In utero smoking exposure induces changes to lung clearance index and modifies risk of wheeze in infants.

BACKGROUND: Fetal exposure to tobacco smoking throughout pregnancy is associated with wheezing in infancy. We investigated the influence of in utero smoking exposure on lung ventilation homogeneity and the relationship between lung ventilation inhomogeneity at 7 weeks of age and wheezing in the first year of life. METHODS: Maternal smoking was defined as self-reported smoking of tobacco or validated by exhaled (e)CO > 6 ppm. Lung function data from healthy infants (age 5-9 weeks) born to asthmatic mothers and parent-reported respiratory questionnaire data aged 12 months were collected in the Breathing for Life Trial (BLT) birth cohort. Tidal breathing analysis and SF6 -based Multiple Breath Washout testing were performed in quiet sleep. Descriptive statistics and regression analysis were used to assess associations. RESULTS: Data were collected on 423 participants. Infants born to women who self-reported smoking during pregnancy (n = 42) had higher lung clearance index (LCI) than those born to nonsmoking mothers (7.90 vs. 7.64; p = .030). Adjusted regression analyzes revealed interactions between self-reported smoking and LCI (RR: 1.98, 95% CI: 1.07-3.63, 0.028, for each unit increase in LCI) and between eCO > 6 ppm and LCI (RR: 2.25, 95% CI: 1.13-4.50, 0.022) for the risk of wheeze in the first year of life. CONCLUSION: In utero tobacco smoke exposure induces lung ventilation inhomogeneities. Furthermore, an interaction between smoke exposure and lung ventilation inhomogeneities increases the risk of having a wheeze in the first year of life.

TLR7 promotes smoke-induced experimental lung damage through the activity of mast cell tryptase.

Toll-like receptor 7 (TLR7) is known for eliciting immunity against single-stranded RNA viruses, and is increased in both human and cigarette smoke (CS)-induced, experimental chronic obstructive pulmonary disease (COPD). Here we show that the severity of CS-induced emphysema and COPD is reduced in TLR7-deficient mice, while inhalation of imiquimod, a TLR7-agonist, induces emphysema without CS exposure. This imiquimod-induced emphysema is reduced in mice deficient in mast cell protease-6, or when wild-type mice are treated with the mast cell stabilizer, cromolyn. Furthermore, therapeutic treatment with anti-TLR7 monoclonal antibody suppresses CS-induced emphysema, experimental COPD and accumulation of pulmonary mast cells in mice. Lastly, TLR7 mRNA is increased in pre-existing datasets from patients with COPD, while TLR7+ mast cells are increased in COPD lungs and associated with severity of COPD. Our results thus support roles for TLR7 in mediating emphysema and COPD through mast cell activity, and may implicate TLR7 as a potential therapeutic target.

SISTAQUIT: training health care providers to help pregnant Aboriginal and Torres Strait Islander women quit smoking. A cluster randomised controlled trial.

BACKGROUND: About 44% of Indigenous Australian women smoke during pregnancy, compared with 12% of pregnant non-Indigenous women. Health care providers can assist smoking cessation, but they are not typically trained in culturally appropriate methods. OBJECTIVES: To determine whether a health care worker training intervention increases smoking cessation rates among Indigenous pregnant smokers compared with usual care. METHODS AND ANALYSIS: Supporting Indigenous Smokers to Assist Quitting (SISTAQUIT) study is a multicentre, hybrid type 1, pragmatic, cluster randomised controlled trial that compares the effects of an intervention for improving smoking cessation by pregnant Indigenous women (16 years or older, 32 weeks' gestation or less) with usual care. Twenty-one health services caring for Indigenous people in five Australian jurisdictions were randomised to the intervention (ten sites) or control groups (eleven sites). Health care providers at intervention sites received smoking cessation care training based on the ABCD (ask/assess; brief advice; cessation; discuss psychosocial context) approach to smoking cessation for Indigenous women, an educational resource package, free oral nicotine replacement therapy for participating women, implementation support, and trial implementation training. Health care providers in control group services provided usual care. PRIMARY OUTCOME: abstinence from smoking (self-reported abstinence via survey, validated by carbon monoxide breath testing when possible) four weeks after enrolment in the study. SECONDARY OUTCOMES: health service process evaluations; knowledge, attitudes, and practices of health care providers; and longer term abstinence, perinatal outcomes, and respiratory outcomes for babies (to six months). Ethics approval: The human research ethics committees of the University of Newcastle (H-2015-0438) and the Aboriginal Health and Medical Research Council of NSW (1140/15) provided the primary ethics approval. Dissemination of results: Findings will be disseminated in peer-reviewed publications, at local and overseas conferences, and via public and social media, and to participating health services in art-based formats and reports. Policy briefs will be communicated to relevant government organisations. TRIAL REGISTRATION: Australia New Zealand Clinical Trials Registry, ACTRN12618000972224 (prospective).

Effect of asthma management with exhaled nitric oxide versus usual care on perinatal outcomes.

INTRODUCTION: Asthma exacerbations in pregnancy are associated with adverse perinatal outcomes. We aimed to determine whether fractional exhaled nitric oxide (F ENO)-based asthma management improves perinatal outcomes compared to usual care. METHODS: The Breathing for Life Trial was a multicentre, parallel-group, randomised controlled trial conducted in six hospital antenatal clinics, which compared asthma management guided by F ENO (adjustment of asthma treatment according to exhaled nitric oxide and symptoms each 6-12 weeks) to usual care (no treatment adjustment as part of the trial). The primary outcome was a composite of adverse perinatal events (preterm birth, small for gestational age (SGA), perinatal mortality or neonatal hospitalisation) assessed using hospital records. Secondary outcomes included maternal asthma exacerbations. Concealed random allocation, stratified by study site and self-reported smoking status was used, with blinded outcome assessment and statistical analysis (intention to treat). RESULTS: Pregnant women with current asthma were recruited; 599 to the control group (608 infants) and 601 to the intervention (615 infants). There were no significant group differences for the primary composite perinatal outcome (152 (25.6%) out of 594 control, 177 (29.4%) out of 603 intervention; OR 1.21, 95% CI 0.94-1.56; p=0.15), preterm birth (OR 1.14, 95% CI 0.78-1.68), SGA (OR 1.06, 95% CI 0.78-1.68), perinatal mortality (OR 3.62, 95% CI 0.80-16.5), neonatal hospitalisation (OR 1.24, 95% CI 0.89-1.72) or maternal asthma exacerbations requiring hospital admission or emergency department presentation (OR 1.19, 95% CI 0.69-2.05). CONCLUSION: F ENO-guided asthma pharmacotherapy delivered by a nurse or midwife in the antenatal clinic setting did not improve perinatal outcomes.

Factors Associated with Asthma Exacerbations During Pregnancy.

BACKGROUND: Asthma exacerbations during pregnancy are associated with adverse pregnancy outcomes. OBJECTIVE: The aim of this study was to establish factors associated with asthma exacerbations during pregnancy. METHODS: We obtained data from three cohorts of pregnant women with asthma recruited in eastern Australia (2004-2019; n = 1461). Severe exacerbations were defined as episodes of asthma requiring hospitalization, an emergency department visit, or prescription of oral corticosteroids after enrollment. Baseline information on potential risk factors included demographic characteristics, asthma characteristics (eg, lung function, asthma triggers, asthma control, medication use), pregnancy factors (eg, fetal sex, parity, antenatal care type), and other maternal factors (body mass index, smoking status, mental health). Backward stepwise logistic regression and Akaike information criterion were used to determine the best-fitting model. RESULTS: A total of 135 participants experienced a severe exacerbation during pregnancy (9.2%). Medium to high ICS dose was most strongly associated with severe asthma exacerbations (adjusted odds ratio = 3.20; 95% confidence interval, 1.85-5.53). Worse asthma control, possession of a written action plan, and a history of asthma exacerbations in the year preceding pregnancy were associated with an increased rate of exacerbations. CONCLUSIONS: Asthma exacerbations before pregnancy and more severe asthma at the beginning of pregnancy were associated with an increased rate of exacerbations during pregnancy. Despite Global Initiative for Asthma step 3 and 4 treatment and optimal management including a written asthma action plan, there is still a significant asthma burden in a group of women at high risk for severe exacerbations in pregnancy.

miR-122 promotes virus-induced lung disease by targeting SOCS1.

Virus-induced respiratory tract infections are a major health burden in childhood, and available treatments are supportive rather than disease modifying. Rhinoviruses (RVs), the cause of approximately 80% of common colds, are detected in nearly half of all infants with bronchiolitis and the majority of children with an asthma exacerbation. Bronchiolitis in early life is a strong risk factor for the development of asthma. Here, we found that RV infection induced the expression of miRNA 122 (miR-122) in mouse lungs and in human airway epithelial cells. In vivo inhibition specifically in the lung reduced neutrophilic inflammation and CXCL2 expression, boosted innate IFN responses, and ameliorated airway hyperreactivity in the absence and in the presence of allergic lung inflammation. Inhibition of miR-122 in the lung increased the levels of suppressor of cytokine signaling 1 (SOCS1), which is an in vitro-validated target of miR-122. Importantly, gene silencing of SOCS1 in vivo completely reversed the protective effects of miR-122 inhibition on RV-induced lung disease. Higher miR-122 expression in nasopharyngeal aspirates was associated with a longer time on oxygen therapy and a higher rate of treatment failure in 87 infants hospitalized with moderately severe bronchiolitis. These results suggest that miR-122 promotes RV-induced lung disease via suppression of its target SOCS1 in vivo. Higher miR-122 expression was associated with worse clinical outcomes, highlighting the potential use of anti-miR-122 oligonucleotides, successfully trialed for treatment of hepatitis C, as potential therapeutics for RV-induced bronchiolitis and asthma exacerbations.

Variation of DNA Methylation in Newborns Associated with Exhaled Carbon Monoxide during Pregnancy.

Fetal exposure to tobacco smoke is an adverse risk factor for newborns. A plausible mechanism of how this exposure may negatively impact long term health is differential methylation of deoxyribonucleic acid (DNAm) and its relation to birth weight. We examined whether self-reported gestational smoking status and maternal exhaled carbon monoxide (eCO) during early pregnancy were associated with methylation of cytosine by guanines (CpG) sites that themselves predicted birth weight. We focused first on CpGs associated with maternal smoking, and secondly, among these, on CpGs related to birth weight found in another cohort. Then in 94 newborns from the Breathing for Life Trial (BLT) DNAm levels in cord blood were determined using Infinium Methylation EPIC BeadChip measuring >850K CpGs. We regressed CpGs on eCO and tested via mediation analysis whether CpGs link eCO to birth weight. Nine smoking related CpG sites were significantly associated with birth weight. Among these nine CpGs the methylation of cg02264407 on the LMO7 gene was statistically significant and linked with eCO measurements. eCO greater than six ppm showed a 2.3% decrease in infant DNAm (p = 0.035) on the LMO7 gene. A 1% decrease in methylation at this site resulted in decreased birth weight by 44.8 g (p = 0.003). None of the nine CpGs tested was associated with self-reported smoking. This is the first study to report potential mediation of DNA methylation, linking eCO measurements during early pregnancy with birth weight.

Factors Associated with Nonadherence to Inhaled Corticosteroids for Asthma During Pregnancy.

BACKGROUND: Nonadherence is common among pregnant women prescribed inhaled corticosteroids (ICS) for asthma and may have serious consequences for mother and baby. Factors associated with ICS nonadherence have not been determined in this population. OBJECTIVES: To determine factors associated with {1} nonadherence to ICS in early-mid pregnancy (cross-sectional) and {2} persistent nonadherence to ICS during pregnancy (longitudinal). METHODS: Data used come from 3 prospective studies (2004-2019) involving women with asthma recruited by 23 weeks' gestation (N = 1614). Demographics, asthma history, and current symptoms were assessed, and spirometry was performed at baseline and throughout pregnancy. Women self-reported current medication use and number of ICS doses missed in the past week. Nonadherence was defined as ≥20% of prescribed dosages missed in the past week (baseline) and on at least 2 occasions during follow-up (persistent). Factors associated with ICS nonadherence were examined using backward stepwise logistic regression. RESULTS: Of 610 (38%) women prescribed ICS at baseline, 236 (39%) were classified as nonadherent. Of 612 (38%) women prescribed ICS during at least 2 follow-up visits, 149 (24%) were classified as persistent nonadherent. Factors associated with nonadherence at baseline were current or ex-smoking, non-Caucasian/non-Indigenous ethnicity, adult diagnosis of asthma, and lower lung function. Factors associated with persistent nonadherence to ICS were lower maternal age, higher parity, and no prescribed ICS at baseline. CONCLUSION: Young multiparous non-Caucasian/non-Indigenous mothers are at increased risk of being nonadherent to ICS during pregnancy. Strategies to improve ICS nonadherence should address maternal smoking and target women who (re-)initiate ICS use in pregnancy.

In vivo targeting of miR-223 in experimental eosinophilic oesophagitis.

OBJECTIVES: Eosinophilic oesophagitis (EoE) is characterised by oesophageal inflammation, fibrosis and dysfunction. Micro (mi)-RNAs interfere with pro-inflammatory and pro-fibrotic transcriptional programs, and miR-223 was upregulated in oesophageal mucosal biopsy specimens from EoE patients. The therapeutic potential of modulating miR-223 expression in vivo has not been determined. We aimed to elucidate the relevance of oesophageal miR-223 expression in an in vivo model of EoE by inhibiting miR-223 tissue expression. METHODS: The expression of miR-223 and the validated miR-223 target insulin-like growth factor receptor 1 (IGF1R) protein was determined in our paediatric cohort of EoE patients. A murine model of Aspergillus fumigatus-induced EoE was employed, and oesophagi were assessed for miR-233, IGF1R, T lymphocyte type 2 (T2) cytokine expression and eosinophil infiltration. Mice were treated with antagomirs targeting miR-223 or resveratrol targeting its upstream regulator Midline-1(MID-1). RESULTS: There was an inverse relationship between an increased expression of miR-223 and a decreased IGF1R protein concentration in biopsy specimens from EoE patients. TNF-related apoptosis-inducing ligand deficiency, MID-1 inhibition and resveratrol treatment suppressed miR-223 expression. Furthermore, inhibition of miR-223 and treatment with resveratrol in the oesophagus resulted in an amelioration of EoE hallmark features including eosinophilic infiltration, oesophageal circumference and a reduction in T2 cytokine expression. CONCLUSION: miR-223 has a key role in the perpetuation of EoE hallmark features downstream of TNF-related apoptosis-inducing ligand and MID-1 in an experimental model. These studies highlight a potentially critical role of miRNA function in EoE aetiology. miR-223 expression in the oesophagus may be therapeutically modulated by resveratrol, providing a potential new therapeutic option to be explored in EoE patients for this increasingly prevalent condition.

Association between active tobacco use during pregnancy and infant respiratory health: a systematic review and meta-analysis.

OBJECTIVE: To evaluate what is known about active tobacco use during pregnancy and the association with infant respiratory health. DESIGN: Systematic review and meta-analysis using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. DATA SOURCES: MEDLINE, EMBASE, Cochrane, CINAHL, and Maternity and Infant Care were searched thoroughly until June 2020. ELIGIBILITY CRITERIA FOR SELECTING STUDIES: We included case-control and cohort studies estimating the association between active tobacco use during pregnancy and infant respiratory health (wheezing and apnoea) and lung function parameters in the first 12 months of life. DATA EXTRACTION AND SYNTHESIS: Extraction and risk of bias assessment were conducted by two independent reviewers. The odds ratio, relative risk and mean differences were pooled with a 95% CI using the generic inverse variance method. Heterogeneity was assessed and expressed by percentage using I2. RESULTS: We identified 4423 abstracts, and 21 publications met the eligibility criteria. Pooled OR showed an increase in wheezing episodes in infants born to mothers who were active tobacco users during pregnancy (OR 1.50, 95% CI 1.27 to 1.77, p<0.01). Mixed results were found on lung function parameters, and a meta-analysis including two studies with comparable methodology showed a trend towards reduced maximum flow rate at functional residual capacity of -34.59 mL/s (95% CI -72.81 to 3.63, p=0.08) in 1-month-old infants born to women who smoked during pregnancy. A higher risk of apnoea was described for infants born to mothers who used smokeless tobacco during pregnancy, while the results in infants born to women who actively smoked tobacco during pregnancy were non-conclusive. CONCLUSION: Infants born to mothers who actively smoked during pregnancy are at higher odds of having wheeze and may have lower lung function. Smokeless tobacco use in pregnancy may increase the risk of apnoea in infancy. PROSPERO REGISTRATION NUMBER: CRD42018083936.

Respiratory, birth and health economic measures for use with Indigenous Australian infants in a research trial: a modified Delphi with an Indigenous panel.

BACKGROUND: There is significant disparity between the respiratory health of Indigenous and non-Indigenous Australian infants. There is no culturally accepted measure to collect respiratory health outcomes in Indigenous infants. The aim of this study was to gain end user and expert consensus on the most relevant and acceptable respiratory and birth measures for Indigenous infants at birth, between birth and 6 months, and at 6 months of age follow-up for use in a research trial. METHODS: A three round modified Delphi process was conducted from February 2018 to April 2019. Eight Indigenous panel members, and 18 Indigenous women participated. Items reached consensus if 7/8 (≥80%) panel members indicated the item was 'very essential'. Qualitative responses by Indigenous women and the panel were used to modify the 6 months of age surveys. RESULTS: In total, 15 items for birth, 48 items from 1 to 6 months, and five potential questionnaires for use at 6 months of age were considered. Of those, 15 measures for birth were accepted, i.e., gestational age, birth weight, Neonatal Intensive Care Unit (NICU) admissions, length, head circumference, sex, Apgar score, substance use, cord blood gas values, labour, birth type, health of the mother, number people living in the home, education of mother and place of residence. Seventeen measures from 1-to 6 months of age were accepted, i.e., acute respiratory symptoms (7), general health items (2), health care utilisation (6), exposure to tobacco smoke (1), and breastfeeding status (1). Three questionnaires for use at 6 months of age were accepted, i.e., a shortened 33-item respiratory questionnaire, a clinical history survey and a developmental questionnaire. CONCLUSIONS: In a modified Delphi process with an Indigenous panel, measures and items were proposed for use to assess respiratory, birth and health economic outcomes in Indigenous Australian infants between birth and 6 months of age. This initial step can be used to develop a set of relevant and acceptable measures to report respiratory illness and birth outcomes in community based Indigenous infants.

TRAIL signals through the ubiquitin ligase MID1 to promote pulmonary fibrosis.

BACKGROUND: Tumour necrosis factor-related apoptosis-inducing ligand (TRAIL) has previously been demonstrated to play a pro-inflammatory role in allergic airways disease and COPD through the upregulation of the E3 ubiquitin ligase MID1 and the subsequent deactivation of protein phosphatase 2A (PP2A). METHODS: Biopsies were taken from eight IPF patients presenting to the Second Affiliated Hospital of Jilin University, China between January 2013 and February 2014 with control samples obtained from resected lung cancers. Serum TRAIL, MID1 protein and PP2A activity in biopsies, and patients' lung function were measured. Wild type and TRAIL deficient Tnfsf10-/- BALB/c mice were administered bleomycin to induce fibrosis and some groups were treated with the FTY720 analogue AAL(s) to activate PP2A. Mouse fibroblasts were treated with recombinant TRAIL and fibrotic responses were assessed. RESULTS: TRAIL in serum and MID1 protein levels in biopsies from IPF patients were increased compared to controls. MID1 levels were inversely associated while PP2A activity levels correlated with DLco. Tnfsf10-/- and mice treated with the PP2A activator AAL(s) were largely protected against bleomycin-induced reductions in lung function and fibrotic changes. Addition of recombinant TRAIL to mouse fibroblasts in-vitro increased collagen production which was reversed by PP2A activation with AAL(s). CONCLUSION: TRAIL signalling through MID1 deactivates PP2A and promotes fibrosis with corresponding lung function decline. This may provide novel therapeutic targets for IPF.

Polysomnography for the management of oxygen supplementation therapy in infants with chronic lung disease of prematurity.

Aim: Some infants with bronchopulmonary dysplasia (BPD) may require oxygen supplementation at home but a role for overnight polysomnography (PSG) in the management of home oxygen therapy has been rarely described. Methods: Forty-one infants with BPD born at less than 30 weeks gestational age were discharged with continuous home oxygen supplementation therapy between 2010 and 2013. PSG data were recorded on oxygen supplementation versus room air at median corrected age of 2 months (range 1-5 months) (first PSG after discharge to home). Those infants who continued oxygen supplementation therapy at home had at least one more PSG before oxygen therapy was discontinued (last PSG). We also collected PSG data in 10 healthy term infants (median age 3.5 months; range 2-4 months). Results: In infants with BPD in room air, increased numbers of central apneas, hypopneas, and SaO2 desaturations were the predominant PSG features with a median apnea-hypopnea index (AHI) of 16.8 events per hour (range 0-155). On oxygen supplementation therapy, median AHI dramatically improved (2.2, range 0-22; p < .001) and was not different from control infants (2.0, range 0-3.9; p = .31). AHI on room air at the last PSG when home oxygen was ceased was 4.1 per hour (range 0-13.8) slightly higher than in healthy infants. Conclusion: Central sleep disordered breathing in infants with BPD dramatically normalizes with low flow nasal cannula home oxygen therapy and improves with age. Mild central sleep disordered breathing remains detectable, although much improved, when compared with healthy infants at the time when the decision to cease home oxygen therapy was made by the physician.

Enhancing tristetraprolin activity reduces the severity of cigarette smoke-induced experimental chronic obstructive pulmonary disease.

OBJECTIVE: Chronic obstructive pulmonary disease (COPD) is a progressive disease that causes significant mortality and morbidity worldwide and is primarily caused by the inhalation of cigarette smoke (CS). Lack of effective treatments for COPD means there is an urgent need to identify new therapeutic strategies for the underlying mechanisms of pathogenesis. Tristetraprolin (TTP) encoded by the Zfp36 gene is an anti-inflammatory protein that induces mRNA decay, especially of transcripts encoding inflammatory cytokines, including those implicated in COPD. METHODS: Here, we identify a novel protective role for TTP in CS-induced experimental COPD using Zfp36aa/aa mice, a genetically modified mouse strain in which endogenous TTP cannot be phosphorylated, rendering it constitutively active as an mRNA-destabilising factor. TTP wild-type (Zfp36 +/+) and Zfp36aa/aa active C57BL/6J mice were exposed to CS for four days or eight weeks, and the impact on acute inflammatory responses or chronic features of COPD, respectively, was assessed. RESULTS: After four days of CS exposure, Zfp36aa/aa mice had reduced numbers of airway neutrophils and lymphocytes and mRNA expression levels of cytokines compared to wild-type controls. After eight weeks, Zfp36aa/aa mice had reduced pulmonary inflammation, airway remodelling and emphysema-like alveolar enlargement, and lung function was improved. We then used pharmacological treatments in vivo (protein phosphatase 2A activator, AAL(S), and the proteasome inhibitor, bortezomib) to promote the activation and stabilisation of TTP and show that hallmark features of CS-induced experimental COPD were ameliorated. CONCLUSION: Collectively, our study provides the first evidence for the therapeutic potential of inducing TTP as a treatment for COPD.

Prevention and Treatment of Smoking and Tobacco Use During Pregnancy in Selected Indigenous Communities in High-Income Countries of the United States, Canada, Australia, and New Zealand: An Evidence-Based Review.

Tobacco smoking during pregnancy is the most important modifiable risk factor for adverse pregnancy outcomes and long-term health complications for mother and baby. Tobacco use during pregnancy has decreased in high-income countries but not in Indigenous women in Australia, New Zealand, the United States, and Canada. This evidence-based review focuses on tobacco use among Indigenous pregnant women in high-income countries that share a history of European colonization. Indigenous women are more likely to use tobacco because of socioeconomic disadvantage, social norms, and poor access to culturally appropriate tobacco cessation support. Complications arising from tobacco smoking during pregnancy, such as low birth weight, prematurity, perinatal death, and sudden infant death syndrome, are much higher in Indigenous populations. Effective approaches to cessation in pregnant nonindigenous women involves behavioral counseling, with or without nicotine replacement therapy (NRT). Higher nicotine metabolism during pregnancy and poor adherence may affect therapeutic levels of NRT. Only two randomized trials were conducted among Indigenous women: neither found a statistically significant difference in cessation rates between the treatment and comparison arms. Considerations should be given to (1) whole life course approaches to reduce tobacco use in Indigenous women, (2) prohibiting tobacco promotion and reducing access to alcohol for minors to prevent smoking initiation in Indigenous youth, and (3) training health-care professionals in culturally appropriate smoking cessation care to improve access to services. It is critical to ensure acceptability and feasibility of study designs, consult with the relevant Indigenous communities, and preempt implementation challenges. Research is needed into the effect of reducing or stopping smoking during pregnancy when using NRT on subsequent maternal and infant outcomes.

Elevated Serum Tissue Transglutaminase Antibodies in Children With Eosinophilic Esophagitis.

OBJECTIVES: This study compared the clinical and histopathological characteristics of children with eosinophilic esophagitis (EoE) and elevated anti-transglutaminase (TTG Ab) with those with EoE and normal TTG Ab titres. METHODS: Single-center chart and blinded histopathological review of patients diagnosed with EoE for a 4-year period, who had esophageal and duodenal biopsies taken at time of endoscopy, and TTG Ab measured within 6 months of biopsy. Patients with histology-proven CD were excluded. RESULTS: Elevated TTG Ab was present in 19/34 (54%) of the study cohort, representing 23% of all patients diagnosed with EoE during the study period. Eight had titers >6× upper limit of normal (ULN) and 4 had >10× ULN. TTG Ab-positive patients were classified as having either potential CD with (n = 3, 16%) and without lymphocytic duodenosis (LD; n = 12, 63%), and no CD (n = 4, 21%) on human leukocyte antigen typing. There was an increase in duodenal eosinophils in patients with elevated TTG Ab (P = 0.01), which remained when patients with LD were excluded (P = 0.018). Of 19 patients with EoE and elevated TTG Ab, 5 responded to elimination diet involving exclusion of wheat, including 2 with a sole wheat trigger and TTG Ab >10× ULN that were CD-associated human leukocyte antigen-negative. CONCLUSIONS: Serum TTG Ab was elevated in almost one-quarter of our total EoE cohort, and at least 20% of these patients did not have potential CD, suggesting EoE is a heterogeneous disease with differing immune mechanisms activated in some patients. These findings also support routine esophageal biopsy during upper endoscopy in children with elevated TTG Ab.

MicroRNA-21 drives severe, steroid-insensitive experimental asthma by amplifying phosphoinositide 3-kinase-mediated suppression of histone deacetylase 2.

BACKGROUND: Severe steroid-insensitive asthma is a substantial clinical problem. Effective treatments are urgently required, however, their development is hampered by a lack of understanding of the mechanisms of disease pathogenesis. Steroid-insensitive asthma is associated with respiratory tract infections and noneosinophilic endotypes, including neutrophilic forms of disease. However, steroid-insensitive patients with eosinophil-enriched inflammation have also been described. The mechanisms that underpin infection-induced, severe steroid-insensitive asthma can be elucidated by using mouse models of disease. OBJECTIVE: We sought to develop representative mouse models of severe, steroid-insensitive asthma and to use them to identify pathogenic mechanisms and investigate new treatment approaches. METHODS: Novel mouse models of Chlamydia, Haemophilus influenzae, influenza, and respiratory syncytial virus respiratory tract infections and ovalbumin-induced, severe, steroid-insensitive allergic airway disease (SSIAAD) in BALB/c mice were developed and interrogated. RESULTS: Infection induced increases in the levels of microRNA (miRNA)-21 (miR-21) expression in the lung during SSIAAD, whereas expression of the miR-21 target phosphatase and tensin homolog was reduced. This was associated with an increase in levels of phosphorylated Akt, an indicator of phosphoinositide 3-kinase (PI3K) activity, and decreased nuclear histone deacetylase (HDAC)2 levels. Treatment with an miR-21-specific antagomir (Ant-21) increased phosphatase and tensin homolog levels. Treatment with Ant-21, or the pan-PI3K inhibitor LY294002, reduced PI3K activity and restored HDAC2 levels. This led to suppression of airway hyperresponsiveness and restored steroid sensitivity to allergic airway disease. These observations were replicated with SSIAAD associated with 4 different pathogens. CONCLUSION: We identify a previously unrecognized role for an miR-21/PI3K/HDAC2 axis in SSIAAD. Our data highlight miR-21 as a novel therapeutic target for the treatment of this form of asthma.

TRAIL signaling is proinflammatory and proviral in a murine model of rhinovirus 1B infection.

the aim of this study is to elucidate the role of TRAIL during rhinovirus (RV) infection in vivo. Naïve wild-type and tumor necrosis factor-related apoptosis-inducing ligand (TRAIL)-deficient (Tnfsf10-/-) BALB/c mice were infected intranasally with RV1B. In separate experiments, Tnfsf10-/- mice were sensitized and challenged via the airway route with house dust mite (HDM) to induce allergic airways disease and then challenged with RVIB or UV-RVIB. Airway hyperreactivity (AHR) was invasively assessed as total airways resistance in response to increasing methacholine challenge and inflammation was assessed in bronchoalveolar lavage fluid at multiple time points postinfection. Chemokines were quantified by ELISA of whole lung lysates and viral load was determined by quantitative RT-PCR and tissue culture infective dose (TCID50). Human airway epithelial cells (BEAS2B) were infected with RV1B and stimulated with recombinant TRAIL or neutralizing anti-TRAIL antibodies and viral titer assessed by TCID50 HDM-challenged Tnfsf10-/- mice were protected against RV-induced AHR and had suppressed cellular infiltration in the airways upon RV infection. Chemokine C-X-C-motif ligand 2 (CXCL2) production was suppressed in naïve Tnfsf10-/- mice infected with RV1B, with less RV1B detected 24 h postinfection. This was associated with reduced apoptotic cell death and a reduction of interferon (IFN)-λ2/3 but not IFN-α or IFN-ß. TRAIL stimulation increased, whereas anti-TRAIL antibodies reduced viral replication in RV1B-infected BEAS2B cells in vitro. In conclusion, TRAIL promotes RV-induced AHR, inflammation and RV1B replication, implicating this molecule and its downstream signaling pathways as a possible target for the amelioration of RV1B-induced allergic and nonallergic lung inflammation and AHR.

TRAIL deficiency and PP2A activation with salmeterol ameliorates egg allergen-driven eosinophilic esophagitis.

Food antigens are common inflammatory triggers in pediatric eosinophilic esophagitis (EoE). TNF-related apoptosis-inducing ligand (TRAIL) promotes eosinophilic inflammation through the upregulation of the E3 ubiquitin ligase Midline (MID)-1 and subsequent downregulation of protein phosphatase 2A (PP2A), but the role of this pathway in EoE that is experimentally induced by repeated food antigen challenges has not been investigated. Esophageal mucosal biopsies were collected from children with EoE and controls and assessed for TRAIL and MID-1 protein and mRNA transcript levels. Wild-type and TRAIL-deficient (Tnfsf10-/-) mice were administered subcutaneous ovalbumin (OVA) followed by oral OVA challenges. In separate experiments, OVA-challenged mice were intraperitoneally administered salmeterol or dexamethasone. Esophageal biopsies from children with EoE revealed increased levels of TRAIL and MID-1 and reduced PP2A activation compared with controls. Tnfsf10-/- mice were largely protected from esophageal fibrosis, eosinophilic inflammation, and the upregulation of TSLP, IL-5, IL-13, and CCL11 when compared with wild-type mice. Salmeterol administration to wild-type mice with experimental EoE restored PP2A activity and also prevented esophageal eosinophilia, inflammatory cytokine expression, and remodeling, which was comparable to the treatment effect of dexamethasone. TRAIL and PP2A regulate inflammation and fibrosis in experimental EoE, which can be therapeutically modulated by salmeterol.