| Part One:Epidemiological survey of asthma in JinanBackgroundAsthma is one of the most common chronic respiratory disorders worldwide, and also is one of the leading causes of morbidity and mortality, with an estimated300million affected individuals. The prevalence of asthma exhibits significant regional differences, its occurrence displayed up to20times of differences among certain regions. Study of such differences among and within countries may provide clues for preventive risk factors. Asthma affects people of all ages, and can place considerable limitations on the physical, emotional, social, and professional lives of the sufferers. However, if treated properly, its symptoms can be controlled so that patients can lead a normal life with normal pulmonary function.. Epidemiological data indicated that asthma control was suboptimal both in developed counties such as USA and European countries and in developing Asia-Pacific countries. To date, there is no report about the asthma prevalence and control in Jinan, China. Thus, the present study performed a cross-sectional epidemiological questionnaire survey in Jinan. The survey was carried out in both urban and rural areas in Jinan at the same time to reveal the asthma prevalence in population of all ages, compare with the data from other countries, determine the related factors ors of asthma, and assess whether the local asthma control met the goals of GNA guidelines.ObjectiveDetermine the prevalence, related factors, and control of asthma in population ol all ages in Jinan by epidemiological survey.MethodsA cross-sectional epidemiological questionnaire survey was performed with all the members from approximately4500randomly-selected families from60communities in the urban area and in40villages in the rural area. The completed questionnaires were focused on asthma, asthma-like respiratory symptoms, medication and asthma control.Results1. A total of13645individuals were interviewed in the survey, and the number of effective questionnaires reached13419. The asthma prevalence of all ages in Jinan was1.1%. Atopy, asthma family history, household size, and age were independent factors related to asthma.2. The control of asthma in Jinan was suboptimal in a high proportion of patients and even worse in the rural area. Combind allergic rhinitis, cardio-pulmonary diseases, hospitalization for asthma, smoking index and overuse of antibiotics were the main impact factors on asthma burden in Jinan.Conclusion1. The asthma prevalence of all ages in Jinan was relatively low compared with that in western countries, however, local asthma control fell markedly short from the goals of GINA (Global Initiative for Asthma) criteria for asthma management; The economic burden of bronchial asthma for patients in Jinan is heavy.2. Low prevalence of allergic diseases, the experience of living in the rural area inearly life, big household size and high rate of breastfeeding might be responsible for the low prevalence in Jinan. The suboptimal asthma control may be attributed to the poor adherence to GINA guidelines, especially the underuse of preventative medication of inhaled corticosteroids (ICSs). Promote smoking cessation, treat asthma follow the GINA guidelines and regulate the use of antibiotics should be effective for reducing the economic burden of asthma.Part Two:Pathogenesis of different ashtma phenotypeBackgroundIt is found in the outcomes of the epidemiological survey that allergy was the independent risk factors or of asthma, nevertheless, a high proportion of asthma patients did not allergy. Many other epidemiological surveys also had similar findings. Therefore, the pathogenesis discrepancy of allergic and non-allergic asthma aroused our great interest. Convincing evidence show that asthma is a highly heterogeneous disease that has complex mechanisms. CD41T cells have been suggested to be indispensable regulators of the immune response in asthma. After being antigen-stimulated, CD4+T cells differentiate into various effector T cell subsets, including Th2, interleukin17(IL-17)-producing T helper (Th17) and regulatory T cells (Treg cells). In the last20years, Th2cells and their secreted cytokines have been proposed to playing a cardinal pivotal role in the pathogenesis of airway inflammation in asthma. However, in recent years, there is robust evidence point to that the Th2-model cannot account for the substantial clinical and molecular heterogeneity that has now been unequivocally documented in asthma. The role of Th17cells, Treg cells are important in the prevention of allergic sensitisation as well as progression to established asthma. We speculate that Th17, Treg and Th2cells and cytokines play different roles in the pathogenesis of different phenotype of asthma. Research on the state of above-mentioned content may be helpful to reveal the different pathogenesis of distinct asthma phenotype, as well as devote to control asthma better.ObjectiveDetect the levels of Th2, Th17, Treg cells and related cytokines in the peripheral blood and induced sputum in both allergic and non-allergic asthma patients, to explore the discrepancy pathogenesis of distinct asthma phenotype.MethodsA total of60asthmatics and30healthy individuals were included. Serum T-IgE and S-IgE antibodies were detected. Th17, Treg and Th2cells in the PBMC were sorted by flow cytometry. RORytmRNA, Foxp3mRNA and GATA-3mRNA were studied by real time RT-PCR. The T cell cytokine profiles (IL-17A. IL-10, IL-4,1L-5and11,-8) in plasm and sputum were measured by ELISA. The eosinophil and neutrophil percentage in sputum as well as FEV1%and ACQ scores were also documented.Results1. Elevated T-IgFE,S-IgE, Th2cells and cytokines IL-4, IL-5and eosinophilic infiltration predominant in the airway were found in allergic asthmatics. Th17cells. IL-17A, IL-8increased in the non-allergic asthma, with neutrophils infiltration predominant in the airway.2. Thl7cells significantly higher in non-allergic asthma patients than in allergic asthma ones. Th2cells raised only in allergic asthma patients. Treg cells were found reduced in both allergic and non-allergic asthmatics.3. In different asthma severity classification, Th17and Treg rather than Th2cells showed difference. Th17cells were positively correlated to the mean ACQ score alone.Conclusion1. Allergic and non-allergic asthmatics appear to have slight differences in airway inflammation. In allergic asthma patients, eosinophilic infiltration was predominant in the airway. On the contrary, in the airway of non-allergic asthma patients, neutrophils inflammation was predominant. Thl7cells were involved in distinct asthma phenotype, severe and steroid-resistant asthma, while Th2cells only play a part in the allergic asthma, and the Treg cells ralated to different asthma severity.2. Thl7cells may be related to severe and steroid-resistant asthma, and may be used to predict the prognosis under current recommended asthma treatment. |
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