Clinical Trial: Gene Expression Profile and Inflammation Profile of Classic Asthma, Cough Variant Asthma and Eosinophilic Bronchitis

Study Status: Recruiting
Recruit Status: Recruiting
Study Type: Observational

Official Title: Difference in Gene Expression Profile in Peripheral Blood Mononuclear Cells and Inflammation Profile in Patients With Classic Asthma, Cough Variant Asthma, and Eosinophilic Bronc

Brief Summary: This study aims to identify and validate the gene expression differentials of peripheral blood mononuclear cells and differential inflammation profiles and other aspects in classic asthma, cough-variant asthma and eosinophilic bronchitis.

Detailed Summary:

Asthma is a common and heterogeneous respiratory disorder affecting millions of people, posing a considerable burden on health care systems globally. The disease is characterized by inflammation of the airways with eosinophils, neutrophils, mast cells, lymphocytes, airway epithelial cells, smooth muscle cells and other cells, by airflow obstruction and by bronchial hyperresponsiveness. The disease is triggered by multiple gene-environment interactions. Asthma heterogeneity is recognized in terms of clinical phenotypes of asthma whereby classic asthma (CA) and cough variant asthma (CVA) are identified. classic asthma is a common phenotype of asthma that presents episodic dyspnoea and wheezing with or without cough. Cough variant asthma is a phenotype of asthma that presents solely cause of chronic cough.

Eosinophilic bronchitis (EB) is a common cause of chronic cough, which like eosinophils asthma is characterized by airway eosinophilic inflammation, but unlike asthma there is no airway hyperresponsiveness or variable airflow obstruction.

Improvement of disease diagnosis and management require a better understanding of disease heterogeneity. A useful biomarker for phenotype recognition will represent underlying pathologic mechanisms of disease, marking heterogeneity and guiding personalized treatment approaches. Our hypothesis was that the different clinical manifestos in patients with eosinophilic bronchitis, classic asthma, and cough-variant asthma could be caused by differential gene expression profiles of peripheral blood mononuclear cells (PBMC) and differential inflammation profiles and other aspects.


Sponsor: State Key Laboratory of Respiratory Disease

Current Primary Outcome: Difference in Gene Expression Profile of Peripheral Blood Mononuclear Cells in Classic Asthma,Cough Variant Asthma and Eosinophilic Bronchitis Compared with Healthy Controls [ Time Frame: 15 months ]

Five milliliters of venous blood was collected. The peripheral blood mononuclear cells(PBMC) were isolated by the Ficoll-Paque plus(GE Healthcare Bio-Sciences Corp, NJ ) according to the manufacture's recommendations. RNA from PBMC was extracted. RNA-seq, a high throughput RNA sequencing technology, would characterize the transcriptome by sequencing complementary cDNAs followed by mapping of the sequence reads to the genome.


Original Primary Outcome: Same as current

Current Secondary Outcome:

  • Induced sputum cytology [ Time Frame: 15 months ]
    Before sputum induction, subjects were instructed to rinse their mouth to remove any cellular debris. Nebulization was conducted using 3% saline via an ultrasonic nebulizer. Following expectoration into the clear sterile plastic pot, the sputum plugs were weighed and treated with 4 aliquots of dithiothreitol to completely dissolve the mucus. The mixture was subsequently vortexed, shaked and centrifuged. The supernatant was stored at -80℃ for inflammation profile analysis. The cell pallets were mounted on a glass slide for fixation with polyaldehyde and Haematoxylin-eosin staining. Samples with 5% or fewer epithelial cells of the total cell count were deemed eligible. This entailed counting of 400 non-squamous cells for cytology assessment. Inflammation phenotype was assigned based on a sputum eosinophil cutoff of greater than 3% and a sputum neutrophil cutoff of greater than 61%.
  • Airway inflammation indices [ Time Frame: 15 months ]
    Sputum Interleukin-1β(IL-1β), IL-2, IL-4, IL-5, IL-6, IL-7, IL-8, IL-10, IL-13, IL-17, G-CSF, GM-CSF, IFN-γ, IP-10 (CXCL10), MCP-1 (CCL2), MIP-1β(CCL4) and C-reactive protein (CRP) were measured using Luminex xMAP multiplex technology. Comparison in airway inflammation in patients with classic asthma, cough variant asthma and eosinophilic bronchitis was performed.
  • Fractional exhaled nitric oxide Measurements [ Time Frame: 15 months ]
    Fractional exhaled nitric oxide Measurements will be performed by using a NIOX MINO device(Aerocrine, Sweden),based on the recommendations of international guidelines. The relationship between FENO levels and eosinophilic airway inflammation was assessed in patients with classic asthma, cough variant asthma and eosinophilic bronchitis.
  • Peripheral blood eosinophil counts, serum IgE assessment [ Time Frame: 15 months ]
    Blood was drawn for differential and total cell counts.Serum total Immunoglobulin E（IgE） and specific IgE was measured using the Unicap system(Pharmacia Diagnostics, Uppasala, Sweden ).Relationship between peripheral blood eosinophilia and IgE was assessed.Relationship between peripheral blood eosinophilia and sputum eosinophilia was assessed.Relationship between FENO and peripheral blood eosinophilia was assessed.Relationship between FENO and sputum eosinophilia was assessed.
  • Cumulative provocative dose causing 20% fall in FEV1 measured through the Methacholine bronchial challenge test [ Time Frame: 15 months ]
    Spirometric values at the baseline are referred to as FEV1, FVC, FEV1/FVC and MMEF. Spirometry tests are carried out using a spirometer (Jaeger, Germany). All operation procedures meet the joint recommendation by ATS and ERS.The predicted values are selected based on the reference regression model established by Jinping Zheng and nanshan Zhong.Methacholine bronchial challenge test was performed only in subjects with a baseline FEV1 greater than 60% predicted using hand-squeeze nebulizers.The bronchial challenge was ceased in case of FEV1 fall being 20% or greater, or the maximal cumulative dose of methacholine (2.50mg) had been given. Airway hyperresponsiveness (AHR) was defined as 20% or greater fall in FEV1.The cumulative provocative dose causing 20% fall in FEV1 (PD20FEV1-MCh) was reported in subjects with AHR. Relationship between FENO,serum IgE,airway and systematic inflammation and AHR was assessed.
  • Using LCQ to evaluate the impact of cough on recruited patients with classic asthma, CVA and EB. [ Time Frame: 15 months ]
    The questionnaire of Leicester Cough Questionnaire(LCQ) comprises 19 questions. Scores range from 3 to 21, with higher scores representing a better quality of life. Comparison in LCQ total scores in patients with classic asthma, cough variant asthma and eosinophilic bronchitis was performed.
  • Circulating markers of inflammation [ Time Frame: 15 months ]
    Serum was collected for analysis of systematic inflammation.systematic inflammation indices including IL-1β, IL-2, IL-4, IL-5, IL-6, IL-7, IL-8, IL-10, IL-13, IL-17, G-CSF, GM-CSF, IFN-γ, IP-10, MCP-1, MIP-1βand CRP.Comparison in systematic inflammation in patients with classic asthma, cough variant asthma and eosinophilic bronchitis was performed.


Original Secondary Outcome: Same as current

Information By: State Key Laboratory of Respiratory Disease

Dates:
Date Received: September 7, 2015
Date Started: October 2014
Date Completion: January 2016
Last Updated: September 17, 2015
Last Verified: September 2015