Asthma transition from childhood into adulthood

Identifying super-responders: A review of the road to asthma remission

Asthma is a chronic respiratory disease marked by heterogeneity and variable clinical outcomes. Recent therapeutic advances have highlighted patients achieving optimal outcomes, termed "remission" or "super-response." This review evaluates the various definitions of these terms and explores how disease burden impedes the attainment of remission. We assessed multiple studies, including a recent systematic review and meta-analysis, on biologic treatments for asthma remission. Our review highlights that type 2 inflammation may be the strongest predictor of biologic response. Key comorbidities (eg, obesity and mood disorders) and behavioral factors (eg, poor adherence, improper inhalation technique, and smoking) were identified as dominant traits limiting remission. In addition, asthma burden and longer disease duration significantly restrict the potential for remission in patients with severe asthma under the current treatment paradigm. We review the potential for a "predict-and-prevent" approach, which focuses on early identification of high-risk patients with type 2 inflammation and aggressive treatment to improve long-term asthma outcomes. In conclusion, this scoping review highlights the following unmet needs in asthma remission: (1) a harmonized global definition, with better defined lung function parameters; (2) integration of nonbiologic therapies into remission strategies; and (3) a clinical trial of early biologic intervention in patients with remission-prone, very type 2-high, moderately severe asthma with clinical remission as a predefined primary end point.

Identification of exhaled volatile organic compounds that characterize asthma phenotypes: A J-VOCSA study

BACKGROUND

Asthma is characterized by phenotypes of different clinical, demographic, and pathological characteristics. Identifying the profile of exhaled volatile organic compounds (VOCs) in asthma phenotypes may facilitate establishing biomarkers and understanding asthma background pathogenesis. This study aimed to identify exhaled VOCs that characterize severe asthma phenotypes among patients with asthma.

METHODS

This was a multicenter cross-sectional study of patients with severe asthma in Japan. Clinical data were obtained from medical records, and questionnaires were collected. Exhaled breath was sampled and subjected to thermal desorption gas chromatography-mass spectrometry (GC/MS).

RESULTS

Using the decision tree established in the previous nationwide asthma cohort study, 245 patients with asthma were divided into five phenotypes and subjected to exhaled VOC analysis with 50 healthy controls (HCs). GC/MS detected 243 VOCs in exhaled breath samples, and 142 frequently detected VOCs (50% of all samples) were used for statistical analyses. Cluster analysis assigning the groups with similar VOC profile patterns showed the highest similarities between phenotypes 3 and 4 (early-onset asthma phenotypes), followed by the similarities between phenotypes 1 and 2 (late-onset asthma phenotypes). Comparisons between phenotypes 1-5 and HC revealed 19 VOCs, in which only methanesulfonic anhydride showed p < 0.05 adjusted by false discovery rate (FDR). Comparison of these phenotypes yielded several VOCs showing different trends (p < 0.05); however, no VOCs showed p < 0.05 adjusted by FDR.

CONCLUSIONS

Exhaled VOC profiles may be useful for distinguishing asthma and asthma phenotypes; however, these findings need to be validated, and their pathological roles should be clarified.

Asthma Inception: Epidemiologic Risk Factors and Natural History Across the Life Course

Asthma is a descriptive label for an obstructive inflammatory disease in the lower airways manifesting with symptoms including breathlessness, cough, difficulty in breathing, and wheezing. From a clinician's point of view, asthma symptoms can commence at any age, although most patients with asthma-regardless of their age of onset-seem to have had some form of airway problems during childhood. Asthma inception and related pathophysiologic processes are therefore very likely to occur early in life, further evidenced by recent lung physiologic and mechanistic research. Herein, we present state-of-the-art updates on the role of genetics and epigenetics, early viral and bacterial infections, immune response, and pathophysiology, as well as lifestyle and environmental exposures, in asthma across the life course. We conclude that early environmental insults in genetically vulnerable individuals inducing abnormal, pre-asthmatic airway responses are key events in asthma inception, and we highlight disease heterogeneity across ages and the potential shortsightedness of treating all patients with asthma using the same treatments. Although there are no interventions that, at present, can modify long-term outcomes, a precision-medicine approach should be implemented to optimize treatment and tailor follow-up for all patients with asthma.

Association Between Clinical Remission of Infantile-Onset Allergic Rhinitis During the School-Age Period and the Type of Housing: A Longitudinal Population-Based Japanese Study

This study investigated the association between housing type and clinical remission of infantile-onset allergic rhinitis (AR) in 53,575 children born in 2001 in Japan. Infantile-onset AR was defined as the presence of AR symptoms reported between ages 1.5 and 4.5 years, and remission was assessed between ages 10 and 12. The type of housing was categorized into detached houses and multi-unit residential buildings with 1-2, 3-5, or ≥6 floors. Among the 4,352 infantile-onset AR, 42.9% experienced remission. Notably, living in multi-unit residential buildings, particularly those with 1-2 and ≥6 floors, was positively associated with AR remission.

Causal associations between pediatric asthma and united airways disease: a two-sample Mendelian randomization analysis

Background

Prior observational research has indicated a potential link between pediatric asthma and united airways disease (UAD). However, these findings could be subject to confounding factors and reverse causation. Therefore, our study utilizes Mendelian randomization (MR) method to further investigate the causal relationship between pediatric asthma and UAD.

Methods

We conducted a comprehensive two-sample Mendelian randomization (MR) analysis to investigate the association between pediatric asthma and seven groups of UAD, including chronic sinusitis, chronic rhinitis, nasopharyngitis and pharyngitis, chronic diseases of tonsils and adenoids, chronic laryngitis and laryngotracheitis, chronic bronchitis, bronchiectasis, chronic obstructive pulmonary disease (COPD). The present study employed a range of methods for two-sample MR analysis, including inverse variance weighted (IVW), MR-Egger regression, Simple mode, weighted median, and weighted models. The conclusion of the MR analysis primarily relies on the IVW results, while other analytical methods are utilized as supplementary evidence to ensure result robustness in this MR analysis. And sensitivity analyses were conducted, including heterogeneity test, horizontal pleiotropy test, MR-PRESSO test, and leave-one-out analysis to validate the results.

Results

The results of the MR analysis indicate significant causal effects of pediatric asthma on chronic rhinitis, nasopharyngitis and pharyngitis (IVW: OR = 1.15, 95%CI: 1.05-1.26, p-value = 0.003), chronic diseases of tonsils and adenoids (IVW: OR = 1.07, 95%CI: 1.00-1.15, p-value = 0.038), chronic bronchitis (IVW: OR = 1.51, 95%CI: 1.42-1.62, p-value <0.001), bronchiectasis (IVW: OR = 1.51, 95%CI: (1.30-1.75), p-value <0.001), and COPD (IVW: OR = 1.43, 95%CI: 1.34-1.51, p-value <0.001). However, no significant causal association was observed between pediatric asthma and chronic sinusitis (IVW: OR = 1.00, 95%CI: 1.00-1.00, p-value = 0.085), chronic laryngitis and laryngotracheitis (IVW: OR = 1.05, 95%CI: 0.90-1.21, p-value = 0.558).

Conclusion

Our findings support a potential causal relationship between pediatric asthma and UAD, suggesting that pediatric asthma may be a potential risk factor for various UAD.

Identification of plasma protein markers of allergic disease risk: a mendelian randomization approach to proteomic analysis

BACKGROUND

While numerous allergy-related biomarkers and targeted treatment strategies have been developed and employed, there are still signifcant limitations and challenges in the early diagnosis and targeted treatment for allegic diseases. Our study aims to identify circulating proteins causally associated with allergic disease-related traits through Mendelian randomization (MR)-based analytical framework.

METHODS

Large-scale cis-MR was employed to estimate the effects of thousands of plasma proteins on five main allergic diseases. Additional analyses including MR Steiger analyzing and Bayesian colocalisation, were performed to test the robustness of the associations; These findings were further validated utilizing meta-analytical methods in the replication analysis. Both proteome- and transcriptome-wide association studies approach was applied, and then, a protein-protein interaction was conducted to examine the interplay between the identified proteins and the targets of existing medications.

RESULTS

Eleven plasma proteins were identified with links to atopic asthma (AA), atopic dermatitis (AD), and allergic rhinitis (AR). Subsequently, these proteins were classified into four distinct target groups, with a focus on tier 1 and 2 targets due to their higher potential to become drug targets. MR analysis and extra validation revealed STAT6 and TNFRSF6B to be Tier 1 and IL1RL2 and IL6R to be Tier 2 proteins with the potential for AA treatment. Two Tier 1 proteins, CRAT and TNFRSF6B, and five Tier 2 proteins, ERBB3, IL6R, MMP12, ICAM1, and IL1RL2, were linked to AD, and three Tier 2 proteins, MANF, STAT6, and TNFSF8, to AR.

CONCLUSION

Eleven Tier 1 and 2 protein targets that are promising drug target candidates were identified for AA, AD, and AR, which influence the development of allergic diseases and expose new diagnostic and therapeutic targets.

TFEB regulates dendritic cell antigen presentation to modulate immune balance in asthma

OBJECTIVE

Asthma stands as one of the most prevalent chronic respiratory conditions in children, with its pathogenesis tied to the actived antigen presentation by dendritic cells (DCs) and the imbalance within T cell subgroups. This study seeks to investigate the role of the transcription factor EB (TFEB) in modulating the antigen presentation process of DCs and its impact on the differentiation of T cell subgroups.

METHODS

Bone marrow dendritic cells (BMDCs) were activated using house dust mites (HDM) and underwent RNA sequencing (RNA-seq) to pinpoint differentially expressed genes. TFEB mRNA expression levels were assessed in the peripheral blood mononuclear cells (PBMCs) of both healthy children and those diagnosed with asthma. In an asthma mouse model induced by HDM, the TFEB expression in lung tissue DCs was evaluated. Further experiments involved LV-shTFEB BMDCs co-cultured with T cells to explore the influence of TFEB on DCs' antigen presentation, T cell subset differentiation, and cytokine production.

RESULTS

Transcriptomic sequencing identified TFEB as a significantly differentially expressed gene associated with immune system pathways and antigen presentation. Notably, TFEB expression showed a significant increase in the PBMCs of children diagnosed with asthma compared to healthy counterparts. Moreover, TFEB exhibited heightened expression in lung tissue DCs of HDM-induced asthmatic mice and HDM-stimulated BMDCs. Silencing TFEB resulted in the downregulation of MHC II, CD80, CD86, and CD40 on DCs. This action reinstated the equilibrium among Th1/Th2 and Th17/Treg cell subgroups, suppressed the expression of pro-inflammatory cytokines like IL-4, IL-5, IL-13, and IL-17, while augmenting the expression of the anti-inflammatory cytokine IL-10.

CONCLUSION

TFEB might have a vital role in asthma's development by impacting the antigen presentation of DCs, regulating T cell subgroup differentiation, and influencing cytokine secretion. Its involvement could be pivotal in rebalancing the immune system in asthma. These research findings could potentially unveil novel therapeutic avenues for treating asthma.

Macrophage polarization: an important role in inflammatory diseases

Macrophages are crucial cells in the human body's innate immunity and are engaged in a variety of non-inflammatory reactions. Macrophages can develop into two kinds when stimulated by distinct internal environments: pro-inflammatory M1-like macrophages and anti-inflammatory M2-type macrophages. During inflammation, the two kinds of macrophages are activated alternatively, and maintaining a reasonably steady ratio is critical for maintaining homeostasis in vivo. M1 macrophages can induce inflammation, but M2 macrophages suppress it. The imbalance between the two kinds of macrophages will have a significant impact on the illness process. As a result, there are an increasing number of research being conducted on relieving or curing illnesses by altering the amount of macrophages. This review summarizes the role of macrophage polarization in various inflammatory diseases, including autoimmune diseases (RA, EAE, MS, AIH, IBD, CD), allergic diseases (allergic rhinitis, allergic dermatitis, allergic asthma), atherosclerosis, obesity and type 2 diabetes, metabolic homeostasis, and the compounds or drugs that have been discovered or applied to the treatment of these diseases by targeting macrophage polarization.

Higher risk of osteoporosis in adult-onset asthma than childhood-onset asthma: from genetic and prospective evidence

Both COA and AOA have a genetically causal effect on osteoporosis. COA and AOA were independently associated with incident osteoporosis, and the risk was greatly higher in AOA. Besides corticosteroids, the increased risk of osteoporosis among asthma patients should be attributed to genetic susceptibility and other asthma medications.

PURPOSE/INTRODUCTION

Childhood-onset asthma (COA) differs with adult-onset asthma (AOA) on genetic susceptibility, severity, and co-morbidities. Whether COA or AOA is independently associated with osteoporosis is unexplored. We aimed to determine the effects of COA and AOA on osteoporosis at genetic and individual level.

METHODS

We used two-sample Mendelian randomization analysis to explore the causal effects of COA and AOA on osteoporosis. In the UK Biobank cohort, we included 478,289 osteoporosis-free participants at baseline (2006-2010). Participants were classified as non-asthma, COA, and AOA at recruitment. Multivariate Cox regression analysis was used to evaluate the effects of COA, AOA, and multiple asthma medications on incident osteoporosis risk.

RESULTS

COA and AOA were causally related to osteoporosis, with odds ratio of 1.007 (95% confidence interval (CI), 1.0003-1.0132) and 1.012 (95% CI, 1.002-1.023), respectively. Multivariate Cox regression analysis suggested that COA (hazard ratio (HR), 1.46; 95% CI, 1.32-1.61) and AOA (HR, 1.70; 95% CI, 1.61-1.80) were independently associated with incident osteoporosis, and the risk was greatly higher in AOA (HR, 1.51; 95% CI, 1.34-1.70). In addition to corticosteroids, monotherapy with leukotriene modifiers (HR, 1.70; 95% CI, 1.20-2.42), long-acting beta agonists (HR, 1.49; 95% CI, 1.18-1.87), and short-acting beta agonists (HR, 1.72; 95% CI1.01-2.93) were independently associated with a higher risk of osteoporosis.

CONCLUSIONS

Both COA and AOA have a genetically causal effect on osteoporosis, and the risk of osteoporosis is greatly higher in AOA. Besides corticosteroids, the increased risk of osteoporosis among asthma patients should be attributed to genetic susceptibility and other asthma medications.

No remission in 60% of those with childhood-onset asthma - A population-based cohort followed from 8 to 28 years of age

BACKGROUND

Although remission occur, childhood-onset asthma may persist until adulthood. Since few longitudinal population-based studies have followed a cohort from childhood until adulthood, the knowledge on predictors of persistence of asthma is sparse.

AIM

To estimate persistence of asthma from 8 to 28 years and its associated factors.

METHODS

Within the OLIN (Obstructive Lung Disease in Northern Sweden) studies, a cohort was recruited in 1996 (age 8y, n = 3430) and followed annually with questionnaires about asthma and risk factors until 19y. Clinical examinations included skin prick tests (at 8, 12 and 19y) and lung function tests (17 and 19y) whereof a subsample performed bronchial hyperreactivity test. We identified n = 248 with asthma at 8y whereof 170 (69%) participated in a follow-up at 28y (73% of possible to invite).

RESULTS

Of the 170 participants at 28y, 105 (61.8%) had persistent asthma (women: 49/76, 64.5%; men: 56/94, 59.6%, p = 0.513). Factors collected at recruitment: allergic sensitization (OR7.8, 95%CI 3.0-20.2), severe respiratory infection (OR2.6, 95%CI 1.1-6.3) and higher asthma severity score (OR1.6, 95%CI 1.1-2.4) were associated with asthma at 28y after adjustment for sex, family history of asthma, breastfeeding <3 months and eczema. Replacing allergic sensitization with rhinoconjunctivitis in the model yielded OR3.4 (95%CI 1.5-8.0). Bronchial hyperreactivity at age 17y associated with asthma at 28y (OR9.0, 95%CI 1.7-47.0).

CONCLUSIONS

Among children with asthma onset by 8y, 62% still had asthma at age 28 years. Persistent asthma was associated with allergic sensitization, rhinoconjunctivitis, severe respiratory infection, a more severe asthma and bronchial hyperreactivity.

The microbiome: an integral player in immune homeostasis and inflammation in the respiratory tract

The last decade of microbiome research has highlighted its fundamental role in systemic immune and metabolic homeostasis. The microbiome plays a prominent role during gestation and into early life, when maternal lifestyle factors shape immune development of the newborn. Breast milk further shapes gut colonization, supporting the development of tolerance to commensal bacteria and harmless antigens while preventing outgrowth of pathogens. Environmental microbial and lifestyle factors that disrupt this process can dysregulate immune homeostasis, predisposing infants to atopic disease and childhood asthma. In health, the low-biomass lung microbiome, together with inhaled environmental microbial constituents, establishes the immunological set point that is necessary to maintain pulmonary immune defense. However, in disease perturbations to immunological and physiological processes allow the upper respiratory tract to act as a reservoir of pathogenic bacteria, which can colonize the diseased lung and cause severe inflammation. Studying these host-microbe interactions in respiratory diseases holds great promise to stratify patients for suitable treatment regimens and biomarker discovery to predict disease progression. Preclinical studies show that commensal gut microbes are in a constant flux of cell division and death, releasing microbial constituents, metabolic by-products, and vesicles that shape the immune system and can protect against respiratory diseases. The next major advances may come from testing and utilizing these microbial factors for clinical benefit and exploiting the predictive power of the microbiome by employing multiomics analysis approaches.

Effectiveness of allergen immunotherapy with house dust mite extract for pediatric bronchial asthma

Aim: We compared the effectiveness of rush subcutaneous immunotherapy (SCIT) and sublingual immunotherapy (SLIT) using standardized house dust mite (HDM) extract for pediatric bronchial asthma (BA). Methods: We followed the pediatric BA treatment score during 3 years of treatment. We assessed the median time to no longer requiring long-term control pharmacotherapy (LTCP) for BA (LTCP-free). We compared the outcomes after adjustment for confounding factors and propensity score matching. Results: Patients in the HDM SCIT group achieved the LTCP-free status significantly earlier than those in the HDM SLIT group after adjustment for confounding factors and propensity score matching. Conclusion: Patients treated for pediatric BA with rush HDM SCIT had earlier onset of therapeutic effects than those with HDM SLIT.

Early-life antibiotic exposure promotes house dust mite-induced allergic airway inflammation by impacting gut microbiota and lung lipid metabolism

Asthma is a chronic inflammatory respiratory disease. Early-life antibiotic exposure is a unique risk factor for the incidence and severity of asthma later in life. Perturbations in microbial-metabolite-immune interaction caused by antibiotics are closely associated with the pathogenesis of allergy and asthma. We investigated the effect of early intervention with common oral antibiotics on later asthma exacerbations and found that different antibiotic exposures can amplify different types of immune responses induced by HDM. Cefixime (CFX) promoted a biased type 2 inflammation, azithromycin (AZM) enhanced Th17 immune response, and cefuroxime axetil (CFA) induced eosinophils recruitment. Moreover, early-life antibiotic exposure can have short- and long-term effects on the abundance, composition, and diversity of the gut microbiota. In the model of CFX-promoted type 2 airway inflammation, fecal metabolomics indicated abnormal lipid metabolism and T cell response. Lipidomic also suggested allergic airway inflammation amplified by CFX is closely associated with abnormal lipid metabolism in lung tissues. Moreover, abnormalities in lipid metabolism-related genes (LMRGs) were found to have cellular heterogeneity be associated with asthma severity by bioinformatics analysis.

Preschool children from lower household incomes experience inequality in asthma treatment: findings from a Danish nationwide cohort study

BACKGROUND

The obligation to pay for asthma medication in a country with universal healthcare might lead to increased asthma exacerbations and inequitable healthcare access for children from low-income households. Thus, the aim of this study was to examine the association between household income and childhood/preschool asthma regarding hospitalization and medication receipt.

METHODS

In this nationwide register-based cohort study, we encompassed all 3-year-old children residing in Denmark, born between 2000 and 2014, along with their linked parents and followed them until their sixth birthday. Household income was divided into quartiles. Asthma was categorized in two mutually exclusive groups as either the redemption of two prescriptions for asthma medication or receiving a hospital diagnosis. We utilized Poisson regression to estimate the risk ratio (RR).

RESULTS

The analysis included 834 422 preschool children. The prevalence of asthma dependent on medication alone was 7.3%, while 1.8% of children necessitated asthma-related hospitalization. Income inequality was evident across all income quartiles. Notably, children from the lowest income quartile had a RR of 0.95 (95% CI: 0.92-0.98) of redeeming asthma medication and conversely a RR of 1.18 (95% CI: 1.14-1.23) of asthma-related hospitalization.

CONCLUSIONS

Despite universal healthcare, income inequality has a dual impact on children from low-income households. They face a diminished risk of redeeming asthma medication and a higher susceptibility to asthma-related hospitalizations indicating an unequal access to healthcare. Prioritizing efforts to reduce childhood health inequalities is crucial. However, further research, particularly qualitative studies, is needed to better comprehend the underlying mechanisms to address the complexities of income inequality.

Lung sound analysis for predicting recurrent wheezing in preschool children

Background

In young healthy children, assessing airflow limitation may be difficult because of narrowing of the airways, which is a pathology of asthma, and responsiveness to bronchodilators.

Objective

We investigated whether lung sound analysis could predict the development of recurrent wheezing (RW), which is one of the signs of asthma.

Methods

In healthy children aged 3 to 24 months, we recorded and analyzed lung sounds before and after inhalation of bronchodilators and conducted a questionnaire survey. The children were followed up and assessed for the development of RW at age 3 years.

Results

Of the 62 patients analyzed, 19 (30.6%) developed RW. The parameters ratio of power and frequency at 50% of the highest frequency of the dB power spectrum (RPF50) and ratio of power and frequency at 75% of the highest frequency of the dB power spectrum (RPF75), calculated by lung sound analysis, were lower in the RW group, with odds ratios of 0.77 (95% CI = 0.61-0.98) and 0.81 (95% CI = 0.66-0.99), respectively. The rate of change of lung sound analysis parameters after bronchodilator inhalation did not differ among the participants as a group; however, in the subgroup of children with a history of atopic dermatitis, the fourth area under the curve (B4) divided by the total area under the curve of 100 Hz to the highest frequency of the dB power spectrum (AT) and difference between the values of the ratio of power and frequency at 50% of the highest frequency of the dB power spectrum (ΔRPF50) were elevated in the RW group (P = .015 and P = .041, respectively). In the subgroup of children with total a IgE level greater than 20 kUA/L, the sensitivities and specificities for predicting the development of RW were 85.7% (95% CI = 48.7-99.3) and 68.8% (95% CI = 44.4-85.8), respectively, when the cutoff value of ΔRPF50 was set at 10.5%.

Conclusion

The method of lung sound analysis allows noninvasive assessment of the airway, including airway hypersensitivity, in young children and may predict the risk of development of RW.

Parents' Beliefs about Medicines and Their Influence on Inhaled Corticosteroid Adherence in Children with Asthma

The most widespread chronic condition observed amid children globally is asthma. Only half of children with asthma adhere to their prescribed inhaled corticosteroids (ICS) therapy. Parents' emotions and perspectives regarding asthma have an impact on inhalation corticosteroid adherence. The participants in this study were 148 parents of children with asthma, with the aim to redintegrate their beliefs about medicines in general and specifically of ICS and the impact on ICS adherence in children with asthma. Children were mostly male (66.9%), older than five years (58.8%), parents were female, mean age 38, employed, and with a history of consumption of some form of corticosteroids. Parents' answers show that 50% of them disagreed with the statement that medicines are addictive, and 90% agree that medicine helps many to live better. A percentage of 77.7% of parents acknowledge that their child's health relies on inhaled corticosteroids (ICS), and 86.5% of parents agree that these medications safeguard their child from worsening health. Most of the parents (93.2%) adhere to the guidelines and instructions of the doctor. In summary, parents who hold the belief that medicines are neither overused nor harmful tend to exhibit a higher adherence. Furthermore, those with elevated adherence levels express lower levels of concern regarding the use of inhaled corticosteroids (ICS) in their children's asthma therapy.

Causal relationship between asthma and inflammatory bowel disease : A two-sample bidirectional mendelian randomization analysis

BACKGROUND

Based on the findings of current observational studies, asthma and inflammatory bowel disease (including Crohn's disease and ulcerative colitis) are associated; however, their causal association cannot be established due to methodological limitations.

OBJECTIVES

we use two-sample bidirectional mendelian randomization (MR) to overcome the confounding factors and explore the causal link between asthma and inflammatory bowel disease.

METHODS

After selecting asthma and IBD-related genome-wide association studies (GWAS) data and screening single nucleotide polymorphisms (SNPs), MR analysis was performed by four methods: inverse variance weighted (IVW), MR-Egger, maximum likelihood, and weighted median (WM), while Cochran's Q test was used to detect heterogeneity and MR-Egger intercept to detect horizontal pleiotropy. Finally, we used the leave-one-out method and funnel plot to perform sensitivity analysis.

RESULTS

We screened 57, 59, and 60 SNPs in the association analysis of asthma and IBD, CD, and UC, respectively. The results of MR analysis showed that asthma only increased the risk of CD (IVW: OR = 1.1712, 95% CI = 1.0418-1.3167, P value = 0.0082; maximum likelihood: OR = 1.1739, 95% CI = 1.0428-1.3215, P value = 0.0080). Neither forward nor reverse MR analysis revealed heterogeneity or horizontal pleiotropy. Similarly, we did not find potential directional pleiotropy by funnel plot, and the leave-one-out method did not suggest a significant effect of a single SNP on the overall results.

CONCLUSIONS

we found a negative correlation between asthma and Crohn's disease, but more research is needed to confirm this.

Effects of Early Diet on the Prevalence of Allergic Disease in Children: A Systematic Review and Meta-Analysis

Recent evidence suggests that the timing of introduction, types, and amounts of complementary foods/allergenic foods may influence the risk of allergic disease. However, the evidence has not been updated and comprehensively synthesized. The Cochrane Library, EMBASE, Web of Science, and PubMed databases were searched from the inception of each database up to 31 May 2023 (articles prior to 2000 were excluded manually). Statistical analyses were performed using RevMan 5. The GRADE approach was followed to rate the certainty of evidence. Compared with >6 mo, early introduction of eggs (≤6 mo of age) might reduce the risk of food allergies in preschoolers aged <6 y (odds ratio [OR], 0.65; 95% confidence interval [CI], 0.53, 0.81), but had no effect on asthma or atopic dermatitis (AD). Consumption of fish at 6-12 mo might reduce the risk of asthma in children (aged 5-17 y) compared with late introduction after 12 mo (OR, 0.61; 95% CI: 0.52, 0.72). Introduction of allergenic foods for ≤6 mo of age, compared with >6 mos, was a protective factor for the future risk (children aged ≤10 y) of AD (OR, 0.93; 95% CI: 0.89, 0.97). Probiotic intervention for infants at high risk of allergic disease significantly reduced the risk of food allergy at ages 0-3 y (OR, 0.72; 95% CI: 0.56, 0.94), asthma at 6-12 y (OR, 0.61; 95% CI: 0.41, 0.90), and AD at aged <6 y (3-6 y: OR, 0.70; 95% CI: 0.52, 0.94; 0-3 y: OR, 0.73; 95% CI: 0.59, 0.91). Early introduction of complementary foods or the high-dose vitamin D supplementation in infancy was not associated with the risk of developing food allergies, asthma, or AD during childhood. Early introduction to potential allergen foods for normal infants or probiotics for infants at high risk of allergies may protect against development of allergic disease. This study was registered at PROSPERO as CRD42022379264.

Age-related differences in IgE between childhood and adulthood allergic asthma: Analysis of NHANES 2005-2006

Background

Asthma exhibits varying clinical features in children and adults. However, previous studies have mainly focused on the clinical significance of immunoglobulin E (IgE) in the diagnosis and treatment of asthma, disregarding the characteristics of IgE and its relevant factors.

Objective

This study aimed to gain a better understanding of the differences in the characteristics of IgE between childhood and adulthood allergic asthma (AA).

Methods

Patients with AA from the 2005 to 2006 National Health and Nutrition Examination Survey (NHANES) were divided into 3 groups based on their current age and onset age of AA: childhood AA (Group 1), childhood-onset adult AA (Group 2), and adulthood-onset AA (Group 3). Intragroup analysis and intergroup comparison were carried out, focusing on the characteristics and relevant factors of IgE, as well as the clinical relevance of total IgE (total IgE, tIgE) and allergen-specific IgE (allergen-specific IgE, sIgE).

Results

A total of 424 patients were analyzed, including 187 with childhood AA, 132 with childhood-onset adult AA, and 105 with adulthood-onset AA. The concentration of tIgE was found to be higher in Group 1 (268.0, 118.0-686.0 kU/L) than in Group 2 (224.0, 78.0-494.0 kU/L) and Group 3 (165.0, 74.4-350.5 kU/L). The sensitization rates did not differ between Group 1 and Group 2 but were higher compared with Group 3, particularly for Alternaria-sIgE (50.3% and 46.2% vs 15.2%) and Aspergillus-sIgE (43.9% and 37.1% vs 16.2%). In Group 1, there was a negative correlation between pollen-sIgEs and indoor allergens, but this correlation was not commonly observed in Group 2 and Group 3. On the other hand, in Group 1, environmental chemicals such as phthalates, polyaromatic hydrocarbons, trihalomethanes, and phenols showed a positive correlation with IgE. However, a greater number of chemicals was observed in Group 2 and Group 3, including cotinine, metals, trihalomethanes, phthalates, phenols, and other volatile organic compounds (VOCs). Furthermore, in Group 1, IgE was positively correlated with asthma-related issues such as emergency visits, absenteeism, limited activities, and medication needs. These correlations were less common in Group 2 and Group 3, particularly in Group 3.

Conclusions

There are notable differences in the characteristics and environmental factors of IgE among childhood AA, childhood-onset adult AA, and adulthood-onset AA. Additionally, IgE plays a more significant role in childhood AA due to its higher concentration, fewer relevant environmental chemicals and greater clinical relevance. This may partially explain the age-related features of asthma.

Asthma and Rhinitis Through the Lifespan of Nonpregnant Women

Increasingly, clinical practice guidelines advocate a precision medicine-based approach to care for asthma. This focus requires knowledge of not only different asthma phenotypes and their associated biomarkers but also sex and gender differences through the lifespan. Evidence continues to build in favor of different lifetime prevalence, clinical presentations, responses to management, and long-term prognosis of asthma. Women transition through many biological and psychosocial phases in their lives, all of which may interact with, and influence, their health and well-being. Historically, explanations have focused on hormonal effects on asthma in reproductive life, but a greater understanding of mechanisms starting before birth and changing over a lifetime is now possible, with immunologic, inflammatory, and hormonal factors playing a role. This article describes the evidence for the differences in asthma and rhinitis between men and women at different stages of life, the potential underlying mechanisms that contribute to this, and the implications for management and research. Future research studies should systematically report sex differences in asthma so that this knowledge can be used to develop a personalized approach to care, to achieve best possible outcomes for all.

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

BACKGROUND

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.

METHODS

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.

RESULTS

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.

CONCLUSION

In young children without sensitization BHR normalizes, whereas HDM allergy indicates a persistence of asthma beyond infancy.

Interleukin-4 (C590T) Gene Polymorphism in Association with Asthma Severity

Background

A significant link between T allele of the IL-4 (C590T) gene and developing asthma in some populations was reported. However, no study discussed the link between IL-4 (C590T) gene polymorphism and asthma severity groups (mild and severe). This study investigated the link between IL-4 gene variation and asthma severity.

Methods

The study included 215 asthmatic patients, of which 102 had mild asthma, and 126 participants were healthy controls. A previously published polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method was used to identify various IL-4 (C590T) gene polymorphism genotypes.

Results

The T allele frequency was higher in mild asthma (p=0.002) but not in severe asthma (p=0.12) compared to controls. In mild asthma, the CT genotype and (CT+TT versus CC) increased the likelihood of asthma threefold (p<0.001, 0.001). However, no significant association with severe asthma was found in either genetic model. Stratification analysis showed that the C allele and CC genotype increased the risk of severe asthma (p=0.01). The recessive genetic model indicated a decrease in the risk of severe asthma (OR=0.5, p=0.01) in the non-adjusted regression analysis. Adjusting for age, sex, and other risk factors revealed that the IL-4 gene polymorphism did not influence the risk of severe asthma (OR=0.92, p=0.80); however, being an elderly female with a history of childhood-onset disease and associated nasal polyp (NP) increased the likelihood of severe asthma, OR=1.08, 2.01, 2.36, 8.42; p<0.001, 0.05, 0.05, <0.001, respectively.

Conclusion

The T allele and CT genotype in the co-dominant genetic model and the (CT+TT) genotype in the recessive model were found to have a higher likelihood of developing mild asthma but not severe asthma; severe asthma was found to be higher in elderly females with a history of childhood-onset disease and associated nasal polyps.

Association of cesarean section with asthma in children/adolescents: a systematic review and meta-analysis based on cohort studies

BACKGROUND

Whether cesarean section (CS) is a risk factor for asthma in offspring is controversial. The purpose of this study was to investigate the association between CS and asthma in children/adolescents.

METHODS

Pubmed, Embase, Web of Science, and Cochrane Library electronic databases were searched for cohort studies on the relationship between mode of delivery and asthma in children/adolescents up to February 2023. Birth via CS was considered an exposure factor. Asthma incidence was taken as a result.

RESULTS

Thirty-five cohort studies (thirteen prospective and twenty-two retrospective cohort studies) were included. The results showed that the incidence of asthma was higher in CS offspring (odds ratio (OR) = 1.18, P < 0.001) than in the vaginal delivery (VD) group. Partial subgroup analyses showed a higher incidence of asthma in female offspring born via CS (OR = 1.26, P < 0.001) compared with the VD group, while there was no difference in males (OR = 1.07, P = 0.325). Asthma incidence was higher in CS offspring than in the VD group in Europe (OR = 1.20, P < 0.001), North America (OR = 1.15, P < 0.001), and Oceania (OR = 1.06, P = 0.008). This trend was not found in the Asian population (OR = 1.17, P = 0.102). The incidence of atopic asthma was higher in offspring born via CS (OR = 1.14, P < 0.001) compared to the VD group. The CS group had a higher incidence of persistent asthma, but the difference did not reach statistical significance (OR = 1.15, P = 0.063).

CONCLUSION

In this meta-analysis, CS may be a risk factor for asthma in offspring children/adolescents compared with VD. The relationship between CS and asthma was influenced by sex and region.

Predicting the therapeutic efficacy of AIT for asthma using clinical characteristics, serum allergen detection metrics, and machine learning techniques

Bronchial asthma is a prevalent non-communicable disease among children. The study collected clinical data from 390 children aged 4-17 years with asthma, with or without rhinitis, who received allergen immunotherapy (AIT). Combining these data, this paper proposed a predictive framework for the efficacy of mite subcutaneous immunotherapy in asthma based on machine learning techniques. Introducing the dispersed foraging strategy into the Salp Swarm Algorithm (SSA), a new improved algorithm named DFSSA is proposed. This algorithm effectively alleviates the imbalance between search speed and traversal caused by the fixed partitioning pattern in traditional SSA. Utilizing the fusion of boosting algorithm and kernel extreme learning machine, an AIT performance prediction model was established. To further investigate the effectiveness of the DFSSA-KELM model, this study conducted an auxiliary diagnostic experiment using the immunotherapy predictive medical data collected by the hospital. The findings indicate that selected indicators, such as blood basophil count, sIgE/tIgE (Der p) and sIgE/tIgE (Der f), play a crucial role in predicting treatment outcome. The classification results showed an accuracy of 87.18% and a sensitivity of 93.55%, indicating that the prediction model is an effective and accurate intelligent tool for evaluating the efficacy of AIT.

Respiratory health effects of e-cigarette substitution for tobacco cigarettes: a systematic review

BACKGROUND

E-cigarettes (electronic nicotine delivery system, ENDS) have been presented as a harm reduction strategy for people who smoke tobacco cigarettes but who cannot achieve abstinence, or for those who wish to continue to enjoy nicotine and the habit of smoking. What are the health effects of the substitution of ENDS for tobacco cigarettes? This systematic review evaluates the evidence of human clinical tests on the respiratory effects of ENDS use in participants who smoke tobacco cigarettes.

METHODS

A registered and published protocol was developed conforming to PRISMA 2020 and AMSTAR2 standards. The literature search was conducted in PubMed, Scopus, and the CENTRAL Cochrane Library and updated to May 2022. Three supplementary searches and a grey literature search were performed. Studies were evaluated with the JBI quality tools and the Oxford Catalogue of Bias. Due to the heterogeneity (diversity) of the studies, a narrative data synthesis was performed on the test findings plus three sub-group analyses.

RESULTS

The review consists of sixteen studies and twenty publications. Spirometry tests comprised the majority of the data. In total, 66 respiratory test measurements were reported, out of which 43 (65%) were not significant. Statistically significant findings were mixed, with 9 tests showing improvements and 14 measuring declines, none of which was clinically relevant. Ten studies were rated at a high risk of bias, and six had some concerns primarily due to inadequate research designs and the conduct of the studies. Reporting bias was documented in thirteen studies.

CONCLUSIONS

Most of the studies showed no difference in respiratory parameters. This indicates that ENDS substitution for smoking likely does not result in additional harm to respiratory health. Due to the low quality of the studies, confidence in the conclusions is rated as low. Robust studies with a longer duration and sufficient power are required to validate any potential benefits or possible harms of ENDS substitution. Registration PROSPERO #CRD42021239094, International Registered Report Identifier (IRRID): DERR1-10.2196/29084.

Investigations of a combination of atopic status and age of asthma onset identify asthma subphenotypes

OBJECTIVE

Subphenotypes of asthma may be determined by age onset and atopic status. We sought to characterize early or late onset atopic asthma with fungal or non-fungal sensitization (AAFS or AANFS) and non-atopic asthma (NAA) in children and adults in the Severe Asthma Research Program (SARP). SARP is an ongoing project involving well-phenotyped patients with mild to severe asthma.

METHODS

Phenotypic comparisons were performed using Kruskal-Wallis or chi-square test. Genetic association analyses were performed using logistic or linear regression.

RESULTS

Airway hyper-responsiveness, total serum IgE levels, and T2 biomarkers showed an increasing trend from NAA to AANFS and then to AAFS. Children and adults with early onset asthma had greater % of AAFS than adults with late onset asthma (46% and 40% vs. 32%; P < 0.00001). In children, AAFS and AANFS had lower % predicted FEV1 (86% and 91% vs. 97%) and greater % of patients with severe asthma than NAA (61% and 59% vs. 43%). In adults with early or late onset asthma, NAA had greater % of patients with severe asthma than AANFS and AAFS (61% vs. 40% and 37% or 56% vs. 44% and 49%). The G allele of rs2872507 in GSDMB had higher frequency in AAFS than AANFS and NAA (0.63 vs. 0.55 and 0.55), and associated with earlier age onset and asthma severity.

CONCLUSIONS

Early or late onset AAFS, AANFS, and NAA have shared and distinct phenotypic characteristics in children and adults. AAFS is a complex disorder involving genetic susceptibility and environmental factors.

Serum autophagy protein 5 is positively related to T helper 2/T helper 1 ratio, inflammation, and exacerbation in adult asthma patients

BACKGROUND

Autophagy protein 5 (ATG5) regulates airway epithelial cell autophagy, immune response, and inflammation, which is involved in asthma progression. This study aimed to evaluate ATG5 levels and its clinical roles in adult asthma patients.

METHODS

Totally, 200 adult asthma patients and 100 healthy controls (HCs) were enrolled in this case-control study. Subsequently, serum ATG5 was measured by enzyme-linked immunosorbent assay.

RESULTS

ATG5 was increased in asthma patients compared with HCs [median (interquartile range): 44.2 (31.7-77.8) vs. 23.2 (16.7-39.2) ng/mL] (P < 0.001). In asthma patients, ATG5 was positively related to male gender (P = 0.022), a family history of asthma (P = 0.035), eosinophil count (P < 0.001), and immune globulin E (P < 0.001), while it was negatively correlated with forced expiratory volume in 1 s (FEV1)/forced vital capacity (P < 0.001) and FEV1 (Predicted) (P < 0.001). Meanwhile, ATG5 was inversely associated with T helper (Th) 1 cells (P = 0.008), while it was positively linked with Th2 cells (P < 0.001), Th2/Th1 ratio (P < 0.001), interleukin (IL)-4 (P = 0.002), and IL-4/interferon-γ ratio (P = 0.015). Additionally, ATG5 was positively correlated with tumor necrosis factor-α (P < 0.001), IL-1β (P = 0.001), IL-6 (P = 0.003), and IL-17 (P = 0.029). Notably, ATG5 was elevated in asthma patients at exacerbation compared to those at remission [median (interquartile range): 53.6 (37.6-90.0) vs. 35.6 (28.2-51.5) ng/mL] (P < 0.001). It was also noteworthy that ATG5 was positively linked with exacerbation severity in asthma patients (P = 0.005).

CONCLUSION

Serum ATG5 is related to increased Th2/Th1 ratio, inflammation, exacerbation risk and severity in adult asthma patients, which serves as a candidate marker for the management of asthma. However, further validation is still needed.

[Diagnosis and treatment of asthma: a guideline for respiratory specialists 2023 - published by the German Respiratory Society (DGP) e. V.]

The management of asthma has fundamentally changed during the past decades. The present guideline for the diagnosis and treatment of asthma was developed for respiratory specialists who need detailed and evidence-based information on the new diagnostic and therapeutic options in asthma. The guideline shows the new role of biomarkers, especially blood eosinophils and fractional exhaled NO (FeNO), in diagnostic algorithms of asthma. Of note, this guideline is the first worldwide to announce symptom prevention and asthma remission as the ultimate goals of asthma treatment, which can be achieved by using individually tailored, disease-modifying anti-asthmatic drugs such as inhaled steroids, allergen immunotherapy or biologics. In addition, the central role of the treatment of comorbidities is emphasized. Finally, the document addresses several challenges in asthma management, including asthma treatment during pregnancy, treatment of severe asthma or the diagnosis and treatment of work-related asthma.

Increased Risk of Rheumatoid Arthritis in Patients With Asthma: A Genetic Association Study Using Two-Sample Mendelian Randomization Analysis

OBJECTIVE

Observational studies have explored the association between asthma and some types of arthritis, including rheumatoid arthritis and osteoarthritis, but the results are largely contradictory. We aimed to investigate the causal effects of asthma on arthritis, including osteoarthritis, rheumatoid arthritis, gout, and ankylosing spondylitis.

METHODS

Two-sample Mendelian randomization (MR) analysis was used to investigate the causal effects of asthma on each arthritis. The genetic instruments for asthma were obtained from a large genome-wide association study of asthma. The inverse-variance weighted (IVW) method was used as the main analysis of MR. Bonferroni-adjusted P value threshold was used to account for multiple comparisons.

RESULTS

MR-IVW analysis suggested that adult-onset asthma (AOA) was associated with increased risk of rheumatoid arthritis. The odds ratio for rheumatoid arthritis associated with AOA and childhood-onset asthma (COA) were 1.018 (95% confidence interval [95% CI], 1.011-1.025; P < 0.001) and 1.006 (95% CI 1.001-1.012; P = 0.046), respectively. For osteoarthritis, gout, or ankylosing spondylitis, all the MR analyses showed no significant causal effects of AOA or COA on them. We also performed a reverse MR analysis to explore the causal effects of rheumatoid on all asthma, allergic asthma, or nonallergic asthma and found no significant causal effects on them.

CONCLUSION

Genetically predicted AOA predisposes patients to an increased risk of rheumatoid arthritis but has no causal effects on osteoarthritis, gout, and ankylosing spondylitis. The result of COA on rheumatoid arthritis is suggestive of potential causal relationship but needs to be confirmed in further studies.

Adolescent Asthma Monitoring: A Preliminary Study of Audio and Spirometry Modalities

Asthma patients' sleep quality is correlated with how well their asthma symptoms are controlled. In this paper, deep learning techniques are explored to improve forecasting of forced expiratory volume in one second (FEV1) by using audio data from participants and test whether auditory sleep disturbances are correlated with poorer asthma outcomes. These are applied to a representative data set of FEV1 collected from a commercially available sprirometer and audio spectrograms collected overnight using a smartphone. A model for detecting nonverbal vocalizations including coughs, sneezes, sighs, snoring, throat clearing, sniffs, and breathing sounds was trained and used to capture nightly sleep disturbances. Our preliminary analysis found significant improvement in FEV1 forecasting when using overnight nonverbal vocalization detections as an additional feature for regression using XGBoost over using only spirometry data.Clinical relevance- This preliminary study establishes up to 30% improvement of FEV1 forecasting using features generated by deep learning techniques over only spirometry-based features.

Mild asthma: Lessons learned and remaining questions

Patients living with mild disease represent the largest proportion of asthma patients. There are significant challenges in proposing a definition that would best describe these patients, while also accurately identifying at-risk individuals. Current literature suggests considerable inflammatory and clinical heterogeneity within this group. Research has shown that these patients are at risk of poor control, exacerbations, lung function decline, and death. Despite conflicting data on its prevalence, eosinophilic inflammation appears to be a predictor of poorer outcomes in mild asthma. There is an immediate need to better understand phenotypic clusters in mild asthma. It is also important to understand factors that influence disease progression and remission, as it is evident that both vary in mild asthma. Guided by robust literature that supports inhaled corticosteroid-based strategies over short-acting beta-agonist (SABA) reliant regimens, the management of these patients has evolved considerably. Unfortunately, SABA use remains high in clinical practice despite strong advocacy from the Global Initiative for Asthma. Future mild asthma research should explore the role of biomarkers, develop prediction tools based on composite risk scores, and explore targeted therapies at least for at-risk individuals.

Biomarkers of asthma relapse and lung function decline in adults with spontaneous asthma remission: A population-based cohort study

BACKGROUND

The extent to which biomarkers of asthma activity persist in spontaneous asthma remission and whether such markers are associated with future respiratory outcomes remained unclear. We investigated the association between sub-clinical inflammation in adults with spontaneous asthma remission and future asthma relapse and lung function decline.

METHODS

The Tasmanian Longitudinal Health Study is a population-based cohort (n = 8583). Biomarkers of systemic inflammation were measured on participants at age 45, and latent profile analysis was used to identify cytokine profiles. Bronchial hyperresponsiveness (BHR) and nitric oxide products in exhaled breath condensate (EBC NOx) were measured at age 50. Participants with spontaneous asthma remission at ages 45 (n = 466) and 50 (n = 318) were re-evaluated at age 53, and associations between baseline inflammatory biomarkers and subsequent asthma relapse and lung function decline were assessed.

RESULTS

We identified three cytokine profiles in adults with spontaneous asthma remission: average (34%), Th2-high (42%) and Th2-low (24%). Compared to the average profile, a Th2-high profile was associated with accelerated decline in post-BD FEV1 /FVC (MD -0.18% predicted per-year; 95% CI -0.33, -0.02), while a Th2-low profile was associated with accelerated decline in both post-BD FEV1 (-0.41%; -0.75, -0.06) and post-BD FVC (-0.31%; -0.62, 0.01). BHR and high TNF-α during spontaneous remission were associated with an increased risk of asthma relapse. In contrast, we found no evidence of association between EBC NOx and either asthma relapse or lung function decline.

CONCLUSION

BHR and serum inflammatory cytokines have prognostic value in adults with spontaneous asthma remission. At-risk individuals with BHR, Th2-high or Th2-low cytokine profiles may benefit from closer monitoring and on-going follow-up.

Asthma

Asthma is one of the most common chronic non-communicable diseases worldwide and is characterised by variable airflow obstruction, causing dyspnoea and wheezing. Highly effective therapies are available; asthma morbidity and mortality have vastly improved in the past 15 years, and most patients can attain good asthma control. However, undertreatment is still common, and improving patient and health-care provider understanding of when and how to adjust treatment is crucial. Asthma management consists of a cycle of assessment of asthma control and risk factors and adjustment of medications accordingly. With the introduction of biological therapies, management of severe asthma has entered the precision medicine era-a shift that is driving clinical ambitions towards disease remission. Patients with severe asthma often have co-existing conditions contributing to their symptoms, mandating a multidimensional management approach. In this Seminar, we provide a clinically focused overview of asthma; epidemiology, pathophysiology, diagnosis, and management in children and adults.

Association between cold weather, influenza infection, and asthma exacerbation in adults in Hong Kong

Despite a conspicuous exacerbation of asthma among patients hospitalized due to influenza infection, no study has attempted previously to elucidate the relationship between environmental factors, influenza activity, and asthma simultaneously in adults. In this study, we examined this relationship using population-based hospitalization records over 22 years. Daily numbers of hospitalizations due to asthma in adults of 41 public hospitals in Hong Kong during 1998-2019 were obtained. The data were matched with meteorological records and air pollutant concentrations. We used type-specific and all-type influenza-like illness plus (ILI+) rates as proxies for seasonal influenza activity. Quasi-Poisson generalized additive models together with distributed-lag non-linear models were used to examine the association. A total of 212,075 hospitalization episodes due to asthma were reported over 22 years. The cumulative adjusted relative risk (ARR) of asthma hospitalizations reached 1.15 (95 % confidence interval [CI], 1.12-1.18) when the ILI+ total rate increased from zero to 20.01 per 1000 consultations. Compared with the median temperature, a significantly increased risk of asthma hospitalization (cumulative ARR = 1.10, 95 % CI, 1.05-1.15) was observed at the 5^th percentile of temperature (i.e., 14.6 °C). Of the air pollutants, oxidant gas was significantly associated with asthma, but only at its extreme level of concentrations. In conclusion, cold conditions and influenza activities are risk factors to asthma exacerbation in adult population. Influenza-related asthma exacerbation that appeared to be more common in the warm and hot season, is likely to be attributable to influenza A/H3N2. The heavy influence of both determinants on asthma activity implies that climate change may complicate the asthma burden.

MiR-185-5p measurement assists in reflecting Th1/Th2 cell imbalance, inflammatory cytokine production, and exacerbation risk for childhood asthma

BACKGROUND

MicroRNA (miR)-185-5p participates in the pathology of asthma by regulating immune imbalance, inflammation, periostin synthesis, and smooth muscle contraction. This study intended to explore the dysregulation of miR-185p and its correlation with T-helper (Th)1, Th2 cells, and inflammatory cytokines in childhood asthma.

METHODS

In 150 childhood asthma patients and 30 healthy controls (HCs), miR-185-5p from peripheral blood mononuclear cells was detected using reverse transcription-quantitative polymerase chain reaction, Th cells from peripheral blood samples were detected using flow cytometry, inflammatory cytokines from serum samples were detected using enzyme-linked immunosorbent assay.

RESULTS

MiR-185-5p was increased in childhood asthma patients versus HCs [median (interquartile range (IQR)): 2.315 (1.770-3.855) versus 1.005 (0.655-1.520)] (P < 0.001). Meanwhile, miR-185-5p was negatively associated with Th1 cells (P = 0.035) but positively correlated with Th2 cells (P = 0.006) and IL-4 (P = 0.003) in childhood asthma patients; however, miR-185-5p was not linked to Th1 cells, Th2 cells, IFN-γ, or IL-4 in HCs (all P > 0.05). In addition, miR-185-5p was positively related to TNF-α (P < 0.001), IL-1β (P = 0.015), and IL-6 (P = 0.008) in childhood asthma patients, miR-185-5p was only linked to TNF-α (P = 0.040) but not IL-1β or IL-6 (both P > 0.05) in HCs. Moreover, miR-185-5p was increased in exacerbated childhood asthma patients versus remissive patients [median (IQR): 3.170 (2.070-4.905) versus 1.900 (1.525-2.615)] (P < 0.001). Besides, miR-185-5p was highest in patients with severe exacerbation followed by patients with moderate exacerbation, and lowest in patients with mild exacerbation (P = 0.010).

CONCLUSION

MiR-185-5p is associated with imbalanced Th1/Th2 cells, increased inflammatory cytokines along with elevated exacerbation risk, and severity in childhood asthma patients.

Study on Intestinal Flora and Asthma: Knowledge Graph Analysis Based on CiteSpace (2001-2021)

Asthma is a common chronic inflammatory disease of the airway. Intestinal flora, a significant risk factor for asthma, has become a widespread concern in the pathogenesis of asthma. To review the literature related to intestinal flora in asthma, summarize research direction, and report trends, this study used CiteSpace to perform bibliometric statistics and analysis on the research papers of intestinal flora and asthma collected in the Web of science core collection from 2001 to 2021. Eventually, a total of 613 articles were included. The results demonstrated that research on gut flora and asthma continued to heat up, with article numbers increasing, especially in the last decade. Moreover, analysis of the keywords showed that the research topics of intestinal flora and asthma range from confirming the link between intestinal flora and asthma to investigating mechanisms and then to asthma treatment. According to the summary of research hotspots, we expand on three emerging issues that require attention in the intestinal flora and asthma research, including (regulatory T)Treg cells, probiotics, and chain fatty acid. Evidence illustrated that Treg cells play a crucial role in the pathogenesis of asthma caused by dysbiosis of the gut flora. Furthermore, in contrast to probiotic supplements, which do not reduce the risk of developing asthma, short-chain fatty acids supplements do. Overall, the research direction in the field of intestinal flora and asthma has recently evolved from macro to micro with depth broadened. As a robust scientific evaluation, our study provided a comprehensive overview of the area, particularly for research focus, which could more precisely direct scholars on future research and clinical diagnosis, therapy, and individualized prevention.

Network analyses of upper and lower airway transcriptomes identify shared mechanisms among children with recurrent wheezing and school-age asthma

Background

Predicting which preschool children with recurrent wheezing (RW) will develop school-age asthma (SA) is difficult, highlighting the critical need to clarify the pathogenesis of RW and the mechanistic relationship between RW and SA. Despite shared environmental exposures and genetic determinants, RW and SA are usually studied in isolation. Based on network analysis of nasal and tracheal transcriptomes, we aimed to identify convergent transcriptomic mechanisms in RW and SA.

Methods

RNA-sequencing data from nasal and tracheal brushing samples were acquired from the Gene Expression Omnibus. Combined with single-cell transcriptome data, cell deconvolution was used to infer the composition of 18 cellular components within the airway. Consensus weighted gene co-expression network analysis was performed to identify consensus modules closely related to both RW and SA. Shared pathways underlying consensus modules between RW and SA were explored by enrichment analysis. Hub genes between RW and SA were identified using machine learning strategies and validated using external datasets and quantitative reverse transcription-polymerase chain reaction (qRT-PCR). Finally, the potential value of hub genes in defining RW subsets was determined using nasal and tracheal transcriptome data.

Results

Co-expression network analysis revealed similarities in the transcriptional networks of RW and SA in the upper and lower airways. Cell deconvolution analysis revealed an increase in mast cell fraction but decrease in club cell fraction in both RW and SA airways compared to controls. Consensus network analysis identified two consensus modules highly associated with both RW and SA. Enrichment analysis of the two consensus modules indicated that fatty acid metabolism-related pathways were shared key signals between RW and SA. Furthermore, machine learning strategies identified five hub genes, i.e., CST1, CST2, CST4, POSTN, and NRTK2, with the up-regulated hub genes in RW and SA validated using three independent external datasets and qRT-PCR. The gene signatures of the five hub genes could potentially be used to determine type 2 (T2)-high and T2-low subsets in preschoolers with RW.

Conclusions

These findings improve our understanding of the molecular pathogenesis of RW and provide a rationale for future exploration of the mechanistic relationship between RW and SA.

Parental occupational exposures prior to conception and offspring wheeze and eczema during first year of life

PURPOSE

Parental exposures prior to conception might influence asthma and allergy risk in offspring. As occupational exposures are established risk factors for asthma and allergies, we investigated if parental occupational exposures prior to conception cause wheeze and eczema in offspring during the first year of life.

METHODS

We analysed data of 436 families from an offspring cohort based on a follow-up study of German participants of the International Study of Asthma and Allergies in Childhood (ISAAC). Offspring cohort data was collected between 2009 and 2019. Occupational exposures were based on participants' work histories and measured by a Job-Exposure-Matrix. We used Bayesian logistic regression models for analysis. Inference and confounder selection were based on directed acyclic graphs.

RESULTS

In mothers, for both allergic and irritative occupational exposures prior to conception suggestive effects on offspring eczema during the first year of life were found (allergens: odds ratio (OR) 1.22, 95% compatibility interval (CI) 0.92-1.57; irritants: OR 1.36, 95% CI 0.99-1.77), while no relation with wheeze was suggested.

CONCLUSIONS

Our results suggest that reduction of asthma-related occupational exposures might not only reduce the burden of disease for occupationally induced or aggravated asthma and allergies in employees but also in their children.

Skin Barrier Function and Infant Tidal Flow-Volume Loops-A Population-Based Observational Study

Background: The relationship between the skin barrier- and lung function in infancy is largely unexplored. We aimed to explore if reduced skin barrier function by high transepidermal water loss (TEWL), or manifestations of eczema or Filaggrin (FLG) mutations, were associated with lower lung function in three-month-old infants. Methods: From the population-based PreventADALL cohort, 899 infants with lung function measurements and information on either TEWL, eczema at three months of age and/or FLG mutations were included. Lower lung function by tidal flow-volume loops was defined as a ratio of time to peak tidal expiratory flow to expiratory time (tPTEF/tE) <0.25 and a tPTEF <0.17 s (<25th percentile). A high TEWL >8.83 g/m2/h (>75th percentile) denoted reduced skin barrier function, and DNA was genotyped for FLG mutations (R501X, 2282del4 and R2447X). Results: Neither a high TEWL, nor eczema or FLG mutations, were associated with a lower tPTEF/tE. While a high TEWL was associated with a lower tPTEF; adjusted OR (95% CI) 1.61 (1.08, 2.42), the presence of eczema or FLG mutations were not. Conclusions: Overall, a high TEWL, eczema or FLG mutations were not associated with lower lung function in healthy three-month-old infants. However, an inverse association between high TEWL and tPTEF was observed, indicating a possible link between the skin barrier- and lung function in early infancy.

Differences Between Early- and Late-Onset Asthma: Role of Comorbidities in Symptom Control

BACKGROUND

Asthma can present in early childhood or de novo in adulthood. Our understanding of the burden of comorbidities in adult asthmatic patients stratified by age at onset is incomplete.

OBJECTIVES

To evaluate how different comorbidities may affect symptom control in two distinct groups of patients with early- and late-onset asthma (EOA and LOA, respectively) and to explore whether reported comorbidities are associated with lung function and inflammatory parameters.

METHODS

We conducted a cross-sectional study of 175 adult asthmatic patients (aged 57.5 ± 17.1 years) recruited at our university asthma clinic. We defined EOA as asthma onset less than 12 years, and LOA as onset greater than 40 years. The primary outcome was symptom control and main comorbidities evaluated were rhinitis, gastroesophageal reflux, obesity, cardiovascular conditions, and bronchiectasis. We used multivariable regression analysis to identify potential predictors of poor control in EOA and LOA.

RESULTS

Of 175 subjects, 77 had EOA (44%), 98 had LOA (56%), and comorbidities had a differential impact in the two groups. Rhinitis was more frequent in EOA (76 vs 53%; P = .02) and was associated with uncontrolled asthma (P < .001), reduced FEV₁/FVC (P = .01), increased eosinophils (P = .003) and total IgE (P < .01). Conversely, in LOA, rhinitis was associated with more controlled asthma and higher FEV₁/FVC (both P < .01). In EOA, only, IgE levels were directly related to blood eosinophils (r = 0.42; P <.001) and inversely to FEV₁/FVC (r = -0.35; P = .002). Obesity was present in 20% of patients in both groups, but only in LOA was it associated with uncontrolled disease (P = .009), reduced FEV₁/FVC (P = .009), and blood neutrophils (P = .03). In multivariable regression analysis, rhinitis in EOA and obesity in LOA were the risk factors most closely associated with poor control. Gastroesophageal reflux, cardiovascular comorbidities, and bronchiectasis did not affect control.

CONCLUSIONS

Early-onset persistent asthma and late-onset asthma are distinct phenotypes with different underlying inflammatory patterns and different comorbidities affecting symptom control.

In Silico Evaluation of Nonsynonymous SNPs in Human ADAM33: The Most Common Form of Genetic Association to Asthma Susceptibility

ADAM33 is a zinc-dependent metalloprotease of the ADAM family, which plays a vital biological role as an activator of Th2 cytokines and growth factors. Moreover, this protein is crucial for the normal development of the lung in the fetus two months after gestation leading to determining lung functions all over life. In this regard, mutations in ADAM33 have been linked with asthma risk factors. Consequently, identifying ADAM33 pathogenic nonsynonymous single-nucleotide polymorphisms (nsSNPs) can be very important in asthma treatment. In the present study, 1055 nsSNPs of human ADAM33 were analyzed using biocomputational software, 31 of which were found to be detrimental mutations. Precise structural and stability analysis revealed D219V, C669G, and C606S as the most destabilizing SNPs. Furthermore, MD simulations disclosed higher overall fluctuation and alteration in intramolecular interactions compared with the wild-type structure. Overall, the results suggest D219V, C669G, and C606S detrimental mutations as a starting point for further case-control studies on the ADAM33 protein as well as an essential source for future targeted mechanisms.

The modification of air particulate matter on the relationship between temperature and childhood asthma hospitalization: An exploration based on different interaction strategies

The influence of temperature on childhood asthma was self-evident, yet the issue of whether the relationship will be synergized by air pollution remains unclear. The study aimed to investigate whether the relationship between short-term temperature exposure and childhood asthma hospitalization was modified by particulate matter (PM). Data on childhood asthma hospitalization, meteorological factors, and air pollutants during 2013-2016 in Hefei, China, were collected. First, a basic Poisson regression model combined with a distributed lag nonlinear model was used to assess the temperature-childhood asthma hospitalization relationship. Then, two interactive strategies were applied to explore the modification effect of PM on the temperature-childhood asthma hospitalization association. We found a greater effect of cold (5th percentile of temperature) on asthma during days with higher PM_2.5 (RR: 2.16, 95% CI: 1.38, 3.38) or PM₁₀ (RR: 1.87, 95% CI:1.20, 2.91) than that during days with lower PM_2.5 (RR: 1.64, 95% CI: 1.06, 2.54) or PM₁₀ (RR: 1.52, 95% CI: 0.98, 2.36). In addition, we observed a greater modification effect of PM_2.5 on the cold-asthma association than did PM₁₀, with a per 10 μg/m³ increase in PM_2.5 and PM₁₀ associated with increases of 0.065 and 0.025 for the RR corresponding to the 5th temperature percentile, respectively. For the temperature-related AF, moderate cold showed the largest change magnitude with the PM levels rising compared with other temperature ranges. For the subgroup, Females and those aged 6-18 years were more sensitive to the modification effect of PM_2.5 or PM₁₀ on the cold-asthma association. Our findings demonstrated that particulate matter could modify the associations between temperature and childhood asthma hospitalization.

GSDM gene polymorphisms regulate the IgE level in asthmatic patients

Background

Gasdermin A (GSDMA) and gasdermin B (GSDMB) have been associated with childhood and adult asthma in many populations including the Jordanian population. It is also known that IgE plays a crucial role in various allergic disorders, such elevated levels of total serum IgE were detected in asthma and allergic rhinitis. IgE immunoglobulin is responsible for the release of numerous inflammatory mediators, such as histamine and prostaglandins, from mast cells in asthmatic patients.

Objective

In this study, single nucleotide polymorphisms of GSDMA (rs7212938, T/G) and GSDMB (rs7216389, T/C) in Jordanian population were investigated for their association with total IgE levels in serum of asthmatic children and adult subjects.

Methods

The genetic polymorphism analysis for SNPs was performed using the polymerase chain reaction (PCR)/restriction fragment length polymorphism method (RFLP). Three analysis models were applied to the genotype data: co-dominant, dominant and recessive.

Results

Our data demonstrate a significant correlation between GSDMB genetic SNP (rs7216389) and the total IgE serum level. Where one minor allele in the GSDMB gene is sufficient to induce significant changes in the IgE serum levels and plays a role in the pathogenesis of asthma in asthmatic children of the Jordanian population. Suggesting that this polymorphism might have a protective effect against asthma risk. While the presence of the GSDMB polymorphism alone might not be sufficient to associate with the high risk of developing asthma or responding to it in adults in Jordanian population.

Conclusion

In conclusion, the current study confirms the significant association of GSDMB genetic SNP (rs7216389) with IgE levels in asthma patients in Jordanian population, while no significant correlation of GSDMA and IgE level was found in both child and adult asthmatic patients.

Early-life residential exposure to moisture damage is associated with persistent wheezing in a Finnish birth cohort

BACKGROUND AND AIMS

Moisture damage increases the risk for respiratory disorders in childhood. Our aim was to determine whether early age residential exposure to inspector-observed moisture damage or mold is associated with different wheezing phenotypes later in childhood.

METHODS

Building inspections were performed by civil engineers, in a standardized manner, in the children's homes-mostly single family and row houses (N = 344)-in the first year of life. The children were followed up with repeated questionnaires until the age of 6 years and wheezing phenotypes-never/infrequent, transient, intermediate, late onset, and persistent-were defined using latent class analyses. The multinomial logistic regression model was used for statistical analysis.

RESULTS

A total of 63% (n = 218) had infrequent or no wheeze, 23% (n = 80) had transient and 9.6% (n = 21) had a persistent wheeze. Due to the low prevalence, results for intermediate (3.8%, n = 13) and late-onset wheeze (3.5%, n = 12) were not further evaluated. Most consistent associations were observed with the persistent wheeze phenotype with an adjusted odds ratio (95% confidence intervals) 2.04 (0.67-6.18) for minor moisture damage with or without mold spots (present in 23.8% of homes) and 3.68 (1.04-13.05) for major damage or any moisture damage with visible mold in a child's main living areas (present in 13.4% of homes). Early-age moisture damage or mold in the kitchen was associated with transient wheezing.

CONCLUSION

At an early age, residential exposure to moisture damage or mold, can be dose-dependently associated especially with persistent wheezing phenotype later in childhood.

Phthalate biomarkers and associations with respiratory symptoms and healthcare utilization among low-income urban children with asthma

BACKGROUND

Phthalates are synthetic chemicals present in building materials, personal care products and other consumer goods. Limited studies link phthalates to pediatric asthma incidence; however, their effects on respiratory-related outcomes among those with pre-existing asthma remains unclear.

OBJECTIVE

We examined associations between phthalates and asthma symptoms, healthcare use, lung function, and lung inflammation among children with asthma.

METHODS

We collected repeated measures of urinary biomarkers for select phthalates and phthalate replacements (MBzP, MCINP, MCIOP, MCPP, MECPTP, MEHHTP, molar sum of DEHP biomarkers [MECPP, MEHHP, MEHP, MEOHP], MEP, MiBP, MnBP) and asthma symptoms, healthcare utilization, lung function, and inflammation among 148 predominantly low-income Black children (5-17 years) with persistent asthma every 3 months for one year. We used generalized estimating equations to assess associations between biomarker concentrations and asthma-related measures adjusting for age, sex, race/ethnicity, caregiver's education level, presence of smokers in the home, and season. We also considered co-exposures to other contaminants previously associated with asthma morbidity.

RESULTS

We observed consistent positive associations with individual DEHP biomarkers, the molar sum of DEHP, and BBzP with increased odds of asthma symptoms and with healthcare utilization (adjusted Odds Ratio for general asthma symptoms: ΣDEHP:1.49,95% Confidence Interval, CI:1.08-2.07; BBzP:1.34, CI:1.04-1.73). We observed similar associations between the DEHP phthalate replacement biomarker MEHHTP and most asthma symptoms evaluated; and with select low molecular weight phthalates (DiBP, DBP) and healthcare utilization. Results were similar when controlling for other environmental exposures (e.g., PM2.5, BPA). No associations were observed with lung function or inflammation, and overall, we did not observe consistent evidence of sexually dimorphic effects.

CONCLUSION

In the present study, we found evidence to suggest that exposure to select phthalates may be associated with asthma symptoms and healthcare utilization. These findings warrant confirmation given the high asthma burden and widespread and disparate phthalate exposures reported among select populations of color.

Age at asthma diagnosis is related to prevalence and characteristics of asthma symptoms

Background

Although asthma may begin at any age, knowledge about relationship between asthma age of onset and the prevalence and character of different symptoms is scarce.

Objectives

The aim of this study was to investigate if adult-diagnosed asthma is associated with more symptoms and different symptom profiles than child-diagnosed asthma.

Methods

A FinEsS postal survey was conducted in a random sample of 16 000 20-69-year-old Finnish adults in 2016. Those reporting physician-diagnosed asthma and age at asthma diagnosis were included. Age 18 years was chosen to delineate child- and adult-diagnosed asthma.

Results

Of responders (N = 8199, 51.5%), 842 (10.3%) reported asthma diagnosis. Adult-diagnosed asthma was reported by 499 (59.3%) and child-diagnosed by 343 (40.7%). Of responders with adult-diagnosed and child-diagnosed asthma, 81.8% versus 60.6% used asthma medication (p < 0.001), respectively. Current asthma was also more prevalent in adult-diagnosed asthma (89.2% versus 72.0%, p < 0.001). Risk factors of attacks of breathlessness during the last 12 months were adult-diagnosis (OR = 2.41, 95% CI 1.64–3.54, p < 0.001), female gender (OR = 1.49, 1.07–2.08, p = 0.018), family history of asthma (OR = 1.48, 1.07–2.04, p = 0.018) and allergic rhinitis (OR = 1.49, 1.07–2.09, p = 0.019). All the analysed asthma symptoms, except dyspnea in exercise, were more prevalent in adult-diagnosed asthma in age- and gender-adjusted analyses (p = 0.032-<0.001) which was also more often associated with 5 or more asthma symptoms (p < 0.001) and less often with non-symptomatic appearance (p < 0.001) than child-diagnosed asthma.

Conclusion

Responders with adult-diagnosed asthma had more often current asthma and a higher and multiform asthma symptom burden, although they used asthma medication more often compared to responders with child-diagnosed 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.

Increased expressions of CD123, CD63, CD203c, and Fc epsilon receptor I on blood leukocytes of allergic asthma

Background : Altered basophil identification markers have been discovered to associate with allergic asthma (AA) in recent years. However, little is known about the expression of basophil markers in blood granulocytes. Aim: To parallel test blood basophils in peripheral blood mononuclear cell (PBMC) and granulocyte populations of patients with AA and AA combined with allergic rhinitis (ARA) Methods: The expressions of surface molecules were determined via flow cytometry. CD123 expressing cells in blood were isolated using a cell sorting technique, and mouse AA models were employed for in vivo study. Results: The numbers of CD123+HLA-DR- cells in the granulocytes of AA and ARA patients markedly increased. However, only 49.7% of CD123+HLA-DR- cells in granulocytes and 99.0% of CD123+HLA-DR- cells in PBMCs were basophils. Almost all CD123+HLA-DR- cells expressed CD63 regardless in granulocytes or PBMC. The numbers of CD63, Fc epsilon receptor I (FcεRI), and CD203c expressing cells markedly enhanced in CD123+HLA-DR- granulocytes of AA and ARA patients. Mean fluorescence intensity (MFI) of CD63 and CD203c expressions on CD123+HLA-DR- PBMC and granulocytes of AA and ARA patients dramatically elevated. House dust mite extract (HDME) and Artemisia sieversiana wild allergen extract (ASWE) enhanced the numbers of CD63+CD123+HLA-DR- granulocytes and PBMC and the MFI of CD203c expression on CD123+HLA-DR- granulocyte of AA and ARA patients. Histamine, tryptase, and PGD2 enhanced proportions of CD123+ KU812 cells. ASWE- and HDME-induced AA mice showed upregulated CD63 expression on basophils. In conclusion, upregulated expressions of CD123, CD203c, CD63, and FcεRIα in PBMC and granulocytes of patients with AA and ARA suggest that CD123+HLA-DR- cells may contribute to the development of AA and ARA.

Static lung volumes and diffusion capacity in adults 30 years after being diagnosed with asthma

BACKGROUND

Long-term follow-up studies of adults with well-characterized asthma are sparse. We aimed to explore static lung volumes and diffusion capacity after 30 + years with asthma.

METHODS

A total of 125 adults with an objectively verified diagnosis of asthma between 1974-1990 at a Danish respiratory outpatient clinic completed a follow-up visit 2017-19. All participants (age range 44-88 years) completed a comprehensive workup and were, based on these assessments, classified as having either active asthma or being in complete remission. The examination program included measurements of static lung volumes and diffusion capacity.

RESULTS

Participants with active asthma were hyperinflated (residual volume/total lung capacity ratio 0.43, 95% CI 0.41-0.45) (RV/TLC ratio) compared with those in remission (RV/TLC ratio 0.38, 95% CI 0.36-0.41) (p < 0.03). A tendency towards higher diffusion capacity per liter lung volume was seen in participants with active asthma (KCO 100% predicted, 95% CI 97-104) compared with those in remission (KCO 94% pred., 95% CI 89-99) (P = 0.10). Longer asthma duration was associated with a higher KCO 0.47% pred./year (95% CI 0.14-0.80), adjusted for age and smoking. Patients on GINA step 4 and 5 treatment were more hyperinflated ([Formula: see text] RV 14% pred., 95% CI 3-27) and had higher airway resistance (mean 53% pred., 95% CI 9-97) than participants on lower GINA steps. Patients with uncontrolled disease had substantially higher airway resistance (72% pred. 95% CI 20-124) than well-controlled patients.

CONCLUSION

Thirty years after a confirmed diagnosis of asthma, those continuing to have active asthma and those having severe asthma, have higher diffusion capacity and more hyperinflation than patients in remission.