Identification of the molecular subgroups in asthma by gene expression profiles: airway inflammation implications

Background Asthma is a heterogeneous disease and different phenotypes based on clinical parameters have been identified. However, the molecular subgroups of asthma defined by gene expression profiles of induced sputum have been rarely reported. Methods We re-analyzed the asthma transcriptional profiles of the dataset of GSE45111. A deep bioinformatics analysis was performed. We classified 47 asthma cases into different subgroups using unsupervised consensus clustering analysis. Clinical features of the subgroups were characterized, and their biological function and immune status were analyzed using Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) and single sample Gene Set Enrichment Analysis (ssGSEA). Weighted gene co-expression network analysis (WGCNA) and protein–protein interaction (PPI) network were performed to identify key gene modules and hub genes. Results Unsupervised consensus clustering of gene expression profiles in asthma identified two distinct subgroups (Cluster I/II), which were significantly associated with eosinophilic asthma (EA) and paucigranulocytic asthma (PGA). The differentially expressed genes (DEGs) between the two subgroups were primarily enriched in immune response regulation and signal transduction. The ssGSEA suggested the different immune infiltration and function scores between the two clusters. The WGCNA and PPI analysis identified three hub genes: THBS1, CCL22 and CCR7. ROC analysis further suggested that the three hub genes had a good ability to differentiate the Cluster I from the Cluster II. Conclusions Based on the gene expression profiles of the induced sputum, we identified two asthma subgroups, which revealed different clinical characteristics, gene expression patterns, biological functions and immune status. The transcriptional classification confirms the molecular heterogeneity of asthma and provides a framework for more in-depth research on the mechanisms of asthma.

EFFECT OF THE ANTIVIRAL DRUG KAGOCEL® ON THE LEVELS OF MATRIX METALLOPROTEINASES MMP-8 AND MMP-9 AND THEIR TISSUE INHIBITORS TIMP-1 AND TIMP-2 IN INDUCED SPUTUM IN THE COMBINED TREATMENT OF COMMUNITY-ACQUIRED VIRAL-BACTERIAL PNEUMONIA

The effect of the antiviral drug Kagocel on the levels of metalloproteinases MMP-8 and MMP-9 and their tissue inhibitors TIMP-1 and TIMP-2 in induced sputum in the treatment of community-acquired viral-bacterial pneumonia was analyzed. 60 adult patients with a confirmed diagnosis of community-acquired pneumonia and viral-bacterial etiology were included in the follow-up research work. Materials and methods. All patients were randomly divided into 2 groups: 1 group (comparison group) included 30 patients receiving Ceftriaxone monotherapy; in the 2nd group (main) - 30 people who were prescribed Ceftriaxone and the antiviral drug Kagocel as etiotropic treatment. Both groups were comparable in terms of gender, age and time of admission to the hospital. Results. During hospitalization, patients in both groups had elevated levels of MMP-8, MMP-9, TIMP-1 and TIMP-2 in induced sputum compared to the reference values. By 7 days of inpatient treatment, the level of MMP-8 continued to be significantly higher than the reference values ​​in both groups, and in patients of the 2nd group there was a decrease compared to baseline values, and in patients in the 1st group at the same time. The activity of MMP-9 during hospitalization was also high in patients of both groups compared with the level of these enzymes in healthy people. By the 7th day of therapy various indicators' changes were recorded. The level of MMP-9 in patients of the 1st group increased, and in patients of the 2nd group - on the contrary - decreased. The level of TIMP-1 decreased in patients of the 1st group below the control value, and in patients of the 2nd group - reached the reference values. The level of TIMP-2 decreased in both groups and reached the level of control values. Conclusion. Inclusion in the standard antibacterial regimen of community-acquired viral-bacterial pneumonia of the antiviral drug Kagocel reduces the level of MMR-9 and reduces the severity of the imbalance in the MMP and TIMP system by 7 days of therapy, which leads to a faster clinical recovery of patients.

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

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.

Evaluation of selected IL6/STAT3 pathway molecules and miRNA expression in chronic obstructive pulmonary disease

COPD has been regarded as a global epidemic due to an increase in pollution and tobacco exposure. Therefore, the study of molecular mechanism as the basis for modern therapy is important. The aim of the study was the assessment of gene expression levels, IL-6, IL-6ST, PIAS3, STAT3, and miRNAs, miRNA-1, miRNA-106b, miRNA-155, in patients with COPD. Induced sputum as well as PBMC were collected from 40 patients clinically verified according to the GOLD 2021 (A–D) classification and from the control group (n = 20). The levels of gene and miRNA expression were analysed by qPCR. In induced sputum IL6 was significantly down-regulated in COPD group compared with control (p = 0.0008), while IL6ST were up-regulated (p = 0.05). The results were also statistically significant for STAT3 (p = 0.04) and miRNA-155 (p = 0.03) with higher expression in the current smokers compared to ex-smokers. Higher expression levels for IL6ST (p = 0.03) in COPD patients with the exacerbation history compared to COPD patients without the exacerbation history were noted. Compared induced sputum and PB lymphocytes we observed higher expression of IL6 (p = 0.0003), STAT3 (p = 0.000001) miRNA-106b (p = 0.000069 and miRNA-155 (p = 0.000016) in induced sputum with lower expression of PIAS3 (p = 0.006), IL6ST (p = 0.002) and miRNA-1 (p = 0.001). Differences in gene expression levels of the IL-6/IL6ST/STAT3 pathway and miRNA depending on the smoking status and classification of patients according to GOLD suggest the importance of these genes in the pathogenesis of COPD and may indicate their potential utility in monitoring the course of the disease.

Diagnostic Stewardship Aiming at Expectorated or Induced Sputum Promotes Microbial Diagnosis in Community-Acquired Pneumonia

PurposeStudies on aetiology of community-acquired pneumonia (CAP) vary in terms of microbial sampling methods, anatomical locations, and laboratory analyses, since no gold standard exists. In this large, multicentre, retrospective, regional study from Norway, our primary objective was to report the results of a strategic diagnostic stewardship intervention, targeting diagnostic yield from lower respiratory tract sampling. The secondary objective was to report in-hospital CAP aetiology and the diagnostic yield of various anatomical sampling locations.MethodsMedical records from cases diagnosed with in-hospital CAP were collected retrospectively from March throughout May for three consecutive years at six hospitals. Between year one and two, we launched a diagnostic stewardship intervention at the emergency room level for the university teaching hospital only. The intervention was multifaceted aiming at upscaling specimen collection and enhancing collection techniques. Year one at the interventional hospital and every year at the five other emergency hospitals were used for comparison.ResultsOf the 1280 included cases of in-hospital CAP, a microbiological diagnosis was established for 29.1 % among 1128 blood cultures and 1444 respiratory tract specimens. Blood cultures were positive for a pathogenic respiratory tract microbe in 4.9 % of samples, whereas upper and lower respiratory tract samples overall provided a probable microbiological diagnosis in 21.3 % and 47.5 %, respectively. Expectorated or induced sputum overall provided aetiology in 51.7 % of the samples. At the interventional hospital, diagnostic yield from expectorated or induced sputum was significantly enhanced from 41.2 % to 62.0 % after the intervention. Non-typeable Haemophilus influenza and Streptococcus pneumoniae accounted for 25.3 % and 24.7 % of microbiologically confirmed cases, respectively.ConclusionExpectorated or induced sputum outperformed other sampling methods in providing a reliable microbiological diagnosis for in-hospital CAP. A diagnostic stewardship intervention significantly improved diagnostic yield of lower respiratory tract sampling.

Paucigranulocytic asthma: Do sputum macrophages matter?

Background: Although paucigranulocytic asthma (PGA) is the most common phenotype of stable asthma, its features have not been adequately studied. In this study, we aimed to display the characteristics of PGA. Method: A total of 116 non-smoking adult patients with asthma (80% women; mean ± standard deviation age, 39 ± 12.9 years) admitted to three tertiary centers were included. Their demographic and clinical features, allergy status, biochemical results, scores of Asthma Control Test (ACT), spirometry, and exhaled nitric oxide (FeNO) measurements were obtained. Induced sputum cytometry was performed. Results: Four phenotypes, according to induced sputum cell counts, were detected: eosinophilic asthma (EA) (22.4%), mixed granulocytic asthma (MGA) (6.9%), neutrophilic (NA) (7.8%), and PGA (62.9%). In the sputum, macrophages were higher in the PGA group compared with the other groups (PGA versus NA and PGA versus MGA, p < 0.001; and PGA versus EA, p =0 .030). The atopy rate between phenotypes was the same. Although the forced expiratory volume in the first second of expiration (FEV1) was similar in four groups, the ratio of FEV1 to the forced vital capacity ratio was higher (p = 0.013) and FEV1 reversibility was lower in the patients with PGA than the corresponding values in other phenotypes (p = 0.015). Low reversibility was comparable both in patients with PGA who were inhaled corticosteroid (ICS) naive and in patients on ICS treatment. Although insignificant, the FeNO values and blood eosinophil counts were higher in the MGA and EA groups, whereas these were the lowest in the PGA group. The uncontrolled asthma ratio was low in PGA (16%), whereas it was 11% for NA, 25% for MG, and 23% in EA. Conclusion: Macrophages are predominant in sputum of patients with PGA. Besides a lower uncontrolled asthma ratio, lower FEV1 reversibility is a prominent characteristic of this phenotype.