Vitamin D constrains inflammation by modulating the expression of key genes on Chr17q12-21.1.

Vitamin D possesses immunomodulatory functions and vitamin D deficiency has been associated with the rise in chronic inflammatory diseases, including asthma (Litonjua and Weiss, 2007). Vitamin D supplementation studies do not provide insight into the molecular genetic mechanisms of vitamin D-mediated immunoregulation. Here, we provide evidence for vitamin D regulation of two human chromosomal loci, Chr17q12-21.1 and Chr17q21.2, reliably associated with autoimmune and chronic inflammatory diseases. We demonstrate increased vitamin D receptor (Vdr) expression in mouse lung CD4+ Th2 cells, differential expression of Chr17q12-21.1 and Chr17q21.2 genes in Th2 cells based on vitamin D status and identify the IL-2/Stat5 pathway as a target of vitamin D signaling. Vitamin D deficiency caused severe lung inflammation after allergen challenge in mice that was prevented by long-term prenatal vitamin D supplementation. Mechanistically, vitamin D induced the expression of the Ikzf3-encoded protein Aiolos to suppress IL-2 signaling and ameliorate cytokine production in Th2 cells. These translational findings demonstrate mechanisms for the immune protective effect of vitamin D in allergic lung inflammation with a strong molecular genetic link to the regulation of both Chr17q12-21.1 and Chr17q21.2 genes and suggest further functional studies and interventional strategies for long-term prevention of asthma and other autoimmune disorders.

Biological treatments in childhood asthma.

PURPOSE OF REVIEW: The aim is to update the information currently available for the use of biologics in severe asthma in children, in order to facilitate their prescription as far as possible. RECENT FINDINGS: The appearance of biologics for the treatment of severe asthma has meant a revolutionary change in the therapeutic approach to this disease. Currently, five biologics have been approved for severe asthma in children and/or adolescents by the regulatory agencies: omalizumab, mepolizumab, benralizumab, dupilumab and tezepelumab. But despite their positive results in terms of efficacy, there are still relevant points of debate that should induce caution when selecting the most appropriate biologic in a child with severe asthma. Indeed, safety is essential and, for several of the existing treatments, the availability of medium-term to long-term data in this regard is scarce. SUMMARY: The use of biologics can facilitate the therapeutic paradigm shift from pleiotropic treatments to personalized medicine. However, the choice of the most appropriate biologics remains a pending issue. On the other hand, to the extent that several of the biologics have been available for a relatively short time, the most robust evidence in terms of efficacy and safety in children is that of omalizumab.

Studying of anti-inflammatory and antioxidant effects of tectorigenin in ovalbumin-induced asthma mice models.

BACKGROUND: Allergic asthma is an important respiratory system problem characterized by airway inflammation, breathlessness, and bronchoconstriction. Allergic asthma and its outcomes are triggered by type 2 allergic immune responses. Tectorigenin is a methoxy-isoflavone with anti-inflammatory effects. In this study, we investigated the effects of tectorigenin on the pathophysiology of allergic asthma in an animal model. METHODS: Asthmatic mice were treated with tectorigenin. Then airway hyperresponsiveness (AHR), eosinophil percentage, levels of interleukin (IL)-33, IL-25, IL-13, IL-5, IL-4, total and ovalbumin (OVA)-specific immunoglobulin (Ig)E, and lung histopathology were evaluated. RESULT: Tectorigenin significantly (P 〈 0.05) reduced eosinophil infiltration (41 ± 7%) in the broncho-alveolar lavage fluid (BALF), serum IL-5 level (41 ± 5, pg/mL), and bronchial and vascular inflammation (scores of 1.3 ± 0.2 and 1.1 ± 0.3, respectively) but had no significant effects on AHR, serum levels of IL-33, -25, -13, and -4 (403 ± 24, 56 ± 7, 154 ± 11, and 89 ± 6 pg/mL, respectively), total and OVA-specific IgE (2684 ± 265 and 264 ± 19 ng/mL, respectively), goblet cell hyperplasia, and mucus production. CONCLUSION: Tectorigenin could control inflammation and the secretion of inflammatory mediators of asthma, so it can be regarded as a potential antiasthma treatment with the ability to control eosinophilia-related problems.

The relationship between prescription rates of oral corticosteroids for respiratory diseases and deprivation in England.

Respiratory diseases, including asthma and chronic obstructive pulmonary disease (COPD), are common in England with the worst respiratory outcomes observed in the most deprived areas. There is limited published research to establish whether the rate of oral corticosteroid (OCS) prescribing for asthma and COPD is linked to levels of deprivation. This study carried out a multivariable regression analysis of publicly available data and found that deprivation is associated with a statistically significant increase in the proportion of patients receiving an OCS prescription for asthma or COPD at a GP practice level (p < 0.001). The model estimated that the proportion of prescriptions is 1.88% (95% CI 1.83% to 1.92%) and 2.84% (95% CI 2.70% to 2.98%) for the least deprived GP practice and the most deprived GP practice, respectively. This study lays the groundwork for future research using individual patient level data to consider the impact of variation in OCS prescribing rates.

The association between waist circumference and adult asthma attack using nationally representative samples.

AIMS: This study aims to explore the relationship between waist circumference and asthma attack in adults. METHODS: In this cross-sectional study, we analysed data from 5,530 U.S. adults diagnosed with asthma. Participants were categorized into two groups based on their experience of asthma attacks: with or without asthma attacks. We employed adjusted weighted logistic regression models, weighted restricted cubic splines, subgroup and sensitivity analyses to assess the association between waist circumference and asthma attack. RESULTS: The median age of all participants was 43 years, and the median waist circumference was 98.9 cm, with a median BMI was 28.50 kg/m2. Participants in the asthma attack group had significantly higher waist circumferences than those in the non-attack group (P < 0.001). After full adjustment for body mass index-defined obesity, age, gender, race, education levels, poverty income ratio levels, smoking status, and metabolic syndrome, every 5 cm increase in waist circumference exhibited a 1.06 times higher likelihood of asthma attack probability. The weighted restricted cubic spline analysis demonstrated an increased risk of asthma attacks with rising waist circumference. Subgroup analyses confirmed this relationship across various groups differentiated by gender, age, and smoking status. When applying a stricter definition of asthma attack, the weighted logistic regression models showed robust association between waist circumference and asthma attack. CONCLUSION: Waist circumference is an independent predictor of asthma attacks. Our findings underscore the importance of waist circumference measurement in evaluating the risk of asthma attacks.

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.

Recommendations for asthma monitoring in children: A PeARL document endorsed by APAPARI, EAACI, INTERASMA, REG, and WAO.

Monitoring is a major component of asthma management in children. Regular monitoring allows for diagnosis confirmation, treatment optimization, and natural history review. Numerous factors that may affect disease activity and patient well-being need to be monitored: response and adherence to treatment, disease control, disease progression, comorbidities, quality of life, medication side-effects, allergen and irritant exposures, diet and more. However, the prioritization of such factors and the selection of relevant assessment tools is an unmet need. Furthermore, rapidly developing technologies promise new opportunities for closer, or even "real-time," monitoring between visits. Following an approach that included needs assessment, evidence appraisal, and Delphi consensus, the PeARL Think Tank, in collaboration with major international professional and patient organizations, has developed a set of 24 recommendations on pediatric asthma monitoring, to support healthcare professionals in decision-making and care pathway design.

Systemic IL-26 correlates with improved asthma control in children sensitized to dog allergen.

BACKGROUND: Interleukin (IL)-26 is produced by T helper type 17 (Type 17) cells and exerts immunomodulatory plus antimicrobial effects. Previous studies show that local IL-26 concentrations in the airways are higher in patients with uncontrolled than in those with controlled asthma, and that this intriguing cytokine bears biomarker potential. Here, we determined how systemic IL-26 relates to allergen sensitization, asthma severity, and to IL-17 A in children. METHODS: Serum samples were obtained from children with (n = 60) and without (n = 17) sensitization to dog allergen, and IL-26 and IL-17 A protein concentrations were measured using ELISA. Self-reported history, including medication use and validated symptom-based questionnaire scores, was recorded. RESULTS: The serum concentrations of IL-26 were enhanced in allergen-sensitized subjects and correlated with those of IL-17 A in a positive manner. However, the IL-26 concentrations did not markedly differ between allergen-sensitized subjects with and without asthma, eczema, allergic rhinitis, or a history of food allergy. Notably, IL-26 concentrations correlated with increasing Asthma Control Test (ACT) scores in a positive manner and with inhaled corticosteroid in a negative manner, amongst sensitized subjects with asthma. Moreover, subjects with asthma requiring ≥ 1 course of oral corticosteroids in the preceding 12 months had decreased IL-26 concentrations. CONCLUSION: This study forwards evidence that systemic IL-26, just like IL-17 A, is involved in allergen sensitization among children. The association of systemic IL-26 with improved asthma control is compatible with the cellular sources being recruited into the airways in severe asthma, which supports that this kinocidin bears potential as a biomarker and therapeutic target.

Seasonal extreme temperatures and short-term fine particulate matter increases pediatric respiratory healthcare encounters in a sparsely populated region of the intermountain western United States.

BACKGROUND: Western Montana, USA, experiences complex air pollution patterns with predominant exposure sources from summer wildfire smoke and winter wood smoke. In addition, climate change related temperatures events are becoming more extreme and expected to contribute to increases in hospital admissions for a range of health outcomes. Evaluating while accounting for these exposures (air pollution and temperature) that often occur simultaneously and may act synergistically on health is becoming more important. METHODS: We explored short-term exposure to air pollution on children's respiratory health outcomes and how extreme temperature or seasonal period modify the risk of air pollution-associated healthcare events. The main outcome measure included individual-based address located respiratory-related healthcare visits for three categories: asthma, lower respiratory tract infections (LRTI), and upper respiratory tract infections (URTI) across western Montana for ages 0-17 from 2017-2020. We used a time-stratified, case-crossover analysis with distributed lag models to identify sensitive exposure windows of fine particulate matter (PM2.5) lagged from 0 (same-day) to 14 prior-days modified by temperature or season. RESULTS: For asthma, increases of 1 µg/m3 in PM2.5 exposure 7-13 days prior a healthcare visit date was associated with increased odds that were magnified during median to colder temperatures and winter periods. For LRTIs, 1 µg/m3 increases during 12 days of cumulative PM2.5 with peak exposure periods between 6-12 days before healthcare visit date was associated with elevated LRTI events, also heightened in median to colder temperatures but no seasonal effect was observed. For URTIs, 1 unit increases during 13 days of cumulative PM2.5 with peak exposure periods between 4-10 days prior event date was associated with greater risk for URTIs visits that were intensified during median to hotter temperatures and spring to summer periods. CONCLUSIONS: Delayed, short-term exposure increases of PM2.5 were associated with elevated odds of all three pediatric respiratory healthcare visit categories in a sparsely population area of the inter-Rocky Mountains, USA. PM2.5 in colder temperatures tended to increase instances of asthma and LRTIs, while PM2.5 during hotter periods increased URTIs.

Suboptimal peak inspiratory flow rate: a noticeable risk factor for inhaler concordance in patients with chronic airway diseases.

BACKGROUND: Inhaler concordance and the peak inspiratory flow rate (PIFR) are important determinants of treatment effects in patients with chronic airway diseases. Adequate PIFR is required for driving aerosol medication into the lower respiratory tract. However, the relationship between them has not been discussed previously. This study aimed to describe the characteristics of inhaler concordance and PIFR in Chinese patients with chronic airway diseases and discuss the associated variables and the relationship between them. METHODS: In this single-centre, observational study, a total of 680 patients with chronic airway diseases were enrolled from July 2021 to April 2023. We collected data on the socio-demographic and clinical variables of inhaler concordance using the test of adherence to inhalers (TAI) and PIFR. Multivariate logistic regression was conducted to examine variables related to inhaler concordance and PIFR. RESULTS: A total of 49.4% of patients had low concordance. Patients with chronic obstructive pulmonary disease (COPD) were more concordant than patients with asthma (mean TAI score: 43.60 vs 41.20; p<0.01), while there was no difference in concordance between the asthma-COPD overlap group and the asthma or COPD group. Suboptimal PIFR (adjusted OR, 1.61; 95% CI 1.04 to 2.51) increased the risk of poor concordance among all patients, while triple therapy (adjusted OR, 0.60; 95% CI 0.35 to 0.86) reduced the risk. A total of 54.9% of patients had suboptimal PIFR. Older age, lower educational level, use of dry powder inhalers and lower forced expiratory volume in 1 s % predicted were significantly correlated with insufficient PIFR. Subgroup analysis revealed a greater proportion of patients with insufficient PIFR during exacerbation than during the stable phase (61.7% vs 43.5%, p<0.001). CONCLUSION: Inhaler concordance was low, and suboptimal PIFR was a risk factor for poor concordance among Chinese patients with chronic airway diseases. In addition, current inhalation devices may not be suitable, and PIFR reassessment should be considered for patients with COPD during exacerbation. TRIAL REGISTRATION NUMBER: The study was registered in chictr.org.cn (ChiCTR2100052527) on 31 October 2021.

PPARγ attenuates cellular senescence of alveolar macrophages in asthma-COPD overlap.

BACKGROUND: Asthma-chronic obstructive pulmonary disease (COPD) overlap (ACO) represents a complex condition characterized by shared clinical and pathophysiological features of asthma and COPD in older individuals. However, the pathophysiology of ACO remains unexplored. We aimed to identify the major inflammatory cells in ACO, examine senescence within these cells, and elucidate the genes responsible for regulating senescence. METHODS: Bioinformatic analyses were performed to investigate major cell types and cellular senescence signatures in a public single-cell RNA sequencing (scRNA-Seq) dataset derived from the lung tissues of patients with ACO. Similar analyses were carried out in an independent cohort study Immune Mechanisms Severe Asthma (IMSA), which included bulk RNA-Seq and CyTOF data from bronchoalveolar lavage fluid (BALF) samples. RESULTS: The analysis of the scRNA-Seq data revealed that monocytes/ macrophages were the predominant cell type in the lung tissues of ACO patients, constituting more than 50% of the cells analyzed. Lung monocytes/macrophages from patients with ACO exhibited a lower prevalence of senescence as defined by lower enrichment scores of SenMayo and expression levels of cellular senescence markers. Intriguingly, analysis of the IMSA dataset showed similar results in patients with severe asthma. They also exhibited a lower prevalence of senescence, particularly in airway CD206 + macrophages, along with increased cytokine expression (e.g., IL-4, IL-13, and IL-22). Further exploration identified alveolar macrophages as a major subtype of monocytes/macrophages driving cellular senescence in ACO. Differentially expressed genes related to oxidation-reduction, cytokines, and growth factors were implicated in regulating senescence in alveolar macrophages. PPARγ (Peroxisome Proliferator-Activated Receptor Gamma) emerged as one of the predominant regulators modulating the senescent signature of alveolar macrophages in ACO. CONCLUSION: The findings suggest that senescence in macrophages, particularly alveolar macrophages, plays a crucial role in the pathophysiology of ACO. Furthermore, PPARγ may represent a potential therapeutic target for interventions aimed at modulating senescence-associated processes in ACO.Key words ACO, Asthma, COPD, Macrophages, Senescence, PPARγ.

Stigmasterol alleviates airway inflammation in OVA-induced asthmatic mice via inhibiting the TGF-ß1/Smad2 and IL-17A signaling pathways.

Stigmasterol is a common dietary phytosterol with high nutritional value and physiological activity. In this study, we evaluated the effects of stigmasterol on inflammatory cytokines and the TGF-ß1/Smad2 and IL-17A signaling pathway in an ovalbumin (OVA)-induced asthma mouse model. Stigmasterol treatment improved airway remodeling. In addition, it significantly attenuated the symptoms of asthma attacks, reduced the number of macrophages, lymphocytes, neutrophils, and eosinophils in BALF and inflammatory cytokines, including IL-1ß, IL-5, IL-6, and IL-13. It further decreased the level of IL-17A in BALF, serum and spleen. Spleen single-cell suspension analysis via flow cytometry showed that IL-17A level was consistent with the results obtained in BALF, serum and spleen. Stigmasterol decreased the protein expression levels of TGF-ß, p-Smad2 and IL-17A in the spleen, by increasing the protein expression level of IL-10. After 24 h of co-culture of TGF-ß, IL-6 and stigmasterol, the level of IL-17 in CD4+ T cell supernatant was lower relative to levels in the group without stigmasterol. Meanwhile, stigmasterol treatment attenuated the expression level of TGF- ß, p-Smad2 and IL-17A proteins in CD4+ T cells and enhanced the expression levels of IL-10 protein. These data suggested that stigmasterol inhibited the TGF-ß1/Smad2 and IL-17A signaling pathway to achieve anti-asthmatic effects in the OVA-induced asthma mouse model. Collectively, the results of this study are that stigmasterol has achieved preliminary efficacy in the non-clinical laboratory, further studies are needed to consider the clinical application of stigmasterol.

Chronic Disease Patterns and Their Relationship With Health-Related Quality of Life in South Korean Older Adults With the 2021 Korean National Health and Nutrition Examination Survey: Latent Class Analysis.

BACKGROUND: Improved life expectancy has increased the prevalence of older adults living with multimorbidities, which likely deteriorates their health-related quality of life (HRQoL). Understanding which chronic conditions frequently co-occur can facilitate person-centered care tailored to the needs of individuals with specific multimorbidity profiles. OBJECTIVE: The study objectives were to (1) examine the prevalence of multimorbidity among Korean older adults (ie, those aged 65 years and older), (2) investigate chronic disease patterns using latent class analysis, and (3) assess which chronic disease patterns are more strongly associated with HRQoL. METHODS: A sample of 1806 individuals aged 65 years and older from the 2021 Korean National Health and Nutrition Examination Survey was analyzed. Latent class analysis was conducted to identify the clustering pattern of chronic diseases. HRQoL was assessed by an 8-item health-related quality of life scale (HINT-8). Multiple linear regression was used to analyze the association with the total score of the HINT-8. Logistic regression analysis was performed to evaluate the odds ratio of having problems according to the HINT-8 items. RESULTS: The prevalence of multimorbidity in the sample was 54.8%. Three chronic disease patterns were identified: relatively healthy, cardiometabolic condition, arthritis, allergy, or asthma. The total scores of the HINT-8 were the highest in participants characterized as arthritis, allergy, or asthma group, indicating the lowest quality of life. CONCLUSIONS: Current health care models are disease-oriented, meaning that the management of chronic conditions applies to a single condition and may not be relevant to those with multimorbidities. Identifying chronic disease patterns and their impact on overall health and well-being is critical for guiding integrated care.

Continuity and breaches in GP care and their associations with mortality for patients with chronic disease: an observational study using Norwegian registry data.

BACKGROUND: Despite many benefits of continuity of care with a named regular GP (RGP), continuity is deteriorating in many countries. AIM: To investigate the association between RGP continuity and mortality, in a personal list system, in addition to examining how breaches in continuity affect this association for patients with chronic diseases. DESIGN AND SETTING: A registry-based observational study using Norwegian primary care consultation data for patients with asthma, chronic obstructive pulmonary disease (COPD), diabetes mellitus, or heart failure. METHOD: The Usual Provider of Care (UPC, value 0-1) Index was used to measure both disease-related (UPCdisease) and overall (UPCall) continuity with the RGP at the time of consultation. In most analyses, patients who changed RGP during the study period were excluded. In the combined group of all four chronic conditions, the proportion of consultations with other GPs and out-of-hours services was calculated. Cox regression models calculated the associations between continuity during 2013-2016 and mortality in 2017-2018. RESULTS: Patients with COPD with UPCdisease <0.25 had 47% increased risk of dying within 2 years (hazard ratio 1.47, 95% confidence interval = 1.22 to 1.64) compared with those with UPCdisease ≥0.75. Mortality also increased with decreasing UPCdisease for patients with heart failure and decreasing UPCall for those with diabetes. In the combined group of chronic conditions, mortality increased with decreasing UPCall. This latter association was also found for patients who had changed RGP. CONCLUSION: Higher disease-related and overall RGP UPC are both associated with lower mortality. However, changing RGP did not significantly affect mortality, indicating a compensatory benefit of informational and management continuity in a patient list system.

Respiratory-related deaths and associated factors in Alicho-Weriro district, southern Ethiopia: verbal autopsy data analysis.

BACKGROUND: Respiratory diseases disproportionately affect people living in resource-limited settings. However, obtaining information that explains respiratory-related deaths has been difficult, mainly due to a lack of medical certification of death and the fact that most deaths occur outside of health institutions. This study aimed to determine the proportion of respiratory-related deaths and identify associated factors in Alicho-Weriro district, southern Ethiopia, using the verbal autopsy method. METHODS: A community-based cross-sectional study was conducted from April to June 2022. All deceased people in the study area from January 2020 to December 2021 were included in the study. Trained physicians ascertained the cause of death from verbal autopsy data that were collected using a pre-tested and modified WHO-designed questionnaire. The binary logistic regression models were used to identify factors associated with respiratory-related deaths. RESULTS: Respiratory-related deaths accounted for 25% of the deaths from all causes, with 20.8% of male and 29.5% of female deaths. Of which, 9.7% were from tuberculosis, 8.3% were from asthma and 6.2% were from acute lower-respiratory tract infections. Moreover, being female (adjusted OR, AOR: 3.3; 95% CI: (1.75 to 6.22)), age 50-64 years (AOR: 9.3; 95% CI: (1.16 to 73.90)), age above 64 years (AOR: 8.9; 95% CI: (1.130 to 70.79)), family size of five persons or more (AOR: 1.9; 95% CI: (1.15 to 3.29)), smoking (AOR: 3.9; 95% CI: (1.86 to 8.35)), using wood and/or animal dung for household cooking (AOR: 6.6; 95% CI: (1.92 to 22.59)) and poor house ventilation (AOR: 3.1; 95% CI: (1.75 to 5.38)) were significantly associated with increased odds of dying from respiratory-related diseases. CONCLUSION: This study has determined that about a quarter of deaths from all causes were due to respiratory diseases, mainly tuberculosis, asthma and acute lower respiratory tract infections. Therefore, interventions to reduce this burden should focus on supporting early case detection and treatment, promoting healthy lifestyles, exercising women's equality at the household level and improving housing conditions.

Systematic review of the effects of patient errors using inhaled delivery systems on clinical outcomes in COPD.

BACKGROUND: Errors using inhaled delivery systems for COPD are common and it is assumed that these lead to worse clinical outcomes. Previous systematic reviews have included patients with both asthma and COPD and much of the evidence related to asthma. More studies in COPD have now been published. Through systematic review, the relationship between errors using inhalers and clinical outcomes in COPD, including the importance of specific errors, was assessed.MethodsElectronic databases were searched on 27 October 2023 to identify cohort, case-control or randomised controlled studies, which included patients with COPD, an objective assessment of inhaler errors and data on at least one outcome of interest (forced expiratory volume in 1 s, (FEV1), dyspnoea, health status and exacerbations). Study quality was assessed using the Newcastle and Ottawa scales. A narrative synthesis of the results was performed as there was insufficient detail in the publications to allow quantitative synthesis. There was no funding for the review. RESULTS: 19 publications were included (7 cohort and 12 case-control) reporting outcomes on 6487 patients. 15 were considered low quality, and most were confounded by the absence of adherence data. There was weak evidence that lower error rates are associated with better FEV1, symptoms and health status and fewer exacerbations. Only one considered the effects of individual errors and found that only some were related to worse outcomes. CONCLUSION: Evidence about the importance of specific errors using inhalers and outcomes would optimise the education and training of patients with COPD. Prospective studies, including objective monitoring of inhalation technique and adherence, are needed. PROSPERO REGISTRATION NUMBER: CRD42023393120.

Neopterin in patients with COPD, asthma, and ACO: association with endothelial and lung functions.

BACKGROUND AND OBJECTIVE: Endothelial dysfunction has been widely recognized in chronic airway diseases, including chronic obstructive pulmonary disease (COPD) and asthma; however, it remains unclear in asthma-COPD overlap (ACO). Neopterin (NP), a metabolite of guanosine triphosphate, is a novel biomarker for identifying the increased risk of adverse cardiovascular events. This study aims to investigate the association of NP with endothelial dysfunction and impaired lung function in COPD, asthma, and ACO patients. METHODS: A total of 77 subjects were prospectively recruited. All the participants underwent lung function test, endothelial function evaluation, including pulse wave velocity (PWV) and flow-mediated dilation (FMD), and blood sample detection. Moreover, the effect of NP on endothelial cells (ECs) in anoxic environments was assessed in vitro. RESULTS: Endothelial function was significantly decreased in the COPD and ACO patients compared with that in the healthy controls (P < 0.05). Forced expiratory volume in 1 s (FEV1) was negatively correlated with PWV and positively correlated with FMD (P < 0.05). NP was significantly increased in patients with chronic respiratory diseases compared with that in the control group, with COPD being the highest, followed by asthma, and ACO as the last (P < 0.05). The plasma level of NP exhibited negative correlations with FEV1 and positive correlations with PWV (P < 0.05). In vitro, a high level of NP increased the reactive oxygen species (ROS) and decreased the mitochondrial membrane potential (ΔΨm) of ECs dose-dependently in a hypoxic environment (P < 0.05). CONCLUSION: NP was related to disease severity of chronic airway diseases and involved in the pathogenesis of endothelial dysfunction. A high NP level may contribute to endothelial dysfunction by increasing the oxidative stress of ECs dose-dependently in a hypoxic environment. Our findings may provide a novel evaluation and therapeutic target for endothelial dysfunction related to chronic airway diseases.