Respiratory Morbidity and Exhaled Nitric Oxide in the First 2 Years of Life: the Generation R Study
Year: 2009
Type: dissertation
Abstract: Asthma is a lung disease characterized by chronic inflammation of the airways \\nassociated with bronchial hyperresponsiveness. The airflow obstruction within the \\nlungs is responsible of recurrent episodes of wheezing, breathlessness, chest tightness \\nand coughing. The physiopathological changes of the airways in asthma are mediated \\nby many cells and cellular elements. It has been argued that asthma is a syndrome \\ncomprising a number of separate conditions, rather than a single disease with a broad \\nrange of severity. It has long been thought that the inappropriate response of the \\nspecific immune system to harmless antigens leading to the polarization of T\\xe2\\x80\\x90cells \\ntoward a T\\xe2\\x80\\x90helper 2 (Th2) phenotype was the central mechanism of asthma. However, \\nin the last years the hypothesis of asthma as one unifying disease concept has \\ndisappeare. Novel disease and bronchial inflammation pathways, many of \\nwhich are independent of adaptive immunity, have been reported. The concept of \\ndisease endotypes has been recently introduced and subtypes of asthma with \\ndifferent and specific pathophysiology, immunology, clinical features and response to \\ntreatment have been described. A simple categorization of the different \\ninflammatory patterns in asthmatics based on sputum eosinophil and neutrophil \\nproportions has been provided and four inflammatory subtypes have been identified: \\nneutrophilic, eosinophilic, mixed granulocytic and paucigranulocytic asthma. A \\nrecent review by Haldar and Pavord suggested that non\\xe2\\x80\\x90eosinophilic asthma \\nrepresents a stable phenotype associated with distinct etiologic factors and less \\nairway pathology. Also, it has been suggested that severe asthma should no longer \\nbe considered as the result of a progressive process, but rather as a separate \\npathological entity with distinct physiologic and clinical characteristics. These \\nheterogeneous inflammatory patterns have been also reported by Brasier et al, who \\nevaluated bronchoalveolar lavage (BAL) samples in mild to severe asthmatic patients. \\nThey showed that cytokine expression patterns in BAL could be used to identify \\ndistinct types of asthma and identify distinct subsets of methacholine \\nhyperresponders. Despite improved understanding of pathophysiology, \\nimmunology and genetics of asthma in childhood, we still do not know the basic \\nmechanisms underlying the development of the disease.
Author: Carmelo Gabriele
Language: English
Subfield: Pulmonary and Respiratory Medicine
Field: Medicine
Domain: Health Sciences
Open Access status: green
OpenAlex ID: W2137100469