Role of early life immune regulation in asthma development

Unveiling the differences: infection disorders associated with tumor necrosis factor α inhibitors in pediatric patients-a pharmacovigilance study (2004-2023)

The increasing use of tumor necrosis factor inhibitors (TNFi) in pediatric patients has raised concerns about their potential impact on the immune system and related adverse events. Infection-related adverse events (AEs) caused by TNFi have already raised widespread concerns in real-world settings. This study aims to comprehensively analyze and summarize the infection-related AEs associated with TNFi in pediatric patients. A retrospective pharmacovigilance study was conducted to identify cases of TNFi-related infections reported to the FDA Adverse Event Reporting System (FAERS) database between Q1 2004 and Q1 2023. TNFi reports were carefully reviewed to exclude confounding factors like other AEs, concomitant medications, and prescription indications. Proportionality analysis was conducted by comparing TNFi reports to the entire FAERS database to identify infection-related AEs significantly associated with TNFi use. Infection-related AEs accounted for 8.36% of all TNFi-related adverse event reports in the FAERS database. A total of 8050 cases of TNFi-associated infections were identified in the pediatric population, with 2.57% of reports resulting in fatalities. Infliximab and golimumab showed a stronger association with infection-related AEs compared to other TNFi. Notably, only adalimumab shows a lower risk of viral infections, while it exhibits an increased risk of bacterial and mycobacterial infections, similar to other TNFi.

CONCLUSIONS

This study identified a significant association between TNFi use and infection-related AEs in pediatric patients, providing the foothold for further research. However, due to its retrospective nature, further investigations are warranted to confirm these findings and identify potential risk factors in a controlled, prospective study setting.

WHAT IS KNOWN

• There is sufficient evidence to demonstrate the infection risk associated with TNFi in adult patients. • Pediatric patients, whose immune systems are still developing, are more vulnerable to certain infections.

WHAT IS NEW

• There is a significant association between TNFi use and infection-related adverse events in pediatric patients, and different TNFi have distinct infection profiles.

Epigenomic and proteomic analyses provide insights into early-life immune regulation and asthma development in infants

Infants with severe bronchiolitis (i.e., bronchiolitis requiring hospitalization) face increased risks of respiratory diseases in childhood. We conduct epigenome-wide association studies in a multi-ethnic cohort of these infants. We identify 61 differentially methylated regions in infant blood (<1 year of age) associated with recurrent wheezing by age 3 (170 cases, 318 non-cases) and/or asthma by age 6 (112 cases, 394 non-cases). These differentially methylated regions are enriched in the enhancers of peripheral blood neutrophils. Several differentially methylated regions exhibit interaction with rhinovirus infection and/or specific blood cell types. In the same blood samples, circulating levels of 104 proteins correlate with the differentially methylated regions, and many proteins show phenotypic association with asthma. Through Mendelian randomization, we find causal evidence supporting a protective role of higher plasma ST2 (also known as IL1RL1) protein against asthma. DNA methylation is also associated with ST2 protein level in infant blood. Taken together, our findings suggest the contribution of DNA methylation to asthma development through regulating early-life systemic immune responses.

Screening and Validation of Potential Biomarkers of Immune Cells in Childhood Asthma Patients via Mendelian Randomization and Machine Learning

Purpose

Asthma is one of the most common chronic respiratory diseases affecting children, and there is currently no clear remedy. Immune cells play a key role in childhood asthma. Therefore, a deeper investigation of the correlation between immune cells and childhood asthma could lead to a better understanding of asthma's origin, the identification of potential treatment targets, and the development of personalized treatment strategies.

Patients and Methods

We used a two-sample Mendelian randomization (MR) analysis to investigate the possible causal relationship between childhood asthma and a total of 731 immune cells, including B cell (190), Maturation stages of T cell (79), Monocyte (43), Myeloid cell (64), TBNK (124), Treg (167), and CDC (64). LASSO logistic regression and SVM algorithms were used to identify key genes associated with childhood asthma. Specific signaling pathways associated with these key genes were further explored through gene set variation analysis (GSVA) and gene set enrichment analysis (GSEA). Subsequently, the four key genes FCGR3A, TCTN3, ALOX5, and IL4R were verified in an established asthma mouse model using quantitative real-time PCR and Western blotting.

Results

MR analysis showed that 60 immune cells were associated with childhood asthma, of which 32 were associated with high risk and 28 were associated with low risk. LASSO logistic regression and SVM algorithm identified six key genes that affect childhood asthma as ATF4, FCGR3A, GAS5, MGAT3, TAB1, and TCTN3. In addition, four genes, FCGR3A, TCTN3, ALOX5, and IL4R, were verified through animal experiments.

Conclusion

Our findings confirmed that immune cells contribute to childhood asthma, highlighting the importance of key genes in the role of the immune microenvironment in this disease. These insights provide a new path for the exploration of the biological underpinnings of childhood asthma and the development of early intervention therapies.

Residential greenness and pollen exposure across gestational trimesters in relation to preschool wheezing: Results for the PIPO birth cohort

INTRODUCTION

Previous studies on prenatal green space exposure and early respiratory health show inconsistent results. This may reflect stage-specific in utero effects and pollen influence. We examine associations of surrounding greenness and pollen exposure during pregnancy (overall and by trimester) with preschool wheezing, and assess potential mediation by pollen.

METHODS

We used data from the PIPO birth cohort (n = 860). Wheezing was reported biannually between 18 and 48 months of age. Residential greenness was measured with Normalized Difference Vegetation Index (NDVI) in 100 and 250 m buffer. Cumulative grass and birch pollen was estimated using modelled airborne pollen counts and categorized per trimester into no, low and high. All exposures were assessed for the overall pregnancy and per trimester. We used Generalized Estimated Equations to obtain odds ratios (OR) and 95% confidence intervals (CI). To assess mediation by pollen we used a data duplication algorithm with a generalized estimation approach.

RESULTS

Approximately 10% of participants wheezed. During pregnancy, greenness (OR = 1.07, CI: 1.05-1.08) and grass pollen exposure (OR = 1.09, CI: 1.03-1.15) increased the odds of wheezing, while birch pollen decreased it (OR = 0.86, CI:0.87-1.00). Per trimester, more greenness during the 2nd trimester increased the odds (OR = 1.21, CI: 1.16-1.26), whereas third-trimester greenness decreased it (OR = 0.87, CI: 0.84-0.91). Grass pollen exposure in the 1st and 3rd trimesters increased the odds of wheezing (OR = 1.23, CI: 1.12-1.34 and OR = 1.13, CI: 1.00-1.27, respectively), while birch pollen exposure in the 1st and 2nd trimesters decreased the odds (OR = 0.88, CI: 0.77-1.00 and OR = 0.83, CI: 0.73-0.95, respectively). No significant associations were found for greenness in the 1st trimester, grass pollen in the 2nd trimester, and birch pollen in the 1st and 3rd trimester. Mediation analysis showed large uncertainty.

DISCUSSION

Surrounding greenness and pollen exposure during pregnancy may impact the likelihood of preschool wheezing differently depending on the timing of exposure and the pollen type.

The Interplay Between Respiratory Syncytial Virus and Asthma Inception: Insights Gained From the COVID-19 Pandemic

BACKGROUND

Respiratory syncytial virus (RSV) infection in the first year of life has been linked with an increased risk for asthma. Some propose that RSV-induced inflammation leads to lasting airway changes, while others contend that RSV bronchiolitis is a marker for underlying predisposition. Social distancing adopted during the COVID-19 pandemic has led to a dramatic reduction in RSV activity, providing an unexpected opportunity to investigate this debate.

OBJECTIVE

To compare the incidence of asthma-related healthcare-utilization (HCU) in 1-3 years of age between children born in March-June 2020 (l-RSV) and children born during the same months in the years 2014-2017 (H-RSV).

STUDY DESIGN AND METHODS

This retrospective study utilized nationwide healthcare database records from Clalit-Healthcare-Services, the largest healthcare organization in Israel. The study analyzed asthma-related HCU, using multivariate logistic regression and Bayesian analyses.

RESULTS

172,463 children were included in the study: 32,927 in the l-RSV group versus 139,536 in the H-RSV group. The l-RSV cohort showed insignificant changes and increased rates of asthma-related HCU between 1 and 3 years of age in some asthma surrogates, compared to the H-RSV group.

CONCLUSION

Reduction in RSV exposure during the first year of life did not correlate with a decrease in asthma-related HCU. This may imply that RSV infection in infancy functions as an indicator of underlying predisposition rather than a direct cause of asthma.

Evaluation of dupilumab on the disease burden in children and adolescents with atopic dermatitis: A population-based cohort study

BACKGROUND

Dupilumab is the first and only biologic agent approved for the treatment of atopic dermatitis (AD) in pediatric patients aged from 6 months to 17 years. The study aimed to evaluate the impact of dupilumab on the occurrence of comorbidities in pediatric patients with AD.

METHODS

In this population-based cohort study, we utilized electronic health records from multiple healthcare organizations across the United States. Pediatric patients (<18 years of age) with a diagnosis of AD initiating dupilumab were propensity-score matched 1:1 to those initiating other systemic agents (azathioprine, cyclosporine, methotrexate, mycophenolate mofetil, or systemic corticosteroids). The primary outcomes were new-onset comorbidities emerging during the study period measured by the risk ratio (RR) and its confidence interval (CI). Subgroup analyses were stratified by age (0-5 years, 6-11 years, and 12-17 years), sex, and race.

RESULTS

A total of 3575 pediatric patients with AD treated with dupilumab were matched to 3575 patients treated with other systemic agents. The dupilumab cohort was associated with a lowered risk of new-onset atopic comorbidities (including asthma [RR, 0.72; 95% CI, 0.59-0.89] and allergic rhinitis [RR, 0.62; 95% CI, 0.52-0.74]), infections (e.g., skin and soft tissue infection [RR, 0.70; 95% CI, 0.63-0.76] and respiratory tract infection [RR = 0.56; 95% CI, 0.51-0.61]), psychiatric disorders (e.g., mood disorder [RR, 0.52; 95% CI, 0.39-0.70] and anxiety [RR, 0.57; 95% CI, 0.46-0.70], sleep disturbance [RR, 0.60; 95% CI, 0.47-0.77]), neurologic and developmental disorders (e.g., attention deficit hyperactivity disorder [RR, 0.54; 95% CI, 0.38-0.75]). Furthermore, the positive effects are found to be more pronounced in younger children (aged 0-5 years) with AD.

CONCLUSIONS

Treatment with dupilumab compared to systemic agents resulted in reductions in AD-related comorbidities in pediatric patients.

Single cell profiling to determine influence of wheeze and early-life viral infection on developmental programming of airway epithelium

Although childhood asthma is in part an airway epithelial disorder, the development of the airway epithelium in asthma is not understood. We sought to characterize airway epithelial developmental phenotypes in those with and without recurrent wheeze and the impact of infant infection with respiratory syncytial virus (RSV). Nasal airway epithelial cells (NAECs) were collected at age 2-3 years from an a priori designed nested birth cohort of children from four mutually exclusive groups of wheezers/non-wheezers and RSV-infected/uninfected in the first year of life. NAECs were cultured in air-liquid interface differentiation conditions followed by a combined analysis of single cell RNA sequencing (scRNA-seq) and in vitro infection with respiratory syncytial virus (RSV). NAECs from children with a wheeze phenotype were characterized by abnormal differentiation and basal cell activation of developmental pathways, plasticity in precursor differentiation and a delayed onset of maturation. NAECs from children with wheeze also had increased diversity of currently known RSV receptors and blunted anti-viral immune responses to in vitro infection. The most dramatic changes in differentiation of cultured epithelium were observed in NAECs derived from children that had both wheeze and RSV in the first year of life. Together this suggests that airway epithelium in children with wheeze is developmentally reprogrammed and characterized by increased barrier permeability, decreased antiviral response, and increased RSV receptors, which may predispose to and amplify the effects of RSV infection in infancy and susceptibility to other asthma risk factors that interact with the airway mucosa.

SUMMARY

Nasal airway epithelial cells from children with wheeze are characterized by altered development and increased susceptibility to RSV infection.

Assessing the Role of Asthma on the Relationship between Neurodevelopmental Disabilities and Adverse Birth Outcomes

BACKGROUND

Investigating asthma as an effect modifier between adverse birth outcomes and neurodevelopmental disabilities (NDDs) across different races is crucial for tailored interventions and understanding variable susceptibility among diverse populations.

METHODS

Data were collected through the National Survey of Children's Health. This cross-sectional study included 131,774 children aged 0 to 17 years. Study exposures comprised adverse birth outcomes including preterm birth and low birth weight. Weighted prevalence estimates and odds ratios with 95% confidence intervals (CIs) among children with and without adverse birth outcomes were calculated for NDDs including attention-deficit/hyperactivity disorder, autism spectrum disorder, cerebral palsy, seizure, and several others including behavior problems. Adjusted odds ratios were stratified by asthma status and separate interactions were assessed for each outcome.

RESULTS

Of 131,774 participants, 10,227 were born low birth weight (9.12%; 95% CI: 8.77% to 9.49%), 14,058 were born preterm (11.35%; 95% CI: 10.94% to 11.76%), and 16,166 participants had asthma (11.97%; 95% CI: 11.58% to 12.37%). There were 68,100 males (51.11%), 63,674 females (48.89%), 102,061 non-Hispanic Whites (NHW) (66.92%), 8,672 non-Hispanic Blacks (NHB) (13.97%), and 21,041 participants (19.11%) categorized as other. NHB children with adverse birth outcomes had higher prevalence of several NDDs compared to NHW children.

CONCLUSIONS

Asthma was not shown to be an effect modifier of the association between adverse birth outcomes and NDDs. Nevertheless, these results suggest that NDDs are more prevalent within US children with adverse birth outcomes, with higher rates among NHB compared to NHW children. These findings support screening for NDDs in pediatric health care settings among patients with adverse birth outcomes, particularly among those from ethnic minority backgrounds.

Human milk oligosaccharides differentially support gut barrier integrity and enhance Th1 and Th17 cell effector responses in vitro

Human milk oligosaccharides (HMOs) can modulate the intestinal barrier and regulate immune cells to favor the maturation of the infant intestinal tract and immune system, but the precise functions of individual HMOs are unclear. To determine the structure-dependent effects of individual HMOs (representing different structural classes) on the intestinal epithelium as well as innate and adaptive immune cells, we assessed fucosylated (2'FL and 3FL), sialylated (3'SL and 6'SL) and neutral non-fucosylated (LNT and LNT2) HMOs for their ability to support intestinal barrier integrity, to stimulate the secretion of chemokines from intestinal epithelial cells, and to modulate cytokine release from LPS-activated dendritic cells (DCs), M1 macrophages (MØs), and co-cultures with naïve CD4+ T cells. The fucosylated and neutral non-fucosylated HMOs increased barrier integrity and protected the barrier following an inflammatory insult but exerted minimal immunomodulatory activity. The sialylated HMOs enhanced the secretion of CXCL10, CCL20 and CXCL8 from intestinal epithelial cells, promoted the secretion of several cytokines (including IL-10, IL-12p70 and IL-23) from LPS-activated DCs and M1 MØs, and increased the secretion of IFN-γ and IL-17A from CD4+ T cells primed by LPS-activated DCs and MØs while reducing the secretion of IL-13. Thus, 3'SL and 6'SL supported Th1 and Th17 responses while reducing Th2 responses. Collectively, our data show that HMOs exert structure-dependent effects on the intestinal epithelium and possess immunomodulatory properties that confer benefits to infants and possibly also later in life.

The role of regulatory B cells in immune regulation and childhood allergic asthma

BACKGROUND

As the most common chronic disease in childhood, asthma displays a major public health problem worldwide with the incidence of those affected rising. As there is currently no cure for allergic asthma, it is mandatory to get a better understanding of the underlying molecular mechanism.

MAIN BODY

By producing IgE antibodies upon allergen contact, B cells play a pivotal role in allergic asthma. Besides that, IL-10-secreting B cell subsets, namely regulatory B cells (Bregs), are reported in mice and humans to play a role in allergic asthma. In humans, several Breg subsets with distinct phenotypic and functional properties are identified among B cells at different maturational and differentiation stages that exert anti-inflammatory functions by expressing several suppressor molecules. Emerging research has focused on the role of Bregs in allergic asthma as well as their role for future diagnostic and preventive strategies.

CONCLUSION

Knowledge about the exact function of human Bregs in allergic asthma is still very limited. This review aims to summarize the current knowledge on Bregs. We discuss different human Breg subsets, several ways of Breg induction as well as the mechanisms through which they exert immunoregulatory functions, and their role in (childhood) allergic asthma.

Use of exhaled nitric oxide in the diagnosis and monitoring of childhood asthma: myth or maxim?

Asthma is a common condition in children. This review describes the evidence from the literature and international asthma guidelines for using fractional exhaled nitric oxide (FENO) in the diagnosis and monitoring of childhood asthma. The accuracy of FENO measuring devices could be further improved, the difference in FENO results between devices are equivalent to what is considered a clinically important difference. For diagnosing asthma no guideline currently recommends FENO is used as the first test, but many recommend FENO as part of a series of tests. A cut-off of 35 ppb is widely recommended as being supportive of an asthma diagnosis, but evidence from children at risk of asthma suggests that a lower threshold of 25 ppb may be more appropriate. Nine randomised clinical trials including 1885 children have added FENO to usual asthma care and find that exacerbations are reduced when care is guided by FENO (OR for exacerbation compared to usual care 0.77, 95% CI 0.62-0.94). What is not clear is what cut-off(s) of FENO should be used to trigger a change in treatment. After 30 years of intensive research there is not sufficient evidence to recommend FENO for routine diagnosing and monitoring asthma in children.

Educational aims

To give the reader an overview of literature that supports and does not support the role of FENO in diagnosing asthma in children.To give the reader an overview of literature that supports and does not support the role of FENO in monitoring asthma in children.To give the reader an understanding of the role of FENO in international guidelines for diagnosing and monitoring asthma in children.

Long term respiratory morbidity of cesarean-delivered second twin compared to their vaginally-delivered sibling: A retrospective population-based cohort study

BACKGROUND

Offspring born via cesarean delivery (CD) may be more prone to develope long-term respiratory diseases, compared to those delivered vaginally (VD). In this study, we compared the rates of respiratory diseases between first twins VD and second twins delivered via CD.

METHODS

This was a retrospective database study. All twin deliveries encompassed at the Soroka University Medical Center, a large tertiary hospital in southern Israel, between 1991 and 2020, in which the first twin was VD and the second via CD were included. Respiratory diseases included respiratory tract diseases such as bronchiolitis and bronchial asthma. The cumulative incidence of respiratory diseases was compared between the twins using Kaplan-Meier survival analysis and multivariable Cox models to adjust for confounding variables.

RESULTS

A total of 395,408 deliveries occurred during the study period, with 13,402 (3.4%) of all deliveries being twins. Of these, 184 (1.4%) were first twins VD and second twins delivered via CD. The second CD twin was more likely to have a non-reassuring fetal heart rate pattern and an Apgar score less than 7 at 5 min. No other differences were found between the siblings. The incidence of long-term respiratory diseases was not statistically different between the CD and VD siblings (7.6% vs. 9.4%, respectively; OR = 0.54; 95% CI: 0.23-1.26). Similarly, the cumulative incidence of respiratory diseases was not statistically different (Kaplan-Meier, log-rank, p = .59), and in the multivariable analysis which adjusted for birthweight and fetal distress during delivery (adjusted hazard ratio = 1.06; 95% CI: 0.43-26.25).

CONCLUSIONS

While the immediate outcomes for the CD twin were slightly worse compared to the VD twin, there was no difference in long-term respiratory diseases between the siblings.

Association between a maternal vegetarian diet during pregnancy and the occurrence of atopic dermatitis in children

BACKGROUND

Atopic dermatitis (AD) is rising globally, with genetics and environmental factors both playing crucial roles. Dietary habits during pregnancy are linked to children's allergic disease risk. However, limited studies have explored the association between maternal vegetarian diets during pregnancy and child AD. Therefore, this study aimed to examine the relationship between maternal vegetarian diets during pregnancy and the occurrence of AD in children.

METHODS

In this study, the Taiwan Birth Cohort Study (TBCS) database was used, comprising a representative national birth cohort of infants born in Taiwan in 2005. Of 24,200 mother-child pairs in the database, 20,172 completed face-to-face interviews at 6 and 18 months. Employing a 1:10 matching strategy based on maternal age, education level, and child sex, 408 mothers who followed a vegetarian diet during pregnancy were matched with 4080 nonvegetarian mothers. This resulted in a final dataset of 4488 subjects. Logistic regression was used to explore the association between maternal vegetarian diets during pregnancy and the occurrence of AD in children.

RESULTS

Among the TBCS participants, there were 292 (1.8%) mothers who adhered to lacto-ovo vegetarianism and 116 (0.7%) mothers who adhered to veganism, totaling 408 (2.4%) vegetarians during pregnancy. Compared to children of nonvegetarian mothers, children of mothers who followed a vegetarian diet during pregnancy showed a lower risk of developing AD before 18 months of age (OR = 0.65, 95% CI = 0.45-0.93, p = 0.018).

CONCLUSION

This study suggests that a vegetarian diet during pregnancy may lower the risk of AD in children. It is essential to carry out long-term follow-up to fully understand the impact of a mother's diet on allergic conditions.

Intergenerational effects of early life-stage temperature modulation on gene expression and DNA methylation in Atlantic cod (Gadus morhua)

After suffering several collapses, the cod farming industry is now in the process of trying to re-establish itself. We have used material from Norway's National Cod Breeding Program to study how different early life-stage temperature regimes affect DNA methylation and gene expression. Long-term effects were detected by sampling fish several weeks after the end of differential treatments, and offspring from the different exposure groups was also sampled. Many overlapping genes were found between the different exposure groups and generations, coupled with genes associated with differential CpG methylation levels. Genes involved in muscle fibre development, general metabolic processes and formation of deformities were significantly affected, and genes relevant for intergenerational transfer of epigenetic marks were also detected. We believe the use of environmental cues can be a useful strategy for improving the production of Atlantic cod.

Identifying sensitive windows of prenatal household air pollution on birth weight and infant pneumonia risk to inform future interventions

BACKGROUND

Prenatal household air pollution impairs birth weight and increases pneumonia risk however time-varying associations have not been elucidated and may have implications for the timing of public health interventions.

METHODS

The Ghana Randomized Air Pollution and Health Study (GRAPHS) enrolled 1,414 pregnant women from Kintampo, Ghana and measured personal carbon monoxide (CO) exposure four times over pregnancy. Birth weight was measured within 72-hours of birth. Fieldworkers performed weekly pneumonia surveillance and referred sick children to study physicians. The primary pneumonia outcome was one or more physician-diagnosed severe pneumonia episode in the first year of life. We employed reverse distributed lag models to examine time-varying associations between prenatal CO exposure and birth weight and infant pneumonia risk.

RESULTS

Analyses included n = 1,196 mother-infant pairs. In models adjusting for child sex; maternal age, body mass index (BMI), ethnicity and parity at enrollment; household wealth index; number of antenatal visits; and evidence of placental malaria, prenatal CO exposures from 15 to 20 weeks gestation were inversely associated with birth weight. Sex-stratified models identified a similar sensitive window in males and a window at 10-weeks gestation in females. In models adjusting for child sex, maternal age, BMI and ethnicity, household wealth index, gestational age at delivery and average postnatal child CO exposure, CO exposure during 34-39 weeks gestation were positively associated with severe pneumonia risk, especially in females.

CONCLUSIONS

Household air pollution exposures in mid- and late- gestation are associated with lower birth weight and higher pneumonia risk, respectively. These findings support the urgent need for deployment of clean fuel stove interventions beginning in early pregnancy.

Human milk oligosaccharides: potential therapeutic aids for allergic diseases

Childhood allergy, including asthma, eczema, and food allergies, is a major global health burden, with prevalence increasing dramatically and novel interventions needed. Emerging research suggests that human milk oligosaccharides (HMOs), complex glycans found in breastmilk, have allergy-protective properties, indicating exciting therapeutic potential. This review evaluates current literature on the role of HMOs in allergy, assesses underlying immunological mechanisms, and discusses future research needed to translate findings into clinical implications. HMOs may mediate allergy risk through multiple structure-specific mechanisms, including microbiome modification, intestinal barrier maturation, immunomodulation, and gene regulation. Findings emphasize the importance of breastfeeding encouragement and HMO-supplemented formula milk for high allergy-risk infants. Although further investigation is necessary to determine the most efficacious structures against varying allergy phenotypes and their long-term efficacy, HMOs may represent a promising complementary tool for childhood allergy prevention.

Persistent Asthma at School Age: Associated Factors in Preschool Children with Asthma

Most patients with childhood asthma present their first symptoms at preschool age. Identifying modifiable risks and protective factors at an early age may help develop asthma prevention and control strategies. This study aimed to identify factors at preschool age that are associated with persistent asthma at school age. This retrospective observational study included preschool children with asthma from 2015 to 2020 at a university hospital in Southern Thailand. In total, 189 eligible participants (70.9% boys; median age, 7.6 [6.7, 8.5] years) were included. Wheeze characteristics included early transient wheeze, persistent wheeze, and late-onset wheeze that accounted for 55%, 27.5%, and 19.5% of the patients, respectively. Approximately 20% of the participants had persistent asthma. Breastfeeding was a protective factor (odds ratio [OR] 0.4 [0.2, 0.9], p = 0.04). The modifiable risk factors were siblings living in the same household (OR 2.6 [1.1, 6.2], p = 0.02) and residence in an industrial area (OR 3.8 [1.4, 10.5], p = 0.009). Additionally, presence of allergic rhinitis was associated with an increased risk of persistent asthma at school age (OR 3.6 [1.6, 8.2], p = 0.002). Early therapeutic interventions targeting modifiable factors provide a window of opportunity to prevent persistent asthma at school age.

The relationship of early-life household air pollution with childhood asthma and lung function

The increase in childhood asthma over the past few decades has made it an important public health issue. Poor lung function growth associated with some phenotypes of asthma compounds its long-term impact on the individual. Exposure to early-life household risk factors is believed to be linked with respiratory health while infants' lungs are still developing. This review summarises epidemiological studies and mechanistic evidence focusing on the detrimental effects of early-life household air exposures on the respiratory health of children, in particular effects on asthma and lung function. Many early-life household air exposures, including tobacco smoke, gases from heating and cooking, mould/dampness and cleaning products are associated with childhood asthma development and lung function growth. These exposures may alter structural and mechanical characteristics of infants' lungs and contribute to deficits in later life. In addition, some risk factors, including tobacco smoke and cleaning products, can transmit effects across generations to increase the risk of asthma in subsequent generations. This review supports the hypothesis that risks of asthma and accelerated lung ageing are established in early life. The timing of exposure may be critical in the pathogenesis of respiratory diseases, in terms of future risk of asthma and reduced lung function in adults.

NLRP3 priming due to skin damage precedes LTP allergic sensitization in a mouse model

Allergic sensitization is initiated by protein and epithelia interaction, although the molecular mechanisms leading this encounter toward an allergic phenotype remain unknown. Here, we apply the two-hit hypothesis of inflammatory diseases to the study of food allergy sensitization. First, we studied the effects of long-term depilation in mice by analyzing samples at different time points. Several weeks of depilation were needed until clear immunological changes were evidenced, starting with upregulation of NLRP3 protein levels, which was followed by overexpression of Il1b and Il18 transcripts. Secondly, we assessed the effects of allergen addition (in this case, Pru p 3 in complex with its natural lipid ligand) over depilated skin. Systemic sensitization was evaluated by intraperitoneal provocation with Pru p 3 and measure of body temperature. Anaphylaxis was achieved, but only in mice sensitized with Prup3_complex and not treated with the NLRP3 inhibitor MCC950, thus demonstrating the importance of both hits (depilation + allergen addition) in the consecution of the allergic phenotype. In addition, allergen encounter (but not depilation) promoted skin remodeling, as well as CD45+ infiltration not only in the sensitized area (the skin), but across several mucosal tissues (skin, lungs, and gut), furtherly validating the systemization of the response. Finally, a low-scale study with human ILC2s is reported, where we demonstrate that Prup3_complex can induce their phenotype switch (↑CD86, ↑S1P1) when cultured in vitro, although more data is needed to understand the implications of these changes in food allergy development.

Cytokine profiles in cord blood in relation to prenatal traffic-related air pollution: The NELA cohort

BACKGROUND

Outdoor air pollution may disturb immune system development. We investigated whether gestational exposure to traffic-related air pollutants (TRAP) is associated with unstimulated cytokine profiles in newborns.

METHODS

Data come from 235 newborns of the NELA cohort. Innate response-related cytokines (IL-6, IFN-α, IL1-β, and TNF-α), Th1-related (IFN-γ and IL-2), Th2-related (IL-4, IL-5, and IL-13), Th17-related (IL-17 and IL-23), and immunomodulatory cytokine IL-10 were quantified in the supernatant of unstimulated whole umbilical cord blood cells after 7 days of culture using the Luminex technology. Dispersion/chemical transport modeling was used to estimate long-term (whole pregnancy and trimesters) and short-term (15 days before delivery) residential exposures to traffic-related nitrogen dioxide (NO₂ ), particulate matter (PM_2.5 and PM₁₀ ), and ozone (O₃ ). We fitted multivariable logistic regression, Bayesian kernel machine regression (BKMR), and weighted quantile sum (WQS) regression models.

RESULTS

NO₂ during the whole pregnancy increased the odds of detection of IL-1β (OR per 10 µg/m³ increase = 1.37; 95% CI, 1.02, 1.85) and IL-6 (OR per 10 µg/m³ increase = 1.32; 95% CI 1.00, 1.75). Increased odds of detected concentrations of IL-10 was found in newborns exposed during whole pregnancy to higher levels of NO₂ (OR per 10 µg/m³ increase = 1.30; 95% CI 0.99, 1.69), PM₁₀ (OR per 10 µg/m³ increase = 1.49; 95% CI 0.95, 2.33), and PM_2.5 (OR per 5 µg/m³ increase = 1.56; 95% CI 0.97, 2.51). Exposure to O₃ during the whole pregnancy increased the odds of detected IL-13 (OR per 10 µg/m³ increase = 1.22; 95% CI 1.01, 1.49). WQS model revealed first and third trimesters of gestation as windows of higher susceptibility.

CONCLUSIONS

Gestational exposure to TRAP may increase detection of pro-inflammatory, Th2-related, and T regulatory cytokines in newborns. These changes might influence immune system responses later in life.

Neonatal Immune System Ontogeny: The Role of Maternal Microbiota and Associated Factors. How Might the Non-Human Primate Model Enlighten the Path?

Interactions between the immune system and the microbiome play a crucial role on the human health. These interactions start in the prenatal period and are critical for the maturation of the immune system in newborns and infants. Several factors influence the composition of the infant's microbiota and subsequently the development of the immune system. They include maternal infection, antibiotic treatment, environmental exposure, mode of delivery, breastfeeding, and food introduction. In this review, we focus on the ontogeny of the immune system and its association to microbial colonization from conception to food diversification. In this context, we give an overview of the mother-fetus interactions during pregnancy, the impact of the time of birth and the mode of delivery, the neonate gastrointestinal colonization and the role of breastfeeding, weaning, and food diversification. We further review the impact of the vaccination on the infant's microbiota and the reciprocal case. Finally, we discuss several potential therapeutic interventions that might help to improve the newborn and infant's health and their responses to vaccination. Throughout the review, we underline the main scientific questions that are left to be answered and how the non-human primate model could help enlighten the path.

Immunological Roles of NLR in Allergic Diseases and Its Underlying Mechanisms

Our understanding on the immunological roles of pathogen recognition in innate immunity has vastly increased over the past 20 years. Nucleotide-binding oligomerization domain (NOD)-like receptors (NLR) are cytosolic pattern recognition receptors (PRR) that are responsible for sensing microbial motifs and endogenous damage signals in mammalian cytosol for immune surveillance and host defense. The accumulating discoveries on these NLR sensors in allergic diseases suggest that the pathogenesis of allergic diseases may not be confined to the adaptive immune response. Therapy targeting NLR in murine models also shields light on its potential in the treatment of allergies in man. In this review, we herein summarize the recent understanding of the role of NLR sensors and their molecular mechanisms involved in allergic inflammation, including atopic dermatitis and allergic asthma.

Differentially expressed serum proteins in children with or without asthma as determined using isobaric tags for relative and absolute quantitation proteomics

Background

Although asthma is one of the most common chronic, noncommunicable diseases worldwide, the pathogenesis of childhood asthma is not yet clear. Genetic factors and environmental factors may lead to airway immune-inflammation responses and an imbalance of airway nerve regulation. The aim of the present study was to determine which serum proteins are differentially expressed between children with or without asthma and to ascertain the potential roles that these differentially expressed proteins (DEPs) may play in the pathogenesis of childhood asthma.

Methods

Serum samples derived from four children with asthma and four children without asthma were collected. The DEPs were identified by using isobaric tags for relative and absolute quantitation (iTRAQ) combined with liquid chromatography tandem mass spectrometry (LC-MS/MS) analyses. Using biological information technology, including Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), and Cluster of Orthologous Groups of Proteins (COG) databases and analyses, we determined the biological processes associated with these DEPs. Key protein glucose-6-phosphate dehydrogenase (G6PD) was verified by enzyme linked immunosorbent assay (ELISA).

Results

We found 46 DEPs in serum samples of children with asthma vs. children without asthma. Among these DEPs, 12 proteins were significantly (>1.5 fold change) upregulated and 34 proteins were downregulated. The results of GO analyses showed that the DEPs were mainly involved in binding, the immune system, or responding to stimuli or were part of a cellular anatomical entity. In the KEGG signaling pathway analysis, most of the downregulated DEPs were associated with cardiomyopathy, phagosomes, viral infections, and regulation of the actin cytoskeleton. The results of a COG analysis showed that the DEPs were primarily involved in signal transduction mechanisms and posttranslational modifications. These DEPs were associated with and may play important roles in the immune response, the inflammatory response, extracellular matrix degradation, and the nervous system. The downregulated of G6PD in the asthma group was confirmed using ELISA experiment.

Conclusion

After bioinformatics analyses, we found numerous DEPs that may play important roles in the pathogenesis of childhood asthma. Those proteins may be novel biomarkers of childhood asthma and may provide new clues for the early clinical diagnosis and treatment of childhood asthma.