Asthma is a chronic respiratory disease characterized by inflammation of the airway and the presence of recurrent attacks (exacerbations) of breathlessness, wheezing, cough, chest tightness, or some combination of these symptoms. In the US, about 53% of people with asthma had an asthma attack in 2008, and 57% of these, were children. One in ten children (10%) had asthma in 2009, and boys were more likely than girls to have asthma. Internationally, the prevalence of asthma varies widely in different countries, but the disparity is narrowing due to rising prevalence in low and middle income countries. Unfortunately, we do not have statistics for asthma in the Republic of Panama, neither epidemiological data nor costs, which is the reason why this research is needed. The Panamanian Social Security Fund (CSS) provides protection to workers, their immediate families and the pensioned. By the end of 2010, the total insured population was 2,862,202 (83% of the total population of Panama). Of the total insured population 58% were dependent. Of this, 1,205,607 (42%) were children. On the basis of this information, we decided to develop the research study using information from the CSS, specifically in the Hospital de Especialidades Pediatricas (HEPOTH). It is the only tertiary level of healthcare children's hospital of the CSS. A quantitative-descriptive design was used to develop this study. Data was collected from medical records of patients diagnosed with asthma in the HEPOTH from January to June 2012. We reviewed the medical records of each care area by month, and numbered each clinical record of children diagnosed with asthma in crisis and randomly selected 10% of the medical records from a minimum of 2000 records. Information on treatment costs was also obtained. Once all the information was collected, it was typed in the digital data log created for this study and the responses were code converted and the information was entered into a database. The data were exported to IBM SPSS Statistics 21. The average cost of asthma attacks in Panama is estimated at $205.52. We were able to confirm that there are variations in this average by gender, age, geographic area of residence, season, severity, whether treated in the emergency department or hospitalization, and the type of treatment received. It was also possible to obtain secondary information about the epidemiology of asthma that allowed us to confirm that our statistics matched international statistics.

Aim. To assess associations between occupational air pollution and respiratory health, especially in miners. Background. Indications of associations between occupational exposure or social economic status and respiratory health have been found in several population-based studies. However, there have been few longitudinal studies of the putative correlations, the effects of environmental and genetic factors have seldom been simultaneously studied, and studies of miners have generated conflicting results. Material and methods. Population-based Obstructive Lung Disease in Northern Sweden (OLIN) cohorts surveyed in 1986, 1992 and 1996, and two industry-based materials, were used in cross-sectional and longitudinal studies. Inflammatory markers were compared in sputa from miners after a vacation of at least four weeks, after repeated occupational exposures for at least three months, and controls. The mortality from silicosis was studied in 7729 miners with at least 1 year of exposure. Multivariate analyses were used to adjust for confounders. Results. Up to about 30-40% (etiologic fraction) of incident symptoms in persons both with and without a family history of asthma (FHA) could be explained by exposure to occupational air pollution. Low socio-economic status (SES) was associated with impaired respiratory health. Population attributable risks for most examined disorders were about 10%. Current and ex-miners had increased prevalence of recurrent wheeze, longstanding cough, physician-diagnosed chronic bronchitis, and a trend for increased sputum production. For physician-diagnosed chronic bronchitis a multiplicative interaction was found between exposure and smoking habits. Ex-miners that had been exposed for on average 13 years and whose exposure had ceased 16 years before the study had an increased prevalence of physician-diagnosed chronic bronchitis and chronic productive cough and a trend to increased use of asthma medicines. Miners exposed underground for 18 years, on average, to diesel exhaust (with 0.28 mg/m3 nitrogen dioxide and 27 μg/m3 elemental carbon on average, EC) and particles (3.2 mg/m3 inhalable dust on average) had signs of higher inflammatory activity in their airways, i.e. significantly higher frequencies of macrophages, neutrophils, and total cells compared with referents. The activity in miners was similar after a vacation of at least four weeks and after repeated exposures for three months. There were 58 deaths from silicosis (underlying and contributing cause of death) and a clear dose-response relationship. The data indicated an increased risk of severe silicosis after long-term exposure to 0.1 mg/m3 respirable quartz, the current maximum allowable concentration (MAC) in Sweden and many other countries. Conclusion. Occupational exposure to dust, gases, and fumes impaired respiratory health, accounting for up to 30-40% of some respiratory symptoms in the general population. Low socio-economic status was associated with impaired respiratory health. The complex profiles of dust and diesel exhaust substances found in mines may cause inflammatory reactions in their lungs and persistent respiratory symptoms in occupationally exposed miners. Long-term exposure to quartz at the present MAC level may cause severe silicosis.

Spleen tyrosine kinase (Syk) plays a critical role in regulation of immune and inflammatory responses. This thesis investigated the role of Syk in the development of the asthma phenotype in acute and chronic mouse models of allergic airways inflammation. Airway hyperresponsiveness (AHR) to methacholine and inflammation increased significantly in HDM-induced compared with the saline control mice. We demonstrated that in vivo inhibition of Syk by selective Syk inhibitors, and genetic deletion of Syk using conditional Syk knockout mice attenuated AHR despite of inflammatory cell influx in the lung. Histological analysis showed airway remodeling in the chronic model, which was attenuated to some degree by deletion of Syk. This study identified a role of Syk in airway hyperresponsiveness and remodeling without significantly affecting leukocyte recruitment in HDM model of airways disease. My results support the improvement of therapeutic strategies in asthma by targeting the Syk pathway.

Spleen tyrosine kinase (Syk) plays a critical role in regulation of immune and inflammatory responses. This thesis investigated the role of Syk in the development of the asthma phenotype in acute and chronic mouse models of allergic airways inflammation. Airway hyperresponsiveness (AHR) to methacholine and inflammation increased significantly in HDM-induced compared with the saline control mice. We demonstrated that in vivo inhibition of Syk by selective Syk inhibitors, and genetic deletion of Syk using conditional Syk knockout mice attenuated AHR despite of inflammatory cell influx in the lung. Histological analysis showed airway remodeling in the chronic model, which was attenuated to some degree by deletion of Syk. This study identified a role of Syk in airway hyperresponsiveness and remodeling without significantly affecting leukocyte recruitment in HDM model of airways disease. My results support the improvement of therapeutic strategies in asthma by targeting the Syk pathway.

Several epidemiological studies have revealed an association between particulate matter (PM) pollution and various health effects. Importantly, there is evidence to suggest that individuals with pre-existing respiratory disease, such as asthma, are more sensitive to elevated ground levels of particulate matter as compared to healthy subjects. Among the various sources of PM pollution, diesel powered vehicles have been identified as important contributors. The aim of this thesis was to investigate the airway effects of experimental chamber exposure to diesel exhaust (DE) in healthy and asthmatic subjects, focusing on airway responsiveness, airway inflammation and lung function. To achieve a comprehensive picture of the airway responses to DE, a number of different methods were used, including lung function measurements, methacholine inhalation tests, induced sputum and bronchoscopy. Each subject acted as his/her own control by being exposed both to filtered air and DE in a crossover design. Short term exposure to DE, at a particle concentration (PMi0) of 300 ug/m3, was associated with a clinically significant increase in bronchial hyperresponsiveness in asthmatic subjects. In accordance with the epidemiological data suggesting a 1-4 day lag effect for most health outcomes to PM pollution, the increase was detected one day after DE exposure, indicating a long lasting response to DE in asthmatic airways. Diesel exhaust induced a range of airway inflammatory changes as reflected in induced sputum, bronchoalveolar lavage and bronchial mucosal biopsies. In healthy subjects, DE exposure was associated with an increase in neutrophils and IL-6 in sputum, elevated levels of IL-8 and IL-6 in bronchial wash (BW), enhanced expression of IL-8 and GRO-a in the bronchial epithelium and with increases in P-selectin and VCAM-1 in the airway mucosa. In contrast, asthmatics responded with an increase in IL-6 in sputum and an enhanced expression of IL-10 in the bronchial epithelium following exposure DE. Thus, clear differences were identified between healthy and asthmatic subjects in the inflammatory response to DE. Airway epithelial cells constitute the first line of cellular defence towards inhaled air pollutants and increasing evidence suggests that these cells contribute markedly to the initiation of airway inflammatory responses. The bronchial epithelium was identified to have an important regulatory role in response to diesel exhaust, including the capacity to produce chemoattractant and immunoregulatory proteins associated with development of airway inflammation and bronchial hyperresponsiveness. Lung function measurements revealed that short-term exposure to DE induces an immediate bronchoconstrictive response in both healthy and asthmatic individuals, with significant increases in airway resistance (Raw) following DE exposure. This thesis also investigated the effects of a lower concentration of DE (PMio 100 ug/m3) than previously studied. It was shown that exposure to DE at a concentration corresponding to a PM level that may be encountered in busy traffic situations, was still associated with potentially adverse airway responses in healthy and asthmatic subjects. In summary, the results presented here indicate that short term exposure to diesel exhaust, at high ambient concentrations, has the potential to induce a range of biological events in the airways of healthy and asthmatic subjects. / <p>Diss. (sammanfattning) Umeå : Umeå universitet, 2002, härtill 4 uppsatser.</p> / digitalisering@umu

Allergic airway disease, i.e. allergic rhinitis (AR) and asthma, is a common health problem. The prevalence is increasing in most countries of the world. Traffic-related air pollution has been found to induce and enhance allergic airway disease, but the underlying mechanisms are not known. Oxylipins are fatty acid metabolites, of which several have been linked to asthmatic airway inflammation. Oxylipin profiles have previously been investigated in bronchoalveolar lavage (BAL), mainly reflecting the peripheral lung, but not in bronchial wash (BW), which better reflect the proximal airways. The airway epithelium is covered by a respiratory tract lining fluid (RTLF) The RTLF contains antioxidants to protect from oxidative stress, which may be caused by exposure to air pollution. Previous studies have reported diminished levels of the antioxidant ascorbate (vitamin C) in the RTLF of patients with asthma. Little is known about the regulation of vitamin C in the lung. The aim of this thesis was to investigate airway inflammatory responses to diesel exhaust exposure in patients with AR and allergic asthma; to evaluate oxylipin profiles in different regions of the lung in patients with allergic asthma; and to study the distribution of vitamin C transporters in the airways of patients with allergic asthma. Diesel exhaust (PM10 100 μg/m3 for 2 h) induced a neutrophilic airway inflammation in healthy individuals evaluated 18 h after exposure. Patients with AR and asthma did not respond with an enhanced airway inflammation. However, a small increase in myeloperoxidase was found in BAL from patients with AR, as well as decreases in epithelial tryptase and BW stem cell factor. This indicates that other mechanisms than classical inflammation are responsible for the increased sensitivity to traffic-related air pollution in patients with allergic airway disease. Oxylipin baseline profiles differed between peripheral and proximal airways in both allergic asthmatics and healthy individuals. Total oxylipin concentrations, and five individual oxylipins, primarily from the lipoxygenase (LOX) pathway, were elevated in BW from asthmatics compared to healthy controls, supported by immunohistochemical staining of 15-LOX-1 in the bronchial epithelium. This suggests that lung compartment-specific sampling should be considered in future studies. Sodium dependent vitamin C transporter 2 (SVCT2) was, for the first time, found present in the human lung epithelium, localised mainly within goblet cells. A negative correlation between SVCT2+ goblet cells and vitamin C suggests that these cells may play a hitherto unknown function in ascorbate re-uptake and recycling at the air-lung interface.

Astma yra lėtinė kvėpavimo takų uždegimo liga. Mokslininkai neabejoja, jog 2-o tipo T limfocitai pagalbininkai bei eozinofilinis kvėpavimo takų uždegimas yra astmos patogenezės pagrindas. Tačiau šis mechanizmas ne visuomet gali paaiškinti astmos metu esančio kvėpavimo takų uždegimo bei klinikinių simptomų įvairumą, eigos ypatumus ir net skirtingą atsaką į gydymą. Eksperimentiniai tyrimai su gyvūnais parodė 17-o tipo T limfocitų pagalbininkų (Th17) svarbą alerginės astmos vystymuisi. Todėl šio mokslinio tyrimo tikslas buvo įvertinti Th17 limfocitų vaidmenį sergant alergine astma. Tyrimo metu sergantiesiems alergine astma nustatytas didesnis Th17 limfocitų kiekis periferiniame kraujyje bei didesnė interleukino (IL)-17 koncentracija serume ir indukuotuose skrepliuose, lyginant su sveikais asmenimis. Be to, bronchų provokacija su Dermatophagoides pteronyssinus alergenu sukėlė Th17 limfocitų ir IL-17 kiekio padidėjimą praėjus 7 ir 24 val.po jos, ypatingai ryškų sergantiems alergine astma su ankstyva ir vėlyva bronchų obstrukcija. Atlikto tyrimo rezultatai parodė, kad Dermatophagoides pteronyssinus alergenas sukelia vietinį ir sisteminį Th17 limfocitų imuninį atsaką kuris yra susiję su vėlyvos fazės kvėpavimo takų uždegimu. / Allergic asthma is a chronic inflammatory disease of the airways associated with the response of predominant type 2 helper T lymphocytes to an inhaled allergen. However, differences in inflammation and clinical symptoms of this disease not always can be explained by this mechanism. Recent animal model studies have shown the importance of type 17 helper T lymphocytes (Th17) in the development of allergic asthma. The role of these cells in causing allergen-induced airway inflammation as well as systemic inflammatory response in human is still not well defined. Therefore, we investigated the peripheral blood Th17 lymphocyte response to inhaled Dermatophagoides pteronyssinus (D. pteronyssinu) allergen in patients with allergic asthma. The present study has shown that patients with allergic asthma have a higher percentage of peripheral blood Th17 lymphocytes and elevated serum as well as induced sputum interleukin-17 levels compared with healthy subjects. Moreover, all studied allergic asthma patients, especially with early- and late-phase asthmatic reaction, showed an enhanced airway and systemic Th17 lymphocyte response 7 h and 24 h after bronchial challenge. We documented an enhanced local and systemic Th17 lymphocyte response to inhaled D. pteronyssinus in association with late-phase allergen-induced airway inflammation in patients with allergic asthma.

Master of Science in Medicine / Rationale: Asthma management aims to achieve optimal control on the minimal effective dose of medication. We assessed the effectiveness of two algorithms to guide ICS dose in well-controlled patients on ICS+LABA in a double-blind study, comparing dose adjustment guided by exhaled nitric oxide (eNO) to clinical care algorithm(CCA) based on symptoms and lung function. Methods: We randomised non-smoking adult asthmatics on minimum FP dose 100μgs daily +LABA to ICS adjustment using eNO or CCA, assessed over 5 visits during 8 months treatment. Primary endpoints were asthma-free days and asthma related quality of life (QOL). Analysis was by mixed model regression and generalised estimating equations with log link. Results: 69 subjects were randomised (eNO:34, CCA:35) and 58 completed the study. At baseline mean FEV1 was 94% pred., mean eNO (200ml/sec) 7.1 ppb, median ACQ6 score 0.33. Median ICS dose was 500 μg (IQR 100-500) at baseline and 100 μg on both eNO (IQR 100-200) and CCA arms (IQR 100–100) at end of study. There were no significant differences between eNO and CCA groups in asthma-free days (RR=0.92, 95% CI 0.8–1.01), AQL (RRAQL<median = 0.95, 95% CI 0.8–1.1) or exacerbation-free days (HR = 1.03, 95%CI 0.6–1.7). Neither clinic FEV1 (overall mean difference FEV1 % pred. -0.24%, 95% CI -2.2–1.7) nor a.m. PEF (mean difference 1.94 L/min (95% CI -2.9–6.8) were significantly different. Similar proportions of subjects were treated for ≥1 exacerbation (eNO: 50%, 95% CI 32.1–67.9; CCA: 60%, 95% CI 43.9–76.2). Conclusion: Substantial reductions in ICS doses were achieved in well controlled asthmatics on ICS+LABA, with no significant differences in outcomes between eNO or clinically based algorithms.

Asthma is an inflammatory airways disease affecting over 339 million people of all ages worldwide. More than 10% of asthmatics have uncontrolled severe disease which is insensitive to high doses of oral corticosteroid treatment. Type 2 innate lymphoid cells (ILC2) are pro-inflammatory lymphomononuclear cells proposed as critical drivers of eosinophilic inflammatory disease of the upper and lower airways. Controlling this activity may provide novel therapies for asthma. This thesis aimed to investigate factors that affect the local activation and expansion of ILC2 in the airways including anti-inflammatory medications such as (i) corticosteroids, (ii) neuro-immune regulation of ILC2, and (iii) effect of locally generated cytokines on ILC phenotypes and the relationship to the ongoing airway inflammatory profile. We firstly investigated the effect of intranasal corticosteroids on activation levels of ILC2 in the upper airway of allergic rhinitics with mild asthma following controlled nasal allergen challenge (Chapter 2). Following pre-treatment with intranasal corticosteroid there was an attenuation in the allergen-induced increase in total ILC2 and IL-5/13+ ILC2 in the nasal mucosa. In addition, HLA-DR expression on ILC2 in the nasal mucosa was down-regulated. Overnight culture with IL-2, TSLP or IFN-γ up-regulated HLA-DR expression on ILC2, in vitro; an effect that is inhibited in the presence of corticosteroids. Attenuation of HLA-DR expression by ILC2 may be an additional mechanism by which corticosteroids modulate adaptive immune responses in the airways. We have previously reported that lung ILC2 are activated within 7h following allergen-inhalation challenge. Since airway mucosal tissue is highly innervated, we investigated whether neuroimmune interactions may trigger early and rapid host immune responses (Chapter 3). In a diluent-controlled allergen-inhalation challenge cross-over study, where mild asthmatics developed early and late bronchoconstrictor responses with sputum eosinophilia (>3%), NMUR1, a receptor for the neuropeptide, neuromedin-U, was up-regulated on sputum ILC2 in 7h post allergen challenge. This was associated with increased expression of IL-5/IL-13 by sputum ILC2 post-allergen and following in vitro culture. ILC2 activation was mediated through a MAPK/PI3 kinase dependent-signaling pathway that was attenuated in the presence of dexamethasone. Co-culture with IL-33 and TSLP, in vitro up-regulated NMUR1 expression on ILC2 at the protein and transcriptomic level which was attenuated by dexamethasone. The close interplay between neuropeptide signalling and tissue-derived alarmin cytokines may be important interactions for rapid ILC2 activation in airway inflammatory responses in asthma. We have reported increased ILC2 with the highest level of IL-5/13+ ILC2 in the airways of severe asthma with uncontrolled eosinophilia (>3%). The prevalence and phenotypic analyses of innate lymphoid cells subsets in severe asthma with neutrophilic or mixed granulocytic airway inflammatory endotypes remains unclear and was investigated in Chapter 4. Sputum ILC3 were most abundant in severe asthma with neutrophilic airway inflammation where IL-17A+ ILC3 correlated with airway neutrophilia. ILC2 were predominant in severe asthma with airway eosinophilia. Importantly, we identified an intermediate ILC2 phenotype displaying ILC3-like markers (c-kit and IL-17A) in severe asthma with neutrophilic and mixed granulocytic airway inflammation. Inflammasome related cytokines, IL-1β and IL-18 were significantly increased in the airways of these patients. At both proteomic and transcriptomic levels, flow sort-purified ILC2 trans-differentiated to the intermediate phenotype when co-cultured with IL-1β+IL-18. Blocking inflammasome-related cytokines may control T2-low severe asthma exacerbations. Collectively, the findings of this thesis highlight the role of corticosteroids, neuropeptides and airway inflammasome related cytokines as modulators of ILC fate and activity in asthma. / Thesis / Doctor of Philosophy (PhD) / Asthma is a disease of the airways that makes breathing difficult. About 10% of asthma patients have uncontrolled severe symptoms despite treatment with high doses of corticosteroids which imposes many unwanted side effects. Investigating processes that worsen the disease will help to discover new treatments for asthma. Type 2 innate lymphoid cells (ILC2) are novel cells that produce large quantities of factors which attract and activate effector cells to the lungs which in turn make breathing difficult. This thesis investigated whether controlling ILC2 activity reduces asthma symptoms by studying i) responsiveness of ILC2 to corticosteroids using a controlled allergen exposure through the nose in people with allergic rhinitis and mild asthma, ii) the role of airway nerves and mediators on ILC2 activation, and iii) the ability of signals produced by the lungs to impact factors released by ILC2 and the relationship to effector cells found in the airways of severe asthma. Overall, ILC2 activation can be modulated by corticosteroids, nerve derived factors and lung tissue derived cytokines, and this is associated with changes in the number and type of effector cells in the lungs.

Doctor of Philosophy / Department of Human Nutrition / Craig A. Harms / The overall aim of this dissertation was to ascertain the influences of lifestyle factors on airway health in children and young adults. In Study 1 (Chapter 2) the effect of a high-fat meal on airway inflammation and hyper-responsiveness was examined. Results revealed a post-prandial increase (p<0.05) in total cholesterol (~4%), triglycerides (~93%), and exhaled nitric oxide (a marker of airway inflammation, ~19%) two-hours following a high-fat meal (74.2±4.1g fat). These novel findings suggest that a high-fat meal may contribute to impaired airway function. In study 2 (Chapter 3) we assessed the role of body fat and physical activity (PA) on airway health in prepubescent children. This study revealed that children with higher-body-fat levels (>21%), who were not meeting current PA recommendations, experienced greater (p<0.05) amounts of post-exercise airway narrowing (FEV1, forced expiratory volume in 1-second, ~11%), as compared to children with lower-body-fat (<21%), who were meeting PA guidelines. These findings suggest that elevated adiposity and low PA levels may place children at risk for development of asthma and asthma-like symptoms. In study 3 (Chapter 4), based on study 2 results, we assessed the impact of 8 weeks of high-intensity interval training on airway health in children who were not meeting PA guidelines. We determined that high-intensity training significantly increased V02max (~24%), and decreased total cholesterol (~11%) and LDL cholesterol (~35%). Additionally, we found improvements (p<0.05) in ∆FEV1 both post-exercise (pre: -7.6±2.2%, post: -1.3±1.8%) and post-eucapnic voluntary hyperventilation (pre: -6.7±2.2%, post: -1.4±1.5%) with training. Further, Lower-body-fat and higher V02max subjects experienced significantly greater improvement in ∆FEV1 following training than higher-body-fat and lower V02max subjects (r=-0.80, r=0.73, respectively). These results suggest that in children, high-intensity training can ameliorate the negative health consequences of inactivity. However, increased body fat, and low V02max levels may constrain these improvements. This series of studies underscores the importance of dietary habits, body composition, and PA for airway health in children and young adults. These findings may be useful in determining policies and practices impacting children’s health, and could facilitate protocol development for prevention of asthma-like symptoms.