Allergen inhalation increases mRNA expression in induced sputum from mild atopic asthmatics*1

Abstract Background: The progression of an abnormal inflammatory response plays a crucial role in the functional decline that occurs in COPD patients[1].Compared to serum biomarkers, inflammatory biomarkers in induced sputum would be a more reliable reflection of the inflammatory processes in the airways. Based on this, we explored the association of inflammatory biomarkers in induced sputum with lung function in COPD patients.Methods: 102 patients with COPD were recruited and underwent spirometry. According to the percentage of the predicted forced expiratory volume in 1 second value (FEV1%pred), participants with COPD were divided into a mild and moderate group (FEV1%pred≥ 50%, n=57) and a severe and extremely severe group (FEV1%pred<50%, n=45). Then we analyzed a series of inflammatory biomarkers in induced sputum and determined their association with lung function in COPD patients.Results: We found an increased levels of eosinophils percentage, MMP9 mRNA, LTB4R mRNA, and decreased levels of CC16 mRNA and miR-155 in the induced sputum of patients with severe and extremely severe COPD. In our analysis, sputum cell CC16 mRNA expression, but not CC16 secretion in the supernatant of the sputum, was closely and independently correlated with lung function decline in patients with COPD. Conclusion: The levels of numerous inflammatory biomarkers in induced sputum were associated with lung function decline in COPD，and the relative CC16 mRNA expression level with a cutoff of 1.09 could be a predictive biomarker of the severity of COPD.

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T2-high Asthma, Classified by Sputum mRNA Expression of IL4, IL5, and IL13, is Characterized by Eosinophilia and Severe Phenotype

Life ◽

10.3390/life11020092 ◽

2021 ◽

Vol 11 (2) ◽

pp. 92

Author(s):

Matija Rijavec ◽

Tomaž Krumpestar ◽

Sabina Škrgat ◽

Izidor Kern ◽

Peter Korošec

Keyword(s):

Gene Expression ◽

Mrna Expression ◽

Asthma Management ◽

Induced Sputum ◽

Variable Response ◽

High Positive Correlation ◽

Expression Levels ◽

Common Chronic Disease ◽

Asthmatic Patients ◽

Oral Corticosteroids

Asthma is a common chronic disease, with different underlying inflammatory mechanisms. Identification of asthma endotypes, which reflect a variable response to different treatments, is important for more precise asthma management. T2 asthma is characterized by airway inflammation driven by T2 cytokines including interleukins IL-4, IL-5, and IL-13. This study aimed to determine whether induced sputum samples can be used for gene expression profiling of T2-high asthma classified by IL4, IL5, and IL13 expression. Induced sputum samples were obtained from 44 subjects, among them 36 asthmatic patients and eight controls, and mRNA expression levels of IL4, IL5, and IL13 were quantified by RT-qPCR. Overall, gene expression levels of IL4, IL5, and IL13 were significantly increased in asthmatic patients’ samples compared to controls and there was a high positive correlation between expressions of all three genes. T2 gene mean was calculated by combining the expression levels of all three genes (IL4, IL5, and IL13) and according to T2 gene mean expression in controls, we set a T2-high/T2-low cutoff value. Twenty-four (67%) asthmatic patients had T2-high endotype and those patients had significantly higher eosinophil blood and sputum counts. Furthermore, T2-high endotype was characterized as a more severe, difficult-to-treat asthma, and often uncontrolled despite the use of inhaled and/or oral corticosteroids. Therefore, the majority of those patients (15 [63%] of 24) needed adjunct biological therapy to control their asthma symptoms/exacerbations. In conclusion, we found that interleukins IL4, IL5, and IL13 transcripts could be effectively detected in sputum from asthmatic patients. Implementation of T2 gene mean can be used as sputum molecular biomarker to categorize patients into T2-high endotype, characterized by eosinophilia and severe, difficult-to-treat asthma, and often with a need for biological treatment.

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Increased MMP12 mRNA expression in induced sputum was correlated with airway eosinophilic inflammation in asthma patients: evidence from bioinformatic analysis and experiment verification

Gene ◽

10.1016/j.gene.2021.145896 ◽

2021 ◽

pp. 145896

Author(s):

Lijuan Du ◽

Fengjia Chen ◽

Changyi Xu ◽

Weiping Tan ◽

Jia Shi ◽

...

Keyword(s):

Mrna Expression ◽

Bioinformatic Analysis ◽

Induced Sputum ◽

Eosinophilic Inflammation ◽

Asthma Patients ◽

Experiment Verification

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Airway IL-1β associates with IL-5 production following dust mite allergen inhalation in humans

Respiratory Research ◽

10.1186/s12931-021-01903-9 ◽

2021 ◽

Vol 22 (1) ◽

Author(s):

Allison J. Burbank ◽

Stephen A. Schworer ◽

Amika Sood ◽

Martha Almond ◽

Kelly Chason ◽

...

Keyword(s):

Allergen Challenge ◽

Allergic Airway Inflammation ◽

Positive Association ◽

Inflammatory Cells ◽

Forced Expiratory Volume ◽

Induced Sputum ◽

Cytokines And Chemokines ◽

Dust Mite ◽

Allergen Inhalation ◽

Relationship Of

Abstract Background Preclinical studies implicate interleukin (IL)-1β as a key mediator of asthma and have shown the efficacy of IL-1 antagonism for treatment of allergic airway inflammation; human studies in this area are lacking. Objectives Our aim was to study the relationship of airway IL-1β to features of acute allergen-induced asthma exacerbation in humans. Methods Dust mite-allergic adults with mild asthma underwent inhalation challenge with Dermatophagoides farinae. Fractional exhaled nitric oxide (FeNO), induced sputum and peripheral blood samples were obtained pre- and 24 h post-challenge. Spirometry was performed before and throughout the challenge at 10-min intervals, and allergen responsiveness was defined by a 20% fall in Forced Expiratory Volume in 1 s (FEV1). Sputum samples were analyzed for inflammatory cells, cytokines and chemokines. Multiple linear regression was employed to test the association between sputum IL-1β concentration and biomarkers of T helper type 2 (T2)-dominant inflammation. Results Fourteen volunteers underwent inhaled allergen challenge. Allergen responsive volunteers showed a greater positive change in IL-1β in sputum following allergen challenge compared to non-responders. Higher pre-challenge sputum IL-1β was associated with greater increase in sputum IL-5 (p = 0.004), sputum eosinophils (p = 0.001) and blood IL-5 (p = 0.003) following allergen challenge. Allergen-induced sputum IL-1β production was significantly associated with sputum and blood IL-5 (p < 0.001 and p = 0.007, respectively), sputum IL-4 (p = 0.001), IL-13 (p = 0.026), eosinophils (p = 0.008) and FeNO (p = 0.03). Conclusions The positive association between production of IL-1β and biomarkers of T2 inflammation, particularly IL-5, in humans is consistent with work in animal models that demonstrates a link between IL-1β and the pathophysiology of allergic asthma. The role of IL-1β in human asthma warrants further study.

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Inflammatory response in induced sputum mononuclear cells from patients with acute exacerbation of asthma

Mediators of Inflammation ◽

10.1080/09629350020002886 ◽

2000 ◽

Vol 9 (3-4) ◽

pp. 147-153 ◽

Cited By ~ 9

Author(s):

A. Hamzaoui ◽

M. Ben Brahim ◽

A. Zhioua ◽

Kh. Ayed ◽

K. Hamzaoui

Keyword(s):

Mrna Expression ◽

Mononuclear Cells ◽

Cytokine Production ◽

Induced Sputum ◽

Healthy Controls ◽

Rt Pcr ◽

Sputum Induction ◽

Asthmatic Patients ◽

Ifn Γ ◽

Pcr Techniques

Examination of sputum provides a direct method to investigate airway inflam mation non-invasively in particular Th1 (IL-2, IFN–γ) and Th2 (IL–4, IL–10) cytokine production.IL–2, IL–4, IL–10 and IFN–γ cytokine were studied in induced sputum mononuclear cells of asthmatic patients.Sputum induction was performed on 10 patients and 10 normal controls. Basal and mitogen-stimulated cytokine production was determined in induced sputum T-cell culture. Supernatants were collected and assayed not only with specific ELISA but also with polymerase chain reaction (PCR) techniques.Data showed a significantly higher production of IL–10 by both the ELISA and the RT-PCR techniques in asthmatic patients compared with sputum mononuclear cells from healthy controls. IL–4 production was detected at a low level using the ELISA method in asthmatic patients. The RT-PCR analysis detected a significantly IL–4-mRNA expression in all asthmatic patients, compared with controls. Results of IL–10 and IL–4 mRNA expression were reproducible. We did not find any alteration in the expression of the type 1 derived cytokines (IL–2 and IFN–γ) in asthmatic patients or in healthy controls.Our study showed a tendency of induced sputum mononuclear cells to express a Th2-like cytokine pattern in acute exacerbation of asthmatic patients, where IL–10 and IL–4 are synthesized in larger amounts. The combination of sputum induction as a non-invasive tool to explore the lung and the identification of disease-associated cytokine expression and of specific cytokine mRNA should help elucidate mechanisms of the immunologically mediated inflammatory responses in asthma.

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