COPD is a group of diseases characterized by limitation of airflow in the airway that is not fully reversible. COPD is the umbrella term for chronic bronchitis and/or emphysema. In COPD the airways become narrowed, leading to a limiation of the flow of air to and from the lungs, which causes shortness of breath. In contrast to asthma, the limitaiton of airflow is poorly reversible and usually gradually gets worse over time. COPD is caused by noxious particles or gases, most commonly from smoking, which trigger an abnormal inflammatory response in the lung.
The major COPDs are astham, chronic bronchitis and emphysema.
Asthma:
Asthma is a chronic condition involving the respiratory system in which the airways constrict, become inflamed and are lined with excessive amounts of mucus, often in response to one or more triggers. Asthma is characterized by a combination of chronic airway inflammation, airway obstruction, and airway hyperresponsiveness (AHR) to various stimuli. It is thought be be mediated priamrily by adpative immune responses mediated by allergen-specific CD4+ T cells, Th2 cytokines and allergen specific IgE, which lead to pulmonary inflammation and AHR.
Asthma is an inflammatory lung disease with airway hyperresponsiveness (AHR). The inflammatory cells release reactive oxygen species (ROS), which leak into surrounding cells.
Treatment:
—Albuterol sulfate is used as a bronchodilator to treat asthma.
—Steroid Receptors: are a major class of nuclear receptors represetning ligand-activated trasncription factors, known to regulate many cellular functios, including inflammatory process, energy production and apoptosis.
–Glucocorticoids (GS): are the mainstay treatment of asthma. They act by activating glucocorticoid receptors (GR).
Gratzio (“Glucocorticoid and estrogen receptors are reduced in mitochondria of lung epithelial cells in asthma” PLoS One, June 2012, 7(6)) disclose that mitochondrial glucocorticoid (mtGR) and estrogen (mtER) receptors participate in the coordination of the cell’s energy requirement and in the mitcohondrial oxidative phosphorylation enzyme (OXPHOS) biosyntesis, affecting reative oxgyen species (ROS) generation and induction of apoptosis. They preset evidence shwoing localizatio of GR and ERbeta in lung epithelial cells.
—Anti-IL-5 Antibodies:
—-Nucala (mepolizumab -Glaxo Smith Kline): is an anti-IL5 monoclonal antibody approved for treatment of IL5 mediated diseases including chronic rhinosinusitis and severe asthma with an easinophilic phenotype and in CRSwNP. In China, asthma affects 46 million adults, 6% of whom experience severe asthma and CRSwNP affects about 35 million people.
Glaxo Smith also presented evidence in 2024 that mepolizumab showed a statistically significant and clinically meaningful reduction in the annualized rate of moderate or severe exacerbations compared to a placebo for COPD.
Bronchiolitis:
Bronchiolitis is inflammation of the bronchioles, the smallest air passages of the lungs.
Emphysema
In emphysema, alveolar walls break down and the lung exhibits larger but fewer alveoli. The lungs also become fibrotic and less elastic. The air passages open adequantely during inhalation but they tend to collapse and obstruct the outflow of air.
People with emphysema become exhausted becasue they expend three to four times the normal amount of energy just to breathe. 80-90% of emphysema deaths are casued by cigarette smoking.