Persistence Of Asthma Research Articles

Association of systemic immune-inflammation index with asthma and asthma-related events: a cross-sectional NHANES-based study.

Asthma is associated with persistent airway inflammation, and numerous studies have investigated inflammatory markers causing asthma. However, the systemic immune-inflammation index (SII) is a novel inflammatory marker, with scarce research reporting on the correlation between SII and asthma and asthma-related events. The purpose of this study was to assess the relationship between SII and asthma and asthma-related events (including whether asthma is still present, asthma flare-ups in the past year, and asthma duration) using data from the National Health and Nutrition Examination Survey (NHANES). The study utilized data from NHANES 2009-2018 with asthma and asthma-related events as dependent variables and SII as an independent variable. Multifactor logistic regression was employed to assess the correlation between the independent and dependent variables. Smoothed curve-fitting and threshold effect analyses were also carried out to determine the presence of non-linear relationships. Subgroup analyses were then performed to identify sensitive populations. In this study, we analyzed data from 40,664 participants to elucidate the association between SII and asthma and its related events. The study findings indicated a positive correlation between SII and asthma, with a relative risk increase of 0.03% for asthma incidence per one percentage point increase in SII (OR = 1.0003, 95% CI: 1.0002, 1.0004). For individuals still suffering from asthma, higher SII also indicated a positive correlation with ongoing asthma (OR = 1.0004, 95% CI: 1.0001, 1.0006). However, no statistically significant association was observed between SII and asthma exacerbations within the following year (OR = 1.0001, p > 0.05). When considering the duration of asthma, we observed a slight positive correlation with SII (β = 0.0017, 95% CI: 0.0005, 0.0029). Additionally, a significant non-linear relationship between SII and asthma duration emerged at the threshold of 504.3 (β = 0.0031, 95% CI: 0.0014-0.0048, p = 0.0003). Subgroup analysis revealed a stronger correlation between SII and asthma in male patients (OR = 1.0004, 95% CI: 1.0002-1.0006) and individuals aged 60 and above (OR = 1.0005, 95% CI: 1.0003-1.0007). No gender differences were observed for individuals still suffering from asthma. However, the positive correlation between SII and asthma was more pronounced in participants under 20 years old (OR = 1.0004 in Model 3, 95% CI: 1.0002-1.0006). Specific sensitive subgroups for asthma exacerbation recurrence within the past year were not identified. When considering asthma duration, we observed this association to be significant in male individuals (β = 0.0031 in Model 3, 95% CI: 0.0014-0.0049) as well as individuals aged 20 to 39 (β = 0.0023 in Model 3, 95% CI: 0.0005-0.0040). Our study concludes that SII is positively correlated with the persistence of asthma yet has limited predictive power for asthma recurrence. This highlights SII's potential as a tool for assessing asthma risk and formulating targeted management strategies.

Health Insurance Type and Outpatient Specialist Care Among Children With Asthma

Although children with asthma are often successfully treated by primary care clinicians, outpatient specialist care is recommended for those with poorly controlled disease. Little is known about differences in specialist use for asthma among children with Medicaid vs private insurance. To examine differences among children with asthma regarding receipt of asthma specialist care by insurance type. In this cross-sectional study using data from the Massachusetts All Payer Claims Database (APCD) between 2014 to 2020, children with asthma were identified and differences in receipt of outpatient specialist care by whether their insurance was public (Medicaid and the Children's Health Insurance Program) or private were examined. Eligible participants included children with asthma in 2015 to 2020 aged 2 to 17 years. Data analysis was conducted from January 2023 to April 2024. Medicaid vs private insurance. The primary outcome was receipt of specialist care (any outpatient visit with a pulmonology, allergy and immunology, or otolaryngology physician). Multivariable logistic regression models estimated differences in receipt of specialist care by insurance type accounting for child and area characteristics including demographics, health status, persistent asthma, calendar year, and zip code characteristics. Additional analyses examined if the associations of specialist care with insurance type varied by asthma persistence and severity, and whether associations varied over time. Among 198 101 unique children, there were 432 455 child-year observations (186 296 female [43.1%] and 246 159 male [56.9%]; 211 269 aged 5 to 11 years [48.9%]; 82 108 [19.0%] with persistent asthma) including 286 408 (66.2%) that were Medicaid insured and 146 047 (33.8%) that were privately insured. Although persistent asthma was more common among child-year observations with Medicaid vs private insurance (57 381 [20.0%] vs 24 727 [16.9%]), children with Medicaid were less likely to receive specialist care. Overall, 64 239 child-year observations (14.9%) received specialist care, with substantially lower rates for children with Medicaid vs private insurance (34 093 child-year observations [11.9%] vs 30 146 child-year observations [20.6%]). Regression-based estimates confirmed these disparities; children with Medicaid had 55% lower odds of receiving specialist care (adjusted odds ratio, 0.45; 95% CI, 0.43 to 0.47) and a regression-adjusted 9.7 percentage point (95% CI, -10.4 percentage points to -9.1 percentage points) lower rate of receipt of specialist care. Compared with children with private insurance, there was an additional 3.2 percentage point (95% CI, 2.0 percentage points to 4.4 percentage points) deficit for children with Medicaid with persistent asthma. In this cross-sectional study, children with Medicaid were less likely to receive specialist care, with the largest gaps among those with persistent asthma. These findings suggest that closing this care gap may be one approach to addressing ongoing disparities in asthma outcomes.

Recent Insights into the Environmental Determinants of Childhood Asthma.

Ubiquitous environmental exposures, including ambient air pollutants, are linked to the development and severity of childhood asthma. Advances in our understanding of these links have increasingly led to clinical interventions to reduce asthma morbidity. We review recent work untangling the complex relationship between air pollutants, including particulate matter, nitrogen dioxide, and ozone and asthma, such as vulnerable windows of pediatric exposure and their interaction with other factors influencing asthma development and severity. These have led to interventions to reduce air pollutant levels in children's homes and schools. We also highlight emerging environmental exposures increasingly associated with childhood asthma. Growing evidence supports the present threat of climate change to children with asthma. Environmental factors play a large role in the pathogenesis and persistence of pediatric asthma; in turn, this poses an opportunity to intervene to change the course of disease early in life.

Time-dependent gene-environment interactions are essential drivers of asthma initiation and persistence.

Asthma is a clinical syndrome caused by heterogeneous underlying mechanisms with some of them having a strong genetic component. It is known that up to 82% of atopic asthma has a genetic background with the rest being influenced by environmental factors that cause epigenetic modification(s) of gene expression. The interaction between the gene(s) and the environment has long been regarded as the most likely explanation of asthma initiation and persistence. Lately, much attention has been given to the time frame the interaction occurs since the host response (immune or biological) to environmental triggers, differs at different developmental ages. The integration of the time variant into asthma pathogenesis is appearing to be equally important as the gene(s)-environment interaction. It seems that, all three factors should be present to trigger the asthma initiation and persistence cascade. Herein, we introduce the importance of the time variant in asthma pathogenesis and emphasize the long-term clinical significance of the time-dependent gene-environment interactions in childhood.

Deep T-Cell Profiling Implicates Lung-Resident Rhinovirus-Specific Cells in the Development and Persistence of Severe Childhood Asthma

Deep T-Cell Profiling Implicates Lung-Resident Rhinovirus-Specific Cells in the Development and Persistence of Severe Childhood Asthma

The Microbiota and Equine Asthma: An Integrative View of the Gut-Lung Axis.

Both microbe-microbe and host-microbe interactions can have effects beyond the local environment and influence immunological responses in remote organs such as the lungs. The crosstalk between the gut and the lungs, which is supported by complex connections and intricate pathways, is defined as the gut-lung axis. This review aimed to report on the potential role of the gut-lung gut-lung axis in the development and persistence of equine asthma. We summarized significant determinants in the development of asthma in horses and humans. The article discusses the gut-lung axis and proposes an integrative view of the relationship between gut microbiota and asthma. It also explores therapies for modulating the gut microbiota in horses with asthma. Improving our understanding of the horse gut-lung axis could lead to the development of techniques such as fecal microbiota transplants, probiotics, or prebiotics to manipulate the gut microbiota specifically for improving the management of asthma in horses.

Atmospheric environment and persistence of pediatric asthma: A population-based cohort study.

Asthma is a heterogeneous disease with different outcomes. For children with asthma at the age of 7 years, 67-75% are symptom-free as adults. Data on the important link between childhood and adult asthma are sparse. We aimed to investigate factors associated with persistence of childhood asthma over three years of follow-up by linking data between Korea childhood Asthma Study (KAS) and their matched claims data from Health Insurance Review and Assessment Service (HIRA). We analyzed data from 450 preadolescent children aged 7 to 10 years and classified them into remission or persistence groups. Baseline clinical characteristics and exposure to air pollution materials including PM2.5 and PM10 during three years of follow-up were compared. The main outcome was asthma persistence which was defined as the presence of asthma episodes with healthcare utilization and prescription of asthma medications within three years after KAS enrollment. At the third year of follow-up, after stepwise regression analysis, lower age at enrollment (adjusted odds ratio (aOR): 0.79; 95% confidence interval (CI): 0.64-0.96), male sex (aOR: 1.66; 95%CI: 1.05-2.63), proximity from an air-polluting facility (aOR: 2.4; 95%CI: 1.34-4.29), higher level outdoor PM2.5 (aOR: 1.1; 95%CI: 1.02-1.20), and higher rate of doctor-diagnosed food allergy (FA) (aOR: 2.33; 95%CI: 1.06-5.12) were significantly associated with persistence. We discovered various independent risk factors for the persistence of childhood asthma. By linking HIRA claims data, we could clarify risk factors for persistence in a well-defined study population.

Severe bronchial hyperresponsiveness along with house dust mite allergy indicates persistence of asthma in young children.

Significant risk factors for persistence of asthma later in life are family history of allergies, early allergic sensitization and bronchial hyperresponsiveness (BHR). The evolution of BHR in young children without allergic sensitization and with house dust mite allergy (HDM) was investigated. In this retrospective analysis, electronic charts of 4850 young children with asthma and wheezy bronchitis between 2005 and 2018 were reviewed in order to study all patients ≤6 years with BHR assessed by methacholine provocation tests (MCT) at least once (n = 1175). Patients with more than two follow-up measurements were divided in group 1 (no allergic sensitization; n = 110) and group 2 (HDM allergy; n = 88). Additionally, skin prick test, exhaled nitrite oxide (eNO), and asthma treatment were analyzed. Forty-seven patients of group 1 aged median 4.3 years and 48 patients of group 2 aged median 4.7 years showed initially severe BHR <0.1 mg. At follow-up, patients with HDM were more likely to show persistence of severe BHR than non-sensitized patients (severe BHR group 1: n = 5 (10.6%) vs. group 2: n = 21 (43.8%), p < .001). In addition, 89.4% of group 1 had mild to moderate or no BHR, compared to only 56.2% of group 2. There was a significant difference in eN0 (median group 1: 9 ppb vs. group 2: 26 ppb, p < .001), at last follow-up. Age, sex, and asthma therapy had no effect on BHR. In young children without sensitization BHR normalizes, whereas HDM allergy indicates a persistence of asthma beyond infancy.

Fungal diversity in homes and asthma morbidity among school-age children in New York City

BackgroundAsthma development has been inversely associated with exposure to fungal diversity. However, the influence of fungi on measures of asthma morbidity is not well understood. ObjectivesThis study aimed to test the hypothesis that fungal diversity is inversely associated with neighborhood asthma prevalence and identify specific fungal species associated with asthma morbidity. MethodsChildren aged 7–8 years (n = 347) living in higher (11–18%) and lower (3–9%) asthma prevalence neighborhoods were recruited within an asthma case-control study. Fungal communities were analyzed from floor dust using high-throughput DNA sequencing. A subset of asthmatic children (n = 140) was followed to age 10–11 to determine asthma persistence. ResultsNeighborhood asthma prevalence was inversely associated with fungal species richness (P = 0.010) and Shannon diversity (P = 0.059). Associations between neighborhood asthma prevalence and diversity indices were driven by differences in building type and presence of bedroom carpet. Among children with asthma at age 7–8 years, Shannon fungal diversity was inversely associated with frequent asthma symptoms at that age (OR 0.57, P = 0.025) and with asthma persistence to age 10–11 (OR 0.48, P = 0.043). Analyses of individual fungal species did not show significant associations with asthma outcomes when adjusted for false discovery rates. DiscussionLower fungal diversity was associated with asthma symptoms in this urban setting. Individual fungal species associated with asthma morbidity were not detected. Further research is warranted into building type, carpeting, and other environmental characteristics which influence fungal exposures in homes.

Prediction of adult asthma risk in early childhood using novel adult asthma predictive risk scores.

Numerous risk scores have been developed to predict childhood asthma. However, they may not predict asthma beyond childhood. We aim to create childhood risk scores that predict development and persistence of asthma up to young adult life. The Isle of Wight Birth Cohort (n = 1456) was prospectively assessed up to 26 years of age. Asthma predictive scores were developed based on factors during the first 4 years, using logistic regression and tested for sensitivity, specificity and area under the curve (AUC) for prediction of asthma at (i) 18 and (ii) 26 years, and persistent asthma (PA) (iii) at 10 and 18 years, and (iv) at 10, 18 and 26 years. Models were internally and externally validated. Four models were generated for prediction of each asthma outcome. ASthma PredIctive Risk scorE (ASPIRE)-1: a 2-factor model (recurrent wheeze [RW] and positive skin prick test [+SPT] at 4 years) for asthma at 18 years (sensitivity: 0.49, specificity: 0.80, AUC: 0.65). ASPIRE-2: a 3-factor model (RW, +SPT and maternal rhinitis) for asthma at 26 years (sensitivity: 0.60, specificity: 0.79, AUC: 0.73). ASPIRE-3: a 3-factor model (RW, +SPT and eczema at 4 years) for PA-18 (sensitivity: 0.63, specificity: 0.87, AUC: 0.77). ASPIRE-4: a 3-factor model (RW, +SPT at 4 years and recurrent chest infection at 2 years) for PA-26 (sensitivity: 0.68, specificity: 0.87, AUC: 0.80). ASPIRE-1 and ASPIRE-3 scores were replicated externally. Further assessments indicated that ASPIRE-1 can be used in place of ASPIRE-2-4 with same predictive accuracy. ASPIRE predicts persistent asthma up to young adult life.

Association of body mass index with asthma occurrence and persistence in adolescents: A retrospective study of NHANES (2011–2018)

ObjectiveTo investigate the association of body mass index (BMI) with asthma and analyze the risk factors of asthma persistence among overweight/obese adolescents and those with a high risk for obesity. MethodsIn this cross-sectional study, adolescents aged 11–17 years with complete general information and asthma diagnoses were selected from the National Health and Nutrition Examination Survey database. For adolescents without self-reported asthma, we performed matching according to age and sex at a case-to-control ratio of 1:3. Logistic regression analysis was employed to identify independent predictors of asthma occurrence followed by constructing a nomogram and comparing its efficacy to independent factors in predicting asthma occurrence. Besides, associations of BMI with asthma occurrence and persistence were evaluated. Finally, we obtained risk factors for asthma persistence in overweight/obese individuals and those at a high risk for obesity. ResultsTotally 753 adolescents with asthma and 2259 adolescents without asthma were included to analyze the occurrence of asthma. BMI and Hispanic Ethnicity were independent predictors of asthma occurrence and were included in nomogram construction. BMI had an efficiency comparable to that of the nomogram model in predicting asthma occurrence, which is superior to that of Hispanic Ethnicity. Of the 753 adolescents diagnosed with asthma, 464 were still diagnosed with asthma of at least a year's duration. Interestingly, BMI may have the ability to predict asthma persistence. Further, Hispanic Ethnicity and household income were significantly related to asthma occurrence among overweight/obese and high-risk obese individuals. ConclusionsHigh BMI could independently predict increased asthma occurrence. Additionally, BMI may play an essential role in predicting asthma persistence. This study may help improve the diagnosis and reduce the occurrence of asthma.

Depressive Symptom Trajectories Across Adolescence and Adulthood Among Individuals With Asthma.

Individuals with asthma experience increased depressive symptoms, which is associated with deleterious health outcomes. No studies have examined depressive symptom trajectories among individuals with asthma despite increased risk. This study expanded prior literature by identifying the following: (1) depressive symptoms trajectories for individuals with and without asthma and (2) predictors of baseline levels and changes in symptoms across time for individuals with asthma. Adolescents with (N = 965) and without (N = 7,392) asthma self-reported on depressive symptoms (CESD-9) across development. Covariates included: demographics and persistence of asthma. Latent growth curve modeling (LGCM) was used to identify depressive symptom trajectories and their predictors. A multigroup LCGM identified no significant differences between depressive symptom trajectories of individuals with and without asthma. Depressive symptoms followed a quadratic shape across time for individuals with asthma (Mintercept = 5.73, p < .00; Mlinear = -0.38,p < .001; Mquad = 0.03, p < .001), with a linear deceleration in depressive symptoms during adolescence and an acceleration of symptoms into adulthood. Next predictors of depressive trajectories among individuals with asthma were examined. Female sex (B = 0.58, p < .001), lower parent education (B = -0.57, p < .001), older age (B = 0.19, p < .001), and identifying as Black (B = 0.31, p = .04) were associated with greater baseline depressive symptoms. Older individuals exhibited faster linear symptom decelerations (B = -0.56, p < .001) and faster symptom accelerations (B = 0.73, p < .001). American Indian (AIAN) individuals exhibited faster linear symptom decelerations (B = -1.98, p = .005) and faster quadratic accelerations (B = 3.33, p = .007). Our results suggest that the depressive symptom trajectories of individuals with asthma are curvilinear and similar to individuals without asthma. When examining predictors of depressive symptom trajectories for those with asthma, socioeconomic disadvantage and racial marginalization were associated with greater baseline depressive symptoms. Although AIAN youth demonstrated more favorable trajectories in adolescence, they also exhibited worse trajectories across young adulthood and adulthood. Findings suggest the need to better understand the impact of multilevel risk and protective factors on depressive symptoms trajectories for individuals with asthma, especially marginalized populations.

Allergic sensitisation and type-2 inflammation is associated with new-onset and persistent allergic disease.

Allergic disease is common. The aim of this study was to look at the change in asthma and rhinitis over time and to characterise factors contributing to remission and persistence of disease. This cohort study included 255 individuals with or without asthma and or rhinitis that participated in a population survey and a follow-up 10years later. The participants were tested for allergic sensitisation, total IgE, multiplex allergen component analysis and type-2 inflammatory markers: exhaled nitric oxide (FE NO), eosinophil cationic protein (ECP) and eosinophil-derived neurotoxin (EDN). Of the 132 healthy individuals, 112 remained healthy, 16 developed rhinitis, 4 asthma and rhinitis over the 10years. Out of 82 subjects with rhinitis, 26 went into remission, 53 remained unchanged and 3 developed asthma in addition to rhinitis. None of the 41 participants with asthma and rhinitis went into remission. Subjects with persistent rhinitis and asthma had higher levels of total IgE (odds ratio [OR]95% confidence interval [CI]: 6.16 [3.05-12.5]) at baseline and after 10years, and FE NO and ECP at baseline (OR per log unit increase, 95% CI 5.21 [1.20-22.7] and 6.32 [1.52-26.4], respectively), compared with those that remained healthy. Subjects with persistent rhinitis were more likely to be sensitised to grass pollen and had higher total IgE levels than those that went into remission. Individuals with persistent asthma were more likely to be sensitised to tree pollen and furry animals than those with only persistent rhinitis (OR 95% CI: 3.50 [1.29-9.49] and 6.73 [2.00-22.6], respectively). IgE sensitisation and total IgE levels are associated with the persistence of rhinitis and asthma. Participants with persistent allergic disease had higher levels of allergen sensitisation and type 2 inflammation markers at baseline than those who remained healthy.

Microbiome and Asthma: Microbial Dysbiosis and the Origins, Phenotypes, Persistence, and Severity of Asthma.

The importance of the microbiome, and of the gut-lung axis in the origin and persistence of asthma, is an ongoing field of investigation. The process of microbial colonisation in the first three years of life is fundamental for health, with the first hundred days of life being critical. Different factors are associated with early microbial dysbiosis, such as caesarean delivery, artificial lactation and antibiotic therapy, among others. Longitudinal cohort studies on gut and airway microbiome in children have found an association between microbial dysbiosis and asthma at later ages of life. A low α-diversity and relative abundance of certain commensal gut bacterial genera in the first year of life are associated with the development of asthma. Gut microbial dysbiosis, with a lower abundance of Phylum Firmicutes, could be related with increased risk of asthma. Upper airway microbial dysbiosis, especially early colonisation by Moraxella spp., is associated with recurrent viral infections and the development of asthma. Moreover, the bacteria in the respiratory system produce metabolites that may modify the inception of asthma and is progression. The role of the lung microbiome in asthma development has yet to be fully elucidated. Nevertheless, the most consistent finding in studies on lung microbiome is the increased bacterial load and the predominance of proteobacteria, especially Haemophilus spp. and Moraxella catarrhalis. In this review we shall update the knowledge on the association between microbial dysbiosis and the origins of asthma, as well as its persistence, phenotypes, and severity.

Factors Associated With Persistence of Severe Asthma From Late Adolescence to Early Adulthood

To determine risk factors in childhood that predict severe persistent asthma in late adolescence and early adulthood.Patients aged 5 to 12 years with mild to moderate asthma and a positive methacholine challenge enrolled in the Childhood Asthma Management Program (CAMP) trial.The CAMP participants above who had data available from late adolescence to early adulthood were included. The first study visit at age 18 years was used to determine asthma activity in late adolescence, whereas the first study at age 22 years was used to determine asthma activity in early adulthood. The American Thoracic Society definition of severe asthma was used for patients on high dose inhaled corticosteroids and the National Asthma Education and Prevention Program Expert Panel Report (NAEPP EPR) 3 definition of severe asthma was used for those not receiving high dose inhaled corticosteroids. Additional criteria for intermittent and persistent asthma were included. The following factors were analyzed: secondhand smoke exposure, maternal smoking during pregnancy, body mass index percentile, hay fever, eczema, food allergy, parental asthma being sensitized and exposed to any perennial aeroallergen, bronchial hyperreactivity, prebronchodilator FEV1/FVC ratio, post bronchodilator FEV1/FVC ratio, bronchial hyperresponsiveness to methacholine challenge, log10 of serum total IgE and log10 of serum absolute eosinophil count. Characteristics were compared from baseline to late adolescence and from baseline to early adulthood.Six hundred eighty-two CAMP participants were included. Of these participants, severe asthma was present in 81 (12%) participants in late adolescence and 131 (19%) participants in early adulthood. Half of the patients with severe asthma in late adolescence continued to have severe asthma into early adulthood. About 18% of patients improved severity, 61% did not change, and 21% of patients worsened in severity from late adolescence to early adulthood. The postbronchodilator percent predicted FEV1 and pre and post bronchodilator FEV1/FVC ratio significantly decreased from childhood to late adolescence and from late adolescence to early adulthood (P < .0001), whereas prebronchodilator FEV1 values increased from childhood to late adolescence (P < .0001) and stabilized in early adulthood (P = .040). Bronchodilator reversibility and bronchial hyperresponsiveness each decreased from childhood to late adolescence (P < .0001), whereas bronchial hyperresponsiveness also significantly decreased from childhood to early adulthood (P = .0003). Patients with persistent and severe asthma had higher serum IgE in late adolescence and were more likely to have a positive aeroallergen skin test, along with sensitization and exposure to perennial allergens in childhood. Significant factors in early childhood that were associated with persistence of severe asthma from late adolescence to early adulthood included a younger age, male sex, no reported hay fever, a low prebronchodilator FEV1/FVC ratio, a low postbronchodilator FEV1/FVC ratio, and a physician diagnosis of moderate asthma during the screening period. Notably, for every 5% decrease in post bronchodilator FEV1/FVC ratio in childhood, the odds of severe asthma persistence increased by 2.36-fold (P < .0001) as well as maternal smoking during pregnancy increased odds of severe asthma persistence by 3.17-fold (P = .020). There was a strong association between a reduced-growth lung function trajectory and severe asthma persistence.Lower FEV1/FVC ratio in childhood and maternal smoking during pregnancy were the strongest predictors for severe asthma between late adolescence and early adulthood.Understanding early factors for persistence of asthma into adulthood can help develop targeted primary prevention measures such as reduction of smoking during pregnancy as well as early intervention measures with therapies to preserve lung function in childhood.URL: www.pediatrics.org/cgi/doi/10.1542/peds.10.1164/rccm.202010-3763OC

From triggers to asthma: a narrative review on epithelium dysfunction.

It is currently recognized that the airway epithelium plays a pivotal role in orchestrating inflammatory, immune, and regenerative responses to allergens, viruses and environmental pollutants that contribute to asthma pathogenesis. The impact of pollen on respiratory epithelium is multifaceted and goes beyond the direct barrier damage driven by the best-known Type-2 response. After pollen-driven activation, airway epithelial cells play an active role in triggering several pathways. In particular, the release of epithelial cytokines (or alarmins) activates both innate and adaptive immunity, with downstream effects implicated to the pathogenesis of asthma. Pollutants also have a pleiotropic effect on respiratory epithelium. Diesel exhaust particles can directly damage the respiratory epithelium with consequent barrier dysfunction, increased permeability, and local inflammation, but they can also activate Th2 responses. Innate immune responses also are triggered by pollutants through release of epithelial cytokines and redox-sensitive pathways that generate mechanical and immunologic changes in the respiratory epithelium. In addition to the typical Type-1 immune response, respiratory virus infections stimulate type-2 innate lymphoid cells in the airway epithelium to release epithelial cytokines. Finally, the action of epithelial triggers on airway smooth muscle is the central element in the induction of remodeling and hyperreactivity of the airways in asthma. This article reviews the pathophysiology and functions of the airway epithelium and the role of epithelial damage by different triggers in the development, persistence, and exacerbations of asthma.

Longitudinal follow-up of the asthma status in a French–Canadian cohort

Asthma affects 340 million people worldwide and varies in time. Twenty years ago, in Canada, the Saguenay–Lac-Saint-Jean asthma family cohort was created to study the genetic and environmental components of asthma. This study is a follow-up of 125 participants of this cohort to explore the appearance, persistence, and progression of asthma over 10–20 years. Participants answered a clinical standardized questionnaire. Lung function was assessed (forced expiratory volume in 1 s, forced vital capacity, bronchial reversibility, and methacholine bronchoprovocation), skin allergy testing was performed, blood samples were obtained (immunoglobulin E, white blood cell counts) and phenotypes were compared between recruitment and follow-up. From the participants without asthma at recruitment, 12% developed a phenotype of adult-onset asthma with the presence of risk factors, such as atopy, high body mass index, and exposure to smoking. A decrease of PC20 values in this group was observed and a decrease in the FEV1/FVC ratio in all groups. Also, 7% of individuals with asthma at recruitment developed chronic obstructive pulmonary disease, presenting risk factors at recruitment, such as moderate-to-severe bronchial hyperresponsiveness, exposure to smoking, and asthma. This study allowed a better interpretation of the evolution of asthma. Fine phenotypic characterization is the first step for meaningful genetic and epigenetic studies.

Allergic Rhinitis and House Dust Mite Sensitization Determine Persistence of Asthma in Children

ObjectiveTo specify clinical and immunological parameters of the mechanisms, which may lead to development of persistent asthma, or regression of the disease symptoms.MethodsEighty children with childhood asthma, diagnosed in the past by using the modified Asthma Predicted Index (mAPI), were divided into two groups: remission group and persistent group. There were 3 study visits (baseline, at 6 mo, and at 12 mo). Clinical remission of asthma was defined as the absence of asthma symptoms for at least 12 mo without treatment. The patients could switch from one group to another during the 12 mo of follow-up. Clinical, inflammatory, and immunoregulatory predictors of asthma remission/persistence were analyzed.ResultsThe presence of mAPI criteria as well as house dust mite (HDM) allergy and allergic rhinitis at 7–10 y, were associated with a reduced prevalence of asthma remission. The increased eosinophil blood count in mAPI criteria was associated with a lower expression of CD25 positive cells. HDM allergy was associated with a higher fractional exhaled nitric oxide (FeNO) level (p = 0.0061) and higher expression of CD25CD71 (p = 0.0232). Allergic rhinitis was associated with a higher expression of PPAR (p = 0.0493) and CD25CD71 (p = 0.0198), and lower expression of glycoprotein A repetitions predominant (GARP).ConclusionsPersistence of childhood asthma was largely determined by the presence of allergic rhinitis and sensitization to HDM. Additionally, API criteria but not immunoregulation processes, were related to asthma persistence.

A Bayesian Logistic Regression approach in Asthma Persistence Prediction

&#x0D; Background: A number of models based on clinical parameters have been used for the prediction of asthma persistence in children. The number and significance of factors that are used in a proposed model play a cardinal role in prediction accuracy. Different models may lead to different significant variables. In addition, the accuracy of a model in medicine is really important since an accurate prediction of illness persistence may improve prevention and treatment intervention for the children at risk.&#x0D; Methods: Data from 147 asthmatic children were analyzed by a new method for predicting asthma outcome using Principal Component Analysis (PCA) in combination with a Bayesian logistic regression approach implemented by the Markov Chain Monte Carlo (MCMC). The use of PCA is required due to multicollinearity among the explanatory variables.&#x0D; Results: This method using the most appropriate models seems to predict asthma with an accuracy of 84.076% and 86.3673%, a Sensitivity of 84.96% and 87.25% and a Specificity of 83.22% and 85.52%, respectively.&#x0D; Conclusion: Our approach predicts asthma with high accuracy, gives steadier results in terms of positive and negative patients and provides better information about the influence of each factor (demographic, symptoms etc.) in asthma prediction.&#x0D;

Impact of lifetime body mass index trajectories on the incidence and persistence of adult asthma.

High body mass index (BMI) trajectories from childhood to adulthood are associated with the development of some chronic diseases, but whether such trajectories influence adult asthma has not been investigated to date. Therefore, we investigated associations between BMI trajectories from childhood to middle age (5-43 years) and incidence, persistence and relapse of asthma from ages 43 to 53 years. In the Tasmanian Longitudinal Health Study (n=4194), weight and height were recorded at eight time-points between 5 and 43 years of age. BMI trajectories were developed using group-based trajectory modelling. Associations between BMI trajectories and asthma incidence, persistence and relapse from age 43 to 53 years, bronchial hyperresponsiveness (BHR) at age 50 years, and bronchodilator responsiveness at age 53 years were modelled using multiple logistic and linear regression. Five distinct BMI trajectories were identified: average, low, child high-decreasing, child average-increasing and high. Compared with the average trajectory, child average-increasing and high trajectories were associated with increased risk of incident asthma (OR 2.6, 95% CI 1.1-6.6 and OR 4.4, 95% CI 1.7-11.4, respectively) and BHR in middle age (OR 2.9, 95% CI 1.1-7.5 and OR 3.5, 95% CI 1.1-11.4, respectively). No associations were observed for asthma persistence or relapse. Participants with child average-increasing and high BMI trajectories from childhood to middle age were at higher risk of incident adult asthma. Thus, encouraging individuals to maintain a normal BMI over the life course may help reduce the burden of adult asthma.