Abstract/Summary Innate immune responses are crucial for host defence but vary markedly between individuals. Although determinants of this variation are well characterised in adults, data from healthy children remain scarce. We therefore profiled whole-blood cytokine responses to innate immune stimulation in 286 children aged approximately four years and examined genetic, host-intrinsic, and environmental correlates of response. Cytokine responses showed marked inter-individual heterogeneity and stimulus-specific patterns. The top 50 genetic variants explained a substantial proportion (∼20-45%) of this variance across many stimulus conditions, including a biologically coherent association of the STING locus with cGAMP-induced cytokine production. In contrast, sex, age, adiposity, and perinatal variables showed limited or modest associations. Systemic inflammatory biomarkers of systemic inflammation (hsCRP, glycoprotein acetyls, granulocyte-to-lymphocyte ratio) were strongly positively associated with cytokine responses. Finally, seasonal population-level viral infection burden was positively associated with antiviral and inflammatory cytokine responses. Collectively, these findings advance our understanding of variation in early-life whole-blood cytokine responses, underscoring this developmental period as a critical window for understanding immune development trajectories relevant to long-term health.

Abstract Background Elexacaftor-tezacaftor-ivacaftor (ETI) has been demonstrated to improve lung function in clinical trials; however, evidence describing effects on trajectories and whether long-term improvements are sustained (>1-year) is lacking. We estimated within-person lung clearance index (LCI) trajectories before and after ETI initiation, assessing changes in level and rate of change, alongside acute LCI change, up to three years after ETI initiation. Methods Prospective observational study of children at a tertiary hospital. Children aged 3–17 years with ≥2 LCI testing occasions (i) before and (ii) after starting ETI were used to describe lung function trajectories. Children with ≥1 pre-ETI and ≥1 post-ETI LCI occasion(s) were used to describe acute LCI change after ETI initiation. Age-adjusted LCI trajectories for time periods (i) before and (ii) after ETI initiation were estimated using linear mixed-effects models, and pre- and post-ETI LCIs were compared using paired Wilcoxon tests. Results Mean pre-ETI and post-ETI longitudinal changes in LCI were -0.007 (95% CI: -0.28, 0.27; n=35) and 0.12 (95% CI: -0.17, 0.41; n=20) turnovers per year, respectively. Before ETI initiation, 57% (30/53) of patients had an LCI≥7.1 turnovers (indicating impaired lung function), compared to 26% (14/53) post-ETI, with a median LCI difference of -0.70 (95% CI -0.84, -0.46; p<0.001) turnovers. Within-individual variability in LCI decreased post-ETI. Conclusions Our real-world data within a unique longitudinal study provide a comprehensive picture of ETI benefit by outlining not only acute improvement in LCI but maintained stability in LCI trajectories and improved LCI stability sustained up to three years post-initiation.

Prolonged exposure to high concentrations of trihalomethanes (THMs), which are water disinfection by-products, poses a significant human health risk. This study investigated the spatial-temporal distribution of THM concentrations, the exceedance of the Australian drinking water guideline value (250 μg/L), and the environmental factors associated with THM concentrations in public drinking water supplies across Queensland, Australia, to help guide strategies for mitigating THM exposure. We employed a data linkage approach, integrating spatial water quality monitoring data covering 27 local government areas (LGAs) from 2009 to 2020 with environmental data from the Bureau of Meteorology. Key outcomes were THM concentrations and exceedances. Analyses included time-trends, multiple generalised linear models and logistic regression models. The median monthly THM concentration was 78 μg/L [IQR 49, 119 μg/L]. Between 2009 and 2020, the median THM concentration increased from 38 μg/L to 73 μg/L, while the incidence of exceedance increased from 2.3% to 3.0%. THM exceedances were significantly lower in water from treatment plants (AOR = 0.15, 95% CI [0.07, 0.30]), in LGAs within South-East Queensland (AOR = 0.07, 95% CI [0.01, 0.33]), during spring (AOR = 0.39, 95% CI [0.21,0.70]), in advantaged socio-economic areas and major cities. Increase in temperature was associated with greater THM exceedance (AOR = 1.21, 95% CI [1.07,1.37]), but lower during periods of bushfire (exp(β) = 0.85, 95% CI [0.76,0.95]). Rainfall and NDVI were not significantly associated with THM concentration and exceedances. The elevated concentrations and repeated exceedances highlight a persistent challenge coupled with systemic inequities. We recommend consistent THM data collection, monitoring, optimizing treatment and infrastructure upgrades in disadvantaged regions to improve water quality and protect public health.

Rationale: Oscillometry-based assessments of bronchodilator response (BDR) typically focus on a specific index but rarely compare relative change across indices. This study explored BDR as impedance (Z) vectors incorporating both resistance and reactance from intrabreath oscillometry (IB-OSC) to distinguish asymptomatic wheezy children from healthy children. Methods: BDR was assessed with IB-OSC (10 Hz sinusoid, triplicate trials) during tidal breathing in 3-6-year-olds with recurrent and severe wheezing at recruitment, six weeks, six months, and 12 months. Placebo response and BDR thresholds in health were determined in age-matched healthy children across separate visits. Linear mixed models explored the effects of wheezing phenotype (mild versus severe based on the frequency of wheezy exacerbations during the study period) and height on BDR measured by resistance at end-expiration (ReE), resistance at end-inspiration (ReI), tidal change in resistance (ΔR=ReE-ReI), reactance at end-expiration (XeE), reactance at end-inspiration (XeI), tidal change in reactance (ΔX=XeE-XeI), ΔX normalised by tidal volume (ΔX/VT), and impedance magnitude at end-expiration (ZeE) and end-inspiration (ZeI). Results: In total, 126 wheezy and 57 healthy children were recruited. After adjusting for height in 249 asymptomatic measurements from 138 children, those with severe recurrent wheezing had a ΔR of -0.20 hPa•s•L-1 (95%CI -0.38 to -0.02, p=0.033), XeE of +0.66 hPa•s•L-1 (95%CI +0.27 to +1.05, p=0.001), ΔX of +0.40 hPa•s•L-1 (95%CI +0.20 to +0.60, p<0.001), and ΔX/VT of +1.28 hPa•s•L-2 (95%CI +0.56 to +2.00, p=0.001) compared to healthy children. Plotting BDR as ZeE vectors on a plane of XeE versus ReE (Figure 1) revealed that asymptomatic severe recurrent wheezers (blue arrows) had a ZeE BDR that differed from healthy (green arrows) after adjusting for height (-0.50 hPa•s•L-1, 95%CI -0.98 to -0.01, p=0.048). The arrow direction indicates pre- to post-bronchodilator change. Pink arrows denote the placebo effect in healthy children to outline short-term repeatability. Conclusion: Steeper BDR vector slopes for severe recurrent wheezers suggest a greater BDR for XeE versus ReE. Physiologically this could be explained by predominant improvements in small airway function, improving ventilation inhomogeneity. Greater BDR in ReE versus XeE BDR in mild recurrent wheezers may reflect predominant improvements in conducting airway caliber. This novel expression of BDR as trajectories in the Z plane provides unique physiological insight into the differing mechanical changes between preschool wheeze phenotypes.

Exposure to plastic additives, such as phthalates and bisphenols, has been associated with a higher risk of allergic conditions, but the evidence is inconsistent for children younger than five. To examine the association between pre- and postnatal urinary phthalates and bisphenols, and allergic conditions, and potential effect modification by sex, in pre-school children, through a pooled analysis. We pooled data from the Barwon Infant Study (Australia), the Canadian Healthy Infant Longitudinal Development Study (Canada), the Health Outcomes and Measures of the Environment (United States) and the Environmental Influences on Child Health Outcomes–wide cohorts (United States). Urinary phthalates and bisphenols were measured during pregnancy and early childhood. We estimated daily intakes from urinary concentrations, except for mono-(3-carboxypropyl) phthalate (MCPP). Outcomes, including asthma, wheeze, eczema, and rhinitis, were assessed up to five years of age through questionnaires and clinical assessments. We used generalised estimating equations for single compounds and quantile G-computation for the chemical mixtures. 5306 children were included. A two-fold increase in prenatal dibutyl phthalates (DBP; risk ratio [RR] = 1.08; 95

ABSTRACT Background Flow cytometry studies have reported an association between lower regulatory T cells (Treg) in cord blood and subsequent food allergy. Flow cytometry, however, is a resource‐intensive technique. We therefore aimed to develop an epigenetic biomarker (nTreg epi ) that correlates with the proportion of naïve regulatory T cells (nTreg) in cord blood white cells (CBWCs) measured by flow cytometry. We then investigated the association between nTreg epi and subsequent food allergy. Methods The Barwon Infant Study (BIS) is a prebirth cohort study ( n = 1074 infants). Illumina Infinium MethylationEPIC v1.0 BeadChips were used to assess DNA methylation in cord whole blood ( n = 936). In a subgroup, flow cytometry was used to measure the proportion of nTregs (CD4 + CD45RA + FOXP3+) in CBWCs ( n = 450). In a training set ( n = 338), we assessed the correlation between methylation at 78 probes in the FOXP3 and TIGIT genes and the proportion of nTregs in CBWCs. LASSO regression was then used to develop a linear methylation predictor of nTregs as a proportion of CBWCs, denoted ‘nTreg epi ’, which was then tested in a validation set ( n = 112). The association between nTreg epi and subsequent IgE‐mediated food allergy was evaluated using logistic regression. Results Methylation levels of 23/78 sites in FOXP3 and TIGIT were associated with the proportion of nTregs in CBWCs ( q < 0.05 for each). LASSO regression of methylation levels for these 21 probes was used to derive a linear predictor (nTreg epi ) which correlated with the log proportion of nTregs in the validation set ( R 2 = 0.22, p < 0.001). In the complete cohort with relevant data available ( n = 693), a higher nTreg epi was associated with decreased odds of food allergy (odds ratio 0.65 (95% CI 0.48–0.88, p = 0.005)). Conclusions A composite epigenetic biomarker in cord whole blood correlates with the proportion of nTreg in CBWCs and is strongly associated with the absence of subsequent food allergy.

Introduction: Preschool wheezing is associated with substantial health burden and lung function deficits that can persist to adulthood. In vitro studies have demonstrated the potential benefits of polyphenol intake on alveolar cell repair and inflammatory responses. Current clinical evidence investigating the relationship between polyphenol intake during pregnancy and risk of preschool wheeze in children is limited. This study aimed to use latent class analysis to derive preschool wheeze profiles and using these profiles test the hypothesis that maternal diet, especially polyphenol intake, reduces risk of preschool wheeze. Methods: In an Australian pre-birth cohort study (n=1074), maternal dietary questionnaires were completed at 28 weeks gestation. Data were extracted to calculate polyphenol intake and dietary indexes. Latent class analysis used wheeze survey responses from eight time points between 1 month and 4 years. Relative risk ratios (RRR) with 95% confidence intervals (CI) were calculated using multinomial logistic regression. Adjustment sets were developed a priori using directed acyclic graphs. Results: We identified four preschool wheeze profiles: “never/infrequent” with minimal wheeze (n=538), “transient” with wheeze present between 6-18 months (n=265), “late-onset” from 18 months – 4 years (n=147), and “early persistent” from 6 months – 4 years (n=82). Early allergic sensitisation was associated with increased risk of “late-onset”, but not “early persistent” and “transient” wheeze profiles. Relative to “never/infrequent” a fifty per cent increase in maternal total polyphenol intake was associated with a reduced risk of “early persistent” [RRR, 0.69; 95% CI, 0.53 – 0.89] and “transient” wheeze [RRR, 0.82; 95% CI, 0.70 – 0.97]. Increasing total proanthocyanidin intake, a subclass of polyphenols, was associated with a decreased risk of “early persistent” wheeze [RRR, 0.76; 95% CI, 0.62 – 0.93]. Lower dietary inflammatory index scores were associated with decreased “early persistent” wheeze risk [RRR, 1.19; 95% CI, 1.01 – 1.39]. Conclusion: Increased maternal polyphenol intake and lower dietary inflammatory index has the potential to decrease the risk of preschool wheeze. This effect was seen in the “early persistent” and “transient” wheeze profiles, suggesting polyphenols impact on preschool wheeze may be independent of allergic sensitisation, warranting investigation into alternative mechanisms of action, such as alveolar cell repair and inflammatory responses to lower respiratory tract infections. Increasing polyphenol-rich foods in pregnant women's diets may be a feasible strategy to reduce preschool wheeze risk. Clinical trials are required to evaluate whether increasing polyphenol intake during pregnancy can reduce preschool wheeze incidence and improve long-term respiratory outcomes.

Objective: Asthma is the most common chronic disease among children. Upper respiratory infections are often the cause of asthma exacerbation. Studies suggested that spore-forming probiotics can reduce viral infections. This study aimed to determine the effect of spore-forming probiotic Bacillus candy on respiratory illnesses in asthmatic children. Methods & materials: In this randomized trial, 69 children aged 7-11 years with mild intermittent asthma were randomized to receive probiotic candy (containing 10(10) CFU probiotic Bacillus coagulans) or placebo candy, daily for 2 months. The primary outcome was the number of viral respiratory infections. Secondary outcomes included salbutamol metered-dose inhaler (MDI) use, oral corticosteroids, school absenteeism, emergency department visits and hospitalizations, and Pediatric Asthma Control Questionnaire (c-ACT). Results: The frequency of symptomatic respiratory illnesses was significantly lower in the probiotic candy group compared to placebo in the first month (0.28 +/- 0.45 vs. 0.51 +/- 0.50, p = 0.054), the second month (0.08 +/- 0.28 vs. 0.41 +/- 0.49, p = 0.001) and the total study (0.37 +/- 0.54 vs. 0.90 +/- 0.73, 0.001). The percent of patients with prednisolone consumption in the probiotic group was lower than the control group (2.9% vs. 14.7%) but did not show a significant difference (p = 0.081) and no difference was seen in the rate of emergency department visits and hospitalization between the 2 groups (both p = 0.254).The use of salbutamol and school absenteeism in the probiotic group was significantly lower than in the control group (p = 0.040 and p = 0.046, respectively. There was no significant difference in the evaluated scores for asthma control (c-ACT) in both probiotic and placebo groups. After the intervention, the difference between the 2 groups has become significant (p < 0.05). Conclusion: Adding spore-forming probiotic candy containing Bacillus coagulans to standard asthma treatments reduced symptomatic respiratory illnesses over two months. Further studies including longer treatment periods are needed before making recommendations for routine use.

Objective To examine the overall incidence rate and trends in emergency department (ED) presentations related to asthma and allergic diseases in regional Australia with a particular focus on First Nations Australians.Design A retrospective analysis of data from the Emergency Department Information System.Setting This study used data from 12 public hospitals in Central Queensland, Australia, a region encompassing regional, rural and remote outback areas.Participants A total of 813 112 ED presentations between 2018 and 2023.Outcome measure Asthma and allergic diseases were identified using the International Classification of Diseases-Tenth Revision-Australian Modification codes.Results There were 13 273 asthma and allergic disease-related ED presentations, with an overall prevalence of 1.6% (95% CI 1.6, 1.7). There was a significantly higher incidence rate of asthma and allergic disease-related ED presentations among First Nations Australians at 177.5 per 10 000 person-years (95% CI 169.3, 186.0) compared with 98.9 per 10 000 person-years (95% CI 97.2, 100.8) among Australians of other descents. The incidence rates, with corresponding 95% CIs, of the four most common cases among First Nations Australians and Australians of other descents, respectively, were as follows: asthma (87.8 (82.0, 93.8) and 40.2 (39.0, 41.3)), unspecified allergy (55.3 (50.8, 60.2) and 36.0 (34.9, 37.1)), atopic/allergic contact dermatitis (17.1 (14.6, 19.9) and 10.6 (10.0, 11.2)) and anaphylaxis (7.2 (5.6, 9.1) and 6.2 (5.7, 6.6)).Conclusion Our findings highlight a significantly higher rate of asthma and allergic disease-related ED presentations among First Nations Australians compared with Australians of other descents. This underscores the urgent need for targeted healthcare interventions integrating culturally appropriate approaches, alongside additional research to understand causality.

BACKGROUND:Ataxia-telangiectasia (A-T) is a rare multisystem disease characterised by neurodegenerative cerebellar ataxia, lung disease, immune deficiency, high cancer risk, and mitochondrial dysfunction. A-T cells demonstrate defective endoplasmic reticulum-mitochondrial connectivity disrupting calcium homoeostasis and mitochondrial fusion, which are corrected in vitro by the triheptanoin metabolite, heptanoate. METHODS:We performed a Phase 2a/b trial of triheptanoin with a three-arm placebo-controlled dose-escalation design. Doses escalated at 2-month intervals for 12 months in the sequence 0%, 10%, 20%, 35% of calculated caloric intake. The primary outcome was cell death in respiratory epithelial cells. Key secondary outcomes included scales for assessment and rating of ataxia (SARA), international cooperative ataxia rating scale (ICARS), speech and swallowing function, and novel biomarker discovery. FINDINGS:31 participants with A-T were enrolled aged from 4 to 37 years (median 16-years). For the maximum dose vs. placebo or no dose, significant improvements was observed for the primary outcome percent nasal cell death (mean difference (MD) = -9.7%, 95% confidence interval (CI) -16.0, 4.6). The SARA subscale kinetic function improved (MD = -5.8, 95% CI -10.4, -1.2), as did ICARS subscales gait (MD = -0.5, 95% CI -0.9, -0.1) and fine motor disturbance (MD = -2.7, 95% CI -4.3, -1.1). Speech intelligibility (MD = -12.8, 95% CI -21.2, -4.3) and swallowing safety (-0.9, 95% CI -1.6, -0.3) improved. Adverse events including abdominal pain, nausea, vomiting, and diarrhoea, requiring dose capping at 20%, were observed in 12 (38%) participants. INTERPRETATION:Improvements in mitochondrial function in A-T cells in vivo in patients occurred after triheptanoin. The biomarkers neurofilament light chain and interferon signature stimulated gene scores may allow for monitoring of disease progression and treatment response. FUNDING:Funded by Medical Researcher Futures Fund Australia (GA89314), The University of Queensland, Wesley Research Institute, and BrAshA-T.

INTRODUCTION:Mycobacteroides abscessus (MABS) is within the non-tuberculous mycobacteria family. It inhabits soil and water, exhibits multi-antibiotic resistance and causes opportunistic lung infections, which may progress to symptomatic MABS-pulmonary disease (MABS-PD) associated with substantial morbidity, increased healthcare utilisation, impaired quality of life and increased mortality. Treatment regimens for MABS-PD are highly variable, not evidence-based and involve complex, expensive drug combinations administered for prolonged periods (>12 months) with frequent adverse effects and treatment failure. There is an urgent need for safe, efficacious and cost-effective MABS-PD therapy. Here, we describe the Master Protocol for the Finding the Optimal Regimen for Mycobacteroides abscessus Treatment (FORMaT) trial. FORMaT aims to determine the most effective and best tolerated treatment for MABS-PD as defined by MABS clearance from respiratory samples with good treatment tolerance. METHODS AND ANALYSIS:FORMaT is an international multicentre, adaptive platform trial evaluating treatment combinations for MABS-PD. Participants are randomised multiple times during the trial, with assessment of the primary outcome of clearance of MABS infection with good treatment tolerance. Initially, therapies recommended in international consensus guidelines are being tested. Data obtained will eliminate therapies lacking efficacy or causing unacceptable toxicity. Novel treatments can then be added and tested against previously determined optimal approaches, leading in an iterative fashion to improved microbiological clearance and health outcomes. In parallel, an Observational cohort and several integrated and discovery studies are embedded in FORMaT to identify biomarkers of MABS-PD and MABS clearance, clinical and radiographic treatment response, drug pharmacokinetics and Mycobacteroides genomics and resistome. ETHICS AND DISSEMINATION:The FORMaT Master Protocol and related documents are approved by regulatory authorities in each participating jurisdiction and/or site. Results will be published in peer-reviewed journals and presented at scientific meetings. De-identified, aggregated data will be shared on an approved online platform. TRIAL REGISTRATION NUMBERS:NCT04310930, ANZCTR12618001831279, 2020-000050-10, ISRCTN67303903.

Background Improved maternal asthma management in pregnancy may reduce recurrent bronchiolitis and wheeze outcomes in infancy. We assessed whether infant bronchiolitis and wheeze outcomes are influenced by inflammation-guided management intervention, inhaled corticosteroid (ICS) use or exacerbations in pregnancy. Methods A randomised controlled trial (RCT) secondary analysis and observational cohort analysis using the same study population was carried out. Pregnant women (12–23 weeks’ gestation) from six centres in Australia were recruited and randomised to inflammation-guided asthma management or usual care between 2013 and 2023. ICS use and asthma exacerbations were reported during pregnancy and postnatally. When infants were 6 (n=691) and 12 (n=606) months of age, respiratory information was collected from parents and medical records. Associations for the RCT and observational analyses were assessed with logistic regression. Results Guided asthma management in pregnancy was not associated with bronchiolitis or wheeze-related outcomes, for example for recurrent bronchiolitis at 12 months, the intervention OR was 1.04 (95% CI 0.62–1.73). In the observational analyses, ICS use in pregnancy was not associated with respiratory outcomes; however, asthma exacerbations in pregnancy were associated with at least one bronchiolitis episode (adjusted odds ratio (adjOR) 2.20, 95% CI 1.28–3.76) or croup episode (adjOR 4.34, 95% CI 1.89–9.96) at 6 months, and wheeze (adjOR 1.80, 95% CI 1.14–2.84) and increasing wheeze episodes at 12 months (adjOR 1.81, 95% CI 1.17–2.79). Conclusion Although there was no evidence that guided asthma management or ICS use in pregnancy reduces infant bronchiolitis or wheeze, maternal asthma exacerbations are an important risk factor for these outcomes. Further research is needed to reduce exacerbations in pregnancy.

AIM:To establish whether the initial positive effect of nusinersen (NUS) on respiratory outcomes in the first year of treatment was maintained in children with Spinal Muscular Atrophy (SMA) type 2 and to further define the effect on children with type 3 treated over 3 years. METHODS:A prospective observational study of children with type 2 and 3 beginning NUS in Queensland, Australia between June 2018-December 2020 was undertaken. Investigations conducted included age-appropriate lung function and polysomnography. Lung function data for two-years preceding NUS initiation was retrospectively collected. Change in lung function/polysomnography was assessed using mixed effects linear regression. RESULTS:24 of 30 children with type 2 and 3 SMA (14 males; 2.6-15.8) were included (type 2 n = 12; type 3 n = 12). No child had respiratory-related admissions during the period of study. For type 2, annual decline in FVC z-score pre-treatment was -0.75 (95 % CI: 1.14, -0.39, p < 0.001), and for the first 3 years on NUS was -0.20 ([95 % CI: 0.33, -0.06, p = 0.01] difference p = 0.008). For type 3 minimal change was seen: pre-NUS and post FVC z-scores -0.20 (95 % CI: 1.00, 0.61 p = 0.05) and -0.46 (95 % CI: 0.88, -0.04 p = 0.40) respectively (difference p = 0.46). Mean change in total apnoea-hypopnoea indices (total AHI) in type 2 tended to reduce -1.75 (95 % CI: 4.95-0.9, p = 0.24); type 3 appeared to remain stable (-0.39 [95 % CI: 1.1-0.33, p = 0.28). One child with type 2 ceased NIV due to normalisation of total AHI and gas exchange. CONCLUSION:Nusinersen lung function (FVC-z-scores) stability seen in the first year was maintained over 3 years and the total AHI tended to improve in type 2, but the long-term effects in type 3 are less clear.