Detection of Bronchiolitis Obliterans Syndrome Using Nitrogen Multiple Breath Washout in Children Posthemopoietic Stem Cell Transplant

Bronchiolitis obliterans syndrome (BOS) is a severe complication following hemopoietic stem cell transplantation (HSCT) and is often undetected until there is significant deterioration in pulmonary function. Lung clearance index (LCI2.5) derived from the nitrogen multiple breath washout (N2MBW) test may be more feasible and sensitive than spirometry, which is currently used for surveillance and detection of BOS. We aimed to examine the feasibility of performing surveillance N2MBW in children post-HSCT, and in an exploratory analysis, determine if LCI2.5 led to earlier detection of BOS when compared to spirometric indices. Participants aged 5 to 17 years were recruited prior to receiving HSCT into a prospective, single-center, feasibility study at the Royal Children's Hospital, Melbourne. N2MBW and spirometry were performed within the month prior to transplant and repeated at 3, 6, 9, and 12 months post-transplant. Data were also collected on the presence of graft-versus-host (GVHD) disease in any organ, including the lungs. Twenty-one (12 male) children with a mean age of 13.4 (range 9.2 to 17.1) years at recruitment participated in this study. Prior to HSCT, all participants had normal LCI2.5, while 16 (76%) demonstrated normal forced expiratory volume in 1 second (FEV1). Ninety-nine percent of N2MBW tests were technically acceptable, compared with 66% of spirometry tests. Three participants developed BOS, while 2 participants died of other respiratory complications. At 6 and 12 months post-transplant, the BOS group had increases in LCI2.5 ranging from 3 to 5 units and mean reductions in FEV1 % predicted of 40% to 53% relative to pre HSCT values, respectively. In those who developed BOS, post-HSCT LCI2.5 values were significantly worse when compared with the no BOS group (P < .001). Relative changes in LCI2.5 and FEV1 were both predictive of BOS at 6 months post HSCT. This study demonstrates that N2MBW is a more feasible test compared with spirometry in children post HSCT. However, in an exploratory analysis, LCI2.5 did not lead to earlier detection of BOS, when compared to spirometry.

Pulmonary immune profiling reveals common inflammatory endotypes of childhood wheeze and suppurative lung disease

Suppurative lung disease and wheezing are common respiratory diseases of childhood, however, due to poor understanding of underlying pathobiology, there are limited treatment options and disease recurrence is common. We aimed to profile the pulmonary and systemic immune response in children with wheeze and chronic suppurative lung disease for identification of endotypes that can inform improved clinical management. We used clinical microbiology data, highly multiplexed flow cytometry and immunoassays to compare pulmonary [bronchoalveolar lavage (BAL)] and systemic immunity in children with lung disease and controls. Unsupervised analytical approaches were applied to BAL immune data to explore biological endotypes. We identified two endotypes that were analogous in both frequency and immune signature across both respiratory diseases. The hyper-inflammatory endotype had a 12-fold increase in neutrophil infiltration and upregulation of 14 soluble signatures associated with type 2 inflammation and cell recruitment to tissue. The non-inflammatory endotype was not significantly different from controls. We showed these endotypes are measurable in a clinical setting and can be defined by measuring only three immune factors in BAL. We identified hyper-inflammatory and non-inflammatory endotypes common across pediatric wheeze and chronic suppurative lung disease that, if validated in future studies, have the potential to inform clinical management.

Benchmarking single-cell hashtag oligo demultiplexing methods

Sample multiplexing is often used to reduce cost and limit batch effects in single-cell RNA sequencing (scRNA-seq) experiments. A commonly used multiplexing technique involves tagging cells prior to pooling with a hashtag oligo (HTO) that can be sequenced along with the cells' RNA to determine their sample of origin. Several tools have been developed to demultiplex HTO sequencing data and assign cells to samples. In this study, we critically assess the performance of seven HTO demultiplexing tools: hashedDrops, HTODemux, GMM-Demux, demuxmix, deMULTIplex, BFF (bimodal flexible fitting) and HashSolo. The comparison uses data sets where each sample has also been demultiplexed using genetic variants from the RNA, enabling comparison of HTO demultiplexing techniques against complementary data from the genetic 'ground truth'. We find that all methods perform similarly where HTO labelling is of high quality, but methods that assume a bimodal count distribution perform poorly on lower quality data. We also suggest heuristic approaches for assessing the quality of HTO counts in an scRNA-seq experiment.

Telehealth use in Australian cystic fibrosis centers: Clinician experiences

BACKGROUND

Telehealth has been rapidly adopted by cystic fibrosis (CF) centers and ongoing use in routine CF care is endorsed by CF consumers. However, data describing CF clinician perceptions regarding telehealth are scarce. We aimed to describe clinician experiences and attitudes towards telehealth in CF care among health professionals across Australia.

METHODS

CF multidisciplinary health professionals from all CF clinics in Australia were sent an anonymous electronic survey.

RESULTS

Eighty-five responses were received representing 15 of 23 (65%) centers. Most clinicians reported using telehealth for routine clinic visits, and a range of other clinical encounters (69.9%). Telehealth was widely perceived as acceptable (91.8%), and clinicians were comfortable/very comfortable (81.2%) integrating telehealth into future CF care. Despite this, 64.1% of respondents considered telehealth clinics to be much worse than face-to-face clinics and 57.5% reported quality of care was somewhat/much worse using telehealth. Home spirometry was available in 73.7% of centers, however, only 26.7% of clinics could provide spirometers for >75% eligible patients. Growth and microbiology assessments were often missed in telehealth clinics and 75.7% reported a technical issue had prevented a telehealth consultation from occurring.

CONCLUSIONS

Telehealth for CF in Australia is considered feasible and acceptable by CF clinicians, although use of telehealth varies widely between centers. Concerns exist around the impact of telehealth on health outcomes, especially given core assessments are frequently omitted. Guidelines may help ensure the benefits of telehealth are realized for people with CF without compromising the standard of care.

Substrate-dependent metabolomic signatures of myeloperoxidase activity in airway epithelial cells: Implications for early cystic fibrosis lung disease

Myeloperoxidase (MPO) is released by neutrophils in inflamed tissues. MPO oxidizes chloride, bromide, and thiocyanate to produce hypochlorous acid (HOCl), hypobromous acid (HOBr), and hypothiocyanous acid (HOSCN), respectively. These oxidants are toxic to pathogens, but may also react with host cells to elicit biological activity and potential toxicity. In cystic fibrosis (CF) and related diseases, increased neutrophil inflammation leads to increased airway MPO and airway epithelial cell (AEC) exposure to its oxidants. In this study, we investigated how equal dose-rate exposures of MPO-derived oxidants differentially impact the metabolome of human AECs (BEAS-2B cells). We utilized enzymatic oxidant production with rate-limiting glucose oxidase (GOX) coupled to MPO, and chloride, bromide (Br-), or thiocyanate (SCN-) as substrates. AECs exposed to GOX/MPO/SCN- (favoring HOSCN) were viable after 24 h, while exposure to GOX/MPO (favoring HOCl) or GOX/MPO/Br- (favoring HOBr) developed cytotoxicity after 6 h. Cell glutathione and peroxiredoxin-3 oxidation were insufficient to explain these differences. However, untargeted metabolomics revealed GOX/MPO and GOX/MPO/Br- diverged significantly from GOX/MPO/SCN- for dozens of metabolites. We noted methionine sulfoxide and dehydromethionine were significantly increased in GOX/MPO- or GOX/MPO/Br--treated cells, and analyzed them as potential biomarkers of lung damage in bronchoalveolar lavage fluid from 5-year-olds with CF (n = 27). Both metabolites were associated with increasing bronchiectasis, neutrophils, and MPO activity. This suggests MPO production of HOCl and/or HOBr may contribute to inflammatory lung damage in early CF. In summary, our in vitro model enabled unbiased identification of exposure-specific metabolite products which may serve as biomarkers of lung damage in vivo. Continued research with this exposure model may yield additional oxidant-specific biomarkers and reveal explicit mechanisms of oxidant byproduct formation and cellular redox signaling.

Telehealth in Cystic Fibrosis. A systematic review incorporating a novel scoring system and expert weighting to identify a 'top 10 manuscripts' to inform future best practices implementation

The ongoing development and integration of telehealth within CF care has been accelerated in response to the Covid-19 pandemic, with many centres publishing their experiences. Now, as the restrictions of the pandemic ease, the use of telehealth appears to be waning, with many centres returning to routine traditional face-to-face services. For most, telehealth is not integrated into clinical care models, and there is a lack of guidance on how to integrate such a service into clinical care. The aims of this systematic review were to first identify manuscripts which may inform best CF telehealth practices, and second, to analyse these finding to determine how the CF community may use telehealth to improve care for patients, families, and Multidisciplinary Teams into the future. To achieve this, the PRISMA review methodology was utilised, in combination with a modified novel scoring system that consolidates expert weighting from key CF stakeholders, allowing for the manuscripts to be placed in a hierarchy in accordance with their scientific robustness. From the 39 found manuscripts, the top ten are presented and further analysed. The top ten manuscripts are exemplars of where telehealth is used effectively within CF care at this time, and demonstrate specific use cases of its potential best practices. However, there is a lack of guidance for implementation and clinical decision making, which remains an area for improvement. Thus, it is suggested that further work explores and provides guidance for standardised implementation into CF clinical practice.

The impact of telehealth based care on paediatric cystic fibrosis outcomes

In response to the COVID-19 pandemic telehealth utilisation amongst the Cystic Fibrosis (CF) population increased. Our aim was to assess the impact of CF telehealth clinics on CF outcomes. We conducted a retrospective chart review of patients seen in the CF clinic at the Royal Children's Hospital (Victoria, Australia). In this review we compared spirometry, microbiology and anthropometry in the year preceding the pandemic to during the pandemic, and to the first in-person appointment in 2021. 214 patients were included. First in-person FEV1 was median 5.4% below individuals' best FEV1 in 12 months prior to lockdown and decreased by >10% in 46 (31.9%) patients. There were no significant findings with regards to microbiology or anthropometry. The reduction in FEV1 observed on return to in-person appointments highlights the importance of ongoing improvement of telehealth-based care along with continued face-to-face review for the paediatric CF population.

Virtual monitoring in CF - the importance of continuous monitoring in a multi-organ chronic condition

Cystic Fibrosis (CF) is a chronic life-limiting condition that affects multiple organs within the body. Patients must adhere to strict medication regimens, physiotherapy, diet, and attend regular clinic appointments to manage their condition effectively. This necessary but burdensome requirement has prompted investigations into how different digital health technologies can enhance current care by providing the opportunity to virtually monitor patients. This review explores how virtual monitoring has been harnessed for assessment or performance of physiotherapy/exercise, diet/nutrition, symptom monitoring, medication adherence, and wellbeing/mental-health in people with CF. This review will also briefly discuss the potential future of CF virtual monitoring and some common barriers to its current adoption and implementation within CF. Due to the multifaceted nature of CF, it is anticipated that this review will be relevant to not only the CF community, but also those investigating and developing digital health solutions for the management of other chronic diseases.

Effectiveness of asthma preventer dispensing for preventing childhood asthma readmissions: a multisite cohort linkage study

OBJECTIVES

To (1) describe the dispensing of asthma preventers at hospital discharge and estimate its effect on hospital readmissions, and (2) estimate the effect of community asthma preventer dispensing on readmissions for the subgroup of children who were not prescribed an asthma preventer at discharge.

DESIGN

Multisite cohort study with linked administrative data.

PARTICIPANTS

Children aged 3-18 years admitted with asthma to a tertiary paediatric, mixed paediatric and adult, or regional hospital between 2017 and 2018.

MAIN OUTCOME MEASURE

Hospital readmission for asthma within 12 months.

RESULTS

Of the 767 participants, 201 (26.2%) were newly prescribed or requested to continue with asthma preventers. Of these, only 91 (45.3%) dispensed their discharge prescription within 3 days or had an active prescription. There was no evidence for a protective effect of discharge asthma preventer dispensing on asthma hospital readmissions within 12 months (OR 1.17, 95% CI 0.69 to 1.97, p=0.57). Of the 566 children who were not prescribed asthma preventers at discharge, 269 (47.5%) had one or more prescriptions dispensed in the community within 12 months. Participants who were in the protected period (asthma preventer dispensed) had reduced risk of an asthma hospital readmission (HR 0.61, 95% CI 0.36 to 1.02, p=0.06), including preschool children (HR 0.48, 95% CI 0.25, 0.93, p=0.03) on subgroup analysis.

CONCLUSIONS

There was a low rate for prescribing and dispensing of hospital discharge asthma preventers and no protective effect was found for its impact on readmissions. A protective effect on readmissions was found for community asthma preventer dispensing.

Modifiable factors associated with pediatric asthma readmissions: a multi-center linked cohort study

OBJECTIVES

To (a) identify rates of hospital readmission and emergency department (ED) re-presentation for asthma within a 12-month period, (b) estimate the effects of modifiable hospital, general practitioner (GP) and home environmental factors on hospital readmission, ED re-presentations and rescue oral corticosteroid use.

METHODS

We recruited 767 children aged 3-18 years who were admitted to 3 hospitals in Victoria, Australia between 2017 and 2018 with a validated diagnosis of asthma on chart review. Primary outcome was hospital readmission with asthma within 12 months of index admission. Secondary outcomes were ED re-presentation for asthma and rescue oral corticosteroid use. All outcomes were identified through linked administrative datasets. Their caregivers and 277 nominated GPs completed study surveys regarding the home environment and their usual asthma management practices respectively.

RESULTS

Within 12 months of an index admission for asthma 263 (34.3%) participants were readmitted to a hospital for asthma, with participants between the ages of 3-5 years accounting for 69.2% of those readmitted. The estimated effect of GP reported guideline discordant care on the odds of readmission was OR 1.57, 95% CI 1.00-2.47, p = 0.05. None of the hospital or home environmental factors appeared to be associated with hospital readmissions.

CONCLUSIONS

Hospital readmissions among Australian children with asthma are increasing, and linked datasets are important for objectively identifying the health services burden of asthma. They also confirm the important role of the GP in the management of pediatric asthma.

A scoping review of lung function in children and adolescents living with HIV in the era of antiretroviral treatment

BACKGROUND

Human immunodeficiency virus (HIV) in children and adolescents remains an important health challenge in many countries and is commonly associated with lung disease. The introduction of antiretroviral therapy (ART) has greatly improved survival but chronic lung disease is a common ongoing challenge. We conducted a scoping review of studies that have reported lung function in school-aged children and adolescents living with HIV.

METHODS

A systematic literature search was performed by searching Medline, Embase, and PubMed databases, limited to articles published between 2011 and 2021 in English language. Inclusion criteria were studies involving participants living with HIV aged 5-18 years and having spirometry data. The primary outcome was lung function as measured by spirometry.

RESULTS

Twenty-one studies were included in the review. Most study participants were living in the sub-Saharan African region. The prevalence of reduced forced expiratory volume in 1 s (FEV₁ ) ranged from 25.3% to 73% across studies, reduced forced vital capacity (FVC) ranged from 10% to 42% and reduced FEV₁ /FVC ranged from 3% to 26%. The mean z-score of FEV₁ ranged from -2.19 to -0.73, mean zFEV₁ /FVC ranged from -0.74 to 0.2, and mean FVC ranged from -1.86 to -0.63.

CONCLUSION

There is a high prevalence of lung function impairment in children and adolescents living with HIV, which persists in the ART era. Further studies are needed of interventions that might improve lung function in these vulnerable populations.

Primary health care utilization and hospital readmission in children with asthma: a multi-site linked data cohort study

OBJECTIVES

To (1) describe primary health care utilization and (2) estimate the effect of primary care early follow-up, continuity, regularity, frequency, and long consultations on asthma hospital readmission, including secondary outcomes of emergency (ED) presentations, asthma preventer adherence, and use of rescue oral corticosteroids within 12 months.

METHODS

An Australian multi-site cohort study of 767 children aged 3-18 years admitted with asthma between 2017 and 2018, followed up for at least 12 months with outcome and primary care exposure data obtained through linked administrative datasets. We estimated the effect of primary care utilization through a modified Poisson regression adjusting for child age, asthma severity, socioeconomic status and self-reported GP characteristics.

RESULTS

The median number of general practitioner (GP) consultations, unique GPs and clinics visited was 9, 5, and 4, respectively. GP care was irregular and lacked continuity, only 152 (19.8%) children visited their usual GP on more than 60% of occasions. After adjusting for confounders, there was overall weak indication of effects due to any of the exposures. Increased frequency of GP visits was associated with reduced readmissions (4-14 visits associated with risk ratio of 0.71, 95% CI 0.50-1.00, p = 0.05) and ED presentations (>14 visits associated risk ratio 0.62, 95% CI 0.42-0.91, p = 0.02).

CONCLUSIONS

Our study demonstrates that primary care use by children with asthma is often irregular and lacking in continuity. This highlights the importance of improving accessibility, consistency in care, and streamlining discharge communication from acute health services.

Exploring gaps and opportunities in primary care following an asthma hospital admission: a multisite mixed-methods study of three data sources

OBJECTIVE

Explore gaps and opportunities in primary care for children following a hospital admission for asthma.

DESIGN

Exploratory mixed-methods, using linked hospital and primary care administration data.

SETTING

Eligible children, aged 3-18 years, admitted to one of three hospitals in Victoria, Australia between 2017 and 2018 with a clinical diagnosis of asthma.

RESULTS

767 caregivers of eligible children participated, 39 caregivers completed a semistructured interview and 277 general practitioners (GPs) caring for 360 children completed a survey. Over 90% (n=706) of caregivers reported their child had a regular GP. However, few (14.1%, n=108) attended a GP in the 24 hours prior to index admission or in the 7 days after (35.8%, n=275). Children readmitted for asthma (34.2%, n=263), compared with those not readmitted (65.8%, n=504), were less likely to have visited a GP in the non-acute phase of their asthma in the 12 months after index admission (22.1% vs 42.1%, respectively), and their GP was more likely to report not knowing the child had an asthma admission (52.8% vs 39.2%, respectively). Fewer GPs reported being extremely confident managing children with poorly controlled asthma (11.9%, n=43) or post-discharge (16.7%, n=60), compared with children with well-controlled asthma (36.4%, n=131), with no difference by child readmission status.

CONCLUSIONS

Given the exploratory design and descriptive approach, it is unknown if the differences by child readmission status have any causal relationship with readmission. Nonetheless, improving preventative patterns of primary care visits, timely communication between hospitals and primary care providers, and guideline concordant care by GPs are needed.

Persistent pleuritic chest pain in a patient with cystic fibrosis

A 14-year-old girl with cystic fibrosis (CF), homozygous for the Phe508del mutation, was electively admitted for optimisation of lung disease. Her CF was complicated by bronchiectasis, gastrostomy feeding, liver disease, and diabetes. Sputum cultures had identified Haemophilus parainfluenzae and Candida albicans in the previous 12 months, but she had never cultured Pseudomonas aeruginosa. She also had comorbid osteogenesis imperfecta (OI), type 3 phenotype, which was complicated by multiple long bone fractures including four rib fractures at birth. Her baseline forced expiratory volume in 1 s (FEV₁) was 44% (0.78 L), forced vital capacity (FVC) 54% (1.06 L), and FEV₁/FVC ratio 81% predicted. The combination of CF and OI had resulted in severe restrictive lung disease with nocturnal hypoventilation managed with bilevel noninvasive ventilation.

Pleural effusion is rare in cystic fibrosis. Infection leading to pleural effusion is likely to be polymicrobial, including contributory fungal infection; microbiology of pleural fluid is commonly discordant with sputum.https://bit.ly/3MJXrhk

Characteristics, management and changing incidence of children with empyema in a paediatric intensive care unit

AIM

Paediatric intensive care unit (PICU) admissions for empyema increased following the 13-valent pneumococcal conjugate vaccine (PCV13). We describe the clinical characteristics, management and outcomes for children with empyema and compare incidence before and after PCV13.

METHODS

Retrospective study of patients <18 years admitted to The Royal Children's Hospital Melbourne PICU with empyema between January 2016 and July 2019. We investigated the incidence of empyema during two time periods: 2007-2010 (pre-PCV13) and 2016-2019 (post-PCV13).

RESULTS

Seventy-one children (1.9% of all PICU admissions) were admitted to PICU with empyema between 2016 and 2019. Sixty-one (86%) had unilateral disease, 11 (16%) presented with shock and 44 (62%) were ventilated. Streptococcus pneumoniae and group A Streptococcus were the most commonly identified pathogens. Forty-five (63%) were managed with video-assisted thoracoscopic surgery (VATS). There was a 31% reduction in empyema hospitalisations as a proportion of all hospitalisations (IRR 0.69, 95% CI 0.59-0.8), but a 2.8-fold increase in empyema PICU admissions as a proportion of all PICU admissions (95% CI 2.2-3.5, P < 0.001). For the PICU cohort, this was accompanied by reduction in PIM2 probability of death (median 1% vs. 1.9%, P = 0.02) and duration of intubation (median 69 h vs. 126.5 h, P = 0.045).

CONCLUSIONS

In children with empyema in PICU 62% required ventilation, 16% had features of shock and 63% received VATS. Empyema admissions, as a proportion of all PICU admissions, increased in the era post-PCV13 compared to pre-PCV13 despite no increase in illness severity at admission.

Fissure adjacent partial lobe atelectasis in primary ciliary dyskinesia

AIM

Establishing the underlying cause in a child with chronic suppurative lung disease (CSLD) allows for targeted treatment and screening for associated complications. One cause of CSLD is primary ciliary dyskinesia (PCD). Testing for PCD requires specialist expertise which is not widely available. Computed tomography (CT) scans are commonly performed when assessing CSLD. Identifying PCD-specific signs on CT would help clinicians in deciding when to refer for specialist testing. One potential PCD-specific sign we have observed is fissure adjacent partial lobe atelectasis (FAPLA). We aimed to assess if FAPLA is commonly found in CT of PCD patients.

METHODS

Fifty-eight CT scans from 42 adult and child PCD patients were analysed. The presence and distribution of FAPLA were noted, and its association to sputum culture and other signs commonly seen in CSLD (bronchiectasis, bronchial wall thickening, air trapping and mucus plugging).

RESULTS

FAPLA was found in 13 of 40 participants in their earliest CT scan. The prevalence of FAPLA was similar in children and adults. FAPLA involved the right middle lobe in all 13 cases and was systematically associated with ≥1 other structural change. There was no association between FAPLA and bacterial isolation from sputum.

CONCLUSION

FAPLA was found in 32.5% PCD scans, without difference between children and adults in terms of frequency. Future work will determine if it is a PCD-specific sign by assessing whether it is also found in other CSLD processes and analysing more scans from children with PCD to determine how early this sign develops.

DNA Methylation Profiles of Purified Cell Types in Bronchoalveolar Lavage: Applications for Mixed Cell Paediatric Pulmonary Studies

In epigenome-wide association studies analysing DNA methylation from samples containing multiple cell types, it is essential to adjust the analysis for cell type composition. One well established strategy for achieving this is reference-based cell type deconvolution, which relies on knowledge of the DNA methylation profiles of purified constituent cell types. These are then used to estimate the cell type proportions of each sample, which can then be incorporated to adjust the association analysis. Bronchoalveolar lavage is commonly used to sample the lung in clinical practice and contains a mixture of different cell types that can vary in proportion across samples, affecting the overall methylation profile. A current barrier to the use of bronchoalveolar lavage in DNA methylation-based research is the lack of reference DNA methylation profiles for each of the constituent cell types, thus making reference-based cell composition estimation difficult. Herein, we use bronchoalveolar lavage samples collected from children with cystic fibrosis to define DNA methylation profiles for the four most common and clinically relevant cell types: alveolar macrophages, granulocytes, lymphocytes and alveolar epithelial cells. We then demonstrate the use of these methylation profiles in conjunction with an established reference-based methylation deconvolution method to estimate the cell type composition of two different tissue types; a publicly available dataset derived from artificial blood-based cell mixtures and further bronchoalveolar lavage samples. The reference DNA methylation profiles developed in this work can be used for future reference-based cell type composition estimation of bronchoalveolar lavage. This will facilitate the use of this tissue in studies examining the role of DNA methylation in lung health and disease.

Is cardiorespiratory disease associated with increased susceptibility of SARS-CoV-2 in children?

BACKGROUND

There are limited data in pediatric populations evaluating whether chronic cardiorespiratory conditions are associated with increased risk of coronavirus disease 2019 (COVID-19). We aimed to compare the rates of chronic cardiac and respiratory disease in children testing positive severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2[+]) compared with those testing negative (SARS-CoV-2[-]) at our institution.

METHOD

Prospective cohort with nested case-control study of all children tested by polymerase chain reaction (PCR) for SARS-CoV-2 by nasopharyngeal/oropharyngeal sampling between March and October 2020. Children were identified prospectively via laboratory notification with age and sex-matching of SARS-CoV-2[+] to SARS-CoV-2[-] (1:2). Clinical data were extracted from the electronic medical record.

RESULTS

In total, 179 SARS-CoV-2[+] children (44% females, median age 3.5 years, range: 0.1-19.0 years) were matched to 391 SARS-CoV-2[-] children (42% female, median age 3.7 years, range: 0.1-18.3 years). The commonest comorbidities showed similar frequencies in the SARS-CoV-2[+] and [-] groups: asthma (n = 9, 5% vs. n = 17, 4.4%, p = 0.71), congenital heart disease (n = 6, 3.4% vs. n = 7, 1.8%, p = 0.25) and obstructive sleep apnoea (n = 4, 2.2% vs. n = 10, 2.3%, p = 0.82). In the SARS-CoV-2[+] group, the prevalence of symptomatic disease was similar among children with and without cardiorespiratory comorbidities (n = 12, 75% vs. n = 103, 57%, p = 0.35). A high proportion of children hospitalized with SARS-CoV-2 infection had cardiac comorbidities (23.8%).

CONCLUSIONS

In this single site data set, rates of pre-existing cardiorespiratory disease were similar in SARS-CoV-2[+] and SARS-CoV-2[-] children. Rates of symptomatic infection were similar between children with and without cardiorespiratory comorbidity. High rates of comorbid cardiac disease were observed among hospitalized children with COVID-19 warranting further research to inform vaccine prioritization.

Mapping Pulmonary and Systemic Inflammation in Preschool Aged Children With Cystic Fibrosis

The immune landscape of the paediatric respiratory system remains largely uncharacterised and as a result, the mechanisms of globally important childhood respiratory diseases remain poorly understood. In this work, we used high parameter flow cytometry and inflammatory cytokine profiling to map the local [bronchoalveolar lavage (BAL)] and systemic (whole blood) immune response in preschool aged children with cystic fibrosis (CF) and aged-matched healthy controls. We demonstrate that children with CF show pulmonary infiltration of CD66b⁺ granulocytes and increased levels of MIP-1α, MIG, MCP-1, IL-8, and IL-6 in BAL relative to healthy control children. Proportions of systemic neutrophils positively correlated with age in children with CF, whilst systemic CD4 T cells and B cells were inversely associated with age. Inflammatory cells in the BAL from both CF and healthy children expressed higher levels of activation and migration markers relative to their systemic counterparts. This work highlights the utility of multiplex immune profiling and advanced analytical pipelines to understand mechanisms of lung disease in childhood.

Pulmonary surveillance in pediatric hematopoietic stem cell transplant: A multinational multidisciplinary survey

Background

Hematopoietic Stem Cell Transplant (HSCT) is an established treatment for malignant and non‐malignant conditions and pulmonary disease is a leading cause of late term morbidity and mortality. Accurate and early detection of pulmonary complications is a critical step in improving long term outcomes. Existing guidelines for surveillance of pulmonary complications post‐HSCT contain conflicting recommendations.

Aim

To determine the breadth of current practice in monitoring for pulmonary complications of pediatric HSCT.

Methods

An institutional review board approved, online, anonymous multiple‐choice survey was distributed to HSCT and pulmonary physicians from the United States of America and Australasia using the REDcap platform. The survey was developed by members of the American Thoracic Society Working Group on Complications of Childhood Cancer, and was designed to assess patient management and service design.

Results

A total of 40 (34.8%) responses were received. The majority (62.5%) were pulmonologists, and 82.5% were from the United States of America. In all, 67.5% reported having a protocol for monitoring pulmonary complications and 50.0% reported adhering “well” or “very well” to protocols. Pulmonary function tests (PFTs) most commonly involved spirometry and diffusion capacity for carbon monoxide. The frequency of PFTs varied depending on time post‐HSCT and presence of complications. In all, 55.0% reported a set threshold for a clinically significant change in PFT.

Conclusions

These results illustrate current variation in surveillance for pulmonary complications of pediatric HSCT. The results of this survey will inform development of future guidelines for monitoring of pulmonary complications after pediatric HSCT.

Associations between peak oxygen uptake, lung function, and bronchiectasis in children with cystic fibrosis in the era of CFTR modulators

BACKGROUND

With the emergence of cystic fibrosis transmembrane conductance regulator (CFTR) modulators, forced expiratory volume in 1 s (FEV₁ ) may become a less sensitive measure of pulmonary disease progression in children with cystic fibrosis (CF). Increasing evidence shows that peak oxygen uptake (VO_2peak ) is a strong predictor of prognosis in CF. The primary aim of this study was to describe the associations between peak oxygen uptake, lung function, and bronchiectasis in children with CF in the era of CFTR modulators.

METHODS

Spirometry and a maximal cardiopulmonary exercise test (CPET) were performed on the same day and compared to markers of disease severity. Markers of disease severity included a number of pulmonary exacerbations resulting in hospital admission within the preceding 12 months, body mass index, Pseudomonas aeruginosa (PsA) infection, and bronchiectasis.

RESULTS

Fifty-two subjects (24 female) with CF participated in the study with a mean (SD) age of 13.8 (2.4) years, range 8-18 years. Forty-nine participants met satisfactory criteria for a maximal CPET. A significant correlation was found between relative VO_2peak %predicted and FEV₁ %predicted (r = .546, p < .001). A total of 4/49 children demonstrated an impaired aerobic capacity despite normal spirometry. Participants who had experienced one or more pulmonary exacerbations in the previous 12 months had a significantly lower relative VO_2peak %predicted (p = .02).

CONCLUSIONS

In children with CF who have mild pulmonary disease, there is significant correlation between FEV₁ and VO_2peak . In all, 8.2% of participants had an abnormal CPET result despite normal spirometry, and preceding pulmonary exacerbations were associated with poorer CPET outcomes. CPET may offer important prognostic information for clinical decision making in this new era of CFTR modulators.

COVID-19 and complicated bacterial pneumonia in children

We read with great interest the recent publication by Steinfortet al. [1] outlining the profound reduction in influenza infections in Australia as a result of social distancing during the COVID-19 pandemic. Similar dramatic effects of social distancing on paediatric hospital activity have been reported, with reduced hospital admissions, presentations for respiratory conditions and detection of other viruses [2–6]. However, the impact of the pandemic on bacterial respiratory infections has not been well characterised. The Australian state of Victoria (population 6.7 million) has experienced a prolonged period of social restrictions (“lockdown”) since March 2020. This period spanned the southern hemisphere autumn to spring, the usual peak period for bacterial respiratory infections.

Social distancing measures instituted due to #SARSCoV2 have dramatically reduced paediatric thoracic empyema cases in Australiahttps://bit.ly/3akG98M

Single-Cell Flow Cytometry Profiling of BAL in Children

Childhood pulmonary diseases not only cause childhood morbidity and mortality but also can cause long-term pulmonary impairment. The clinical management of many childhood pulmonary diseases is hampered by a limited understanding of the underlying pathophysiological mechanisms. Flow cytometry, which can be used to phenotype individual cell populations or isolate cells for downstream analysis, represents a crucial technology that can help to elucidate the pathophysiology of these conditions. Here, we describe a flow cytometry-based method for purification and characterization of cell populations in BAL from children. This includes assessment of the effect of cryopreservation on cell phenotype and frequency, a knowledge gap recently identified by an American Thoracic Society report on flow cytometry in lung samples. To our knowledge, this is the first study to simultaneously quantify alveolar macrophages, T cells (CD4 and CD8), B cells, natural killer cells, dendritic cells, granulocytes, and monocytes (CD16⁺/CD16^-) in the BAL of children. The protocols described can be used to advance investigation of the pathophysiology of childhood pulmonary diseases.

DNA methylation biomarkers of future health outcomes in children

Biomarkers which predict future health outcomes are key to the goals of precision health. Such biomarkers do not have to be involved in the causal pathway of a disease, and their performance is best assessed using statistical tests of clinical performance and evaluation of net health impact. DNA methylation is the most commonly studied epigenetic process and represents a potential biomarker of future health outcomes. We review 25 studies in non-oncological paediatric conditions where DNA methylation biomarkers of future health outcomes are assessed. Whilst a number of positive findings have been described, the body of evidence is severely limited by issues with outcome measures, tissue-specific samples, accounting for sample cell type heterogeneity, lack of appropriate statistical testing, small effect sizes, limited validation, and no assessment of net health impact. Future studies should concentrate on careful study design to overcome these issues, and integration of DNA methylation data with other 'omic', clinical, and environmental data to generate the most clinically useful biomarkers of paediatric disease.

Gene modifiers of cystic fibrosis lung disease: A systematic review

BACKGROUND

Lung disease is the major source of morbidity and mortality in cystic fibrosis (CF), with large variability in severity between patients. Although accurate prediction of lung disease severity would be extremely useful, no robust methods exist. Twin and sibling studies have highlighted the importance of non-cystic fibrosis transmembrane conductance regulator (CFTR) genes in determining lung disease severity but how these impact on the severity in CF remains unclear.

METHODS

A systematic review was undertaken to answer the question "In patients with CF which non-CFTR genes modify the severity of lung disease?" The method for this systematic review was based upon the "Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA)" statement, with a narrative synthesis of results planned.

RESULTS

A total of 1168 articles were screened for inclusion, with 275 articles undergoing detailed assessment for inclusion. One hundred and forty articles were included. Early studies focused on candidate genes, whereas more recent studies utilized genome-wide approaches and also examined epigenetic mechanisms, gene expression, and therapeutic response.

DISCUSSION

A large body of evidence regarding non-CFTR gene modifiers of lung disease severity has been generated, examining a wide array of genes. Limitations to existing studies include heterogeneity in outcome measures used, limited replication, and relative lack of clinical impact. Future work examining non-CFTR gene modifiers will have to overcome these limitations if gene modifiers are to have a meaningful role in the care of patients with CF.

Utility of Endobronchial Ultrasound in Assessment of Intrathoracic Lesions in Paediatric Patients

INTRODUCTION

In adults, linear endobronchial ultrasound (EBUS) is the preferred modality to sample intrathoracic adenopathy and radial EBUS is a useful tool to biopsy peripheral pulmonary nodules. Utility in children is less well known.

OBJECTIVES

The objective of this study was to review the EBUS experience of two specialist centres to better define the current role of EBUS in paediatric practice.

METHODS

A retrospective record review of EBUS procedures undertaken in patients aged 0-17 years at the Royal Children's Hospital (Melbourne, Australia) and Thoraxklinik (Heidelberg, Germany) was performed. Data extracted included patient demographics, clinical presentation, bronchoscope (size and model), EBUS technique used, pathologic results, need for further invasive investigation, and complications.

RESULTS

Between 2008 and 2017, ten EBUS procedures were performed (6 linear EBUS and 4 radial EBUS). No complications were reported. Linear EBUS was performed on subjects who were between 4 and 15 years old, with a 100% diagnostic yield. Radial EBUS was non-diagnostic in three cases of non-malignant disease. In one case, it was used successfully for imaging alone.

CONCLUSION

Both linear and radial EBUS are safe and feasible in children. Diagnostic yield of linear EBUS was 100%. Radial EBUS did not demonstrate utility, likely reflecting the pathologies of underlying parenchymal masses in paediatric populations.

Pulmonary Mycobacterium abscessus complex in children with cystic fibrosis: A practical management guideline

The treatment of Mycobacterium abscessus complex (MABSC) pulmonary infections is an emerging challenge in patients with cystic fibrosis (CF). Multidrug therapy for prolonged durations is required and carries the significant burden of drug-related toxicity, cost and selective pressure for multiresistant bacteria. International guidelines acknowledge that clinical and in vitro data to support treatment regimens are limited, particularly in children. As part of a collaboration between the infectious diseases and respiratory units at our institution, we have developed a modified treatment guideline that aims to balance the aims of MABSC eradication and slowing disease progression with minimising drug toxicity and resistance. The outcomes of this treatment approach will be monitored and reported. In this manuscript, we discuss the available evidence for treatment choices and present our treatment guideline for paediatric patients with CF and MABSC infection.

Clinical utility of surveillance computed tomography scans in infants with cystic fibrosis

BACKGROUND

In cystic fibrosis (CF), irreversible lung disease arises in early life, and is often asymptomatic and unrecognised. Chest computed tomography (CT) scans have been used to detect asymptomatic lung disease in research; however, the clinical utility of chest CT is unknown. This study aimed to determine the effect of surveillance CT in early life on the clinical management of patients with CF.

WORKING HYPOTHESIS

Surveillance CT in early life changes the management of patients with CF.

METHODS

A medical record review of patients in the AREST-CF cohort who had chest CT at 1 and 3 years of age was performed. Information extracted included CT scan findings and the effect of CT results on clinical management.

RESULTS

The chest CT scans and records of 50 subjects with CF were reviewed. The majority of CT scans (n = 75; 75%) were abnormal. N = 31 (31%) of scans overall led to a direct change in management. The number of CT scans needed to be performed to lead to a treatment change was 3.2. The majority (n = 18, 58%) of changes in management were prompted by the finding of bronchiectasis.

CONCLUSION

To the authors knowledge, this is the first study to highlight that early life surveillance CT frequently results in changes in clinical management, and hence may have a role beyond research and in routine care. If this can be shown to contribute to improved outcomes (such as reduced rates of bronchiectasis), then, as radiation doses diminish, chest CT could have an important clinical role.

Quality of inpatient care in public and private hospitals in Sri Lanka

OBJECTIVE

To compare the quality of inpatient clinical care in public and private hospitals in Sri Lanka.

METHODS

A retrospective, cross-sectional comparison was done of inpatient quality, in a sample of 11 public and 10 private hospitals in three of 25 districts. Data were collected for 55 quality indicators from medical records of 2523 public and 1815 private inpatient admissions. These covered treatment of asthma, acute myocardial infarction (AMI), childbirth and five other conditions, along with outcome indicators, and medicine prescribing indicators.

RESULTS

Overall quality scores were better in the public sector than the private sector (77 vs 69%). Performance was similar for management of AMI and childbirth and somewhat better in the private sector for management of asthma. The public sector performed better in those indicators that are not constrained by resources (94 vs 81%), but worse in indicators that are highly resource intensive (10 vs 31%). Quality was comparable in assessment and investigation, but the public sector performed better in treatment and management (70 vs 62%) and drug prescribing (68 vs 60%), and modestly worse in terms of outcomes (92 vs 97%).

CONCLUSIONS

For a range of indicators where comparisons were possible, quality of inpatient clinical care in Sri Lanka was comparable to levels reported from upper-middle income Asian countries, and often approaches that in developed countries, although the findings cannot be generalized. Quality in the public sector is better than in the private sector in many areas, despite spending being substantially less. Quality in public hospitals is resource constrained, and needs greater government investment for improvement, but when resource limitations are not critical, the public sector appears able to deliver equal or better quality than the private sector. Overall similarities in quality between the two sectors suggest the importance of physician training and other factors.

Pulmonary sarcoidosis in a preschool patient

Sarcoidosis is a rare disease, especially in the preschool age group where it usually presents with eye, joint, and skin involvement sparing the lungs. Multiple treatment regimes have been described with oral prednisolone being the usual first line treatment. We describe a case of a 4-year-old boy presenting with pulmonary sarcoidosis with no other organ involvement. The child was successfully managed with pulse intravenous methylprednisolone followed by oral prednisolone and has had a good outcome. This case reports a rare presentation of preschool sarcoidosis as well as the novel and successful use of pulse methylprednisolone in paediatric pulmonary sarcoidosis.

Development of validated stability indicating assay method for simultaneous estimation of metformin hydrochloride and vildagliptin by RP-HPLC

A simple, precise and stability-indicating HPLC method was developed and validated for the simultaneous determination of metformin hydrochloride (MET) and vildagliptin (VLG) in pharmaceutical dosage forms. The method involves use of easily available inexpensive laboratory reagents. The separation was achieved on Grace Cyano column (250 mm×4.6 mm) 5 µm with isocratic flow. The mobile phase was pumped at a flow rate of 1.0 mL/min, consisted of 25 mM ammonium bicarbonate buffer and acetonitrile (65:35, v/v). The UV detection was carried out at 207 nm. A linear response was observed over the concentration range of 25-125 µg/mL for MET and 50-250 µg/mL for VLG respectively. Limit of detection and limit of quantification for MET were 0.36 µg/mL and 1.22 µg/mL, and for VLG were 0.75 µg/mL and 2.51 µg/mL respectively. The method was successfully validated in accordance to ICH guidelines acceptance criteria for specificity, linearity, accuracy, precision, robustness, and system suitability. Individual drugs (MET and VLG) were exposed to thermal, photolytic, hydrolytic and oxidative stress conditions. The resultant stressed samples were analyzed by the proposed method. The method gave high resolution among the degradation products and the analytes. The peak purity of analyte peak in the stressed samples was confirmed by photo diode array detector. The proposed method was successfully applied for the quantitative analysis of MET and VLG in tablet dosage form, which will help to improve quality control and contribute to stability studies of pharmaceutical tablets containing these drugs.