung. Infection with P. aeruginosa occurs early, and although eradication can be achieved following early detection, chronic infection occurs in over 60% of adults with CF. Chronic infection is associated with accelerated disease progression and increased mortality. Extensive research has revealed complex mechanisms by which P. aeruginosa adapts to and persists within the CF airway. Yet knowledge gaps remain, and prevention and treatment strategies are limited by the lack of sensitive detection methods and by a narrow armoury of antibiotics. Further developments in this field are urgently needed in order to improve morbidity and mortality in people with CF. Here, we summarize current knowledge of pathophysiological mechanisms underlying P. aeruginosa infection in CF. Established treatments are discussed, and an overview is offered of novel detection methods and therapeutic strategies in development

COVID-19 in patients with pulmonary alveolar proteinosis: a European multicentre study

Adult PAP patients experience similar #COVID19 rates to the general population, and high rates of hospitalisation and deaths, underscoring their vulnerability and the need for measures to prevent infection. The impact of iGM-CSF must be considered. https://bit.ly/3M0wKnZ