Sphingolipid classes and the interrelationship with pediatric asthma and asthma risk factors.

BACKGROUND: While dysregulated sphingolipid metabolism has been associated with risk of childhood asthma, the specific sphingolipid classes and/or mechanisms driving this relationship remain unclear. We aimed to understand the multifaceted role between sphingolipids and other established asthma risk factors that complicate this relationship. METHODS: We performed targeted LC-MS/MS-based quantification of 77 sphingolipids in plasma from 997 children aged 6 years from two independent cohorts (VDAART and COPSAC2010 ). We examined associations of circulatory sphingolipids with childhood asthma, lung function, and three asthma risk factors: functional SNPs in ORMDL3, low vitamin D levels, and reduced gut microbial maturity. Given racial differences between these cohorts, association analyses were performed separately and then meta-analyzed together. RESULTS: We observed elevations in circulatory sphingolipids with asthma phenotypes and risk factors; however, there were differential associations of sphingolipid classes with clinical outcomes and/or risk factors. While elevations from metabolites involved in ceramide recycling and catabolic pathways were associated with asthma and worse lung function [meta p-value range: 1.863E-04 to 2.24E-3], increased ceramide levels were associated with asthma risk factors [meta p-value range: 7.75E-5 to .013], but not asthma. Further investigation identified that some ceramides acted as mediators while some interacted with risk factors in the associations with asthma outcomes. CONCLUSION: This study demonstrates the differential role that sphingolipid subclasses may play in asthma and its risk factors. While overall elevations in sphingolipids appeared to be deleterious overall; elevations in ceramides were uniquely associated with increases in asthma risk factors only; while elevations in asthma phenotypes were associated with recycling sphingolipids. Modification of asthma risk factors may play an important role in regulating sphingolipid homeostasis via ceramides to affect asthma. Further function work may validate the observed associations.

Preventive effects of prenatal administration of OM-85/BV on asthma and respiratory infection risk in the offspring: A review of animal models.

Asthma is the most common chronic disease in childhood affecting the daily lives of many patients despite current treatment regimens. Therefore, the need for new therapeutic approaches is evident, where a primary prevention strategy is the ultimate goal. Studies of children born to mothers in farming environments have shown a lower risk of respiratory infections and asthma development. Already at birth, these newborns have demonstrated accelerated maturation and upregulation of host defense immune functions suggesting a prenatal transplacental training of the innate immune system through maternal microbial exposure. This mechanism could possibly be utilized to help prevent both respiratory infections and asthma in young children. Human studies exploring the potential preventative effects of pregnancy bacterial lysate treatment on asthma and respiratory infections are lacking, however, this has been studied in experimental studies using mice through administrations of the bacterial lysate OM-85. This review will present the current literature on the immunomodulatory effects relevant for respiratory infections and asthma in the offspring of mice treated with OM-85 throughout pregnancy. Further, the review will discuss the cellular and molecular mechanisms behind these effects. In conclusion, we found promising results of an accelerated immune competence and improved resistance to airway challenges as a result of prenatal bacterial lysate treatment that may pave the way for implementing this in human trials to prevent asthma and respiratory infections.

Supplementation With Fish Oil in Pregnancy Reduces Gastroenteritis in Early Childhood.

BACKGROUND: We hypothesized that insufficient intake of fish oil-derived omega-3 long-chain polyunsaturated fatty acids (n-3 LCPUFAs) during pregnancy is a contributing factor to gastroenteritis in early childhood. We examined the effect of n-3 LCPUFA supplementation on gastroenteritis symptoms in the offspring's first 3 years of life. METHODS: This was a double-blinded, randomized controlled trial whereby 736 mothers were administered n-3 LCPUFA or control from pregnancy week 24 until 1 week after birth. We measured the number of days with gastroenteritis, number of episodes with gastroenteritis, and the risk of having a gastroenteritis episode in the first 3 years of life. RESULTS: A median reduction of 2.5 days with gastroenteritis (P = .018) was shown, corresponding to a 14% reduction in the n-3 LCPUFA group compared with controls in the first 3 years of life (P = .037). A reduction in the number of gastroenteritis episodes (P = .027) and a reduced risk of having an episode (hazard ratio, 0.80 [95% confidence interval, .66-.97]; P = .023) were also shown. CONCLUSIONS: Fish oil supplementation from the 24th week of pregnancy led to a reduction in the number of days and episodes with gastroenteritis symptoms in the first 3 years of life. The findings suggest n-3 LCPUFA supplementation as a preventive measure against gastrointestinal infections in early childhood. CLINICAL TRIALS REGISTRATION: NCT00798226.

Outcomes reported in randomized controlled trials for mixed and non-IgE-mediated food allergy: Systematic review.

BACKGROUND: Mixed and non-IgE-mediated food allergy is a subset of immune-mediated adverse food reactions that can impose a major burden on the quality of life of affected patients and their families. Clinical trials to study these diseases are reliant upon consistent and valid outcome measures that are relevant to both patients and clinicians, but the degree to which such stringent outcome reporting takes place is poorly studied. OBJECTIVE: As part of the Core Outcome Measures for Food Allergy (COMFA) project, we identified outcomes reported in randomized clinical trials (RCT) of treatments for mixed or non-IgE-mediated food allergy. DESIGN: In this systematic review, we searched the Ovid, MEDLINE and Embase databases for RCTs in children or adults investigating treatments for food protein-induced enterocolitis syndrome, food protein-induced allergic proctocolitis, food protein-induced enteropathy and eosinophilic gastrointestinal disorders including eosinophilic esophagitis [EoE], eosinophilic gastritis and eosinophilic colitis published until 14 October 2022. RESULTS: Twenty-six eligible studies were identified, with 23 focused on EoE (88%). Most interventions were corticosteroids or monoclonal antibodies. All EoE studies assessed patient-reported dysphagia, usually using a non-validated questionnaire. Twenty-two of 23 EoE studies used peak tissue eosinophil count as the primary outcome, usually using a non-validated assessment method, and other immunological markers were only exploratory. Thirteen (57%) EoE studies reported endoscopic outcomes of which six used a validated scoring tool recently recommended as a core outcome for EoE trials. Funding source was not obviously associated with likelihood of an RCT reporting mechanistic versus patient-reported outcomes. Only 3 (12%) RCTs concerned forms of food allergy other than EoE, and they reported on fecal immunological markers and patient-reported outcomes. CONCLUSIONS: Outcomes measured in clinical trials of EoE and non-IgE-mediated food allergy are heterogeneous and largely non-validated. Core outcomes for EoE have been developed and need to be used in future trials. For other forms of mixed or non-IgE-mediated food allergies, core outcome development is needed to support the development of effective treatments. SYSTEMATIC REVIEW REGISTRATION: OSF public registry DOI:10.17605/OSF.IO/AZX8S.

Asthma medication and risk of dental diseases in children - A prospective cohort study.

BACKGROUND: Dental caries and enamel defects are the main causes of poor dental health in children, with a substantial impact on their well-being. Use of inhaled asthma medication is a suspected risk factor, but there is a lack of prospective studies investigating this and other prenatal and early life risk factors. METHODS: Copenhagen Prospective Studies on Asthma in Childhood 2010 mother-child cohort (COPSAC2010 ) consists of 700 women who were recruited at 24 weeks of pregnancy. 588 of their children participated in a dental examination at 6 years of age (84%) at the COPSAC2010 research unit. Caries was defined as decayed, missing, or filled surfaces. Enamel defect was defined as demarcated opacity, post-eruptive enamel breakdown, and/or atypical restoration on at least one molar. Caries and enamel defects were assessed in both deciduous and permanent dentitions. RESULTS: We found no associations between inhaled corticosteroids or ß2 -agonists or asthma symptoms in early childhood and the risk of caries or enamel defects by 6 years of age. Furthermore, we found no strong pre-, peri-, or postnatal risk factors for dental diseases at 6 years, except from nominally significant associations between antibiotic use in pregnancy (OR = 1.25, [1.01-1.54]), maternal education level (OR = 1.57, [1.01-2.45]), having a dog at home (OR = 0.50, [0.27-0.93]), and risk of enamel defects. CONCLUSIONS: Use of inhaled corticosteroids, ß2 -agonists, or asthma symptoms in the first 6 years of life were not associated with the development of caries or enamel defects. This finding is reassuring for parents and physicians prescribing asthma medication for young children.

Genome-wide study of early and severe childhood asthma identifies interaction between CDHR3 and GSDMB.

BACKGROUND: Asthma with severe exacerbation is one of the most common causes of hospitalization among young children. Exacerbations are typically triggered by respiratory infections, but the host factors causing recurrent infections and exacerbations in some children are poorly understood. As a result, current treatment options and preventive measures are inadequate. OBJECTIVE: We sought to identify genetic interaction associated with the development of childhood asthma. METHODS: We performed an exhaustive search for pairwise interaction between genetic single nucleotide polymorphisms using 1204 cases of a specific phenotype of early childhood asthma with severe exacerbations in patients aged 2 to 6 years combined with 5328 nonasthmatic controls. Replication was attempted in 3 independent populations, and potential underlying immune mechanisms were investigated in the COPSAC2010 and COPSAC2000 birth cohorts. RESULTS: We found evidence of interaction, including replication in independent populations, between the known childhood asthma loci CDHR3 and GSDMB. The effect of CDHR3 was dependent on the GSDMB genotype, and this interaction was more pronounced for severe and early onset of disease. Blood immune analyses suggested a mechanism related to increased IL-17A production after viral stimulation. CONCLUSIONS: We found evidence of interaction between CDHR3 and GSDMB in development of early childhood asthma, possibly related to increased IL-17A response to viral infections. This study demonstrates the importance of focusing on specific disease subtypes for understanding the genetic mechanisms of asthma.

Height and bone mineral content after inhaled corticosteroid use in the first 6 years of life.

BACKGROUND: Infants and young children might be particularly susceptible to the potential side effects from inhaled corticosteroid (ICS) on height and bone mineral content (BMC), but this has rarely been studied in long-term prospective studies. METHODS: Children from two Copenhagen Prospective Studies on Asthma in Childhood cohorts were included. ICS use was registered prospectively from birth to age 6 and the cumulative dose was calculated. Primary outcomes were height and BMC from dual-energy X-ray absorptiometry (DXA) scans at age 6. RESULTS: At age 6, a total of 930 children (84%) from the cohorts had a valid height measurement and 792 (71%) had a DXA scan. 291 children (31%) received a cumulated ICS dose equivalent to or above 10 weeks of standard treatment before age 6. We found an inverse association between ICS use and height, -0.26 cm (95% CI: -0.45 to -0.07) per 1 year standard treatment from 0 to 6 years of age, p=0.006. This effect was mainly driven by children with ongoing treatment between age 5 and 6 years (-0.31 cm (95% CI: -0.52 to -0.1), p=0.004), while there was no significant association in children who stopped treatment at least 1 year before age 6 (-0.09 cm (95% CI: -0.46 to 0.28), p=0.64). There was no association between ICS use and BMC at age 6. CONCLUSIONS: ICS use in early childhood was associated with reduced height at age 6 years but only in children with continued treatment in the sixth year of life.

Associations between Inhaled Corticosteroid Use in the First 6 Years of Life and Obesity-related Traits.

Rationale: Infants and young children might be particularly likely to experience the potential clinical side effects of inhaled corticosteroids (ICSs) on body mass index (BMI), adiposity rebound (AR), and body composition, but this has rarely been studied in long-term studies in this age group. Objectives: To determine the association between ICS exposure in the first 6 years of life and the BMI, AR, body composition, and blood lipid concentrations. Methods: Children from the two mother-child cohorts of the COPSAC (Copenhagen Prospective Studies on Asthma in Childhood) were included. ICS use was registered prospectively to age 6 years, and the cumulative dose was calculated. Multiple linear regression models were used for analysis. Measurements and Main Results: A total of 932 (84%) of the 1,111 children from the COPSAC cohorts had BMI data, 786 (71%) had dual-energy X-ray absorptiometry scan data at the age of 6 years, and 815 (73%) had an AR age calculated. Two hundred ninety-one children (31%) received a cumulative ICS dose higher than that from 10 weeks of standard treatment before the age of 6. ICS treatment during 0-6 years of age was associated with an increased BMI z-score (0.05 [95% confidence interval, 0.005 to 0.09] SDs per each year of standard treatment; P = 0.03) an earlier age at AR (-0.18 [95% confidence interval, -0.28 to -0.08] yr; P = 0.0006), and a 2% increased geometric mean android fat percentage (P = 0.05). ICS exposure and dual-energy X-ray absorptiometry scan data were not associated. Conclusions: ICS use in early childhood was associated with an increased BMI z-score at age 6, an earlier AR, and a trend of association with an increased android body fat percentage.

Characteristics and Mechanisms of a Sphingolipid-associated Childhood Asthma Endotype.

Rationale: A link among sphingolipids, 17q21 genetic variants, and childhood asthma has been suggested, but the underlying mechanisms and characteristics of such an asthma endotype remain to be elucidated.Objectives: To study the sphingolipid-associated childhood asthma endotype using multiomic data.Methods: We used untargeted liquid chromatography-mass spectrometry plasma metabolomic profiles at the ages of 6 months and 6 years from more than 500 children in the COPSAC2010 (Copenhagen Prospective Studies on Asthma in Childhood) birth cohort focusing on sphingolipids, and we integrated the 17q21 genotype and nasal gene expression of SPT (serine palmitoyl-CoA transferase) (i.e., the rate-limiting enzyme in de novo sphingolipid synthesis) in relation to asthma development and lung function traits from infancy until the age 6 years. Replication was sought in the independent VDAART (Vitamin D Antenatal Asthma Reduction Trial) cohort.Measurements and Main Results: Lower concentrations of ceramides and sphingomyelins at the age of 6 months were associated with an increased risk of developing asthma before age 3, which was also observed in VDAART. At the age of 6 years, lower concentrations of key phosphosphingolipids (e.g., sphinganine-1-phosphate) were associated with increased airway resistance. This relationship was dependent on the 17q21 genotype and nasal SPT gene expression, with significant interactions occurring between the genotype and the phosphosphingolipid concentrations and between the genotype and SPT expression, in which lower phosphosphingolipid concentrations and reduced SPT expression were associated with increasing numbers of at-risk alleles. However, the findings did not pass the false discovery rate threshold of <0.05.Conclusions: This exploratory study suggests the existence of a childhood asthma endotype with early onset and increased airway resistance that is characterized by reduced sphingolipid concentrations, which are associated with 17q21 genetic variants and expression of the SPT enzyme.

Objective confirmation of asthma diagnosis, treatment adherence and patient outcomes in children and adolescents.

AIM: The aim of this study was to investigate the diagnostic workup in children with asthma hypothesising that objective confirmation of the diagnosis is associated with improved treatment adherence and patient outcomes. METHODS: We reviewed medical records of children aged 5-18 years diagnosed with asthma at the Department of Paediatric and Adolescent Medicine, Herlev-Gentofte Hospital, Denmark, in 2018. Objective confirmation of the diagnosis was based on either (1) lung function, (2) bronchodilator response, (3) bronchial hyperresponsiveness and/or (4) elevated FeNO and was associated with treatment adherence (proportion of days covered, PDC), lung function development and exacerbations during a two-year follow-up period. RESULTS: A total of 88 children were included. Asthma was objectively confirmed in 67 (76%). Children with objective confirmation of the diagnosis were more likely to redeem short-acting beta-2-agonist prescriptions: at least once, aOR = 1.3 (95% CI, 1.1-13.1), p = 0.036, and were more adherent to inhaled corticosteroid treatment: PDC>80%, aOR = 10.4 (1.8-201.1), p = 0.033. Further, objective confirmation was associated with improved lung function and reduced bronchodilator response, but not with exacerbations. CONCLUSION: Objective confirmation of the asthma diagnosis in children is associated with an increased treatment adherence and improved lung function, which underlines the importance of conducting objective tests in the diagnostic workup in paediatric asthma management.

[Analyze of obesity indicators and effect of fertility preservation treatment in patients with endometrial atypical hyperplasia and early endometrial cancer].

Objective: To investigate the clinical features of obesity indicators in patients with endometrial atypical hyperplasia (EAH) and early endometrial cancer (EC) and analyze the relationship between these indexes and effect of fertility preservation therapy. Methods: The clinical data of patients with EAH, EC and endometrial benign lesions treated in Peking University People's Hospital from January 1, 2018 to June 30, 2021 who required fertility-sparing treatment were collected, and obesity indicators were calculated and analyzed retrospectively. Results: (1) Obesity indicators: the obesity [body mass index (BMI) ≥28 kg/m2] rate of patients with fertility preservation treatment was 40% (32/80), and abdominal obesity [waist circumference (WC) ≥80 cm] rate was 79% (63/80), and obesity indicators [BMI, WC, waist-hip ratio (WHR), weight height ratio (WHTR), body roundness index (BRI), lipid accumulation index (LAP), visceral adiposity index (VAI)] were higher than those with endometrial benign lesions (all P<0.001). (2) Related factors affecting the efficacy of fertility preservation treatment and their predictive value: EC, higher BMI, WC, WHR, WHTR and BRI were risk factors for lower complete remission rate after nine months' treatment (all P<0.05). The predictive values of BRI and WHTR combined with pathological type were superior to other indicators [area under the curve (AUC)=0.716; AUC=0.714]. (3) Relation of obesity indicators and glucolipid indicators:BMI, WC, WHR, WHTR, BRI, LAP and VAI were positively correlated with homeostasis model assessment-insulin resistance index, glycosylated hemoglobin, and triacylglycerol (all P<0.05); while VAI was negatively correlated with high density lipoprotein cholesterol (P<0.001). Conclusions: For patients with EAH and EC treated with fertility preservation therapy, abnormal obesity indexes affect the treatment effect. BRI and WHTR combined pathology have good predictive value for effect of fertility preservation treatment. In clinical practice, appropriate indicators could be selected to evaluate body shape, glucolipid metabolism and predict efficacy.

Maternal 17q21 genotype influences prenatal vitamin D effects on offspring asthma/recurrent wheeze.

BACKGROUND: Prenatal vitamin D3 supplementation has been linked to reduced risk of early-life asthma/recurrent wheeze. This protective effect appears to be influenced by variations in the 17q21 functional single nucleotide polymorphism rs12936231 of the child, which regulates the expression of ORMDL3 (ORM1-like 3) and for which the high-risk CC genotype is associated with early-onset asthma. However, this does not fully explain the differential effects of supplementation. We investigated the influence of maternal rs12936231 genotype variation on the protective effect of prenatal vitamin D3 supplementation against offspring asthma/recurrent wheeze. METHODS: We determined the rs12936231 genotype of mother-child pairs from two randomised controlled trials: the Vitamin D Antenatal Asthma Reduction Trial (VDAART, n=613) and the Copenhagen Prospective Studies on Asthma in Childhood 2010 (COPSAC2010, n=563), to examine the effect of maternal genotype variation on offspring asthma/recurrent wheeze at age 0-3 years between groups who received high-dose prenatal vitamin D3 supplementation versus placebo. RESULTS: Offspring of mothers with the low-risk GG or GC genotype who received high-dose vitamin D3 supplementation had a significantly reduced risk of asthma/recurrent wheeze when compared with the placebo group (hazard ratio (HR) 0.54, 95% CI 0.37-0.77; p<0.001 for VDAART and HR 0.56, 95% CI 0.35-0.92; p=0.021 for COPSAC2010), whereas no difference was observed among the offspring of mothers with the high-risk CC genotype (HR 1.05, 95% CI 0.61-1.84; p=0.853 for VDAART and HR 1.11, 95% CI 0.54-2.28; p=0.785 for COPSAC2010). CONCLUSION: Maternal 17q21 genotype has an important influence on the protective effects of prenatal vitamin D3 supplementation against offspring asthma/recurrent wheeze.

Association between childhood asthma and attention deficit hyperactivity or autism spectrum disorders: A systematic review with meta-analysis.

BACKGROUND: Children with asthma are at risk of depression and anxiety and growing evidence suggest they may also be at risk of attention deficit hyperreactivity disorder (ADHD) and autism spectrum disorder (ASD). Here, we conducted a systematic review with meta-analysis of studies investigating association between asthma and ADHD or ASD in children. METHODS: A comprehensive search using PubMed, EMBASE and Cochrane Library databases was completed in March 2019. Observational human studies published in English, clinic-based or population-based with a healthy comparator group, evaluating asthma-ADHD or asthma-ASD overlap in children 18 years or younger using categorical diagnoses (yes/no) were considered for inclusion. Random effects meta-analysis models were used to analyse data. The Newcastle Ottawa Scale was used to evaluate risk of bias. RESULTS: A total of 25 asthma-ADHD studies were included of which 17 showed significant positive associations and one a negative association: 17/25 studies were population-based, 19/25 were cross-sectional or cohort studies and 7/25 had a low risk of bias. We performed a meta-analysis of 23 of the studies, which showed a significant association between asthma and ADHD: odds ratio (OR) 1.52 (1.42-1.63), P < .001, I2 = 60%. All studies were adjusted for age and sex and a large proportion; that is, 19/23 were further adjusted for relevant confounders. Seventeen asthma-ASD studies were included, whereof 7 showed a positive association and 3 a negative association; 8/17 were population-based with a cross-sectional study design and 4/17 had a low risk of bias. We performed a meta-analysis of 14 of the studies, which did not show a significant association between asthma and ASD: OR 1.12 (0.93-1.34), P = .24, I2 = 89%. All studies were adjusted for age and sex and 10/14 were further adjusted for relevant confounders. CONCLUSIONS: This systematic review with meta-analyses shows a significant overlap between asthma and ADHD, but not between asthma and ASD in children. Clinicians taking care of children with asthma or ADHD should be aware of such association to aid an early diagnosis and treatment of such comorbidity.

Innate IL-23/Type 17 immune responses mediate the effect of the 17q21 locus on childhood asthma.

BACKGROUND: Several childhood asthma risk loci that relate to immune function have been identified by genome-wide association studies (GWAS), but the underlying mechanisms remain unknown. OBJECTIVE: Here, we examined whether perturbed innate immune responses mediate the association between known genetic risk variants and development of childhood asthma. METHODS: Peripheral blood mononuclear cells from 336 six-month-old infants from the Copenhagen Prospective Studies on Asthma in Childhood (COPSAC2000 ) cohort were stimulated in vitro with six different innate ligands (LPS, CpG, poly(I:C), R848, HDMAPP and aluminium hydroxide together with low levels of LPS) followed by quantification of 18 released cytokines and chemokines 40 h after the stimulations. The innate immune response profiles were decomposed by principal component (PC) analysis, and PC1-5 were used in mediation analyses of the effect of 25 known genetic risk variants on childhood asthma until age 7. RESULTS: The effects of two variants from the 17q21 locus (rs7216389, rs2305480) on asthma and exacerbation risk were significantly mediated by immune parameters induced in response to ligands mimicking intracellular colonization; bacterial DNA (CpG) and double-stranded viral RNA (poly(I:C)). The Th17 and innate lymphoid cell type 3-amplifying cytokine IL-23 was the most prominent cytokine involved. CONCLUSION: The 17q21 effect on childhood asthma and exacerbations was partly mediated by deregulation of IL-23 in response to intracellular microbial ligands, which may suggest ineffective clearance of intracellular pathogens in the lungs.

Null association between serum 25-hydroxyvitamin D levels with allergic rhinitis, allergic sensitization and non-allergic rhinitis: A Mendelian randomization study.

BACKGROUND: Previous observational studies have not found a conclusive association between serum 25-hydroxyvitamin D (25(OH)D) levels and allergic rhinitis (AR) or allergic sensitization (AS). OBJECTIVE: To investigate a causal association between 25(OH)D levels with risk of AR and AS, using a two-sample Mendelian randomization (MR) approach. METHODS: Seven single nucleotide polymorphisms (SNPs), previously shown to be associated with serum 25(OH)D levels, were identified as instrumental variables. The primary outcome was AR, and the secondary outcomes were AS and non-allergic rhinitis (NAR). The genome-wide association (GWA) summary statistics of the outcomes were obtained from two cohort studies (EAGLE Consortium and UK Biobank). An MR analysis with random-effects inverse-variance weighted method was performed as the primary analysis to estimate overall effect size (odds ratio [OR] and 95% confidence interval [CI]). Sensitivity analysis using weighted median method and MR-Egger regression method was conducted. A subgroup analysis based on 25(OH)D synthesis-related SNPs was further applied. RESULTS: Serum 25(OH)D levels were not causally associated with risk of AR (OR: 0.960; 95% CI: 0.779-1.184), AS (OR: 1.059; 95% CI: 0.686 to 1.634) or NAR (OR: 0.937; 95% CI: 0.588-1.491). Subgroup analysis also showed null association between 25(OH)D synthesis-related SNPs and the outcomes. Sensitivity analyses yielded similar results. CONCLUSIONS AND CLINICAL RELEVANCE: This MR study found no evidence supporting a causal association between serum 25(OH)D levels and risk of AR, AS and NAR in European-ancestry population. This argues against the previous postulation that vitamin D supplementation is effective in prevention of allergic diseases.

The causal role of gut microbiota in development of osteoarthritis.

OBJECTIVE: There is considerable evidence for relationship between gut microbiota and osteoarthritis (OA), but no studies have investigated their causal relationship. METHOD: This study utilized large-scale genome-wide association studies (GWAS) summary statistics to evaluate the causal association between gut microbiota and OA risk. Specifically, two-sample Mendelian randomization (MR) approach was used to identify the causal microbial taxa for OA. Comprehensively sensitive analyses were performed to validate the robustness of results and novel multivariable MR analyses were further conducted to ensure the independence of causal association. Reverse-direction MR analyses were performed to rule out the possibility of reverse associations. Finally, enrichment analyses were used to investigate the biofunction. RESULTS: After correction, three microbial taxa were identified to be causally associated with diverse joint OA (PFDR < 0.100), namely Methanobacteriaceae family for knee OA (PFDR = 0.043) and any OA (PFDR = 0.028), Desulfovibrionales order for knee OA (PFDR = 0.045) and Ruminiclostridium5 genus for knee OA (PFDR = 0.063). In addition, we also identified five suggestive microbial taxa that were significant with three different methods under the nominal significance (P < 0.05). Sensitive analysis excluded the influence of heterogeneity and horizontal pleiotropy and multivariable MR analysis ruled out the possibility of horizontal pleiotropy of BMI. GO enrichment analysis illustrates the protective mechanism of the identified taxa against OA. CONCLUSIONS: This study found that several microbial taxa were causally associated with diverse joint OA. The results enhanced our understanding of gut microbiota in the pathology of OA.

Airway immune mediator levels during asthma-like symptoms in young children and their possible role in response to azithromycin.

BACKGROUND: Asthma-like symptoms in young children are orchestrated by the local airway immune response, but current knowledge largely relies on in vitro airway models. Azithromycin has been shown to reduce the duration of episodes with asthma-like symptoms, but efficacy may depend on the individual child's immune response. OBJECTIVES: To investigate in vivo upper airway immune mediator levels during episodes with asthma-like symptoms in young children and their ability to predict the clinical response to azithromycin treatment. METHODS: A total of 535 children aged 0-3 years from the Copenhagen Prospective Studies of Asthma in Childhood-2010 mother-child cohort were examined for immune mediator levels in samples of nasal epithelial lining fluid during episodes with asthma-like symptoms as well as in the asymptomatic state. In a sub-study, children with recurrent asthma-like symptoms were randomized to either a 3-day course of oral azithromycin (10 mg/kg; n = 32) or placebo (n = 38). In the current study, we compared the pretreatment immune mediator levels with the clinical response to treatment with azithromycin in an exploratory post hoc analysis. RESULTS: The immune mediator concentrations during vs outside episodes were significantly upregulated for IFN-É£ (ratio 1.73), TNF-α (ratio 2.05), IL-1ß (ratio 1.45), IL-10 (ratio 1.97), while CCL22 (ratio 0.65) was downregulated. Low levels of TNF-α and IL-10 and high levels of CCL22 predicted better treatment response to azithromycin (P-values < .05). CONCLUSION: Upper airway immune mediator levels were altered during episodes of asthma-like symptoms, and levels of TNF-α, CCL22, and IL-10 may predict the response to azithromycin treatment.

Neonatal airway immune profiles and asthma and allergy endpoints in childhood.

BACKGROUND: The immune system plays a key role in the pathogenesis of asthma and allergy, but the role of the airway cytokine and chemokine composition in vivo in early life prior to symptom development has not been described previously. Here, we aimed to examine whether the neonatal airway immune composition associates with development of allergy and asthma in childhood. METHODS: We measured unstimulated levels of 20 immune mediators related to the Type 1, Type 2, Type 17, or regulatory immune pathways in the airway mucosal lining fluid of 620 one-month-old healthy neonates from the COPSAC2010 birth cohort. Allergy and asthma were diagnosed at our research clinic by predefined algorithms and objective assessments at age 6 years. Principal component analyses were used to describe the airway cytokine and chemokine composition. RESULTS: A neonatal airway immune profile particularly characterized by enhanced IL-1ß and reduced CCL26 was significantly associated with later development of elevated specific IgE to inhaled allergens, a positive skin prick test, and allergic rhinitis, but not with food sensitization. Conversely, reduced Type 17 immune-associated markers, including IL-1ß and CXCL8, showed trend of association with development of early asthma endpoints. CONCLUSIONS: Development of early asthma endpoints and inhalant allergy during the first 6 years of life seems associated with distinctly perturbed airway immune profiles in neonatal life, which is suggestive of an early origin and different pathogenesis of childhood asthma and allergy. These exploratory findings suggest pre- and perinatal life as an important window of opportunity for prevention of asthma and inhalant allergy.

High-dose vitamin D during pregnancy and pathway gene polymorphisms in prevention of offspring persistent wheeze.

BACKGROUND: Randomized controlled trials (RCTs) suggest a protective effect of high-dose vitamin D supplementation in pregnancy on offspring risk of persistent wheeze, but only in some individuals, which might be explained by variations in vitamin D pathway genes. This study aimed to investigate the effect of vitamin D supplementation by maternal and offspring vitamin D receptor (VDR) genotype and GC genotype, encoding vitamin D binding protein (VDBP), in two RCTs. METHODS: In the Copenhagen Prospective Studies on Asthma in Childhood (COPSAC2010 ) RCT, we analyzed the effect of high-dose vitamin D during pregnancy on the risk of persistent wheeze age 0-3 years by variants in single nucleotide polymorphisms (SNPs) in VDR (rs1544410, rs2228570, rs7975128, rs7975232) and GC (rs4588, rs7041). Replication was sought in the Vitamin D Antenatal Asthma Reduction Trial (VDAART). RESULTS: In COPSAC2010 , VDR SNP rs1544410 influenced the effect of high-dose vitamin D: maternal Pinteraction  = .049 and child Pinteraction  = .001, with the largest effect in offspring from mothers with TT genotype: hazard ratio (95% CI), 0.26 (0.10-0.68), P = .006, and no effect among CT or CC genotypes: 0.85 (0.48-1.51), P = .58 and 0.94 (0.47-1.89), P = .87, respectively. However, these findings were not replicated in VDAART. There was no significant effect modification from maternal or offspring GC genotype in either COPSAC2010 or VDAART: all Pinteraction  ≥ .17. CONCLUSIONS: We found that the effect of high-dose vitamin D supplementation during pregnancy on offspring risk of persistent wheeze was significantly influenced by VDR genotype in the COPSAC2010 RCT, but not VDAART, which may be due to population differences.

Symptom burden of atopic dermatitis in early childhood assessed from daily monitoring of symptoms and topical steroid use.

BACKGROUND: To our knowledge, disease burden of atopic dermatitis (AD) as number of days with symptoms and medical treatment has never been studied as measure of severity. OBJECTIVES: To investigate risk factors for AD burden in the first 3 years of life. METHODS: The Copenhagen Prospective Studies on Asthma in Childhood2010 included 700 children. AD burden was assessed by daily diary entries with information on AD and steroid days measuring 18 possible heritable, prenatal, and postnatal environmental exposures. RESULTS: The children with AD had a median (interquartile range) of 136 symptom days (61-294 days) and 72 steroid days (27-145 days) during the first 3 years of life, with the highest disease burden in the second year of life. The multivariable risk factor analysis showed that maternal AD and childhood allergic sensitization were associated with a higher number of AD days and maternal AD, filaggrin mutation, and allergic sensitization were associated with a higher number of steroid days. LIMITATIONS: Participants with a personal interest in atopic diseases could be more likely to participate. CONCLUSION: Children's burden of AD, assessed quantitatively as AD and steroid days, demonstrated positive associations with maternal AD, filaggrin mutation, and early-life allergic sensitization, with the highest disease burden in the second year of life.